OBJECTIVETo study the coordination of facial soft tissue in Angle's Class I, II1, III malocclusion, providing reference for the clinical practice.

METHODS60 lateral cephalometric radiographs of three classes of Angle's malocclusion were included. 13 measurements were analyzed by SPSS 10.0.

RESULTSProtrusion of the upper and lower lips increased in Angle's II1 comparing with Angle's I and protrusion of the upper lip was larger than the lower lip, no difference was found in the facial convexity. Increase of upper lip inclination and underdevelopment of maxillary in Angle's III comparing with Angle's I. No significant different was found in the form of lower lip, soft tissue facial angle and Z angle. Comparing Angle's II1 with Angle's III, every measurements were significantly different except upper lip inclination, nasolabial angle, representing the formation mechanism of malocclusion.

CONCLUSIONSome differences were found in form and position of lip in three classes of Angle's malocclusion. However, the deformity was not obvious in Angle's II1 and Angle's III because of compensation mechanism. Nasolabial angle only reflected change of upper lip, but could not reflect characters of facial profile.