Lower Facial Height Treatment Changes in Bi-maxillary Protrusion Orthodontic Cases

Aim of the study was to investigate the change in lower anterior facial height (LAFH) following 1st premolar extraction and incisor retraction in bimaxillary proclination orthodontic cases. 35 patients (M:F ratio 18:17) with bimaxillary protrusion with age ranging from 14-17 years (mean calculated age 15.6 years) were treated with 1st premolar extractions followed by retraction of the upper and lower labial segments with fixed orthodontic appliances. Pre and post cephalometric values were recorded for each patient. The skeletal parameters measured were SNA, SNB, ANB, MMA, SN-MP and the facial height ratio. The angular soft tissue parameters measured were the naso-labial and the labio-mental angle to investigate the soft tissue changes compared with lower facial height. Pre and post cephalometric values were calculated separately for each patient and the mean value was calculated. The lower anterior facial height decreased by 3 percent following 1st premolar extraction space closure and retraction of the upper and lower labial segments. The naso-labial angle showed 4 degrees mean value change following upper incisor retraction, while the labio-mental angle demonstrated a mean value change of 2 degrees post-treatment. Lower facial height can be altered following 1st premolar extractions and incisor retraction in bimaxillary proclination patients with increased anterior vertical discrepancies. Skeletal effects were more pronounced as compared to the overall soft tissue profile changes.