Change of lip canting after bimaxillary orthognathic surgery

Lee, Jun Hee; Hong, Jong rak; Kim, Young Ho

Abstract

PURPOSE: The purpose of study was to investigate the correlationship between lip canting change and occlusal canting change after bimaxillary orthognathic surgery, and the ratio of lip canting change and occlusal canting change after the surgery.
PATIENTS AND METHODS
The subjects for this study was obtained from a group of 25 patients who took bimaxillary orthognathic surgery for occlusal canting correction at the Department of the Oral and Maxillofacial Surgery, Samsung Medical Center in Seoul, Korea between January 2000 and December 2005 and a patient's chart had to contain a resting frontal facial photograph in natural head position and a corresponding PA cephalogram in occlusion on the same day before the surgery and post-op 6 months later. The lip canting change was assessed with the angle each labial commissure and the bipupilary reference line. And, the occlusal caning change in the frontal plane was assessed with the angle between the each maxillary first molar occulasal surface and the bi-frontozygomatic suture reference line.
RESULTS
In angular measurement, average occlusal canting change was 3.09degrees and standard deviation was 1.05degrees, average lip canting change was 1.56degrees and standard deviation was 1.05degrees. In linear measurement, average occlusal canting change was 2.41mm and standard deviation was 2.75mm, average lip canting change was 1.18mm and standard deviation was 0.43mm. Lip canting correction ration to occlusal canting correction was 51.5(+/-8.4)percent in angular measurement and 48.8 (+/-9.1)percent in linear measurement. Under Pearson's correlation analysis, Pearson's correlation coefficient was 0.869 in angular measurement and 0.887 in linear measurement (p-value < 0.01). High correlationship was shown between occlusal canting change and lip canting change.
CONCLUSION
First, Bimaxillary orthognathic surgery can correct lip canting as well as occlusal canting. Second, The average amount of lip canting correction is 51.5+/-8.4percent, 48.8+/-9.1percent of occlusal canting correction in the study.