Accuracy of predicting the pharyngeal airway space on the cephalogram after mandibular setback surgery.
OBJECTIVE
The aim of the present study was to evaluate the accuracy of a formula predicting the change of pharyngeal airway space (PAS) on the cephalogram after mandibular setback surgery.


METHODS
Twenty-nine female adults with mandibular prognathism underwent surgery by bilateral sagittal split ramus osteotomy. The postoperative anteroposterior (A-P) PAS dimension was calculated from the change of C3-Me (distance between the anteroinferior point of the third cervical vertebra and menton) using 2 cephalograms taken before treatment and at 1 year after surgery. The regression equation used was y = -21.105 + 0.402x (y: PAS; x: C3-Me; r = 0.854).


RESULTS
The predicted and measured values were nearly same on average, and the difference between both ranged within +/-1.5 mm for each case individually.


CONCLUSIONS
This study suggested that the postoperative A-P PAS dimension can be predicted from the change in C3-Me, matching the amount of the mandibular setback.
Muto
Toshitaka
T
Department of Oral & Maxillofacial Surgery, National Defense Medical College, Saitama, Japan. muto@ndmc.ac.jp
Yamazaki
Atsue
A
Takeda
Shigehiro
S
Sato
Yasunori
Y
D000328:Adult; D000402:Airway Obstruction / Q000175:diagnosis; D000465:Algorithms; D002508:Cephalometry; D005260:Female; D006801:Humans; D008313:Malocclusion, Angle Class III / Q000601:surgery*; D008334:Mandible / Q000002:abnormalities / Q000601:surgery*; D019647:Oral Surgical Procedures; D010027:Osteotomy; D010614:Pharynx / Q000033:anatomy & histology*; D011237:Predictive Value of Tests; D011378:Prognathism / Q000601:surgery; D012044:Regression Analysis