Method for determining the target cranial shape for correction

Abstract

To provide a method for determining an oblique head and / or short head correction target skull shape, the method enabling creation of a skull deformation correction helmet optimal for being applied to an individual patient depending on the degree of an oblique head and / or short head.SOLUTION: On the basis of three-dimensional scan data showing a patient's skull shape, oblique head and / or short head ideal correction data for ideally correcting an oblique head and / or short head is created. Furthermore, an oblique head and / or short head correction ratio is designated depending on the degree of the oblique head and / or short head. On the basis of the oblique head and / or short head ideal correction data and the oblique head and / or short head correction ratio, oblique head and / or short head correction target data showing an oblique head and / or short head correction target skull shape is created.SELECTED DRAWING: Figure 2

Description

Technical Field

[0001] The present invention relates to a method for obtaining a corrective target skull shape for correcting a deformed skull, i.e., plagiocephaly and / or brachycephaly.

Background Art

[0002] The following Patent Document 1 discloses a skull deformation correction helmet for correcting the skull deformation of a patient (usually an infant). Such a skull deformation correction helmet recognizes the skull shape of an individual patient, determines how to correct according to the skull deformation of the individual patient, in other words, obtains a corrective target skull shape, and it is important to manufacture according to such a corrective target skull shape. On the other hand, the following Patent Document 2 conceptually discloses obtaining ideal skull shape data based on three-dimensional scan data showing the skull shape of an infant and manufacturing a skull deformation correction helmet based on the ideal skull shape data.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, Patent Document 1 does not describe at all how to determine the target cranial shape for correction. On the other hand, Patent Document 2 conceptually discloses that, as mentioned above, ideal cranial shape data is obtained based on three-dimensional scan data showing the patient's cranial shape, and a cranial deformation correction helmet is manufactured based on the ideal cranial shape data, but it does not describe at all how to specifically obtain the ideal cranial shape data. In addition, the following facts should be noted regarding the disclosure of Patent Document 2. That is, although ideal cranial shape data is obtained and a cranial deformation correction helmet is manufactured based on such ideal cranial shape, the inventors' experience has shown that, for example, if the degree of plagiocephaly and / or brachycephaly is considerably large, it is practically impossible to correct to the ideal cranial shape, and it has also been found that applying a cranial deformation correction helmet intended to correct to the ideal cranial shape to the target patient is not necessarily appropriate.

[0005] The present invention has been made in view of the above facts, and its main technical problem is to provide a novel and improved method for determining a target cranial shape for plagiocephaly and / or brachycephaly, which enables the creation of a cranial deformity correction helmet that is optimally suited to individual patients depending on the degree of plagiocephaly and / or brachycephaly. [Means for solving the problem]

[0006] As a result of diligent research, the inventors have found that the above-mentioned main technical problem can be achieved by generating plagiocephaly and / or brachycephaly ideal correction data based on three-dimensional scan data showing the cranial shape of a patient, specifying a plagiocephaly and / or brachycephaly correction rate according to the degree of plagiocephaly and / or brachycephaly, and generating plagiocephaly and / or brachycephaly target correction data showing the target cranial shape for plagiocephaly and / or brachycephaly based on the plagiocephaly and / or brachycephaly ideal correction data and the plagiocephaly and / or brachycephaly correction rate.

[0007] That is, according to the first aspect of the present invention, as a method for achieving the above-mentioned main technical problem, A scan data reading process that reads three-dimensional scan data showing the shape of the patient's skull, A process for generating ideal plagiocephaly correction data that shows the ideal plagiocephaly correction shape of a patient based on the three-dimensional scan data, A plagiocephaly correction rate specification process, which specifies the plagiocephaly correction rate according to the degree of plagiocephaly, A plagiocephaly correction target data generation step generates plagiocephaly correction target data that indicates the target skull shape for plagiocephaly correction based on the ideal plagiocephaly correction data and the plagiocephaly correction rate, A method for determining the target cranial shape for correction is provided, characterized by including the following:

[0008] According to a second aspect of the present invention, as a method for achieving the above-mentioned main technical problem, A scan data reading process that reads three-dimensional scan data showing the shape of the patient's skull, A brachycephaly ideal correction data generation step that generates brachycephaly ideal correction data showing the patient's brachycephaly ideal corrected shape based on the three-dimensional scan data, A brachycephaly correction rate specification process, which specifies the brachycephaly correction rate according to the degree of brachycephaly, A brachycephaly correction target data generation step generates brachycephaly correction target data that indicates the brachycephaly correction target skull shape based on the brachycephaly ideal correction data and the brachycephaly correction rate, A method for determining the target cranial shape for correction is provided, characterized by including the following:

[0009] According to a third aspect of the present invention, as a method for achieving the above-mentioned main technical problem, A scan data reading process that reads three-dimensional scan data showing the shape of the patient's skull, A process for generating ideal plagiocephaly correction data that shows the ideal plagiocephaly correction shape of a patient based on the three-dimensional scan data, A plagiocephaly correction rate specification process, which specifies the correction rate according to the degree of plagiocephaly, A plagiocephaly correction target data generation step generates plagiocephaly correction target data that indicates the target skull shape for plagiocephaly correction based on the ideal plagiocephaly correction data and the correction rate, A brachycephaly ideal correction data generation step that generates brachycephaly ideal correction data showing the patient's brachycephaly ideal corrected shape based on the three-dimensional scan data, A brachycephaly correction rate specification process, which specifies the correction rate according to the degree of brachycephaly, A brachycephaly correction target data generation step generates brachycephaly correction target data that indicates the brachycephaly correction target skull shape based on the brachycephaly ideal correction data and the correction rate, A method for determining the target cranial shape for correction is provided, characterized by including the following:

[0010] The process for generating ideal plagiocephaly correction data is as follows: Based on the three-dimensional scan data, three reference points are set, and a reference plane including these three reference points is set. Setting multiple planes parallel to the reference plane, and selecting one specific plane from the set multiple planes, In the specified plane, four intersections are determined between the skull shape and two inclined lines that are inclined at a predetermined angle in opposite directions with respect to a center line extending in the anterior-posterior direction from the center of the skull. It is preferable to include, The process for generating data for ideal brachycephaly is as follows: A horizontal centerline is established extending horizontally from the serion backward through the center of the skull, and a width line is established passing through both trazione landmarks. Based on the three-dimensional scan data, three reference points are set, and a reference plane including these three reference points is set. Setting multiple planes parallel to the reference plane, and selecting one specific plane from the set multiple planes, Project the horizontal center line and the widthwise straight line passing through both trazione landmarks onto the specific plane, determine the two anterior-posterior intersections between the projected horizontal center line and the skull shape on the specific plane, and determine the two widthwise intersections between the projected width line and the skull shape. Determine the length PLx between the two intersections in the longitudinal direction and the length PLy between the two intersections in the width direction, and then calculate PLx / PLy. It is preferable to include, The three reference points are preferably a serion and two trazione landmarks. The plurality of planes preferably includes a vertex plane passing through the vertex of the skull and parallel to the reference plane and intermediate planes disposed at equal intervals between the reference plane and the vertex plane. In order to assist in specifying the plagiocephaly and / or brachycephaly correction rate, it is preferable to include a display step of displaying a skull shape corrected at the arbitrary plagiocephaly and / or brachycephaly correction rate based on the ideal plagiocephaly and / or brachycephaly correction data and the arbitrary plagiocephaly and / or brachycephaly correction rate. It is desirable to obtain the length Lx from the sellion to the intersection of the horizontal center line and the back of the skull and the length Ly of both tragion landmark rods, calculate Lx / Ly, and determine whether brachycephaly correction is necessary from the calculated value.

Advantages of the Invention

[0011] In the present invention, in addition to generating ideal plagiocephaly and / or brachycephaly correction data for ideally correcting the plagiocephaly and / or brachycephaly of a patient, a correction rate is specified according to the degree of plagiocephaly and / or brachycephaly, and based on the ideal plagiocephaly and / or brachycephaly correction data and the correction rate, plagiocephaly and / or brachycephaly correction target data indicating a plagiocephaly and / or brachycephaly correction target skull shape is generated. Therefore, plagiocephaly and / or brachycephaly correction target data indicating a plagiocephaly and / or brachycephaly correction target skull shape, which enables the creation of a skull deformation correction helmet optimal for application to individual patients according to the degree of plagiocephaly and / or brachycephaly, is obtained.

[0012] In a form including a display step of displaying a skull shape corrected at an arbitrary plagiocephaly and / or brachycephaly correction rate in a specific plane based on the ideal plagiocephaly and / or brachycephaly correction data and the arbitrary plagiocephaly and / or brachycephaly correction rate in order to assist in specifying the plagiocephaly and / or brachycephaly correction rate, an appropriate plagiocephaly and / or brachycephaly correction rate can be specified sufficiently easily and quickly by observing the skull shape corrected at the arbitrary plagiocephaly and / or brachycephaly correction rate in the specific plane.

Brief Description of the Drawings

[0013] [Figure 1] A schematic diagram showing a system used for obtaining a correction target skull shape according to the present invention. [Figure 2] A flowchart showing a preferred embodiment for obtaining a corrected target skull shape for correcting plagiocephaly and brachycephaly according to the present invention. [Figure 3] An inclined plane image displaying three-dimensional scan data showing the skull shape of a patient. [Figure 4] A schematic diagram showing an example of the shape of a reference plane in the skull shape of a patient. [Figure 5] A schematic diagram showing a reference plane, a vertex plane, and a plurality of intermediate planes in the skull shape of a patient. [Figure 6] A schematic diagram showing a mode of generating ideal plagiocephaly correction data on a selected specific plane. [Figure 7] A schematic diagram for explaining the determination of the necessity for brachycephaly correction. [Figure 8] A schematic diagram showing a mode of generating ideal brachycephaly correction data on a selected specific plane

Embodiments for Carrying Out the Invention

[0014] Hereinafter, a preferred embodiment of a method for obtaining a corrected target skull shape for correcting plagiocephaly and / or brachycephaly of the present invention will be described in detail with reference to the accompanying drawings.

[0015] FIG. 1 shows a system for performing a method for obtaining a corrected target skull shape of the present invention. This system includes a central processing means 2 composed of an appropriate computer, an image display means 4 connected to the central processing means 2, and scanning means 6 for scanning the skull of a patient to generate three-dimensional data showing the skull shape of the patient, which may be in a well-known form per se.

[0016] Figure 2 shows a flowchart for obtaining plagiocephaly correction target data and brachycephaly correction target data. Steps n-1 to n-9 in Figure 2 relate to plagiocephaly correction target data, and steps n-10 to n-18 relate to brachycephaly correction target data. Referring to Figure 2 together with Figure 1, in step n-1 (scan data reading step), three-dimensional scan data showing the shape of the patient's skull, generated by scanning the patient's skull with the scanning means 6, is read into the central processing means 2. Next, in step n-2 (reference 3 point setting step), three reference points are manually set on the image of the patient's skull shape, as illustrated in Figure 3, which is displayed on the image display means 4 based on the three-dimensional scan data. It is convenient that these three reference points are the selion P1 located in the center between the eyes and two trazione landmarks P2 and P3, which are specific points on both earlobes, as shown in Figure 3. In step n-3 (reference plane setting step), a reference plane PL0 including the above three points is set. Next, in step n-4 (center line and inclined line setting step), as shown in Figure 4, a center line CL is drawn on the reference plane PL, extending in the anterior-posterior direction from the center of the skull, and two inclined lines IL1 and IL2 are drawn, inclined at a predetermined angle α in the opposite direction relative to the center line CL. The predetermined angle α may be, for example, 30 degrees. In step n-5 (multiple plane setting and center line and inclined line duplication step), multiple planes parallel to the reference plane are set. As shown in Figure 5, these multiple planes may be, for example, a vertex plane PL10 that passes through the vertex of the patient's skull and is parallel to the reference plane PL0, and nine intermediate planes PL1 to PL9 that pass through points evenly distributed between this vertex plane and the reference plane and are parallel to the reference plane PL0. In step n-5, the center line CL and the two inclined lines IL1 and IL2 drawn on the reference plane PL0 are further projected onto the vertex plane PL10 and intermediate planes PL1 to PL9, respectively, and duplicated.

[0017] Subsequently, in step n-6 (specific plane selection step), one of the above intermediate planes PL1 to PL9 is selected as the specific plane. It is desirable to select an intermediate plane that clearly displays the state of the plagiocephaly, judging from the slope image shown in Figure 3, and usually the third intermediate plane from the bottom, i.e., intermediate plane PL3, can be selected. Furthermore, as shown in Figure 6, in the selected specific plane (for example, intermediate plane PL3), four intersections C1, C2, C3, and C4 are obtained between the skull shape in intermediate plane PL3 and the two slope lines IL1 and IL2 that are replicated in intermediate plane PL3. Next, in step n-7 (plagiocephaly degree setting process), the concavity relationship between intersection C1 and intersection C2 on the anterior side of the skull is determined, as shown in Figure 6, to be L1 recessed from the center relative to the tolerance point C2. The concavity relationship between intersection C3 and intersection C4 on the lateral side of the skull is also determined, as shown in Figure 6, to be L2 recessed from the center relative to the tolerance point C4. In step n-8 (plagiocephaly ideal correction data generation process), plagiocephaly ideal correction data, which represents the shape with plagiocephaly ideally corrected, is generated, and the ideal skull shape IS1 with plagiocephaly ideally corrected is determined. More specifically, data for the ideal skull shape IS1, which is obtained by displacing intersection C1 anterolaterally by L1 relative to the center and intersection C3 posteriorlaterally by L2, is generated, i.e., plagiocephaly ideal correction data.

[0018] Based on the inventors' experience, it has been found that, especially when the degree of plagiocephaly is high, attempting to correct it to an ideal shape can result in correction failures or even complete failure, and that the production of a corrective helmet to correct to an ideal shape is not always appropriate. Therefore, in the present invention, in step n-9 (corrective target skull data generation step), corrective target skull data is generated based on an appropriate plagiocephaly correction rate R1. More specifically, preferably, the corrected skull shape when correcting with an arbitrary plagiocephaly correction rate R based on the ideal skull shape IS generated in step n-8 (i.e., when intersection C1 is displaced by L1 × R instead of L1, and intersection C3 is displaced by L2 × R) is appropriately displayed as an image, and the plagiocephaly correction rate R is specified by referring to this image display. In other words, in order to assist in specifying the plagiocephaly correction rate R1, the corrected skull shape at the intermediate surface PL3 when correcting with an arbitrary plagiocephaly correction rate R is appropriately displayed as an image. Then, the above ideal plagiocephaly correction data is corrected by the specified plagiocephaly correction rate R1 to generate target plagiocephaly correction data for when plagiocephaly is corrected with an appropriate plagiocephaly correction rate R (this target plagiocephaly correction data is used in the manufacture of the corrective helmet). If desired, the correction rate R for L1 and the correction rate R for L2 can be set separately instead of being the same. That is, R1 can be used as the correction rate for L1 and R2 can be applied as the correction rate for L2 (R1 ≠ R2).

[0019] In step n-10 (setting the horizontal center line), as shown in Figure 7, a horizontal center line HCL is set that extends horizontally from the serion P1 (see also Figure 3) posteriorly through the center of the skull, and the intersection C5 between this horizontal center line HCL and the posterior surface of the skull is obtained. Next, in step n-11 (setting the width line), a width line WL is set connecting the trazione landmarks P2 and P3 (see also Figure 3). In step n-12 (calculating skull length and width), the distance Lx between the serion P1 and the intersection C5 between the horizontal center line HCL and the posterior surface of the skull is calculated, and the distance Ly between the two trazione landmarks P2 and P3 on the width line WL is calculated. Next, in step n-13 (determining the necessity of brachycephaly correction), Lx / Ly is calculated to determine whether brachycephaly correction is necessary or not. Typically, the ideal value for Lx / Ly is around 1.15 (ideal ratio 1.15 to 1.00). For example, if Lx / Ly is 0.95 or less, it is determined that brachycephaly correction is necessary. If it is determined that brachycephaly correction is not necessary, the process proceeds to step n-14 (data output process), where the plagiocephaly target correction data generated in step n-9 is output as data for helmet manufacturing. On the other hand, if it is determined that brachycephaly correction is necessary, the process proceeds to step n-15 (horizontal centerline and widthline duplication process).

[0020] In step n-15 (horizontal centerline and widthline duplication process), the horizontal centerline HCL and widthline WL are projected and duplicated onto the reference plane PL0, the nine intermediate planes PL1 to PL9 set in step n-5, and the apex plane PL10, respectively. Next, in step n-16 (acquisition of cranial length and width in a specific plane), one of the nine intermediate planes PL1 to PL9 is selected as a specific plane. Similar to the case of plagiocephaly correction, it is desirable to select an intermediate plane that clearly displays the brachycephaly situation based on the slope image shown in Figure 3, and usually the third intermediate plane from the bottom, i.e., intermediate plane PL3, can be selected. Then, as shown in Figure 8, the anterior-posterior intersections C6 and C7 between the duplicated horizontal centerline HCL and the cranial shape are obtained in the selected specific plane, and the widthwise intersections C8 and C9 between the duplicated widthline WL and the cranial shape are also obtained. In step n-16, it is preferable that the cranial shape used is based on the plagiocephaly target correction data generated in step n-9 (i.e., the cranial shape after plagiocephaly target correction). In step n-17 (brachycephaly ideal correction data generation process), the cranial length (i.e., the distance between intersections C6 and C7) PLx and the cranial width (i.e., the distance between intersections C8 and C9) Ply are calculated. Then, in order to achieve the specified ideal value of PLx / Ply (usually around 1.15), the length IL3 required to move intersection C7 posteriorly to the back of the skull is calculated, generating brachycephaly ideal correction data, which is the shape after ideal brachycephaly correction, and the ideal cranial shape IS2 after ideal brachycephaly correction is obtained. Furthermore, similar to the case of plagiocephaly correction, in step n-18 (correction target cranial data generation process), correction target cranial data is generated based on an appropriate brachycephaly correction rate R2. More specifically, based on the ideal cranial shape IS2 generated in step n-17, the corrected cranial shape when corrected with an arbitrary brachycephalic correction rate R (i.e., when the intersection C7 is displaced by IL3 × R instead of just IL3) is displayed as an image as appropriate, and the brachycephalic correction rate R is specified by referring to this image display. In other words, in order to assist in specifying the brachycephalic correction rate R2, the corrected cranial shape when corrected with an arbitrary brachycephalic correction rate R is displayed as an image as appropriate.Then, the above ideal plagiocephaly correction data is corrected by the specified plagiocephaly correction rate R2 to generate brachycephaly target correction data for when the brachycephaly is corrected with an appropriate brachycephaly correction rate R2 (this plagiocephaly target correction data is used in the manufacture of the corrective helmet). In step n-17, the skull shape based on the plagiocephaly target correction data generated in step n-9 is used, so the data output in step n-18 is skull target correction data that takes into account both plagiocephaly target correction and brachycephaly target correction. In step n-19, the skull target correction data generated in step n-18 is output as data for helmet manufacture.

[0021] The target correction data output in steps n-14 and n-19 above is cranial shape data in a specific plane, i.e., two-dimensional data. To determine the target cranial shape for correction based on such two-dimensional data, one can convert the two-dimensional data into three-dimensional data using the "Grasshopper" function of a 3D CAD software, such as the commercially available "Rhinoceros," based on the required algorithm. If desired, the cranial target correction data generated in steps n-13 and n-18 can be converted into three-dimensional data prior to outputting the target correction data in steps n-14 and n-19, and the target correction data can then be output as three-dimensional data in steps n-14 and n-19.

[0022] Although preferred embodiments of the method for determining the target cranial shape for correction, configured according to the present invention, have been described in detail above with reference to the attached drawings, it goes without saying that the present invention is not limited to these embodiments, and various modifications and alterations are possible without departing from the scope of the present invention.

[0023] For example, in the embodiment described above, the cranial shape with plagiocephaly target correction applied, generated in step n-9, is used in step n-17. However, if desired, the cranial shape in a specific plane generated based on 3D scan data can also be used in step n-17. In this case, in an additional step, the plagiocephaly target correction data generated in step n-9 and the brachycephaly target correction data generated in step n-18 can be added together to obtain the target corrected cranial shape.

[0024] Furthermore, although the above-described embodiment generates only target correction data for one specific plane, it is also possible to generate target correction data for multiple specific planes as needed and determine the target cranial shape based on this data.

[0025] Furthermore, in the embodiments described above, plagiocephaly target formation data and brachycephaly target correction data as needed are generated. However, it is also possible to generate only plagiocephaly target correction data (in which case steps n-10 to 13 and steps n-15 to 19 are omitted) or to generate only brachycephaly target correction data (in which case steps n-2, n-4 and n-5 to 9 can be omitted). [Explanation of Symbols]

[0026] 2: Central Processing Unit 4: Image display device 6: Scanning method P1: Serion P2: Tradition Landmark P3: Tradition Landmark PL0: Reference plane PL1 to PL9: Intermediate plane PL10: Vertex Plane CL: Center line IL1: Inclined line IL2: Inclined line HCL: Horizontal center line WL::Width line C1 to 9: Intersection

Claims

1. A central processing unit comprising a scan data reading step in which a scanning means reads three-dimensional scan data showing the shape of the patient's skull, The central processing unit inputs reference points set to derive plagiocephaly ideal correction data from a patient's skull shape image displayed on an image display means based on the three-dimensional scan data, creates a reference plane and a plurality of parallel planes from the three-dimensional scan data and the reference points, and generates plagiocephaly ideal correction data showing the patient's plagiocephaly ideal correction shape based on one of the plurality of parallel planes, in a plagiocephaly ideal correction data generation step, The central processing unit performs a plagiocephaly correction rate acquisition step, which appropriately displays images of the corrected cranial shape when correcting with an arbitrary plagiocephaly correction rate, and acquires a plagiocephaly correction rate corresponding to the degree of plagiocephaly selected based on the image display. The central processing unit includes a plagiocephaly correction target data generation step, which generates plagiocephaly correction target data indicating the target skull shape for plagiocephaly correction based on the ideal plagiocephaly correction data and the plagiocephaly correction rate, A method for determining the target cranial shape for correction, characterized by including the following:

2. A central processing unit comprising a scan data reading step in which a scanning means reads three-dimensional scan data showing the shape of the patient's skull, The central processing unit inputs reference points set to derive brachycephaly ideal correction data from a patient's skull shape image displayed on an image display means based on the three-dimensional scan data, creates a reference plane and a plurality of parallel planes from the three-dimensional scan data and the reference points, and generates brachycephaly ideal correction data showing the patient's brachycephaly ideal correction shape based on one of the plurality of parallel planes, in a brachycephaly ideal correction data generation step. The central processing unit appropriately displays images of the corrected skull shape when correcting with an arbitrary brachycephaly correction rate, and obtains a brachycephaly correction rate corresponding to the degree of brachycephaly selected based on the image display, The central processing unit includes a brachycephaly target data generation step that generates brachycephaly target data indicating the brachycephaly target skull shape based on the brachycephaly ideal correction data and the brachycephaly correction rate, A method for determining the target cranial shape for correction, characterized by including the following:

3. The method for determining a target cranial shape for correction according to Claim 2, wherein the central processing unit determines the length Lx from the serion to the intersection of the horizontal center line and the posterior surface of the skull and the lengths Ly of both trazione landmarks, calculates Lx / Ly, and determines from the calculated value whether or not brachycephaly correction is necessary.

4. A scanning data reading step in which a central processing unit reads three-dimensional scan data showing the shape of the patient's skull using a scanning means, The central processing unit inputs reference points set to derive plagiocephaly ideal correction data from a patient's skull shape image displayed on an image display means based on the three-dimensional scan data, creates a reference plane and a plurality of parallel planes from the three-dimensional scan data and the reference points, and generates plagiocephaly ideal correction data showing the patient's plagiocephaly ideal correction shape based on one of the plurality of parallel planes, in a plagiocephaly ideal correction data generation step, The central processing unit performs a plagiocephaly correction rate acquisition step, which appropriately displays images of the corrected cranial shape when correcting with an arbitrary plagiocephaly correction rate, and acquires a plagiocephaly correction rate corresponding to the degree of plagiocephaly selected based on the image display. The central processing unit includes a plagiocephaly correction target data generation step, which generates plagiocephaly correction target data indicating the target skull shape for plagiocephaly correction based on the ideal plagiocephaly correction data and the plagiocephaly correction rate, The central processing unit inputs reference points set to derive brachycephaly ideal correction data from a patient's skull shape image displayed on an image display means based on the three-dimensional scan data, creates a reference plane and a plurality of parallel planes from the three-dimensional scan data and the reference points, and generates brachycephaly ideal correction data showing the patient's brachycephaly ideal correction shape based on one of the plurality of parallel planes, in a brachycephaly ideal correction data generation step, The central processing unit appropriately displays images of the corrected skull shape when correcting with an arbitrary brachycephaly correction rate, and obtains a brachycephaly correction rate corresponding to the degree of brachycephaly selected based on the image display, The central processing unit includes a brachycephaly target data generation step that generates brachycephaly target data indicating the brachycephaly target skull shape based on the brachycephaly ideal correction data and the brachycephaly correction rate, A method for determining the target cranial shape for correction, characterized by including the following:

Images