Orthodontists' perceptions of the need for orthognathic surgery in patients with Class II Division 1 malocclusion based on extraoral examinations.

INTRODUCTION

The purpose of this study was to establish the influence of soft-tissue profile values on the decision of orthodontists to recommend orthognathic surgery for patients with Class II Division 1 malocclusion.

METHODS

A questionnaire containing 40 profile photographs of adults with Class II Division 1 malocclusion was sent to all 256 consultant orthodontists in the United Kingdom asking for a "yes" or "no" response to the question: "Based on the profile view of this patient, would you treat this patient using an orthognathic surgical approach?" A soft-tissue analysis was carried out on each photograph, and multi-level logistic regression was used to investigate factors that affect the decision to recommend surgery.

RESULTS

The response rate was high: 208 of 256 questionnaires (81.3%). Intraexaminer reliability of the photographic analysis method with a Bland-Altman plot showed good (95% CI) limits of agreement for each measurement. Consultants who carried out more orthognathic surgery treatment were more likely to recommend surgery. Secondary analysis with a logistic regression model indicated that 80% of the consultants would recommend surgery if B-point was more than or equal to -14.1 mm posterior to the true vertical through subnasale (95% CI, -29.9 to -10.9 mm), the facial profile angle was less than or equal to 148.9° (95% CI, 6.7° to 151.1°), pogonion to true vertical through subnasale was more than or equal to -12.0 mm (95% CI, -48.7 to -8.6 mm).

CONCLUSIONS

The facial profile angle and the positions of soft-tissue pogonion and B-point are useful clinical guides for planning treatment for adults with Class II Division 1 malocclusion.