| Objective:The study aims to explore the immense advantages and potentials of computer-aided technologies, as well as to discuss the implementation of the technologies in treatment of the hemimandibular hyperplasia (HH). Three-dimensional cephalometry and surgical planning based on computer-aided technologies and their applications were presented in this work. The author also proposed classification of hemimandibular hyperplasia based on a review on the current terminology and classification of the disease, and subsequently discussed the importance and significance of the classification methods, which led to application of different medical treatment strategies for patients in different categories.Methods:The author studied7hemimandibular hyperplasia cases during2009to2013. The study classified the patients into typical and atypical HH groups based on whether the diseases were accompanied by signs such as tilted occlusal plane, open bite/malocclusion and hyperplastic condyle, etc. Accordingly, the study applied computer-aided technology in clinical treatments of the two groups. The author leveraged three-dimensional cephalometry to quantify the severity-of the diseases, and used technologies including surgical planning and simulation, model manufacturing etc., to develop the surgical strategy. Subsequently, for patients in typical HH group, the study implemented surgical treatments including maxillary Le Fort I osteotomy, bilateral mandibular ramus sagittal split osteotomy, resection of the excessive lower mandibular margin and genioplasty, while preserving enlarged condylar head. On the other hand for the atypical group, the study included unilateral mandibular angle ostectomy, resection of the excessive lower mandibular margin or bilateral mandibular angle ostectomy into the clinical surgery.Results:Of the7patients,3were classified as typical HH patients, while the other4were diagnosed as atypical HH. The three-dimensional cephalometry provided accurate data onthe skewness of occlusal plane,deviation of mandibular sagittal plane, bilateral differences of mandibular ramus and body, and the level of resectionsof the excessive lower mandibular marginon the affected side. Other computer-aided technologies such as surgical planning and simulation, and model manufacturing have significantly improved the accuracy of the analysis of osteotomy and reposition. For typical HH patients, the treatmentsuccessfullycorrected issues of tilted occlusal plane and facial asymmetry and resulted better occlusion after orthodontic treatment. The study followed the typical group for a time span longer than one and half a year, during which period no recurrence of temporomandibular joint(TMJ) disorders or mandibular deviation was reported. Nor any change in the preserved part of the enlarged condylar head was discovered duringskull CT or panoramic X-ray. In the cases of atypical HH patients, lower facial symmetry also improved. Two patients in the group have successfullyachievedcosmetic goal of facial contourby receiving bilateral mandibular angle ostectomy.Conclusion:The study proved that the implementation of the computer-aided technology in treatment of the hemimandibular hyperplasia has significantly reduced the surgical risk and operational time, and greatly improved the outcomes of the treatment. The use of technology also helped to improve the communication between the patients and the doctors. With the unique three-dimensional analysis and surgical planning based on the clinical characteristics of the disease, the author successfully quantified the severity of diseases of the patient group, which led to an efficient simulation and improved surgical results. The classification of the hemimandibular hyperplasia not only addressed the issue of complicated diagnosis, but also enabled the differentiation of clinical treatments on patients with various levels of disorders. Based on the proposed classification, the author developed different treatmentplanning and surgical strategies. |
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