Abstract
The combination of proclined upper anteriors with high gingival exposure is challenging for the orthodontist. Correction of proclined upper anteriors sometimes leads to deepening of the bite and loss of posterior anchorage resulting in worsening of gingival exposure. Routinely correction of high gingival exposure was done prior to space closure resulting in increased treatment duration. However, application of sound biomechanical strategies can help us overcome these challenges without compromising treatment time. This presentation will describe the meticulous orthodontic biomechanics using a 3-piece intrusion arch to simultaneously correct excessive gingival exposure as well as accomplish space closure. The patient presented with Class I malocclusion with proclined upper anterior teeth, crowding in upper and lower arches and an excessive gingival exposure. Fixed orthodontic therapy was initiated with first premolar extractions and the primary strategies after correcting of the crowding was the effective use of a 3-piece intrusion arch for simultaneous intrusion and retraction of proclined anterior teeth. Biomechanics strategies utilizing the 3 piece intrusion arch effectively aided in closure of spaces, correction of high gingival exposure, intrusion of the upper anteriors and controlling posterior anchorage. All desired treatment outcomes were achieved without prolonging treatment time. Proper biomechanics strategies can effectively bring about true intrusion of the upper anteriors as well as correct the upper incisor proclination without prolonging treatment time. The use of threepiece intrusion arch to achieve orthodontic correction assures the attainment of predictable treatment results. Loss of anchorage is seldom observed because of the tip back moment on the posterior teeth. Another advantage of intrusion mechanics is the control of the vertical dimension.