Reiko Shibazaki-Yorozuya1, Akira Yamada2, Satoru Nagata3, Kouichi Ueda4, Arthur J Miller5, Koutaro Maki6. 1. Assistant professor, Department of Orthodontics, School of Dentistry, Showa University, Tokyo, Japan. Electronic address: reikosyoroz@dent.showa-u.ac.jp. 2. Lecturer, Department of Plastic and Reconstructive Surgery, Osaka Medical School, Osaka, Japan; visiting professor, World Craniofacial Foundation, Dallas, Tex. 3. Director, Nagata Microtia and Reconstructive Plastic Surgery Clinic, Saitama, Japan; visiting professor, Department of Plastic and Reconstructive Surgery, University of California Irvine School of Medicine, Irvine, Calif. 4. Professor and chair, Department of Plastic and Reconstructive Surgery, Osaka Medical School, Osaka, Japan. 5. Professor, Division of Orthodontics, Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco, Calif. 6. Professor and chair, Department of Orthodontics, School of Dentistry, Showa University, Tokyo, Japan.
Abstract
INTRODUCTION: The purpose of this study was to evaluate the concept that the affected and contralateral sides do not grow at the same rate in patients with hemifacial microsomia. Changes in the cranial base, maxilla, mandible, and occlusal plane were evaluated on 3-dimensional images from cone-beam computed tomography data in untreated patients. METHODS: Six patients were classified as having mandibular Pruzansky/Kaban type I, IIA, or IIB hemifacial microsomia. Cone-beam computed tomography (MercuRay; Hitachi, Tokyo, Japan) scans were taken before orthodontic treatment during both growth and postpuberty periods. RESULTS: The cranial base as defined by the position of the mastoid process was in a different position between the affected and contralateral control sides. The nasomaxillary length or height was shorter on the affected side for all 6 patients with hemifacial microsomia regardless of its severity, and it grew less than on the contralateral control side in 5 of the 6 patients. The occlusal plane angle became more inclined in 4 of the 6 patients. The mandibular ramus was shorter on the affected side in all patients and grew less on the affected side in 5 of the 6 patients. The mandibular body grew slower, the same, or faster than on the control side. CONCLUSIONS: The cranial base, position of the condyle, lengths of the condyle and ramus, and positions of the gonial angle and condyle can vary between the affected and contralateral control sides of patients with hemifacial microsomia, with the ramus and nasomaxillary length usually growing slower than they grow on the control side. These results suggest that many factors affect the growth rate of the craniofacial region and, specifically, the mandible in patients with hemifacial microsomia.
INTRODUCTION: The purpose of this study was to evaluate the concept that the affected and contralateral sides do not grow at the same rate in patients with hemifacial microsomia. Changes in the cranial base, maxilla, mandible, and occlusal plane were evaluated on 3-dimensional images from cone-beam computed tomography data in untreated patients. METHODS: Six patients were classified as having mandibular Pruzansky/Kaban type I, IIA, or IIB hemifacial microsomia. Cone-beam computed tomography (MercuRay; Hitachi, Tokyo, Japan) scans were taken before orthodontic treatment during both growth and postpuberty periods. RESULTS: The cranial base as defined by the position of the mastoid process was in a different position between the affected and contralateral control sides. The nasomaxillary length or height was shorter on the affected side for all 6 patients with hemifacial microsomia regardless of its severity, and it grew less than on the contralateral control side in 5 of the 6 patients. The occlusal plane angle became more inclined in 4 of the 6 patients. The mandibular ramus was shorter on the affected side in all patients and grew less on the affected side in 5 of the 6 patients. The mandibular body grew slower, the same, or faster than on the control side. CONCLUSIONS: The cranial base, position of the condyle, lengths of the condyle and ramus, and positions of the gonial angle and condyle can vary between the affected and contralateral control sides of patients with hemifacial microsomia, with the ramus and nasomaxillary length usually growing slower than they grow on the control side. These results suggest that many factors affect the growth rate of the craniofacial region and, specifically, the mandible in patients with hemifacial microsomia.
Authors: R Christian Solem; Antonio Ruellas; Joni L Ricks-Oddie; Katherine Kelly; Snehlata Oberoi; Janice Lee; Arthur Miller; Lucia Cevidanes Journal: Am J Orthod Dentofacial Orthop Date: 2016-08 Impact factor: 2.650