Treatment of severe bimaxillary protrusion with miniscrew anchorage: treatment and complications

Problems involving excessive face height and severe bimaxillary protrusion are usually treated with orthognathic surgery. When this form of treatment is rejected, retraction and intrusion of the anterior teeth using skeletal anchorage afforded by miniscrews may be employed.

To describe the treatment of severe bimaxillary protrusion with the aid of miniscrews and to discuss the complications encountered during treatment.

Following extraction of the four first premolars, miniscrews were placed bilaterally in both jaws to permit maximum retraction of the anterior teeth, and intrusion of the posterior and upper anterior teeth.

The upper incisors were retracted 12 mm and intruded 5 mm over 20 months. The mandible rotated forward and upward, the face height reduced and the facial aesthetics improved. During treatment an irregular ridge of bone developed labial to the upper incisors, bone was deposited in the incisive fossae and the apices of the upper incisors were resorbed. An alveoloplasty was carried out to recontour the labial bone and the incisive fossae.

Absolute anchorage provided by miniscrews may become an effective alternative to orthognathic surgery for treatment of severe bimaxillary protrusion. During extensive retraction, the teeth may contact structures not normally encountered during conventional orthodontic treatment.