Facial Profile Changes in Early Class II Correction with Cervical Headgear

Abstract

To characterize the effects of early cervical headgear treatment on the facial profile of children in Class II division 1 malocclusion. Forty children aged 9.1 (7.2-11.5) years with Class II division 1 malocclusion were treated using a cervical headgear appliance. The headgear consisted of a long outer bow bent upward 15 degrees and a large expanded inner bow. Lateral cephalograms were taken before and after treatment, and the facial profile was estimated from the cephalograms. The results were compared to an age- and sex-matched normal cohort of 644 Finnish children. Class I molar relationship was achieved in all treated children. The treatment time was 1.6 (0.3-3.1) years on average. Compared to the controls, the treatment restricted the forward growth of maxillary A-point, and the SNA angle decreased 1.4 degrees +/- 1.2 degrees per year (P < .00001). Decreased maxillary prognathism was associated with decreased facial convexity, g-sn-pg (P = .02), and the ANB (P < .00001) angles decreased compared to the controls. Upper lip protrusion (distance ls to sn-pg; P < .00001) was decreased, and the nasolabial angle (cm-sn-ls) widened despite the increased facial inclination of the upper incisors (P = .0005). The treatment significantly decreased the gap between the lips (P = .0009) in their relaxed position. Cervical headgear treatment in Class II correction is associated with a decreased facial convexity caused by the restriction of forward growth of the maxillary A-point, while the rest of the facial profile, including the mandible, continue to grow forward at a normal rate.