Three-dimensional longitudinal changes in craniofacial growth in untreated hemifacial microsomia patients with cone-beam computed tomography.
BACKGROUND
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.
Assistant professor, Department of Orthodontics, School of Dentistry, Showa University, Tokyo, Japan. Electronic address: reikosyoroz@dent.showa-u.ac.jp.
Reiko
R
Shibazaki-Yorozuya
Lecturer, Department of Plastic and Reconstructive Surgery, Osaka Medical School, Osaka, Japan; visiting professor, World Craniofacial Foundation, Dallas, Tex.
Akira
A
Yamada
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.
Satoru
S
Nagata
Professor and chair, Department of Plastic and Reconstructive Surgery, Osaka Medical School, Osaka, Japan.
Kouichi
K
Ueda
Professor, Division of Orthodontics, Department of Orofacial Sciences, School of Dentistry, University of California, San Francisco, Calif.
Arthur J
AJ
Miller
Professor and chair, Department of Orthodontics, School of Dentistry, Showa University, Tokyo, Japan.
Koutaro
K
Maki
D059925:Anatomic Landmarks / Q000000981:diagnostic imaging; D002508:Cephalometry / Q000379:methods; D002648:Child; D002675:Child, Preschool; D054893:Cone-Beam Computed Tomography / Q000379:methods*; D003766:Dental Occlusion; D005147:Facial Bones / Q000000981:diagnostic imaging / Q000254:growth & development*; D005260:Female; D005500:Follow-Up Studies; D006053:Goldenhar Syndrome / Q000145:classification / Q000000981:diagnostic imaging / Q000503:physiopathology*; D006801:Humans; D021621:Imaging, Three-Dimensional / Q000379:methods*; D008137:Longitudinal Studies; D008297:Male; D008334:Mandible / Q000000981:diagnostic imaging / Q000254:growth & development; D008335:Mandibular Condyle / Q000000981:diagnostic imaging / Q000254:growth & development; D008416:Mastoid / Q000000981:diagnostic imaging / Q000254:growth & development; D008437:Maxilla / Q000000981:diagnostic imaging / Q000254:growth & development; D009666:Nose / Q000000981:diagnostic imaging / Q000254:growth & development; D011627:Puberty; D012189:Retrospective Studies; D012886:Skull / Q000000981:diagnostic imaging / Q000254:growth & development*; D019291:Skull Base / Q000000981:diagnostic imaging / Q000254:growth & development; D013704:Temporomandibular Joint / Q000000981:diagnostic imaging / Q000254:growth & development