Method for planning an orthodontic treatment

Abstract

The invention relates to medicine, and more particularly to orthodontics, and is intended for planning an orthodontic treatment and calculating the appropriate direction and amount of tooth movement. The technical results of the invention consist in improving the quality of orthodontic treatment and making it possible to plan the direction and amount of tooth movement required to obtain an optimal orthodontic treatment outcome. The proposed invention is directed toward the use of a method in which the direction and amount of tooth movement is calculated for the purpose of drawing up an orthodontic treatment plan.

Description

[0001] METHOD OF PLANNING ORTHODONTIC TREATMENT

[0002] Field of technology

[0003] The invention relates to medicine, namely to orthodontic dentistry, and is intended for planning orthodontic treatment and calculating the direction and magnitude of tooth movement.

[0004] State of the art

[0005] There are two main types of methods for planning the amount and direction of tooth movements during orthodontic treatment.

[0006] 1. The calculation method, when the doctor tries to understand, through certain calculations based on the initial diagnostic data, by what amount and in what direction the teeth should be moved in order to obtain the optimal result.

[0007] 2. A method for modeling the final result using a so-called setup, that is, by moving teeth on virtual dental models. Previously, this method involved moving teeth on plaster dental models, but has been almost completely replaced by digital setups.

[0008] The second method is more accurate but requires scanning of the dental arches, specialized software, skill in its use, and a significant investment of time and money. This method is more often available to specialized laboratories, where orthodontists can send scanned images of the dental arches to create, for example, clear aligner systems. However, the orthodontist, as a professional in orthodontics and the specialist responsible for the patient's treatment, must still instruct the laboratory technician on what, where, and by how much to move. The laboratory, using various algorithms for planning the stages of tooth movement, implements this plan as a sequence of SUBSTITUTE SHEET (RULE 26) movement stages for each individual aligner. However, technologies that would create a fundamental movement plan for the doctor to achieve optimal results are currently unavailable. The doctor must do this themselves, using calculations.However, in most cases, given the complex geometry of the initial situation, doctors find this difficult. Consequently, there is no input data for virtual modeling of the treatment outcome, which significantly reduces the practical applicability of laboratory-based treatment plan modeling.

[0009] It's important to note that creating a treatment plan poses challenges for orthodontists, as there are only approximate treatment protocols for various specific types of malocclusions. For example, for treating distal overbite, mesial overbite, crowded teeth, and so on.

[0010] However, in real-life practice, especially in adult patients, mixed malocclusions are often encountered, encompassing several different geometric occlusion issues. For example, excessive inclination of the upper anterior teeth, displacement of the center of the upper dental arch relative to the facial center, displacement of the center of the lower dental arch relative to the facial center, crowding of teeth on one side of the upper dental arch, excess space on the other side, missing teeth in the lower dental arch with partial closure of the spaces due to displacement of adjacent teeth, distal occlusion (Angle's Class 2) on the right, mesial occlusion (Angle's Class 3) on the left, atypical sizes of individual anterior teeth, and so on.

[0011] Such initial clinical situations can be conventionally called "cases with complex geometry." Their planning poses serious difficulties even for experienced orthodontists, as there are currently no clear step-by-step calculation algorithms for planning movements that are universal for the vast majority of mixed malocclusions.

[0012] Current planning methods utilize geometrically constructed ideal dental arch shapes, comparing these shapes with the initial situation, and developing tooth movement targets to bring the teeth closer to ideal positions. These methods do not take into account the position of the maxillary midline relative to the facial center, the aesthetic inclination of the upper anterior teeth, the position of the upper and lower teeth within the alveolar bone, the relationship of the upper and lower canines at the end of treatment, missing teeth, etc.

[0013] Disclosure of the essence of the invention

[0014] The present invention is aimed at achieving technical results consisting of improving the quality of orthodontic treatment, obtaining the ability to plan the direction and magnitude of tooth movement to obtain the optimal result of orthodontic treatment.

[0015] Using this invention, orthodontists can obtain clear plans for the most important tooth movements in their daily practice to achieve optimal results, and then implement them either using braces or send them to aligner manufacturing laboratories, but with clear instructions for creating a virtual setup for technicians.

[0016] The stated technical results are provided by a method for planning orthodontic treatment, which includes the following steps:

[0017] 1) We determine the data of the initial occlusion geometry;

[0018] SUBSTITUTE SHEET (RULE 26)2) We calculate the corrected space balance on the more normal side (U_Space_Norm_Correct) and the required mesiodistal movement of the first molar on this side (U6_Norm), where the more normal side is considered to be either the side with a smaller space deficit or the side opposite the displacement of the center of the upper dental arch;

[0019] 3) We calculate the required movement of the molar on the opposite side of the upper dental arch (U6_Contr);

[0020] 4) We calculate the required movement of the molars on the lower row of teeth on each side separately;

[0021] 5) We recalculate the balance of space on the lower dental row taking into account the initial data and step 4 (L_Space_Correct);

[0022] 6) We calculate the expected change in the inclination of the lower incisors (LI_Inc_Change) and evaluate the adequacy of their final position;

[0023] 7) We draw up an orthodontic treatment plan based on the results of the above steps.

[0024] The claimed technical results are achieved by the features of the invention listed in the claims. The feasibility of achieving these technical results is explained below, taking into account the description of the invention.

[0025] Brief description of images

[0026] The claimed technical solution is explained by images:

[0027] Fig. 1 - Determination of the position of the midline of the upper dental arch; Fig. 2 - Evaluation of the inclination of the upper anterior teeth when smiling in profile; Fig. 3 - Photographs for assessing the value of the balance of space in the dental arches;

[0028] Fig. 4 - Determination of the symmetry of the position of the upper first molars relative to the perpendicular to the median palatine suture;

[0029] SUBSTITUTE SHEET (RULE 26) Fig. 5 - Lateral photographs of dental arches at a right angle to assess the class of occlusion of lateral teeth;

[0030] Fig. 6 - Sections of computer tomograms in the area of ​​the lower incisors to determine their position in the symphysis;

[0031] Fig. 7 - Evaluation of the biotype of the gums in the vestibular side in the area of ​​the lower anterior teeth;

[0032] Fig. 8 - Automatic orthodontic treatment plan displayed on the user interface.

[0033] Implementation of the invention

[0034] The most important tooth movements and actions during orthodontic treatment are those that either (or)

[0035] A) Complex, time-consuming, and require additional devices, increasing the cost of treatment. This involves the so-called distalization of posterior teeth—moving them backward—and mesialization—moving them forward.

[0036] B) They have limits, meaning there's a high risk of failure if a certain amount of movement is exceeded. This involves distalization of the posterior teeth, including their roots, by more than 3 mm.

[0037] B) Associated with the removal of individual teeth for orthodontic reasons.

[0038] D) Involves creating space and installing dental implants.

[0039] This method primarily allows for the calculation of the necessity and magnitude of the above-mentioned movements and actions. The optimal outcome of orthodontic treatment is achieving a specific bite geometry that, among other things, meets the following key conditions:

[0040] 1. The center of the upper dental arch coincides with the center of the upper jaw.

[0041] SUBSTITUTE SHEET (RULE 26) 2. The lower canines are set according to what is known as Angle's Class 1, that is, in a specific, precise position relative to the upper canines. Moreover, the molars may have different classes on the right and left, depending on the number of teeth on the right and left sides, and may also have different Angle's classes (1, 2, 3), depending on the number of teeth in the upper and lower arches. There is no scientific evidence that occluding molars according to Class 2 or 3, provided that the canines occlude according to Class 1, is harmful. There is also no evidence that asymmetrical molar occlusion on the right and left sides is harmful, provided that the canines on both sides are Class 1.

[0042] 3. The upper front teeth have an optimal tilt - vertical when smiling in profile and are located in the middle of the spongy bone of the alveolar process of the upper jaw.

[0043] 4. The lower incisors are located parallel to the symphysis of the lower jaw.

[0044] 5. The lateral teeth are positioned at the correct angles and within the spongy bone tissue.

[0045] The invention is aimed at achieving this optimal final geometry. However, it allows the clinician to deviate from the ideal plan toward certain compromises in cases of so-called skeletal malocclusions in adults, where an optimal outcome is only possible with maxillofacial orthognathic surgery. In the case of such deviations from the ideal, the algorithm provides options for achieving an adequate, clinically acceptable compromise or determining that, in this case, it is impossible without surgery.

[0046] The claimed method can be divided into several steps:

[0047] Step 1. Defining the initial occlusion geometry data.

[0048] SUBSTITUTE SHEET (RULE 26) 1. The position of the center of the upper dental arch relative to the center of the upper lip (Midline). Determined as the average value based on a smile photo, a photo of the upper anterior teeth exposed during conversation, and a CT scan (if available). Estimated in millimeters.

[0049] 2. Upper incisor tilt. This is assessed using a profile photo of the patient's smile in a natural head position. Traditionally, orthodontics uses standards for upper incisor tilt based on a lateral teleradiograph. However, this method does not always result in an aesthetically pleasing tilt of the upper anterior teeth, as the standard is an average figure that does not take into account the tilt of the patient's upper jaw, head position, tooth shape, etc. The doctor evaluates the tilt of the anterior teeth using a profile photo of the smile and determines the number of millimeters their incisor edges need to be moved forward or backward (ulchange) to achieve vertical incisors. If they are already positioned optimally, no change in tilt is required. If the anterior teeth need to be tilted forward, the value is positive; if they need to be tilted backward, the value is negative.

[0050] 3. Space balance in the upper arch on the right (URspace), left (ULspace), and overall space balance in the lower arch (Lspace). This is calculated using generally accepted methods for calculating space deficit or surplus in orthodontics. Space deficit is indicated by a minus sign, while space surplus is indicated by a plus sign. For the lower arch, the planned correction of the deep curve of Spee (Spee) in millimeters is subtracted from the space balance (the additional space deficit is determined by the number of millimeters of the curve of Spee that needs to be corrected).

[0051] 4. Symmetry of the upper first molars relative to the perpendicular to the midpalatine suture (UMsym). This is determined using a photograph of the upper dentition, a scan of the palate, or a plaster cast. The photograph, scan, or cast is oriented so that the midpalatine suture is strictly vertical. A SUBSTITUTE SHEET (RULE 26) is drawn perpendicular to it (horizontal) through the contact point between teeth 5 and 6. It is noted which first molar—the right or the left—is located more medially (anteriorly) and by how many millimeters relative to this line. If the right molar is anterior, the value is positive; if the left molar is anterior, the value is negative. If they are completely symmetrical, the value is zero. The significance of this parameter is due to the fact that the symmetry of the first molars determines the location of the center of the upper dentition after teeth alignment and normalization of the width of the dentition.If the teeth are symmetrical in size, and the molars are aligned symmetrically with respect to the line indicated above, then regardless of the initial position of the central line and the asymmetrical width of the dental arches and crowding, after aligning the teeth using standard methods and normalizing the width, the center of the upper row will be aligned with the center of the maxilla. If at least one first molar is missing before treatment, the assessment is based on the distal edges of the second premolars. If these are also missing, the assessment is based on the first premolars, and so on up to the canines.

[0052] 5. The inclination (inclination) of the upper and lower canines and posterior teeth relative to the vertical position of the tangent to their outer surface. By how many millimeters can the dental arch in the area of ​​these teeth be expanded so that they assume a vertical position for optimal smile aesthetics? The expansion should take into account the bone tissue according to x-rays, as well as the possibility of expanding the opposite dental arch to ultimately achieve the correct occlusion of the upper and lower teeth. Clinically significant expansion is provided by the canines (UR3 - upper right, UL3 - upper left, LR3 - lower right, LL3 - lower left), as well as by the first premolars (UR4 - upper right, UL4 - upper left, LR4 - lower right, LL4 - lower left).

[0053] SUBSTITUTE SHEET (RULE 26) 6. Angle's Class for the first molars on the right (ClassR) and left (ClassL). Determined using lateral intraoral photographs of closed dental arches, scans of the dental arches, or plaster models. The assessment should be performed at a right angle to avoid class assignment errors. If there is no upper or lower first molar on a given side, the assessment is based on the distal edges of the second premolars; if there are none, the assessment is based on the first premolars. If there is a suspicion of a forced position of the lower jaw (a discrepancy between centric occlusion and centric relation), the molar class is assessed taking this into account. The class is assessed in millimeters of deviation from Angle's Class I. The assessment methodology is described in more detail in the analysis of the extraction rules below. If the class is shifted from the first toward the second, the class parameter value is positive; if it is shifted toward the third, the value is negative.

[0054] 7. The initial inclination of the lower incisors at the symphysis, or more precisely, the required direction and magnitude of incisor deviation to achieve their parallel position at the symphysis (31рага1 - for tooth 31, 32рага1 - for tooth 32, 41рага1 - for tooth 41, 42рага1 - for tooth 42). Historically, the inclination of the lower incisors was assessed using a lateral teleradiograph as the angle between the long axis of these teeth and the base of the mandible. The active introduction of computed tomography into orthodontic practice has shown that the average numerical norms for incisor inclination using this method often do not reflect the most anatomically comfortable position of the lower incisors at the symphysis. Their optimal position is one where the long axis of the lower incisor is parallel to the axis of the symphysis.Using CT scans or a lateral teleradiograph (if tomography data is unavailable), the doctor evaluates the position of each lower incisor and determines the required direction and magnitude of movement of the incisor's cutting edge, taking into account the incisor's tilt, so that it is positioned as parallel as possible to the symphysis axis. If the tooth needs to be tilted backward, the value is indicated with a minus sign; if forward, with a plus sign. The sum of the required movements of all four lower incisors is added together, taking into account the signs, and the sum is divided by 4, yielding the average required direction and magnitude of change in the inclination of the lower incisors in millimeters (LIparal) to achieve their optimal position.

[0055] LIparal = (31paral + 32paral + 41paral + 42paral) / 4

[0056] 8. Gum biotype in the lower anterior region. It can be thin, medium, or thick. It is determined using generally accepted methods.

[0057] Step 2. Calculate the corrected space balance on the “more normal” side (U_Space_Norm_Correct) and the required mesiodistal movement of the first molar on that side (U6_Norm).

[0058] 1. The "more normal" side is considered to be either the side with the least amount of space deficit or the side opposite the center displacement of the upper dental arch. If these conditions contradict each other, the center displacement takes precedence.

[0059] 2. We calculate the corrected space balance on it. We denote it as U_Space_Norm_Correct. U_Space_Norm_Correct is calculated using the formula. If the "more normal side" is the right one, then U_Space_Norm_Correct = URSpace + Ulchange x 0.7 - Midline + UR3 x 0.7 + UR4 x 0.2 + SEx 0.5 + IPR

[0060] If we are talking about the left side, then

[0061] U_Space_Norm_Correct = ULSpace + Ulchange x 0.7 - Midline + UL3 x 0.7 + UL4 x 0.2 + SE x 0.5 + IPR,

[0062] SUBSTITUTE SHEET (RULE 26)where SE (skeletal expansion) denotes the magnitude of skeletal expansion (the magnitude of the planned diastema), if it is planned during treatment. IPR (interproximal enamel reduction) is the magnitude of interproximal enamel reduction in the anterior dentition (separation from canine to canine), if it is envisaged for aesthetic reasons. The remaining components of the formula are described in Step 1. Expansion along teeth 5, 6, and 7 is not considered in the formula in practice, since, according to our own research, it provides only 0.1 mm of space for every millimeter of expansion. Furthermore, significant expansion along these teeth is rarely possible. The final result will show us the remaining balance of space on a given side after normalizing the center, inclination of the incisors, and width.

[0063] 3. If the value is negative (deficit), then the first molar on that side will need to be distalized (moved backward) by that amount. The required amount of distalization allows the dentist, after assessing the presence of cancellous bone distally behind the upper molars, the height of the sinus, and the presence or absence of the eighth tooth, to decide whether such a degree of backward movement of the posterior teeth on that side of the upper dentition is feasible. Distalization will require time and support from orthodontic mini-screws. If the required distalization is greater than 3.5 mm, it is usually recommended to consider tooth extraction on that side (usually the fifth tooth or the tooth with the worst dental prognosis), with the anterior teeth closing the gap to the required amount of distalization and the rest being filled with the posterior teeth.The magnitude of the forward displacement of the molar in the case of extraction is equal to the difference between the mesiodistal size of the tooth being extracted according to the plan and the magnitude of the corrected (calculated) space deficit.

[0064] SUBSTITUTE SHEET (RULE 26)4. If the value in point 3 is positive, this indicates excess space. This means that the posterior teeth on this side require forward displacement by the calculated amount (mesialization). This will require support in the form of miniscrews and time. If mesialization of more than 4 mm is required, then space can be created for a premolar dental implant. The required backward displacement of the molar is equal to the difference between the implant space (usually 6.5 mm) and the calculated excess space. The final results of the second step of the algorithm will be:

[0065] • Understanding the need for tooth extraction if the deficiency results in more realistic distalization – point 3.

[0066] • Understanding the need to install a dental implant if too much mesialization is required and the patient is not ready for very long treatment - from point 4.

[0067] • Understanding the need to use orthodontic mini-screws if distalization or mesialization is planned. • Accurate knowledge of the amount of required forward or backward movement of the first molar from points 3 or 4. The amount of required displacement of the first molar on the “more normal side” will be designated as U6_Norm. Forward movement is a positive value, backward movement is negative. U6_Norm = U_Space_Norm_Correct provided that the dentist decides to perform distalization or mesialization, that is, treatment on this side without removing the premolar and without creating space for installing a dental implant. If the decision is made to remove, then U6_Norm = Size of the tooth to be removed + U_Space_Norm_Correct. If space is created for a premolar implant, then U6_Norm = U_Space_Norm_Correct is the size of the space for the implant.

[0068] SUBSTITUTE SHEET (RULE 26) Step 3. Calculation of the required movement of the molar on the opposite side of the upper dental arch (U6_Contr).

[0069] 1. Count the number of teeth on a given side medially from 6. If all the teeth are present, the value is 5; if there are none, for example, a lateral incisor before treatment or a premolar, the value is 4, etc.

[0070] 2. Counting the number of teeth medially from 6 on the “more normal” side of the dental arch, which was worked with during step 2. The calculation logic is the same as in the previous point.

[0071] 3. Comparison of the number of teeth on the right and left counted in points 1 and 2. Possible options: the same, less on the right than on the left, less on the left than on the right.

[0072] 4. If the teeth are identical, the right and left first molars should be placed in a "completely symmetrical position," meaning the contact points of teeth 6 and 5 on each side should be on the same horizontal line, perpendicular to the midpalatal suture (described in Step 1). The final position of the first molars relative to each other is designated as U6_Diff_Final. If the position should be symmetrical, the value of this parameter is zero.

[0073] 5. If there are fewer teeth on one side, then the molar on that side should be positioned medially (anterior) to the specified line at the end of treatment, compared to the first molar on the other side, by the distance of the missing tooth. This molar position will be called "completely asymmetrical." If the right molar is positioned anteriorly, the U6_Diff_Final value is positive; if the left molar is positioned anteriorly, the U6_Diff_Final value is negative.

[0074] 6. Knowing how many teeth are on the side of the upper dental arch calculated in this step (opposite to the “more normal” side) relative to the “more normal” side, we understand how the first molar on this side should stand relative to the molar on the opposite side, taking into account the explanations in points 3, 4, 5, and we obtain the value and sign of the parameter U6_Diff_Final.

[0075] 7. Knowing,

[0076] a) how the first molars on different sides of the upper dental arch initially stand relative to each other (item 4 of step, UMsym);

[0077] b) what final position they should take relative to each other (item 2, 3, 4, 5, U6Diff_Final);

[0078] c) how much and in which direction the molar on the “more normal” side will move (item 5 of step 2, U6_Norm),

[0079] Let's calculate the required direction and magnitude of movement on the side opposite the "more normal" one. We'll designate this parameter as U6_Contr_Need. Positive movement indicates forward movement, negative movement indicates backward movement. For the right side of the dentition, U6_Contr_Need_R = U6_Diff_Final - UMsym + U6_Norm; for the left side, U6_Contr_Need_L = UMsym + U6_Norm - U6_Diff_Final.

[0080] 8. Check the accuracy of your initial data by recalculating the space balance on the side opposite the "more normal" one (U_Space_Contr_Correct). For the right side: U_Space_Contr Correct = URSpace + Ulchange x 0.7 + Midline + UR3 x 0.7 + UR4 x 0.2 + SE x 0.5 + IPR - U6_Contr_Need. If we are talking about the left side, then U Space Contr Correct = ULSpace + Ulchange x 0.7 + Midline + UL3 x 0.7 + UL4 x 0.2 + SE x 0.5 + IPR - U6_Contr_Need. If all the initial parameters were determined perfectly correctly, then the resulting balance will be close to zero. If the balance differs from zero by more than 1 mm, then the original data must be rechecked and refined, ensuring that the U_Space_Contr Correct parameter has a modulus of no more than 1.

[0081] SUBSTITUTE SHEET (RULE 26)9. Taking into account the value from point 7 of this step and the logic of reasoning from points 3, 4, and 5 of step 2, we obtain information about the need for extraction on this side, the need to create space for a dental implant, the need for miniscrews for support, and the final required amount and direction of molar displacement on this side. If the U6_Contr_Need value is negative, then distalization of the first molar on this side (reverse movement) will be required. The required distalization value allows the clinician, after assessing the presence of cancellous bone distally behind the upper molars, the height of the sinus, and the presence or absence of 8 teeth, to decide whether such a volume of backward movement of the posterior teeth on this side of the upper dentition is possible in this case. Distalization will require time and support from orthodontic miniscrews. If the required distalization value is greater than 3.If the tooth on this side is 5 mm, it is usually recommended to consider extracting the tooth on that side (usually the 5th tooth or the tooth with the worst dental prognosis), with the anterior teeth closing the gap to the desired distalization distance, and the rest to be done with the posterior teeth. The amount of forward molar displacement with extraction is equal to the difference between the mesiodistal dimension of the tooth to be extracted according to the plan and the corrected (calculated) space deficit. If the U6_Contr_Need value is positive, this indicates the need to move the molar on that side forward. This means that the posterior teeth on this side must be moved forward by the calculated distance (mesialization). This will require support in the form of miniscrews and time. If mesialization of more than 4 mm is required, then space can be created for a premolar dental implant. The required backward molar displacement in this case (SUBSTITUTE SHEET (RULE 26)) is equal to the difference in the implant space (usually 6 mm).5 mm) and the calculated amount of excess space. The final results of this step in the algorithm will be for the opposite "more normal" side:

[0082] • Understanding the need for tooth extraction if too much distalization is required.

[0083] • Understanding the need for dental implant placement if too much mesialization is required and the patient is not prepared for a very long treatment period.

[0084] • Understanding the need for orthodontic mini-screws if distalization or mesialization is planned. • Accurate knowledge of the amount of forward or backward movement of the first molar that is actually required (U6_Contr_Fact).

[0085] For non-extraction treatment and without awareness of the space available for a dental implant, U6_Contr_Fact = U6_Contr_Need. If the decision is made to extract, then U6_Contr_Fact = Tooth size to be extracted + U6_Contr_Need. If space is being created for a premolar implant, then U6_Contr_Fact = U6_Contr_Need — the size of the space available for the implant.

[0086] Step 4. Calculation of the required movement of the molars on the lower row of teeth on each side separately.

[0087] 1. The logic described below applies first to the right side, then to the left side equally.

[0088] 2. Calculation of the number of lower teeth medially from 6 on a given side and the planned final treatment, taking into account the plan from steps 3 and 4, of the number of upper teeth medially from 6 on a given side.

[0089] 3. Comparison of these values. Three options are possible: the number of teeth medial to 6 on a given side of the lower dental arch is equal to the planned number of upper teeth medial to 6 on a given side of the dental arch (1); there will be fewer teeth at the top than at the bottom (2); there will be fewer teeth at the bottom than at the top (3).

[0090] 4. If the teeth are identical, then for the canines to close according to Angle's Class 1, the first molars must also close according to Class 1. If there are fewer teeth on the upper than lower teeth, then for the canines to close according to Class 1, the molars must close according to a full Angle's Class 2. If there are fewer teeth on the lower than upper teeth, the molars must close according to a full Class 3. If the molars close according to a full Class 3, it is necessary to ensure that there are more molars on the lower side than on the upper side, otherwise the last upper molar will be left without an antagonist (it will have nothing to close with, which will lead to its excessive eruption, similar to the Popov-Godon phenomenon, requiring future extraction). If this condition is not met, there is no point in placing Class 3 molars. Therefore, it is necessary to obtain an equal number of teeth medial to the 6th molar, both upper and lower, to achieve Class 1 molar occlusion. Either do not extract the lower molars, or extract the upper molars as well.We will designate the required molar occlusion class as Class_6_Need. If the molars should close at the end according to Class 1, then Class_6_Need = 0. If the molars should close at the end according to Class 2, then Class _6_Need = 7. If the molars should close at the end according to Class 3, then Class _6_Need = -7.

[0091] 5. Knowing the magnitude and direction of the displacement of the upper molars on a given side (item 5 of step 2 or 3, parameters U6_Norm and U6_Contr_Fact - depending on the side), as well as the original class for molars on a given side (item 6 of step 1), we calculate the required direction and magnitude of displacement of the lower molars to obtain the desired class for molars (item 4). We designate the required movement of the lower first molars as L6_Need. For the "more normal" side, if it is the right one, L6_Need = ClassR + U6_Norm - Class _6_Need. For the "more normal" side, if it is the left one, L6_Need = ClassL + U6 Norm - Class_6_Need. For the side opposite the "more normal" one, if it is the right one, L6_Need = ClassR + U6_Contr_Fact - Class j5_Need. For the side opposite the "more normal" one, if it is the left one, L6_Need = ClassL + U6_Contr_Fact - Class_6_Need. The resulting unobservable movement on the lower left side is denoted as L6_Need_L, on the right side - as L6_Need_R. Their calculation is indicated above.

[0092] 6. Knowing the direction and magnitude of the required displacement of the lower molars on the right and left, we apply the logic of points 3 and 4 of step 2 to decide on the need to remove individual teeth or create space for a dental implant, or the use of mini-screws.

[0093] Step 5. Recalculation of the space balance in the lower dental arch taking into account the initial data and step 4 (L_Space_Correct).

[0094] L_Space -Correct = Lspace + LR3 x 0.6 + LR4 x 0.4 + LL3 x 0.6 + LL4 x 0.4 + SEx 0.5 + IPR - L6_Need_L -L6_Need_R

[0095] All parameters have already been described in the previous steps, SE - skeletal expansion in the lower jaw area (distraction), if it is provided for in the plan, IPR - possible separation (interproximal enamel reduction) in the area of ​​the lower anterior teeth if it is necessary to reduce the space deficit or for aesthetic reasons (the likelihood of so-called "black triangles" between the lower anterior teeth with point contacts).

[0096] Step 6. Calculation of the expected change in the inclination of the lower incisors (LI_Inc_Change) and assessment of the adequacy of their final position.

[0097] SUBSTITUTE SHEET (RULE 26) 1. Based on the author's clinical experience, the limits for the final position of the lower incisors (LI_limit) are established as follows: with a thin gingival biotope, a deviation of the lower incisors more than 1.5 mm forward or backward from the parallel position at the symphysis is undesirable. With an average gingival biotope, no more than 2-3 mm is desirable; with a thick biotope, no more than 4-5 mm.

[0098] 2. We calculate the expected change in the position of the lower incisors according to our treatment plan in mm. LI Inc Change = -L Space Correct x 0.7. A positive value indicates forward movement of the lower anterior teeth, a negative value indicates backward movement.

[0099] 3. Calculate the final deviation of the lower incisors from parallelism with the symphysis (LI_final_symph). LI_final_symph = LI Inc Change - LIparal. Compare the resulting value by modulus with the limit benchmarks from point 1 (LI_limit), taking into account the gingival biotype. If the modulus of LI_fmal_symph is greater than the modulus of LI_limit, then the deviation of the lower incisors from the parallel position in the symphysis exceeds the acceptable clinical limits, taking into account the gingival biotype. Otherwise, the inclination is acceptable. For example, in the initial data, it turned out that the lower incisors need to be moved forward by an average of 2 mm (LIparal = +2) to achieve parallelism with the symphysis axis (point 7, step 1). When calculating the planned movement of the lower incisors according to the current treatment plan (point 2), we got LI_Inc_Change = +4 (4 mm forward). Subtracting +2 from +4 gives +2. That is, taking into account the initial position of the lower incisors and their planned movement, their final position will be 2 mm forward from the position parallel to the axis of the symphysis.If in point 8 of step 1 we defined the gum biotype as, for example, medium, then taking into account the data from point 1 of the current step, we consider this situation acceptable.

[0100] SUBSTITUTE SHEET (RULE 26)

[0101] 4. If the position is acceptable, the treatment plan is considered adequate. It includes information on the required movements in each of the four segments of the dental arch, including approximate timeframes, the need for individual tooth extractions for orthodontic reasons, implant placement, the use of mini-screw support, and the final inclination of the lower incisors. This treatment plan, when implementing the movements specified in it, will ensure an aesthetic inclination of the upper anterior teeth, the center of the upper dental arch in the center of the face, the placement of the canines in Class I, and thus a correct and stable occlusion.

[0102] 5. If the expected final position of the lower incisors calculated in point 3 is unsatisfactory because it exceeds the limits specified in point 1 of this step, this indicates that the patient has a skeletal malocclusion, which can only be addressed ideally by using orthognathic surgery to resize the jaws in addition to orthodontic treatment. This requires consultation with the surgeon and the patient's approval. The approximate magnitude of the change in jaw size relative to each other is equal to the excess deviation of the lower incisors at the final calculated plan from a position parallel to the symphysis axis (LI_final_symph). If the value is positive, the size of the lower jaw relative to the upper jaw should be increased; if the value is negative, the opposite is true.

[0103] 6. If the patient is not ready for combined treatment using orthognathic surgery, then we move on to searching for compromise options (see step 7).

[0104] Step 7. Recalculate the treatment plan taking into account trade-offs.

[0105] SUBSTITUTE SHEET (RULE 26) 1. Possible compromises for recalculating the plan include two main methods. First, the final position of the upper incisors (Ulchange) can be slightly altered from the optimal position. Based on clinical experience and scientific data, we can tilt the upper incisors 1.5-2 mm forward from the vertical position, after consulting with the patient. Second, we can tilt them backward by approximately 1 mm and shift them back corporally (with roots) by approximately 2 mm on average. Thus, we can shift their position from +2 mm to -3 mm from the optimal position. In addition to working with the position of the upper anterior teeth, we may not achieve a clear Class I canine position, but we advise the patient accordingly. Shifting the canines toward Class III by more than 0.5 mm is usually not possible, as this could lead to a direct occlusion of the incisors. We can shift more towards class 2, allowing at the end a total deviation from class 1 for the canines on the right and left of approximately 6 mm.These options may include leaving 2 mm of Class 2 on each canine, or achieving Class 1 on one side and leaving Class 2 on the other. Such compromises in class are optimally verified later through modeling on the setup to ensure there is no sagittal gap.

[0106] 2. If, in step 3 of the previous paragraph, we found that the position of the lower incisors (LI_final_symph) is too protrusive (a positive value greater in absolute value than the Ll limit), we change the required position of the upper incisors (Ulchange) in the initial data, shifting them backward by the number of millimeters corresponding to the excess inclination of the lower incisors relative to the limit, but no more than 3 mm backward. If this is insufficient, a compromise class is added, and in step 4, the movement of the lower molars is calculated taking into account the resulting compromise class SUBSTITUTE SHEET (RULE 26) (the Class_6_Need parameter is changed from the standard). The value of this parameter, as already indicated, can be increased by a total of 6-7 mm on both the right and left sides. The total compromise class multiplied by 0.7 will yield the reduction in protrusion of the lower incisors. Thus, in total, the protrusion of the lower incisors can be reduced at the end of treatment by a maximum of approximately 7 mm (3 + 6 x 0.7).If this is still not enough, then treatment is only possible with surgery; it is most likely impossible to reach normal compromises.

[0107] 3. If, in step 4 of the previous chapter, we found that the position of the lower incisors is too retrusive (a negative value greater in absolute value than LI_limit), we change the required position of the upper incisors (Ulchange) in the initial data to a more protrusive position, but no more than 2 mm. If this is insufficient, treatment is only possible with surgery; reasonable compromises are unlikely to be reached.

[0108] 4. If points 3 and 4 indicate that a compromise is possible, then the entire plan is recalculated from step 2 to step 6 using the new data on the position of the upper incisors (Ulchange) (included in point 2 of step 2) and the new data on the desired final class (Class_6_Need) (included in point 5 of step 4). This treatment plan will compensate for the skeletal malocclusion, is carried out with the patient's consent, and only after informing them of the optimal surgical plan and the compromises involved in the compensatory plan.

[0109] The above steps, as well as the invention as a whole, can be included in the logic of software implemented on an electronic device and described below, but can also be used without software by

[0110] SUBSTITUTE SHEET (RULE 26) for independent calculation by the physician based on the basic logic and principles indicated above in the description of the steps.

[0111] Personal computers, tablets, etc. may be used as electronic devices. The electronic device contains hardware and / or application software and / or system software (or a combination thereof) capable of executing the present method, within a corresponding program having a user interface.

[0112] The implementation of the invention using software implemented on an electronic device is divided into the following steps:

[0113] 1. The doctor enters the initial data (the above-mentioned initial geometry parameters, as well as other diagnostic parameters, ranging from anamnesis data to the patient’s dental formula) for the patient using the user interface.

[0114] 2. Using the entered initial data, the software generates an automatic treatment plan via the user interface, following the steps outlined above. The automatic treatment plan includes an informational section—all explanations and warnings for the patient that the doctor should provide during the treatment plan discussion—as well as a geometric section—the directions and magnitudes of movements in each of the four segments of the dental arches. The geometric section of the plan, generated automatically by the program, corresponds to steps 2–6 of the method.

[0115] 3. The software calculates and visually displays the directions and magnitudes of the necessary movements of the posterior teeth, but fundamentally does not make decisions about the need for extractions or the creation of space for implants. This is the responsibility of the orthodontist. Based on the required movement values, the orthodontist makes a decision about the need for extractions or the creation of space for an implant, indicating this in the corresponding section of the dental formula. The visual movement plan is then automatically adjusted, updating all informational aspects of the treatment plan. For example, the plan for the patient and the orthodontist indicates which teeth will be extracted and whether mini-screws are required for support.

[0116] 4. Step 7 of the compromise design process is also performed independently by the dentist. In the compromise block of the plan creation tab, they can change the final position of the upper incisors, as well as the final class of the canines. The software automatically recalculates the plan. This allows the dentist to quickly find the most effective compromise or determine that there is no such compromise, and that combined treatment with surgery is required.

[0117] 5. The software also provides prompts to the doctor to provide reassurance. For example, if the planned distalization is too great, it will suggest considering extraction. If the treatment plan results in the absence of antagonists for any teeth, a warning will also be issued. Any illogical actions are accompanied by alerts and warnings. However, the final responsibility for the final plan rests with the doctor, which we consider fundamentally important. The software simply relieves the doctor of the need for calculations and provides reassurance in case they overlook something or make a mistake.

[0118] 6. The software also automatically generates a treatment plan for discussion with the patient, highlighting all aspects that require discussion. It also creates a completed treatment plan for the patient to sign (SUBSTITUTE SHEET (RULE 26)), as well as a plan of action and treatment mechanics for the physician. This saves significant time in the practice and significantly reduces the likelihood of forgetting to inform the patient of any important aspects of the treatment plan.

[0119] Special rules have been developed to verify the treatment plan, as a physician implementing the invention without software could make a mistake. The rules are based on the logic described in the invention, but are simplified and serve as a safety net for quickly verifying the logic of a treatment plan that includes irreversible procedures, such as the extraction of individual teeth for orthodontic reasons. These rules are an integral part of the described method.

[0120] Two groups of rules are proposed.

[0121] 1) Rules for checking the logic of the decision on unilateral removal of the upper dental arch.

[0122] 1A) Rule for checking the logic of unilateral removal in the initial presence of all teeth in the upper dental row.

[0123] If the doctor, based on the results of applying the proposed method or using his own logic, has come to the conclusion that he needs to treat the patient with the extraction of a premolar on one side of the upper dental arch (unilateral extraction), provided that a full set of upper teeth is initially present, then this is usually logical if the first molar on this side relative to the perpendicular to the median palatine suture is located medially (anteriorly) at least 3-4 mm compared to the position of the first molar on the opposite side, taking into account the planned mesiodistal movements of the latter.

[0124] SUBSTITUTE SHEET (RULE 26) For example, a patient initially has a complete upper dentition, with all teeth present, an asymmetrical space deficit, and a midline shift relative to the facial center. The dentist has decided to extract the second upper right premolar during treatment. Initially, the upper right first molar is positioned 1.5 mm more medially (anteriorly) than the molar on the opposite side. The first molar on the upper left side is not planned to be moved forward or backward. Therefore, the asymmetry in the position of the first molars is 1.5 mm, which is less than 3.5 mm, meaning the treatment plan is likely illogical. It is illogical because in this case, when extracting tooth #15, of the average 6.5 mm of space remaining from it, only 1.5 mm will need to be covered by the anterior teeth. This means that this space deficit is insufficient to justify the extraction of a healthy permanent tooth. 5 mm will need to be covered by displacement of the back teeth, which is difficult.It's usually easier to distalize all lateral teeth by 1.5 mm. Another example: A patient initially has a full upper arch, with all teeth present, an asymmetrical space deficit, and a midline offset from the facial center. The doctor has decided to extract the second upper right premolar during treatment. Initially, the upper right first molar is positioned 2.5 mm more medially (anteriorly) than the molar on the opposite side. The first molar on the upper left is planned to be moved back (distalized) by 2 mm. Therefore, the asymmetry in the position of the first molars is 2.5 mm + 2 mm = 4.5 mm. This is more than 3.5 mm, meaning the treatment plan is likely logical.

[0125] 1B) The rule for checking the logic of unilateral removal in the case of the initial absence of one tooth from group 2, 3, 4, 5 on the upper

[0126] REPLACEMENT SHEET (RULE 26)dentition on one side, which is not planned to be replaced by a dental implant.

[0127] That is, if the upper dental arch is initially asymmetrical in the number of teeth on the right and left sides, and the missing tooth is not planned to be replaced with a dental implant, then the rule is as follows. Extraction on the side with the larger number of teeth initially makes sense if the first upper molar on that side is positioned distally (posteriorly) relative to the perpendicular to the median palatal suture by no more than 3-4 mm relative to the first molar on the opposite side, taking into account the latter's mesiodistal movements.

[0128] 2) Rules for checking the logic of the combination of extractions on the upper and lower dental arches on a given side, provided that the dental arches are initially full.

[0129] To formulate these rules, the concept of "rounded molar class" was introduced. According to Angle's classification, molar classes are 1, 2, and 3. However, from a practical standpoint, this can be confusing, as there are many intermediate variations. For example, if the maxillary first molar is displaced forward by 2 mm relative to the ideal molar relationship according to Angle's Class 1, then formally it is no longer Class 1, although it still needs to be displaced forward by approximately 5 mm to reach the typical Class 2 relationship. The approximate difference between Classes 1, 2, and 3 is 7 mm between each position (the width of the middle premolar). If a patient has the described situation, with a molar relationship 2 mm away from Class 1 toward Class 2, some clinicians in practice call it Class 1, since it is closer to it, while others refer to it as Class 2, since it is no longer formally Class 1.The most accurate description would include such wording as "4 mm class 2 on the right," or "clean class 1 SUBSTITUTE SHEET (RULE 26) on the left," or "3 mm class 3 on the right," etc. These parameters are used in the algorithm described above.

[0130] However, for the sake of simplicity, we use a "rounded class" for the rules. When defining it, we assume that the "midpoint" between classes is a 3.5 mm difference from the "pure" class.

[0131] 3.5 mm is the average value that marks the boundary between molar distalization and premolar extraction, which is why this value is included in the rule regarding the logic of tooth extraction. The rules assume that if distalization of more than 3-4 mm is required, it often makes sense to consider premolar extraction. Conversely, if the anterior teeth need to cover less than 3-4 mm, it is often possible to avoid extraction by distalizing the molars and, if necessary, separating the posterior teeth.

[0132] 3.5 mm is a value approximately equal to half the mesiodistal dimension of the middle premolar. When the upper and lower teeth occlude in this relationship, it is often called a "cusp-to-cusp" relationship, as the premolars interdigitate cuspidally. The cusp-to-cusp relationship of premolars and canines can be Class 2, which we will call "cusp-to-cusp"; or Class 3, which we will call "cusp-to-cusp" occlusion. Visually, the "cusp-to-cusp" relationship is easier to determine by the occlusion of the second premolars, if they are relatively even and there are no gaps between the 5th and 6th teeth. In a "cusp-to-cusp" relationship, the cusp of the upper 5th tooth interdigitates exactly with the cusp of the lower 5th tooth. If the specified conditions for the second premolars are not met, then we define "Tubercular Class 2" based on the projection of the occlusion of the mesial edges of the upper and lower first molars. For "Tubercular Class 3," it is more difficult to orientate the molars, so it is easier to mentally align the first and second premolars and understand

[0133] SUBSTITUTE SHEET (RULE 26) What will be their relationship? In "class 3 cusp," the upper 4th tooth aligns exactly with the cusp of the lower 5th tooth.

[0134] The following options are used to determine the "rounded class":

[0135] 1. “Better than the tubercular 2nd class in the direction of the 1st class and better than the tubercular 3rd class in the direction of the 1st class” = “rounded 1st class”;

[0136] 2. “Worse than tubercular 2nd class towards full 2nd class” = “rounded 2nd class”;

[0137] 3. “Worse than the tubercular 3rd class towards the full 3rd class” = “rounded 3rd class”.

[0138] "Rounded Class 1" refers to a relationship between the posterior teeth on a given side that is closer to Class 1, that is, "better than the cusp of Class 2 toward Class 1 and better than the cusp of Class 3 toward Class 1." This ranges from a relationship where the cusp of the upper 4th tooth is medial to the cusp of the lower 5th tooth to a relationship where the cusp of the upper 5th tooth is distal to the cusp of the lower 5th tooth.

[0139] We have a "rounded Class 2" when the relationship of the lateral teeth on a given side is closer to Class 2, that is, "worse than the cusp Class 2 toward a full Class 2." This is when the cusp of the upper 5th tooth is located medial to the cusp of the lower 5th tooth.

[0140] We have a "rounded Class 3" when the relationship of the lateral teeth on a given side is closer to Class 2, that is, "worse than the cusp Class 3 toward a full Class 3." This is when the cusp of the upper 4th tooth is distal to the cusp of the lower 5th tooth.

[0141] 2A) The "rounded 1st class" rule for molars

[0142] If the molar class on a given side (right or left) is initially closer to the first, that is, there is a ratio of "better than a cusp class 2 toward a cusp class 1 and better than a cusp class 3 toward a cusp class 1," then it is logical to either remove nothing on that side or remove both the upper and lower premolars. Another example of the wording of the second part of the rule is "it is not logical to remove only one dental arch."

[0143] 2B) The "rounded 2nd class" rule for molars

[0144] If the molar class on a given side (right or left) is initially closer to Class II, that is, there is a ratio of "worse than Class II cusp toward a full Class II," then it makes sense to extract the premolar on that side only in the upper arch. Another example of the wording of the second part of the rule is "it is not logical to extract a premolar in the lower arch."

[0145] 2B) The "rounded 3rd class" rule for molars

[0146] If the molar class on a given side (right or left) is initially closer to 3rd molar, that is, there is a ratio of "worse than cusp class 3 toward a full class 3," then it is logical to extract only the premolar on this side in the lower arch, provided that at the end of treatment, a lower third molar will be present in the dental arch. Another example of the wording of the second part of the rule is "it is not logical to extract a premolar in the upper arch." The condition that when extracting only the lower premolar on a given side, given the initial presence of all teeth on the upper and lower arch, is based on the fact that with this extraction option, the final molar occlusion will be in class 3, and the upper second molar will be left without an antagonist (there will be no tooth with which to occlude), unless there is a lower third molar in the oral cavity.

[0147] Let us emphasize once again that the rules do not address the need for tooth extraction for orthodontic reasons. This is always a matter of space constraints or compensation for skeletal sagittal anomalies, which is addressed using the proposed method. The rules only specify which combinations and combinations of extractions are logical to avoid having to cover more space with posterior teeth from an extracted tooth than would be used to address the space constraints and retract the incisors. In other words, to make the extraction more justified.

[0148] Similar rules based on the logic of 3.5 mm and the "tubercular" class can also be applied when quickly deciding on the advisability of creating a place for an implant in the area of ​​teeth 5, 4, 3, 2, 1 or closing gaps in the case of edentia in the area of ​​these teeth.

[0149] The general idea is that when reviewing a treatment plan with a variable number of teeth, the patient should consider a more logical final tooth count based on the initial position of the first molars (their symmetry in the upper arch and molar class). These principles can be called "rules for optimal final tooth count."

[0150] Rules for the optimal final number of teeth

[0151] • If the initial situation on the upper dental row is closer to the “symmetrical position of the first molars”, then it is more logical to have at the end of the treatment the same number of teeth on the right and left from the number of teeth medial to the first molar (1, 2, 3, 4, 5);

[0152] • If the initial situation on a given side is closer to the “rounded 1st class”, then it is more logical to have the same number of teeth on the upper and lower dental arches on this side at the end of treatment;

[0153] • If the initial situation on a given side is closer to the “rounded 2nd class”, then it is more logical to have on this side at the end of treatment one tooth less on the upper dental row than on the lower dental row from the number of teeth medial to the first molar (1, 2, 3, 4, 5)

[0154] • If the initial situation on this side is closer to the “rounded 3rd class”, then it is more logical to have on this side at the end of treatment on the lower dental row one tooth less than the REPLACEMENT SHEET (RULE 26) on the upper dental row from the number of teeth medial to the first molar (1, 2, 3, 4, 5), but subject to the presence of the 8th tooth below.

[0155] All these rules are used provided that there is no planned change in the position of the lower jaw and / or its size, that is, the jaw is not in a forced position, and orthognathic surgery is not planned during the treatment process.

[0156] Thus, the proposed method improves the efficiency of orthodontic treatment planning in practice, reducing errors and providing a clear visual plan of movements with indication of direction and magnitude. This invention improves the quality of orthodontic treatment, thereby enhancing the aesthetics of smiles and the dental health of the population.

[0157] An example of the method implementation.

[0158] Step 1. Obtaining the initial occlusion geometry data.

[0159] 1. Midline. Midline = 1.5 mm to the right (the center is shifted to the right from the center of the upper lip by 1 mm according to the smile photo and by 2 mm according to the incisor exposure photo, average = 1.5 mm (see Fig. 1).

[0160] 2. Inclination of the upper incisors. Ulchange = -1.5 mm (the upper incisors must be tilted back by 1.5 mm to achieve a vertical position) (see Fig. 2).

[0161] 3. Space balance on the upper dental arch on the right (URspace), left (ULspace) and overall space balance on the lower dental arch (Lspace).

[0162] URspace = - 5 mm, ULspace = 0 mm, Lspace = - 1 mm, the curve of Spee is flat, Spee = 0, the balance of space below therefore does not require recalculation taking into account the curve of Spee (see Fig. 3).

[0163] 4. Symmetry of the position of the upper first molars relative to the perpendicular to the median palatine suture (UMsym) UMsym = -2 mm (see Fig. 4).

[0164] SUBSTITUTE SHEET (RULE 26)5. Expansion of canines and premolars, skeletal expansion.

[0165] Expansion of these teeth is not indicated, as they are almost vertical, with optimal aesthetic inclinations. An exception is that tooth #14 can be expanded by 1 mm, as it is inclined inward. UR4exp = 1 mm, and the remaining parameters are zero (see Fig. 1).

[0166] 6. Angle's class for the first molars on the right (ClassR) and left (ClassL). On the right and left, the first Angle's class for molars, that is, ClassR = 0, ClassL =

[0167]

[0168] 0 (see Fig. 5).

[0169] 7. Initial inclination of the lower incisors at the symphysis, the required direction and magnitude of incisor deviation to achieve their parallel position at the symphysis. For all incisors in this case, we set the parameter value to -2 mm, since to position them parallel to the symphysis, they must be tilted backward by approximately 2 mm. Accordingly, LIparal is -2 mm (see Fig. 6).

[0170] 8. Gum biotype in the lower anterior region. In this case, it is average (see Fig. 7).

[0171] Step 2. Calculate the corrected space balance on the “more normal” side (U Space Norm Correct) and the required mesiodistal movement of the first molar on that side (U6_Norm).

[0172] 1. The "more normal" side is considered to be either the side with the least space deficit or the side opposite the center displacement of the upper dental arch. If these conditions contradict each other, the center displacement takes precedence. In this case, the patient's left side is considered "more normal," since the center displacement is to the right.

[0173] 2. We calculate the adjusted space balance on it. In our case, there will be no skeletal expansion and no separation.

[0174] SUBSTITUTE SHEET (RULE 26) U_Space_Norm_Correct = 0 -1.5 x 0.7 - 1.5 + 0 x 0.7 + 0 x 0.2 + 0 x 0.5 + O = -2.5 mm.

[0175] 3. This amount of distalization (reverse movement) of the first molar on this side will be required. The required distalization is less than 3.5 mm in absolute value, meaning we are not planning extraction; we are incorporating a 2.5 mm distalization of the upper left molar into the treatment plan. U6_Norm = -2.5 mm

[0176] Step 3. Calculation of the required movement of the molar on the opposite side of the upper dental arch (U6_Contr).

[0177] 1. Count the number of teeth on this side medially from 6. All teeth are present, the value is 5

[0178] 2. Counting the number of teeth medially from 6 on the “more normal” side of the dental arch, all teeth are present, the value is 5.

[0179] 3. Comparison of the number of teeth on the right and left, counted in points 1 and 2. Answer = the same.

[0180] 4. If the teeth are identical, the right and left first molars should be placed in a "completely symmetrical position," meaning the contact points of teeth 6 and 5 on each side should be on the same horizontal line, perpendicular to the midpalatal suture (described in Step 1). The final position of the first molars relative to each other is U6_Diff_Final. If the position should be symmetrical, the value of this parameter is zero. This is the case in our case.

[0181] 5. Calculate the required direction and magnitude of movement on the side opposite the "more normal" one. For the right side of the dentition, U6_Contr_Need_R = U6_Diff_Final - UMsym + U6_Norm = 0 -(-2) -2.5 = -4.5 mm.

[0182] SUBSTITUTE SHEET (RULE 26)6. Check the accuracy of your initial data by recalculating the space balance on the side opposite the "more normal" one (U_Space_Contr_Correct). For the right side: U_Space_Contr Correct = URSpace + Ulchange x 0.7 + Midline + UR3 x 0.7 + UR4 x 0.2 + SE x 0.5 + IPR - U6_Contr_Need = -5 -1.5 x 0.7 + 1.5 + 0 + 1 x 0.2 + 0 + 4.5 = 0. A value of 0 indicates that all initial parameters were determined correctly.

[0183] 7. The U6_Contr_Need value is negative (-4.5 mm), meaning the first molar on this side will need to be distalized (moved backward) by 4.5 mm. If the required distalization is greater than 3.5 mm, it is usually recommended to consider extracting a tooth on this side (usually tooth 5 or the tooth with the worst dental prognosis), with the anterior teeth covering the gap to the required distalization value and the posterior teeth filling the remainder. Here, we decide to extract tooth 14 (approximately 7 mm), with the anterior teeth covering 4.5 mm and the posterior teeth filling the remaining 2.5 mm.

[0184] 8. Planned displacement of the first molar on this side. U6_Contr_Fact = Tooth size to be removed + U6_Contr_Need = 7 - 4.5 = 2 mm. This means removal of tooth 14 and displacement of tooth 16 forward by 2.5 mm.

[0185] Step 4. Calculation of the required movement of the molars on the lower row of teeth on each side separately.

[0186] 1. Calculate the number of lower teeth medial to 6 on the given side and the planned final treatment number of upper teeth medial to 6 on the given side, taking into account the plan from steps 3 and 4, and compare these values. Three options are possible: the number of teeth medial to 6 on the given side of the lower dental arch is equal to the planned number of upper teeth medial to 6 on the given side of the dental arch (1); there will be fewer teeth on the top than on the bottom (2); there will be fewer teeth on the bottom than on the top (3).

[0187] 2. In our situation, the upper and lower left teeth are planned to have the same number (all teeth). If the number of teeth is equal, then for the canines to occlude according to Angle's Class 1, the first molars must also occlude according to Class 1. Class_6_Need = 0.

[0188] 3. In our situation, we plan to have fewer teeth on the upper right side than we currently have on the lower right side (removal of 15 teeth). If there are fewer teeth on the upper side, then for the canines to occlude according to Angle's Class 1, the first molars must also occlude according to Class 2. Class_6_Need = 7.

[0189] 4. Knowing the magnitude and direction of the displacement of the upper molars on a given side (item 5 of step 2 or 3, parameters U6_Norm and U6_Contr_Fact - depending on the side), as well as the original class for molars on a given side (item 6 of step 1), we calculate the required direction and magnitude of displacement of the lower molars to obtain the desired class for molars - L6_Need. For the "more normal" side, if it is the left one, L6_Need_L = ClassL + U6_Norm - Class_6_Need = 0 -2.5 -0 = -2.5. That is, on the lower left we plan a distalization of 2.5 mm.

[0190] 5. For the side opposite the "more normal" side, if it's the right side, L6_Need_R = ClassR + U6_Contr_Fact - Class_6_Need = 0 + 2.5 - 7 = -4.5. This means that to achieve the desired Class 2 molars on the lower right, 4.5 mm of distalization is required. This is more than 3.5 mm, so we're considering removing a premolar, for example, tooth 45 (7 mm is the average width). The anterior teeth will cover 4.5 mm of the space, and the remaining 2.5 mm will be covered by the posterior teeth.

[0191] SUBSTITUTE SHEET (RULE 26) Step 5. Recalculation of the space balance in the lower dental arch taking into account the initial data and step 4 (L_Space_Correct).

[0192] L Space Correct = Lspace + LR3 x 0.6 + LR4 x 0.4 + LL3 x 0.6 + LL4 x 0.4 + SE x 0.5 + IPR - L6_Need_L -L6_Need_R = -1 + 0 + 0 + 0 + 0 + 0 + 0 + 2.5 + 4.5 = 6 mm

[0193] That is, after the calculated movements in the lower row of teeth (distalization of the lower left by 2.5 mm, extraction of 45 mm, and closing of the anterior teeth by 4.5 mm), there will be an excess of 6 mm of space in the lower row of teeth. This excess space will be used to move the incisors backward (flattening the lower row of teeth).

[0194] Step 6. Calculation of the expected change in the inclination of the lower incisors (LI_Inc_Change) and assessment of the adequacy of their final position.

[0195] 1. Based on the author's clinical experience, the limits for the final position of the lower incisors (LI_limit) for an average gingival biotype are no more than 2-3 mm. In our case, LI_limit = 2.5 mm.

[0196] 2. We calculate the expected change in the position of the lower incisors according to our treatment plan in mm. LI_Inc_Change = -L_Space_Correct x 0.7 = -6 x 0.7 = -4 mm rounded. A negative value indicates backward movement of the incisors.

[0197] 3. Calculate the final deviation of the lower incisors from parallelism to the symphysis (LI_fmal_symph). LI_final_symph = LI_Inc_Change - LIparal = -4 + 2 = -2 mm. Compare the resulting value with LI_limit (2.5 mm). 2 < 2.5, which means we consider this position acceptable. That is, taking into account the initial position of the lower incisors and their planned movement, their final position will be 2 mm back from the parallel position to the symphysis axis. The limit for the average biotype is 2-3 mm, that is,

[0198] We followed the SUBSTITUTE SHEET (RULE 26). Since the situation was acceptable, the treatment plan was considered adequate, and further steps were not required. The software, taking into account the inputted initial data, generates an automatic treatment plan via the user interface, according to the above steps for implementing the method (see Fig. 8).

[0199] SUBSTITUTE SHEET (RULE 26)

Claims

FORMULA 1. A method for planning orthodontic treatment that includes the following steps: 1) We determine the data of the initial occlusion geometry; 2) We calculate the corrected space balance on the more normal side (U_Space_Norm_Correct) and the required mesiodistal movement of the first molar on this side (U6_Norm), where the more normal side is considered to be either the side with less space deficit or the side opposite to the displacement of the center of the upper dental arch; 3) We calculate the required movement of the molar on the opposite side of the upper dental arch (U6_Contr); 4) We calculate the required movement of the molars on the lower row of teeth on each side separately; 5) We recalculate the balance of space on the lower dental row taking into account the initial data and step 4 (L_Space_Correct); 6) We calculate the expected change in the inclination of the lower incisors (LI Inc Change) and evaluate the adequacy of their final position; 7) We draw up an orthodontic treatment plan based on the results of the above steps.

2. A method for planning orthodontic treatment, implemented on an electronic device using software and including the following steps: 1) Entering initial data of occlusion geometry and diagnostic parameters of the patient using the user interface; 2) Calculation of the corrected space balance on the more normal side (U_Space_Norm_Correct) and the required mesiodistal movement of the first molar on this side SUBSTITUTE SHEET (RULE 26)(U6_Norm), where the more normal side is considered to be either the side with less space deficit or the side opposite to the displacement of the center of the upper dental arch; 3) Calculation of the required movement of the molar on the opposite side of the upper dental arch (U6_Contr); 4) Calculation of the required movement of molars on the lower dental row on each side separately; 5) Recalculation of the balance of space on the lower dental row taking into account the initial data and step 4 (L_Space_Correct); 6) Calculation of the expected change in the inclination of the lower incisors (LI_Inc_Change) and assessment of the adequacy of their final position; 7) Output of an orthodontic treatment plan using the user interface based on the results of the above steps.

3. A method for planning orthodontic treatment, implemented on an electronic device using software, characterized in paragraph 2 in that the orthodontic treatment plan displayed on the user interface contains an information part with all the explanations and warnings for the patient that need to be given to the doctor at the stage of discussing the treatment plan, as well as a geometric part with the directions and magnitudes of movements in each of the four segments of the dental arches.

4. A method for planning orthodontic treatment, differing in paragraph 1 in that at the last step the treatment plan is recalculated taking into account compromises if, based on the results of steps 1-6, the patient is not ready for combined treatment using orthognathic surgery.

5. A method for planning orthodontic treatment, characterized in accordance with paragraph 1 in that the data of the initial occlusion geometry include the position of the center of the upper dental arch SUBSTITUTE SHEET (RULE 26) relative to the center of the upper lip (Midline), the inclination of the upper incisors, the balance of space on the upper dental arch on the right (URspace), on the left (ULspace) and the overall balance of space on the lower dental arch (Lspace), the symmetry of the position of the upper first molars relative to the perpendicular to the median palatine suture (UMsym), the inclination of the upper and lower canines and lateral teeth relative to the vertical position of the tangent to their outer surface, the Angle class for the first molars on the right (ClassR) and on the left (ClassL), the necessary direction and magnitude of deviation of the incisors to obtain their parallel position in the symphysis, the biotype of the gum in the lower anterior region.

6. A method for planning orthodontic treatment, differing in paragraph 1 in that if the value (U_Space_Norm_Correct) is negative, then the first molar on that side will need to be distalized by that amount; if it is positive, then this means there is excess space and the lateral teeth on that side will need to be moved forward by the obtained amount.

7. A method for planning orthodontic treatment, differing in paragraph 1 in that the calculation of the necessary movement of the molar on the opposite side of the upper dental arch (U6_Contr) includes counting the number of teeth on this side medially from 6 and the number of teeth medially from 6 on the more normal side, comparing the number of teeth on the right and left, if the teeth are the same, then the right and left first molars should be placed in a completely symmetrical position, if there are fewer teeth on one side, then on this side the molar should be at the end of the treatment the amount of the missing tooth medially from the specified line in comparison with the first molar on the second side, determining the position of the first molar and calculating SUBSTITUTE SHEET (RULE 26)the required direction and magnitude of movement on the side opposite to the more normal one.

8. A method for planning orthodontic treatment, characterized in paragraph 1 in that the calculation of the required movement of the molars in the lower dental arch on each side separately includes counting the number of lower teeth medially from 6 on the required side and the planned number of upper teeth medially from 6 on the required side at the end of the treatment, comparing the obtained values ​​and determining the required occlusion class for the molars, calculating the required direction and magnitude of displacement of the lower molars to obtain the required class for the molars, knowing the direction and magnitude of the required displacement of the lower molars on the right and left, making a decision on the need to remove individual teeth or create space for a dental implant, using mini-screws.

9. A method for planning orthodontic treatment, differing in paragraph 1 in that the calculation of the expected change in the inclination of the lower incisors (LI_Inc_Change) and the assessment of the adequacy of their final position includes establishing limits for the final position of the lower incisors (LI_limit), calculating the expected change in the position of the lower incisors according to the treatment plan, calculating the final deviation of the lower incisors from parallelism to the symphysis, if the expected final position of the lower incisors turned out to be acceptable, then the treatment plan is considered adequate, otherwise we add maxillofacial orthognathic surgery to the orthodontic treatment to change the size of the jaws, if the patient is not ready for combined treatment using orthognathic surgery, then we proceed to the search for compromise options. SUBSTITUTE SHEET (RULE 26)10. The method of planning orthodontic treatment, differing from paragraph1 in that recalculation of the treatment plan taking into account compromises includes replacing the final position of the upper incisors (Ulchange) from the optimal one or shifting towards class 2 according to Angle, allowing at the end a total deviation from class 1 for the canines on the right and left of up to 6 mm, if in step 6 it turned out that the position of the lower incisors (LI_final_symph) will be too protrusive, then we change the required position of the upper incisors (Ulchange) in the initial data, shifting them back by how many millimeters, by how much the excess inclination of the lower incisors relative to the limit was obtained, but not more than 3 mm back, otherwise we change the required position of the upper incisors (Ulchange) in the initial data to a more protrusive one, but not more than 2 mm, if the above calculations showed that a compromise is possible, then the entire plan is recalculated again from step 2 to step 6 with new data on the position of the upper incisors (Ulchange) and new data on the desired final class (Class_6_Need).

11. A method for planning orthodontic treatment, differing in paragraph 1 in that the recalculation of the space balance in the lower dental arch taking into account the initial data and step 4 (L_Space_Correct) is performed using the following formula: L_Space_Correct = Lspace + LR3 x 0.6 + LR4 x 0.4 + LL3 x 0.6 + LL4 x 0.4 + SE x 0.5 + IPR - L6_Need_L - L6_Need_R, where SE is the skeletal expansion in the area of ​​the lower jaw, if provided for by the plan, IPR is the possible separation in the area of ​​the lower anterior teeth if it is necessary to reduce the space deficit or for aesthetic reasons, Lspace is the overall balance of space in the lower dental arch, LR3 is the expansion along the right lower canine, LR4 is the expansion along the right lower premolar, LL3 is the expansion along the left lower canine, LL4 - SUBSTITUTE SHEET (RULE 26) expansion along the left lower premolar, L6_Need_L - final unobserved movement on the left lower side, L6_Need_R - final unobserved movement on the right lower side.

12. A method for planning orthodontic treatment, characterized in paragraph 1 in that it is carried out using software implemented on an electronic device.

13. A method for planning orthodontic treatment, differing in paragraph 1 in that the final orthodontic treatment plan is verified using the rules for verifying the logic of unilateral extraction given the initial presence of all teeth in the upper dental row, verifying the logic of unilateral extraction given the initial absence of one tooth from group 2, 3, 4, 5 in the upper dental row on one side, which is not planned to be replaced with a dental implant, verifying the logic of combining extraction on the upper and lower dental rows on a given side given the initial full dental rows. SUBSTITUTE SHEET (RULE 26)

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