Roberto L Velásquez1,2,3, Jorge C Coro4,5,6, Alejandra Londoño7,8, Susan P McGorray9, Timothy T Wheeler5, Sadao Sato10. 1. a Department of Oral and Maxillofacial Rehabilitation , Kanagawa Dental University , Yokosuka , Japan. 2. b Department of Orthodontics , UNICOC , Bogotá , Colombia. 3. c Department of Orthodontics , Universidad de Cartagena , Cartagena , Colombia. 4. d Private Practice in Orthodontics and Dentofacial Orthopedics , Coral Gables , FL , USA. 5. e Department of Orthodontics , University of Florida College of Dentistry , Gainesville , FL , USA. 6. f Department of Orthodontics , Nova Southeastern University College of Dental Medicine , Ft. Lauderdale , FL , USA. 7. g Department of Oral and Maxillofacial Rehabilitation , Kanagawa Dental University , Yokosuka , Japan. 8. h Department of Orthodontics , University of CIEO-UNICIEO , Bogotá , Colombia. 9. i Department of Biostatistics , University of Florida College of Medicine, College of Public Health and Health Professions , Gainesville , FL , USA. 10. j Institute of Occlusion Medicine, Kanagawa Dental University , Yokosuka , Japan.
Abstract
OBJECTIVE: The purpose of this study was to evaluate the morphologic characteristics of MLD malocclusions using 3D imaging. MATERIALS AND METHODS: MLD characteristics were examined using CBCT data in 40 subjects. A 3D Cephalometric analysis was developed to describe the spatial position of the mandible and temporal bones. RESULTS: Vertical dental heights were shorter and the posterior occlusal plane (POP) presented a steeper sagittal inclination on the shifted side (the side of the laterally displaced bony chin) than on the contralateral side. (p < 0.01). The MLD was related to a superiorly inclined POP Cant in the same direction (r = 0.82; p < 0.01). The shifted side condyle was dislocated medially and was smaller. Temporal bone sagittal inclination showed a more forward and medial inclination on the contralateral side (p < 0.01). CONCLUSIONS: A unilateral decrease in the vertical height of the dentition and the subsequent steeper occlusal plane inclinations correlated with (1) mandibular rotational displacement and condylar lateral displacement, (2) mandibular and condylar morphologic changes (3) changes in temporal bone position.
OBJECTIVE: The purpose of this study was to evaluate the morphologic characteristics of MLD malocclusions using 3D imaging. MATERIALS AND METHODS:MLD characteristics were examined using CBCT data in 40 subjects. A 3D Cephalometric analysis was developed to describe the spatial position of the mandible and temporal bones. RESULTS: Vertical dental heights were shorter and the posterior occlusal plane (POP) presented a steeper sagittal inclination on the shifted side (the side of the laterally displaced bony chin) than on the contralateral side. (p < 0.01). The MLD was related to a superiorly inclined POP Cant in the same direction (r = 0.82; p < 0.01). The shifted side condyle was dislocated medially and was smaller. Temporal bone sagittal inclination showed a more forward and medial inclination on the contralateral side (p < 0.01). CONCLUSIONS: A unilateral decrease in the vertical height of the dentition and the subsequent steeper occlusal plane inclinations correlated with (1) mandibular rotational displacement and condylar lateral displacement, (2) mandibular and condylar morphologic changes (3) changes in temporal bone position.