Facial Profile and Lip Position Changes in Adult Class II, Division 2 Subjects Treated with the Herbst-Multi bracket Appliance. A Radiographic Cephalometric Pilot Study

Abstract

To examine the treatment and post-treatment effects of the Herbst-Multibracket (MB) appliance on facial profile and lip position in adult Class II, Division 2 subjects. Lateral head films of 16 consecutively-treated adult Class II, Division 2 subjects (8 males, 8 females) with an average age of 18.8 years pre-treatment were analyzed on three occasions: before treatment (T1), after Herbst-MB treatment (T2) and 2 years post-treatment (T3). Treatment period (T2-T1): an increase occurred in the hard tissue profile angle (2.5 degrees; p < 0.001), the soft tissue profile angle excluding the nose (2.6 degrees ; p < 0.01), and the soft tissue profile angle including the nose (1.8 degrees; p < 0.05). The upper lip became more retrusive in relation to the Esthetic line (EL) (0.8 mm; p < 0.05) while the lower lip's position was unchanged. Lower lip coverage of the upper incisors was reduced (0.8 mm; p < 0.05). Post-treatment period (T3-T2): the soft tissue profile angle (excluding the nose) increased (1.6 degrees; p < 0.01), while the hard and soft tissue profile angles including the nose remained unchanged. Both, the upper and lower lips became more retrusive in relation to the EL (0.9 mm; p < 0.01 and 1.0 mm; p < 0.001). The lower lip coverage of the upper incisors remained unchanged. The hard and soft tissue profiles were straightened during Herbst-MB treatment, including a brief follow-up period. The lips became more retrusive while the lower lip coverage of the upper incisors was reduced.