A whole-process simulation dental model for endodontic treatment

Abstract

This invention belongs to the field of endodontics, specifically relating to a simulated dental jaw model for the entire process of endodontic treatment. It includes a maxillary model, a maxillary base, a maxillary joint, a mandibular model, a mandibular base, a mandibular joint, a connecting device, a cervical joint, and a tail fixation device. The mandibular model includes a mandibular shell, a movable micro-adjustment module, and an extracted tooth. The mandibular shell is filled with a water-absorbing gel-like material. The movable micro-adjustment module is detachable. This invention allows for the rapid fixation and replacement of extracted human teeth, and can also recreate the adjacent relationships, periodontal microenvironment, and moist conductive environment around the tooth root. It can highly simulate the physiological conditions of extracted teeth within the dentition and jawbone, and is suitable for various teaching and training programs in endodontic microsurgery, dental restoration, and microsurgical root canal treatment, greatly expanding its application scenarios.

Description

Technical Field

[0001] This invention belongs to the field of dental endodontics, specifically relating to a simulated dental jaw model of the entire process of dental endodontic treatment. Background Technology

[0002] Endodontics is a discipline that demands a high level of proficiency from dentists. Both medical students and doctors need extensive in-vitro simulation training when learning new technologies or mastering endodontic treatment techniques. This in-vitro simulation training is typically conducted by dentists on a dental model or a model containing extracted human teeth.

[0003] The commonly used item for training in external manipulation of dental pulp is a simulated head model (instruction manual included). Figure 1 The simulated head mold contains upper and lower jaw models, which can be standardized plastic dental arch models and plastic teeth (instruction manual included). Figure 2 It can also be a disposable plaster casting model and extracted human teeth (instructions included). Figure 3 The existing model is a general model and is not specifically designed for endodontic treatment, thus failing to meet the needs of clinical training.

[0004] Standardized plastic dental models consist of a plastic base and plastic teeth. The shape and internal structure of the plastic teeth mimic natural teeth, and they are replaceable after use. These models are soft and uniform, lacking the tactile feel and personalized feedback of natural teeth. They are only suitable for beginners training in posture and procedures. Dentists find it difficult to learn the entire clinical skill process through practice on plastic teeth. Even with the existence of 3D-printed simulated teeth, their high cost and soft texture limit their application.

[0005] Plaster-cast dental models are created by placing extracted teeth in a specific position within a dental mold and then pouring plaster over them. Dental dentists practice oral manipulation on these plaster models with the extracted teeth. While they offer the tactile experience and personalization of natural teeth, the production process is quite complex. Furthermore, the three-dimensional position of the extracted teeth is not adjustable, making it difficult to achieve the desired location. They also lack realistic neighboring tooth relationships and periodontal environment. After practice, the plaster models cannot be reused, as the extracted teeth are difficult to remove for secondary analysis. The production cost is high, while the practical experience and teaching effectiveness are limited.

[0006] Furthermore, neither the standardized plastic dental arch models nor the plaster-filled dental arch models used for teaching can simulate the physiological environment of the tooth roots, teeth, and dentition within the oral cavity. Teeth exist in a moist environment in the mouth, with the gingiva surrounding the neck of the tooth, and the roots embedded in the alveolar bone, surrounded by blood vessels and nerves. During clinical dental fillings or restorations, gingival crevicular fluid and blood seep out around the neck of the tooth, and neither existing plaster nor plastic models can simulate this periodontal microenvironment. In root canal treatment, the electrical resistance between the periodontal ligament and the oral mucosa is constant, allowing for the measurement of root canal length. Existing models lack electrolytes around the roots of extracted teeth and are not cross-linked with the external environment, making it impossible to measure root canal length during root canal treatment and thus failing to recreate the entire clinical procedure. Current teaching models cannot meet the requirements for simulating the entire process of clinical skills training in endodontics. Many key and challenging operational steps cannot be practiced externally, resulting in a poor operating experience for doctors. Moreover, due to the limitations of the models, the standardization of training procedures cannot be assessed and evaluated. External training that is detached from the entire clinical procedure is fragmented and incomplete. It can only simulate a certain step of dental endodontic treatment. After training, doctors still need a long time to learn and adapt in order to connect each step of the treatment into a whole.

[0007] After in vitro training using existing models, doctors can only understand the basic procedures. Proficiency in the entire treatment process can only be gradually developed through clinical practice, exploration, and knowledge integration until mastery is achieved. However, as people's demands for medical service levels increase, society has higher requirements for doctors' treatment skills and proficiency from both ethical and medical quality management perspectives. The margin for error is smaller, and the intensity and precision of pre-service training for doctors need to be improved. Furthermore, the training, assessment, and promotion of modern endodontic treatment lack easily operable, reusable, full-process simulated dental arch models. Summary of the Invention

[0008] To address the above issues, this invention proposes a simulated dental jaw model for the entire process of endodontic treatment. This highly realistic dental jaw model can not only quickly fix and replace extracted human teeth, but also restore the adjacent relationships of extracted teeth, the periodontal microenvironment, and the moist and conductive environment around the tooth roots. It can highly mimic the physiological conditions of extracted teeth in the dentition and jawbone, and is suitable for various teaching, training, and assessment in endodontics, and can also greatly broaden the application scenarios.

[0009] The technical solution of the present invention is as follows:

[0010] A simulated dental and jaw model for the entire process of dental endodontic treatment includes a maxillary model, a maxillary base, a maxillary joint, a mandibular model, a mandibular base, a mandibular joint, a connecting device, a cervical joint, and a tail fixation device. The maxillary model is fixed to the maxillary base, which is connected to the maxillary joint. The mandibular model is fixed to the mandibular base, which is connected to the mandibular joint. The maxillary and mandibular joints are connected to the cervical joint via a "Y"-shaped connecting device, and the cervical joint is fixedly connected to the tail fixation device.

[0011] The structure of the mandibular model is as follows:

[0012] The mandibular model includes a mandibular shell, a movable fine-tuning module, and extracted teeth.

[0013] The mandibular shell is made of a hollow, transparent, rigid material; the interior has a U-shaped cavity structure, with a closed end at the bottom to simulate the shape of alveolar bone, and an open upper part to facilitate the insertion of extracted teeth from top to bottom through the top; the interior of the mandibular shell is filled with a water-absorbing gel-like material, and there is a fixing track at the bottom.

[0014] The upper part of the inner and outer sides of the mandibular shell is provided with 14 pairs of elongated oval-shaped, interlocking inner and outer fixing slots, corresponding to the positions of different teeth. The inner fixing nut passes through the inner plate and the inner fixing slot, inserting into the inner side of the movable fine-tuning module; the outer fixing nut passes through the outer plate and the outer fixing slot, inserting into the outer side of the movable fine-tuning module, thus realizing the adjustment and fixation of the movable fine-tuning module and the extracted tooth. The tails of the inner and outer fixing nuts are rotatable force-applying ends with an outer circle and an inner square, while the heads are used to fix the root of the extracted tooth.

[0015] The movable micro-adjustment module is a detachable, position-adjustable module, an open, transparent cubic structure, fixed to a predetermined position on the mandibular shell by internal and external fixing nuts. After the extracted tooth is inserted from top to bottom, the neck of the tooth is fixed by the internal and external fixing nuts, while the root is immersed in a water-absorbing gel-like material inside the mandibular shell. The width of the movable micro-adjustment module depends on the position of the tooth, approximately 2-15 mm.

[0016] The movable micro-adjustment module is open at the top, bottom, and adjacent sides, with transparent flat plate structures on the inner and outer sides, connected by a bottom connecting rod. Each of the inner and outer plates of the movable micro-adjustment module has a clamping and fixing nut hole at its top. After the extracted tooth is placed to the predetermined position, it is fixed by adjusting the inner and outer fixing nuts. The movable micro-adjustment module can move horizontally along the inner and outer fixing slots of the mandibular shell. By adjusting the tightness and position of the inner and outer fixing nuts, the three-dimensional position of the extracted tooth can be adjusted, highly replicating the three-dimensional position of the tooth in the dentition, and allowing for quick replacement of the extracted tooth, achieving the goal of model reusability. The crown of the extracted tooth is exposed above the mandibular shell, while the root is placed inside the mandibular shell and surrounded by a moist, absorbent hydrogel material, placing the extracted tooth in a hydroelectrolyte environment, thus simulating the moist environment of alveolar bone.

[0017] The mandibular shell has a water inlet on each of its left and right sides, connecting the inside and outside of the shell. This inlet serves two purposes: it allows for the attachment of a metal hook for a root canal measuring instrument, and it allows for the injection of deionized water to quantitatively control the internal moisture content of the model, mimicking the moist environment of alveolar bone. This, in turn, simulates and recreates conditions such as root length measurement and blood interference during root canal perforation repair in root canal treatment. A square, detachable piece is located on the outer side of the anterior teeth, premolars, and molar regions of the mandibular shell. This detachable piece is fixed to the mandibular shell with clips and is replaceable, used to simulate buccal bone windowing during periapical surgery.

[0018] The mandibular shell is mechanically fixed to the mandibular base by screws at the bottom. The mandibular base connects to the mandibular joint, enabling linkage between the mandibular shell and the mandibular joint. The end of the mandibular shell is a removable closure plug, allowing the movable fine-tuning module to be horizontally installed, removed, and replaced. The top of the mandibular shell has an inward-folding structure, restricting the upward movement of the movable fine-tuning module within the mandibular shell; a track exists at the bottom of the inner layer of the mandibular shell, restricting the downward movement of the fine-tuning module.

[0019] The mandibular model is covered by a highly elastic silicone skin, the shape of which matches the outer shell of the mandible. The silicone skin has holes on its inner and outer sides to expose the internal and external fixing nuts. The lower part of the silicone skin is open for easy fitting onto the mandibular model. The upper part of the silicone skin has a wavy, open structure to simulate gingival morphology. The top has 14 round holes through which the extracted tooth crown protrudes, the silicone skin wrapping around the neck of the extracted tooth, leaving the crown exposed.

[0020] The maxillary model has the same structure as the mandibular model.

[0021] The maxillary and mandibular joints are connected by a rotating axis, allowing for adjustable opening and closing angles, which can mimic opening, closing, and biting movements.

[0022] The cervical joint can mimic the up, down, left, and right rotation of the head, controlling the overall orientation of the model's head.

[0023] The tail fixing device can be fixed in various scenarios such as dental chairs or operating tables to achieve overall fixation of the simulated dental jaw model.

[0024] To save costs, absorbent gel materials can be replaced with elastic absorbent materials to achieve a three-dimensional, elastic wrapping of the extracted tooth.

[0025] To save costs, water-absorbing gel materials can be replaced with water, which can mimic the environment of root canal length measurement, but cannot mimic the conditions of root canal perforation repair.

[0026] This invention addresses the shortcomings of existing dental arch models used for oral practice or research by overcoming them one by one, and solves the following problems:

[0027] First, the simulated dentition of this invention features multiple detachable micro-adjustment modules internally, along with fixing nuts penetrating the jawbone shell and the inner and outer sides of the movable micro-adjustment modules. This securely holds the extracted teeth, enabling rapid replacement of extracted teeth and cyclical model reuse. Furthermore, the square detachable piece on the outer side of the model provides conditions for multiple replacements during bone window opening training in periapical surgery, solving the problems of complex, time-consuming, and disposable plaster model fabrication, which consumes significant manpower and resources.

[0028] Secondly, the movable fine-tuning module of the simulated dental arch of this invention is equipped with a nut fine-tuning knob, which enables three-dimensional adjustment of the position of the extracted teeth, highly replicating the three-dimensional position of the teeth in the dental arch. This solves the problem that the position of extracted teeth cannot be adjusted after being fixed by plaster in plaster models, and the angle and position of extracted teeth usually deviate significantly from the normal situation, making operation and practice difficult.

[0029] Third, in the simulated dentition of this invention, after the three-dimensional position of the extracted teeth is properly adjusted, they can not only have good contact and occlusal relationships with adjacent teeth and opposing teeth, but also have slight mobility to simulate the physiological mobility of teeth, providing a full-process clinical operation simulation for dental restoration. This solves the problem that in existing plaster models, extracted teeth do not have normal contact relationships with adjacent teeth or normal occlusal relationships with opposing teeth. This means that during oral operation practice, dentists can only experience the feel of grinding extracted teeth, but cannot reproduce or judge the actual operation scenario, directly affecting the students' operation practice results and greatly reducing the practice effect; for example, when preparing tooth defects, it is impossible to determine whether the space for the restoration is sufficient; in filling Class 2 cavities, it is impossible to place the molding piece and wedge in place, thus preventing standardized practice of dental filling treatment; and during rubber dam operations, it is impossible to wrap the rubber sheet around the neck of the tooth, among other problems.

[0030] Fourth, the highly realistic dental arch in this invention can use both artificial teeth and extracted human teeth, making it suitable for dentists at all levels to practice various oral procedures. Extracted human teeth are ideal in vitro practice and research subjects for dentists. For advanced training, using extracted teeth for operational exercises can overcome the shortcomings of current dental teaching methods, such as poor tactile feedback and lack of personalized feedback when using plastic artificial teeth.

[0031] Fifth, the highly realistic dental arch of this invention uses a transparent material to simulate the shape of the alveolar bone. The model has a hollow structure filled with absorbent gel-like material and microchannels, allowing the tooth roots to be in a humidity-adjustable environment, thus simulating the moist environment of the alveolar bone. This provides a full-process clinical operation condition simulation for surgical and non-surgical pulp treatments. The absorbent gel-like material surrounds the tooth roots, and deionized water is injected through the water injection hole to quantitatively control the internal moisture content of the model, mimicking the moist environment of the alveolar bone and reproducing conditions such as root length measurement and blood interference during root canal perforation repair. This solves the problems of traditional plaster dental arch models and currently standard plastic dental arch models on the market, which lack simulation of the tooth root environment and are limited in design and application due to the use of plastic or plaster to embed the tooth roots.

[0032] Sixth, the invention has a wider range of applications and reduces the requirements for the external environment. It is not limited to teaching and internship rooms, but can be used next to clinical chairs or in ordinary internship rooms. Attached Figure Description

[0033] Figure 1 : The head model in the existing technology.

[0034] Figure 2 : Existing plastic dental arch model.

[0035] Figure 3 Plaster models containing extracted teeth in existing technology.

[0036] Figure 4 The present invention provides a simulated dental model, comprising: 1. a mandibular model; 11. a mandibular base; 12. a mandibular joint; 2. a maxillary model; 21. a maxillary base; 22. a maxillary joint; 3. a cervical joint; 4. a connecting device; and 5. a tail fixing device.

[0037] Figure 5 : Schematic diagram of the mandibular shell model of the present invention; wherein: 6, mandibular shell; 61, outer fixing slot; 62, inner fixing slot; 63, track; 64, connecting water injection hole; 65, square detachable piece; 66, sealing plug.

[0038] Figure 6: Schematic diagram of the movable fine-tuning module of the present invention; wherein: 7, movable fine-tuning module; 71, external fixing nut; 711, outer side plate; 72, internal fixing nut; 722, inner side plate; 73, bottom connecting rod; 74, extracted tooth.

[0039] Figure 7 : Schematic diagram of the mandibular base of the present invention. Detailed Implementation

[0040] To more clearly illustrate the purpose, technical solution, and advantages of this invention, a detailed description will be provided below in conjunction with the accompanying drawings and specific embodiments. The drawings illustrate only exemplary embodiments of the invention and are not intended to limit its implementation. This invention can be implemented in various forms, and its design concept and core technology are not limited to the embodiments shown in the drawings. These embodiments are provided to facilitate understanding of the principles, structure, and function of this invention by those skilled in the art, thereby enabling them to better master and apply its technical solutions. The terminology used in this specification is only for describing specific embodiments and does not constitute a limitation of the invention.

[0041] Example 1:

[0042] Combined with appendix Figure 4-7 A simulated dental and jaw model for the entire process of dental endodontic treatment includes a maxillary model 2, a maxillary base 21, a maxillary joint 22, a mandibular model 1, a mandibular base 11, a mandibular joint 12, a connecting device 4, a cervical joint 3, and a tail fixing device 5. The maxillary model 2 is fixed to the maxillary base 21, and the maxillary base 21 is connected to the maxillary joint 22. The mandibular model 1 is fixed to the mandibular base 11, and the mandibular base 11 is connected to the mandibular joint 12. The maxillary joint 22 and the mandibular joint 12 are connected to the cervical joint 3 through the "Y"-shaped connecting device 4, and the cervical joint 3 is fixedly connected to the tail fixing device 5.

[0043] The structure of the mandibular model 1 is as follows:

[0044] The mandibular model 1 includes a mandibular shell 6, a movable fine-tuning module 7, and extracted teeth 74.

[0045] The mandibular shell 6 is made of hollow, transparent, and rigid material; the interior has a U-shaped cavity structure, with a closed end at the bottom to simulate the shape of alveolar bone and an open upper part to facilitate the insertion of the extracted tooth 74 from top to bottom through the top; the interior of the mandibular shell 6 is filled with a water-absorbing gel-like material, and there is a fixing track 63 at the bottom.

[0046] The upper part of the inner and outer sides of the mandibular shell 6 is provided with 14 pairs of elongated oval-shaped, interlocking inner fixing slots 62 and outer fixing slots 61, corresponding to the positions of different teeth. An inner fixing nut 72 passes through the inner side plate 722 and the inner fixing slot 62, and inserts into the inner side of the movable fine-tuning module 7; an outer fixing nut 71 passes through the outer side plate 711 and the outer fixing slot 61, and inserts into the outer side of the movable fine-tuning module 7, thereby achieving adjustment and fixation of the movable fine-tuning module 7 and the extracted tooth 74. The tails of the inner fixing nut 72 and the outer fixing nut 71 are rotatable force-applying ends with an outer circle and an inner square shape, while the heads are used to fix the root of the extracted tooth 74.

[0047] The movable fine-tuning module 7 is a detachable, position-adjustable module. It is an open, transparent cubic structure, fixed to the mandibular shell 6 at a predetermined position by an internal fixing nut 72 and an external fixing nut 71. After the extracted tooth 74 is inserted from top to bottom, the neck of the tooth is fixed by the internal fixing nut 72 and the external fixing nut 71, while the root is immersed in a water-absorbing gel-like material inside the mandibular shell 6. The width of the movable fine-tuning module 7 is determined according to the position of the tooth, approximately 2-15 mm.

[0048] The movable micro-adjustment module 7 is open at the top, bottom, and adjacent sides, with transparent flat plate structures on the inner and outer sides, connected by a bottom connecting rod 73. Each of the inner plate 722 and outer plate 711 of the movable micro-adjustment module 7 has a clamping and fixing nut hole at its top. After the extracted tooth 74 is placed to the predetermined position, it is fixed by adjusting the inner fixing nut 72 and the outer fixing nut 71. The movable micro-adjustment module 7 can move horizontally along the inner fixing slot 62 and the outer fixing slot 61 of the mandibular shell 6. By adjusting the tightness and position of the inner fixing nut 72 and the outer fixing nut 71, the three-dimensional position of the extracted tooth 74 can be adjusted, highly replicating the three-dimensional position of the tooth in the dentition, and allowing for quick replacement of the extracted tooth 74, achieving the purpose of model reusability. The crown of the extracted tooth 74 is exposed above the mandibular shell 6, while the root is placed inside the mandibular shell 6 and surrounded by a moist, absorbent hydrogel material, placing the extracted tooth 74 in a water-electrolyte environment, thus simulating the moist environment of the alveolar bone.

[0049] The mandibular shell 6 has a water injection hole 64 on each of its left and right sides. These holes connect the inside and outside of the mandibular shell 6, serving two purposes: firstly, to hang the metal hook of a root canal measuring instrument; and secondly, to inject deionized water to quantitatively control the internal moisture content of the model, mimicking the moist environment of the alveolar bone. This allows for the simulation and reproduction of conditions such as root length measurement and blood interference during root canal perforation repair in root canal treatment. A square detachable piece 65 is located on the outer side of the anterior teeth, premolars, and molar regions of the mandibular shell 6. This square detachable piece 65 is fixed to the mandibular shell 6 with clips and is replaceable, used to simulate buccal bone windowing during periapical surgery.

[0050] The mandibular shell 6 is mechanically fixed to the mandibular base 11 by screws at the bottom. The mandibular base 11 is connected to the mandibular joint 12, realizing the linkage between the mandibular shell 6 and the mandibular joint 12. The end of the mandibular shell 6 is a removable sealing plug 66, through which the movable fine-tuning module 7 can be horizontally installed, removed, and replaced. The top of the mandibular shell 6 has an inward folding structure, which restricts the upward movement of the movable fine-tuning module 7 within the mandibular shell 6; the bottom of the inner layer of the mandibular shell 6 has a track 63, which restricts the downward movement of the fine-tuning module.

[0051] The mandibular model 1 is wrapped with a highly elastic silicone skin, the shape of which is consistent with the mandibular shell 6. The silicone skin has holes on its inner and outer sides to expose the internal fixing nut 72 and the external fixing nut 71. The lower part of the silicone skin is open for easy fitting onto the mandibular model 1. The upper part of the silicone skin has a wavy open structure to simulate the gingival morphology. The top has 14 round holes through which the crown of the extracted tooth 74 protrudes, the silicone skin wraps around the neck of the extracted tooth 74, and the crown of the extracted tooth 74 is exposed.

[0052] The maxillary model 2 has the same structure as the mandibular model 1.

[0053] The maxillary joint 22 and mandibular joint 12 are connected by a rotating shaft to achieve adjustable opening and closing angles, which can mimic the opening, closing, and biting movements.

[0054] The neck joint 3 can mimic the up, down, left, and right rotation of the head, controlling the overall orientation of the model's head.

[0055] The tail fixing device 5 can be fixed in various scenarios such as dental chair or operating table to achieve overall fixation of the simulated dental jaw model.

[0056] Finally, it is important to emphasize that the embodiments provided herein are only a portion of the embodiments of the present invention, and not all of them. All other embodiments obtained by those skilled in the art based on this invention without inventive effort should fall within the scope of protection of this invention.

Claims

1. A simulated dental jaw model for the entire process of endodontic treatment, comprising a maxillary model, a maxillary base, a maxillary joint, a mandibular model, a mandibular base, a mandibular joint, a connecting device, a cervical joint, and a tail fixation device; characterized in that: The maxillary model is fixed to the maxillary base, which is connected to the maxillary joint; the mandibular model is fixed to the mandibular base, which is connected to the mandibular joint; the maxillary and mandibular joints are connected to the cervical joint via a "Y"-shaped connecting device, and the cervical joint is fixedly connected to the tail fixing device; the mandibular model includes a mandibular shell, a movable micro-adjustment module, and an extracted tooth; the mandibular shell is filled with hydrogel material; the movable micro-adjustment module is a detachable module that can be finely adjusted in position, with the crown of the extracted tooth exposed above the mandibular shell, and the root placed inside the mandibular shell and surrounded by hydrogel material; The upper inner and outer sides of the mandibular shell are provided with 14 pairs of elongated oval-shaped inner and outer fixing slots that cooperate with each other, corresponding to the positions of different teeth; the inner fixing nut passes through the inner plate and the inner fixing slot and is inserted into the inner side of the movable fine-tuning module; the outer fixing nut passes through the outer plate and the outer fixing slot and is inserted into the outer side of the movable fine-tuning module, so as to realize the adjustment and fixation of the movable fine-tuning module and the extracted tooth; The movable fine-tuning module is open at the top, bottom, and adjacent sides, and the inner and outer sides are transparent flat plate structures connected by a bottom connecting rod. The top of the inner and outer side plates of the movable fine-tuning module each has a clamping and fixing nut hole. When the extracted tooth is inserted to the predetermined position, the extracted tooth is fixed by adjusting the inner and outer fixing nuts, and the three-dimensional position of the extracted tooth is adjusted to highly restore the three-dimensional position of the tooth in the dental arch.

2. The model according to claim 1, characterized in that: The mandibular shell is made of a hollow, transparent, rigid material; the interior has a "U"-shaped cavity structure, with a closed end at the bottom to simulate the shape of alveolar bone, and an open upper part to facilitate the insertion of extracted teeth from top to bottom through the top; there is a fixing track at the bottom of the mandibular shell.

3. The model according to claim 1, characterized in that: The movable fine-tuning module is an open, transparent cubic structure that is fixed to a predetermined position on the mandibular shell by internal and external fixing nuts. After the extracted tooth is inserted from top to bottom, the neck of the tooth is fixed by the internal and external fixing nuts, while the root of the tooth is immersed in a water-absorbing gel-like material inside the mandibular shell. The width of the movable fine-tuning module is determined according to the position of the tooth and is 2-15mm.

4. The model according to claim 1, characterized in that: The mandibular shell has a water injection hole on each of its left and right sides, which connects the inside and outside of the mandibular shell to simulate root canal length measurement during root canal treatment. There is a square detachable piece on the outer side of the anterior teeth, premolars and molars of the mandibular shell, which is fixed to the mandibular shell by a buckle.

5. The model according to claim 1, characterized in that: The mandibular shell is mechanically fixed to the mandibular base by screws at the bottom, and the mandibular base is connected to the mandibular joint; the end of the mandibular shell is a pluggable closure plug, through which the movable fine-tuning module can be horizontally installed, removed, and replaced; the top of the mandibular shell has an inward folding structure, which restricts the upward movement of the movable fine-tuning module inside the mandibular shell; there is a track at the bottom of the inner layer of the mandibular shell, which restricts the downward movement of the fine-tuning module.

6. The model according to claim 1, characterized in that: The mandibular model is wrapped in silicone skin, which is identical in shape to the mandibular shell. The silicone skin has holes on the inside and outside to expose the internal and external fixing nuts. The lower part of the silicone skin is open, the upper part is a wave-shaped open structure, and the top has 14 round holes through which the extracted tooth crown protrudes. The silicone skin wraps around the neck of the extracted tooth, and the extracted tooth crown is exposed.

7. The model according to any one of claims 1-6, characterized in that: The maxillary model has the same structure as the mandibular model.

8. The model according to claim 7, characterized in that: The maxillary and mandibular joints are adjustable in opening and closing angles via a rotating shaft; the cervical joint mimics the up, down, left, and right rotations of the head; and the tail fixing device is fixed to the dental chair or operating table to achieve overall fixation of the simulated dental model.

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