Bimaxillary dentoalveolar protrusion: traits and orthodontic correction.

A group of 48 ethnically diverse patients with bimaxillary protrusion was used to study the pretreatment cephalometric traits of this malocclusion and the effect of orthodontic correction. All patients were treated with four premolar extractions and retraction of the anterior teeth. Pre- and posttreatment lateral cephalograms were evaluated using a series of 18 linear and angular measurements, and the effect of orthodontic correction was determined using paired t-tests. Cephalometric standards were developed for bimaxillary protrusions, which clarify the overall presentation of this malocclusion for clinicians. Patients with bimaxillary protrusion demonstrated increased incisor proclination and protrusion, a vertical facial pattern, increased procumbency of the lips, a decreased nasolabial angle, and thin and elongated upper and lower anterior alveoli. This study also showed that the extraction of four premolars can be extremely successful in reducing the dental and soft tissue procumbency seen in patients with bimaxillary protrusion, thus providing a stronger evidence-based rationale for this treatment modality.