[Prediction and assessment of facial profile after bimaxillary orthognathic surgery in skeletal Class III malocclusion].

PURPOSE: To predict and assess the facial profile after bimaxillary orthognathic surgery in a patient model.

METHODS

One patient with skeletal Class III malocclusion was selected. The orthognathic surgery design was simulated through Photoshop CS4 software. Preoperative photograph and lateral cephalometric radiograph were processed to produce the first standard facial profile photography P1. The maxillary hard tissue was moved forward according to Andrews theory II, and soft tissue also moved in proportion until the mandible recessed to the Chinese G-Sn-Pog' angle .Then the mandible was moved forward and back ±1,±2,±3,±5,±7 mm, generating 20 facial profile photographs. Two groups of reviewer were chosen for evaluation:specialists (40 orthodontists),undergraduates (68 undergraduates from Chongqing Medical University).They were asked to rank the 21 random profiles in descending order. The difference of the score of 21 photographs given by two groups of reviewer was compared using Wilcoxon rank sum test with SPSS13.0 software package.

RESULTS

The scores of 21 profile photographs were significantly different(P<0.05).Profile D3 was considered to be the most beautiful,followed by D2,D1,B1,A1,P1,C1,A2 and B2. C4,A5,B5 and C5 were not acceptable. The scores for each photograph given by the two groups of reviewer were not significantly different (P>0.05).

CONCLUSIONS

The reviewers give different scores for 21 profiles. Straight profile is most beautiful, followed by profile with minor mandibular or chin retraction.Profiles with severe protrusion or retrusion is not acceptable.