| Since Orthognathic surgery has become the treatment for patients with maxillofacial deformities obtained the very good treatment effect.After the orthognathic surgery changes the shape and position structure of mandible and maxilla,it is bound to have different degrees of impact on the temporomandibular joint.Due to the pre-existent TMD or the condylar and fossa relationship incoordination in many patients.When the direction and function of the masticatory muscles and the occlusal relationship changed after the surgery,it will definitely change the TMJ's position and function.Among them,some patients with joint symptoms can improve their symptoms after the orthognathic surgery,while some will get worse;But some patients will also have worse symptoms,while patients without joint symptoms before surgery will have joint discomfort or even TMD after orthognathic surgery,indicating that orthodontic surgery is closely related to TMJ.Although a large number of studies have analyzed the relationship between orthodontic surgery and TMJ from various perspectives,traditional research methods are still difficult to explain the internal relationship on it.However,the clinical evaluation of the postoperative effect of the orthognathic surgery is mainly led by the therapeutic physicians,which is only limited to the objective evaluation of the morphological observation,imaging outcome Pre and postsurgery and the oral function.In general,the evaluation lacks the comprehensive impact of the patients' own quality of life.With the development of computer science and digital technology,three-dimensional imaging technology is widely used in the study of jaws morphology,which can accurately analyze the three-dimensional structure of TMJ.Therefore,by obtaining imaging data of skeletal class ? malocclusion patients underwent double jaws surgery before and after surgery,the study observed the changes of TMJ structure and analyzed the impact of orthognathic surgery on the TMJ position.In addition,with social development and the transformation of medical model,clinical medical practice and research has been expanded from a purely biological and clinical perspective to the physiological-psychological-social functions of patients.Therefore,in this study,the survey was used to understand the subjective evaluation of the patients' own quality of life,and the changes in the quality of life of patients before and after orthognathic surgery were discussed.Part 1.Assessing the changes of condyle and mandibular ramus before and after surgery by using three-dimensional superimposition mapping techniquePurpose: Collecting the CT image data of 20 patients with skeletal class ? malocclusion before and after 6 months of orthognathic surgery,the spatial position changes of condyles and mandibular ramus before and after surgery were compared and analyzed by using Mimics and 3-Matic software.Methods: The CT image data of 20 skeletal class ? patients underwent double jaws surgery were collected,and the Mimics software was used to convert them into 3D models which were registered by 3-Matic based on the cranial base surface as the template to obtain the position changes of condyles and mandibular ramus,and the displacement analysis was carried out.Meanwhile,the two sides of condylar volumes before and after surgery was compared.Results: The condyle and mandibular ramus of position of 20 patients were changed six months after surgery.The shape and size of condyle in most patients was asymmetric before surgery,but there was no significant difference in condyle volume.Conclusion: Three-dimensional superimposition mapping technique described well the position changes of the condyle and mandibular ramus before and after the surgery.Before surgery,the two sides condyle shape in most patients was asymmetric,and the volume of male condyle was significantly larger than that of female.After the orthognathic surgery,the condyle and mandibular ramus had slight displacement irregularly.Part 2.Three-dimensional reconstruction and comparison of temporomandibular joint space before and after surgeryObjective: To reconstruct the TMJ space by using the CT image data of patients with skeletal class ? malocclusion before and 6 months after surgery,the registration was computed by Mimics and 3-Matic software,and to compare and analyze the spatial changes of the temporomandibular space before and after surgery.Methods: The CT image data of 20 skeletal class ? patients underwent double jaws surgery were collected,and the Mimics software was used to convert them into 3D models for segmentation.Temporomandibular joint space was reconstructed in 3-Matic while the TMJ space volume was calculated and analyzed before and after surgery.Results: After surgery joint space was statistically increased(p < 0.05).By linear regression analysis,bilateral joint volume was positively correlated before and after orthognathic surgery.Conclusion: There was a positive correlation between left and right joint space before and after surgery.Six months after surgery,the joint space was larger than that before surgery,especially in the right joint space,and there was no difference in gender group.Part 3.Study on the relationship between the articular fossa and condyle before and after surgeryObjective: To compare the condyle-fossa relationship before and after surgery by using the CT data of orthognathic patients,and registration was computed by Mimics and 3-Matic software.Methods: The CT data of 20 skeletal class ? patients who underwent double jaws surgery were collected and converted into a 3D model on Mimics software.The model was then divided and calculated to reconstruct the 3D model of the temporomandibular fossa.The transverse dimension of articular fossa and condylar process were measured.The intersection angle between the articular fossa and the central sagittal plane and condylar angle in axial plane was measured.Results: The transverse diameter of the condyle of 20 patients had a positive correlation with the transverse diameter of the articular fossa.The horizontal angle of the right condyle showed a significant difference(p < 0.05)before and after surgery.The correlation coefficients of the two sides of the horizontal Angle of the articular fossa and the two sides of the condyle after surgery both were r =0.65,indicating a positive correlation.Conclusion: There was a positive correlation between the bilateral transverse diameter of the condyle and the articular fossa,but there was no correlation between anteroposterior diameters.In general,the horizontal angle of the condyle decreases slightly,and the lateral condyle pronates after operation.Part 4.Evaluation of quality of life before and after orthognathic surgeryObjective: To evaluate the quality of life of patients before and after orthognathic surgery by using the oral health impact profile scale and the orthognathic quality of life questionnaire.Methods: From November 2016 to March 2017,85 patients with dentofacial deformities who underwent orthognathic surgery were collected in the department of oral and maxillofacial surgery of Air Force Medical University.The questionnaires were developed and collected before and after 6 months surgery and 96 without maxillofacial deformities were enrolled as controls.Results: The preoperative total score and subscale scores of the patients were significantly higher than that of after surgery,higher than those of the control group,and after surgery lower than those of the control group.The OQLQ total scores before and after surgery were statistically significant between males and females(P < 0.05).The total OQLQ score of the older patients was significantly higher than that of the younger group(P < 0.05).All of the postoperative scores of the class ? double-jaw surgery group was significantly different from that of the preoperative group(P < 0.001).Conclusion: Quality of life in dentofacial deformity patients is lower than that of the normal group,orthognathic surgery has benefit on patients ' quality of life,and the patients with ? classes who had double jaw surgery benefit most.To sum up,the spatial structure of the temporomandibular joint was changed half a year after the orthognathic surgery,compared with that before the surgery,the joint space was enlarged,and the lateral condyle head had slight forward rotation,but the overall displacement was not significant.Orthognathic surgery has a positive effect on improving the quality of life of patients. |
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