Yoon Jeong Choi1, Chooryung J Chung, Kyung-Ho Kim. 1. a Clinical Assistant Professor, Department of Orthodontics, Gangnam Severance Dental Hospital, College of Dentistry, The Institute of Craniofacial Deformity, Yonsei University, Seoul, Korea.
Abstract
OBJECTIVE: To test the hypothesis that periodontal changes are similar between proclined and minimal-changed mandibular incisor position groups during presurgical orthodontic treatment for Class III orthognathic surgery. MATERIALS AND METHODS: The following measurements were performed before and after presurgical orthodontic treatment of 75 patients (proclination group, 39 subjects; minimal-change group, 36 subjects): clinical crown length, sulcus and bone probing depths, and width of attached gingiva from clinical examination; infradentale-to-MP (perpendicular distance of infradentale to mandibular plane) from examination of lateral cephalograms; and the distance between the cementoenamel junction and alveolar crest from examination of periapical radiographs. Data were compared between the two groups, and a regression analysis was performed to investigate factors affecting the periodontal changes. RESULTS: In both groups, clinical crown length and bone probing depth increased during presurgical orthodontics (P < .05). Infradentale-to-MP and the width of attached gingiva decreased more in the proclination group than in the minimal-change group (P < .05). Proclination and protrusion of the mandibular incisors, and treatment duration affected the periodontal changes. CONCLUSIONS: The null hypothesis was rejected. Proclination of the mandibular incisors for decompensation in Class III surgery patients seems to result in labial alveolar bone recession and a decrease in width of attached gingiva. However, the amount of the periodontal recession appeared to be clinically insignificant.
OBJECTIVE: To test the hypothesis that periodontal changes are similar between proclined and minimal-changed mandibular incisor position groups during presurgical orthodontic treatment for Class III orthognathic surgery. MATERIALS AND METHODS: The following measurements were performed before and after presurgical orthodontic treatment of 75 patients (proclination group, 39 subjects; minimal-change group, 36 subjects): clinical crown length, sulcus and bone probing depths, and width of attached gingiva from clinical examination; infradentale-to-MP (perpendicular distance of infradentale to mandibular plane) from examination of lateral cephalograms; and the distance between the cementoenamel junction and alveolar crest from examination of periapical radiographs. Data were compared between the two groups, and a regression analysis was performed to investigate factors affecting the periodontal changes. RESULTS: In both groups, clinical crown length and bone probing depth increased during presurgical orthodontics (P < .05). Infradentale-to-MP and the width of attached gingiva decreased more in the proclination group than in the minimal-change group (P < .05). Proclination and protrusion of the mandibular incisors, and treatment duration affected the periodontal changes. CONCLUSIONS: The null hypothesis was rejected. Proclination of the mandibular incisors for decompensation in Class III surgery patients seems to result in labial alveolar bone recession and a decrease in width of attached gingiva. However, the amount of the periodontal recession appeared to be clinically insignificant.
Entities:
Keywords:
Class III malocclusion; Mandibular incisor proclination; Orthodontic treatment; Periodontal tissue change