MyKAO
October 28-30, 2022 · COEX, Seoul, Korea
Objectives: The purpose of this study was to evaluate craniocervical posture and hyoid bone position in orthodontic patients with temporomandibular joint (TMJ) disk displacement (DD). Materials and Methods: The subject population consisted of 170 adult female orthodontic patients who consented to bilateral TMJ magnetic resonance imaging (MRI). Subjects were divided into three groups based on the results of TMJ MRI: bilateral normal disk position (BN), bilateral disk displacement with reduction, and bilateral disk displacement without reduction (DDNR). Twenty-five variables from lateral cephalograms were analyzed with one-way analysis of variance to investigate differences in craniocervical posture and hyoid bone position with respect to TMJ DD status. Pearson correlation coefficients were calculated to analyze the relationships between the craniofacial morphology and craniocervical posture or hyoid bone position. Results: Subjects with TMJ DD were more likely to have an extended craniocervical posture with Class II hyperdivergent patterns. In particular, the most significant differences were found between patients with BN and DDNR. However, hyoid bone position in relation to craniofacial references was not significantly different among the TMJ DD groups, except for variables related to the mandible. Pearson correlation coefficients indicated that extended craniocervical posture was significantly correlated with backward positioning and clockwise rotation of the mandible. Conclusion: The present study suggests that the craniocervical posture is significantly influenced by TMJ DD, which may be associated with hyperdivergent skeletal patterns with retrognathic mandible.
Introduction: The treatment of adult patients with severe anterior open bite frequently requires orthognathic surgery, especially when the chin is severely retruded. If a patient have multiple missing posterior teeth, it is difficult to control the occlusal plane as it is challenging to obtain anchorage during orthodontic treatment. Case Summary: We report the case of a 25-year-old woman who had a skeletal Class II malocclusion, severe anterior open bite, a vertical maxillary asymmetry, and severe dental caries on her molars. There was no posterior occlusal contact between maxillary and mandibular molars because five of her molars were extracted for the caries treatment. Lingual fixed appliances and double jaw surgery were performed to treat her skeletal and dental problems, and dental implants helped restore her masticatory function. Pre-treatment, post-treatment and retention photographs of this patient demonstrate effective, esthetically-pleasing, and stable treatment results. Conclusion: Fixed orthodontic treatment with invisible lingual appliance and double jaw surgery was performed to correct the patient's malocclusion and improve facial esthetics.