Effects of bimaxillary surgery and mandibular setback surgery on pharyngeal airway measurements in patients with Class III skeletal deformities.
BACKGROUND
The purpose of this study was to compare the short-term and long-term effects of bimaxillary surgery with those of mandibular setback surgery concerning pharyngeal airway measurements at 3 levels: nasopharynx, oropharynx, and hypopharynx.


METHODS
The sample included 66 Japanese women in 2 groups who had been diagnosed with Class III skeletal deformities and had undergone surgical-orthodontic treatment. Those in group A (35 patients) underwent bilateral sagittal split ramus osteotomies; those in group B (31 patients) underwent LeFort I procedures with bilateral sagittal split ramus osteotomies. Lateral cephalograms were assessed within 6 months before surgery and at short-term (3-6 months after surgery) and long-term (at least 2 years after surgery) follow-ups.


RESULTS
In group A, the pharyngeal airway was constricted significantly at the oropharyngeal and hypopharyngeal levels at both the short-term and the long-term follow-ups. In group B, significant changes were shown at the 3 pharyngeal levels at the short-term follow-up, whereas no significant changes were shown at the long-term follow-up.


CONCLUSIONS
These results indicate that, when possible, bimaxillary surgery rather than only mandibular setback surgery is preferable to correct a Class III deformity to prevent narrowing of the pharyngeal airway space, a possible predisposing factor in the development of obstructive sleep apnea.
Chen
Fengshan
F
Department of Orthodontics, Dental School, Tongji University, Shanghai, China. chenfengshan@hotmail.com
Terada
Kazuto
K
Hua
Yongmei
Y
Saito
Isao
I
D000293:Adolescent; D000328:Adult; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008313:Malocclusion, Angle Class III / Q000000981:diagnostic imaging / Q000601:surgery*; D008334:Mandible / Q000000981:diagnostic imaging / Q000601:surgery*; D008437:Maxilla / Q000000981:diagnostic imaging / Q000601:surgery*; D019340:Osteotomy, Le Fort / Q000009:adverse effects / Q000379:methods*; D010614:Pharynx / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D011859:Radiography; D011897:Random Allocation; D020181:Sleep Apnea, Obstructive / Q000209:etiology / Q000517:prevention & control*; D013997:Time Factors