Orthodontic Treatment In Adults With Class â…¢ Malocclusion Combined Low Angle By Extraction Four Premolars

Objective: To evaluate the orthodontic treatment effects in adults with classⅢmalocclution combined low angle by extraction four premolars in using edgewise arch wire technique. To evaluate the changes in dentoskeletal sturctures and profile after the treatment.Materials and method: A male case with classⅢwas selected from Dalian Ortho clinic in July 2009,who was 22.5 years old, bimaxillary protrusion, classⅢmolar and cuspid relationship ;Ⅱ°crowding and anterior crossbite. The patient was treated by extraction of four premolars with edgewise technique. Uptake x-ray lateral radiographic films pre-and post-treatment in a week. 25 typical measurements were selected from Tweed,MEAW analysis,so as to observe the changes from pre-treament and post-treament.Results: The course of orthodontical treament is 20 months.Compared the changes between pre-treament and post-treament: classⅢmolar relationship was changed to classⅠ, classⅢskeletal facial profile was improved: SNA wasn't changed;SNB decreased 2°;ANB decreased 2°, AO-BO increased 3.5mm, ,the mandibular was clockwise rotated, mandibular plane angle was increased (FMA increased from 16°to 17°,Po-NB decreased from 2.5mm to 1.5 mm). The lower insior uprighted (IMPA decreased from 102 to 88). The profile of soft tissue improved obvious,Li-E decreased by 4mm. The patient and his parents were satisfied with the result of orhtherapy after treatment.Conclusions: ClassⅢmalocclusion with low angle and anterior crossbite in adults can be treated successfully in using edgewise technique and classⅢelastics by extraction four first premolars. The result can be satisfied from the improved: molar relationship,overjet,the profile of soft tissue.