CN-122005118-A - Midline positioning ruler for orthognathic surgery and manufacturing method thereof

CN122005118ACN 122005118 ACN122005118 ACN 122005118ACN-122005118-A

Abstract

The invention discloses a midline positioning ruler for orthognathic surgery and a manufacturing method thereof, and relates to the technical field of medical appliances. The method comprises the steps of designing a multi-curved positioning rule main body, drawing a limiting structure and a retaining structure on the positioning rule main body, virtually designing a buckle, drawing a clamping groove on the buckle, carrying out maxillofacial scanning on a target object, manufacturing an anhydrite tooth model, establishing a virtual three-dimensional craniomaxillary tooth model, carrying out laser scanning on the anhydrite tooth model to obtain virtual dentition data, replacing dentition data in maxillofacial data, adjusting positions of the positioning rule main body and the buckle, virtually connecting the buckle and an intermediate occlusion guide plate into a whole, manufacturing the positioning rule main body by laser cutting, and integrally printing the buckle and the intermediate occlusion guide plate. The midline positioning ruler is used for rapidly positioning the midline of the maxillary dentition in orthognathic surgery, improves the surgery accuracy, saves the surgery time, improves the surgery efficiency and reduces the dependence of surgery on the experience of doctors.

Inventors

HE WEI
SUN XIANTAO
WANG LIN
LEI JIE
WANG XIAOXIA
LI YANG

Assignees

北京大学口腔医学院

Dates

Publication Date: 20260512
Application Date: 20260409

Claims (10)

1. The manufacturing method of the midline positioning ruler for orthognathic surgery is characterized by comprising a positioning ruler main body and a buckle, and comprises the following steps of: In three-dimensional virtual design software, simulating a contour curve of a human right side appearance, and designing a multi-curve positioning ruler main body; drawing a limiting structure extending a target length in the face direction at the upper end of the positioning ruler main body; drawing a protruding retention structure at a position of the positioning rule main body corresponding to the cleft; virtually designing a buckle, and drawing a clamping groove which is matched with the retention structure in a clamping way at the middle position of the buckle; the virtually designed positioning rule main body is clamped with the buckle, and the assembled design file of the positioning rule main body and the buckle is saved; performing maxillofacial spiral CT scanning on a target object, collecting maxillofacial data, and manufacturing an anhydrite tooth model; Importing the maxillofacial data into craniomaxillofacial surgery planning software, establishing a virtual three-dimensional craniomaxillofacial model, and scanning the anhydrite tooth model by laser to obtain virtual dentition data, and replacing the dentition data in the maxillofacial data; simulating a target operation type on the virtual craniomaxillary model, and determining a target position of the mandibular dental bone section based on a final occlusion relationship; The design files of the positioning ruler main body and the buckle are imported into craniomaxillofacial surgery planning software, the lower end of the positioning ruler main body is consistent with the central line of the maxillary dentition, the upper end of the positioning ruler main body is consistent with the central line of the face, and the height of the buckle position is consistent with the occlusion plane; virtually designing an intermediate engagement guide and a final engagement guide; Virtually connecting the buckle and the middle occlusion guide plate into a whole to obtain a target design file; And according to the target design file, the positioning ruler main body is manufactured by laser cutting, and the buckle and the middle occlusion guide plate are integrally printed in a three-dimensional mode.
2. The method of manufacturing a midline positioning ruler for orthognathic surgery according to claim 1, wherein after the step of introducing the design file of the positioning ruler body and the buckle into craniomaxillofacial surgery planning software to keep the lower end of the positioning ruler body consistent with the maxillary dentition midline, the upper end of the positioning ruler body is kept consistent with the facial midline and the height of the buckle position is made consistent with the occlusal plane, further comprising: And adjusting the distances between the positioning ruler main body and the soft tissues of the face and the buckle so as to reserve a safe distance.
3. The method of manufacturing a midline positioning ruler for orthognathic surgery according to claim 1, wherein in the step of introducing the design file of the positioning ruler body and the buckle into craniomaxillofacial surgery planning software, the lower end of the positioning ruler body is kept consistent with a maxillary dentition midline, the upper end of the positioning ruler body is kept consistent with a facial midline, and the height of the buckle position is kept consistent with an occlusion plane, if the maxillofacial data of the target object is not matched with the positioning ruler body, the length of the positioning ruler body is stretched or contracted in virtual design software, or the appearance of the positioning ruler body is trimmed.
4. The method of manufacturing a midline positioning ruler for orthognathic surgery according to claim 1, wherein in the step of drawing a limiting structure extending a target length in a facial direction at an upper end of the positioning ruler body, the length of the limiting structure is 1.8-2.2 cm.
5. The method of manufacturing a midline positioning ruler for orthognathic surgery according to claim 1, wherein in the step of manufacturing the positioning ruler body by laser cutting according to the target design file and integrally three-dimensionally printing the buckle and the middle occlusion guide plate, the positioning ruler body is made of medical 304 stainless steel.
6. The method of manufacturing a midline positioning ruler for orthognathic surgery according to claim 1 or 5, wherein in the step of manufacturing the main body of the positioning ruler by laser cutting according to the target design file and integrally three-dimensionally printing the buckle and the middle occlusion guide plate, the buckle and the middle occlusion guide plate are made of acrylic resin.
7. The method of manufacturing a midline positioning ruler for orthognathic surgery according to claim 1, wherein in the step of simulating a target surgical type on a virtual craniomaxillary model and determining a target position of a mandibular dental bone segment based on a final occlusion relationship, the target surgical type includes a Le Fort type I osteotomy, a mandibular sagittal cleavage.
8. The method for manufacturing a midline positioning ruler for orthognathic surgery according to claim 1, wherein the midline positioning ruler is used for determining a maxillary midline in orthognathic surgery based on a double occlusion guide plate and determining a maxillary midline in double jaw surgery based on a single occlusion guide plate.
9. The method of claim 1, wherein the midline positioning ruler is further used for assisting the operator in judging the symmetry of the chin.
10. A midline positioning ruler, characterized in that the midline positioning ruler is manufactured by adopting the manufacturing method of the midline positioning ruler for orthognathic surgery according to any one of claims 1-9.

Description

Midline positioning ruler for orthognathic surgery and manufacturing method thereof Technical Field The invention relates to the technical field of medical appliances, in particular to a midline positioning ruler for orthognathic surgery and a manufacturing method thereof. Background Facial asymmetry deformity is one of common diseases of orthognathic surgery and is also one of dentofacial deformity with great treatment difficulty, and the main clinical manifestation is that the bilateral maxillofacial region is asymmetric relative to the facial midline, and one third of the lower surface is deflected to one side, and can be accompanied by error deformity, deflection of the dentition midline, plane deflection, temporomandibular joint symptoms and the like. Orthodontic orthognathic joint treatment is a common clinical strategy for treating facial asymmetry deformities, wherein restoring the consistency of the offset dentition midline with the facial midline, and thus restoring the maxillofacial symmetry on this basis, is the key content of the treatment of facial asymmetry deformities. When the traditional model surgery technology is used for preoperative design, an orthognathic surgeon moves the maxillary dentition midline to be consistent with the facial midline on the model surgery according to the deviation degree of the maxillary dentition midline of clinical examination, and then an intermediate occlusion guide plate and a final occlusion guide plate are manufactured for assisting in positioning of the maxillary and mandibular segments. With the widespread use of digitization technology in orthognathic surgery, the digitization design of facial asymmetry deformities has become increasingly popular. The basic method is similar to the model surgical technique, and a doctor moves the maxillary bone segment in a computer according to the offset distance of the maxillary dentition midline relative to the facial midline in clinical examination, so as to move the maxillary dentition midline to be consistent with the facial midline. After the orthognathic surgery scheme is virtually designed, the middle and final occlusion guide plates are virtually designed and three-dimensionally printed and manufactured, so that the orthognathic surgery scheme is used for assisting surgery. The existing research shows that the traditional model surgical technology and the digital design can obviously improve all the result indexes of the patients with the facial asymmetry deformity. The improvement in facial midline and overall facial symmetry is significantly greater for the virtual design compared to traditional surgical planning. However, whether the bite guide is made by conventional methods or by virtual design three-dimensional printing, although the preoperatively designed midline plan has been incorporated into the bite guide, whether the maxillary dentition midline is aligned with the facial midline or not during the performance of orthognathic surgery requires careful intraoperative alignment by the physician, usually by visual inspection or with the aid of a ruler. Because the guide plate is used for determining the positions of the maxillary dental segments based on the positions of the condyles, diaphysis disturbance among bone fracture ends in operation, soft tissue swelling, backward movement of the positions of the condyles caused by general anesthesia, nose deflection caused by trachea cannula and other factors can influence judgment of consistency of a dentition midline and a facial midline when orthodontist observes visually. At present, a learner designs a digital composite occlusion guide plate comprising four indicating rods on the basis of the digital occlusion guide plate. The specific method is that after the virtual design of orthognathic surgery and the virtual design of the occlusion guide plate are completed, a horizontal rod, a median sagittal forward rod, a median sagittal upward rod and a median sagittal downward rod are designed on the occlusion guide plate. For intraoperative assessment of dental and bony midlines, facial soft tissue midlines, occlusal planes, and the like. It verifies the maxillary angle deviation and the line distance deviation immediately after the operation in 17 cases of single bite plate operation mode patients, and the result is ideal. However, the length of the indication rod designed by the method is 7-10mm, the length is limited to the upper lip area and the lower lip area, the indication rod cannot be compared with the main mark points of the facial midline, the consistency judgment precision of the maxillary dentition midline and the facial midline is general, in addition, the judgment of the mandibular position, the dentition midline and the like is required by a special individuation facial arch during operation, the operation is more troublesome, and the operation efficiency is not high. Based on this, it is necessary to design a midline positioning ruler for