Excessive gingival display is an unattractive smile characteristic with multiple etiologies. Vertical maxillary excess, supraeruption of the maxillary incisors, and shortness or hypermobility of the upper lip are some of the most common factors involved.Vertical maxillary excess is characterized by excessive posterior and anterior dentoalveolar height and is often associated with excessive lower facial height and a wide interlabial gap. From a sagittal view, such a patient may also have a convex profile due to apparent downward and backward mandibular rotation.
A patient with vertical maxillary excess exhibiting these facial characteristics can benefit greatly from a maxillary impaction Le Fort I osteotomy.This procedure not only reduces the gingival display when smiling and the incisor display at rest, but also promotes an upward and forward rotation of the mandible that reduces the lower facial height and the interlabial gap, often resulting in a more orthognathic profile. Because orthognathic surgery is associated with considerable costs and risks, however, alternative treatment options are often explored, including orthodontic intrusion of the maxillary incisors.
The maxillary incisors can be predictably intruded about 2mm with orthodontic appliances.Any further correction is difficult to achieve or may generate esthetic problems, such as a reverse smile architecture due to the discrepancy between the posterior occlusal planes and the anterior incisal plane . To increase the degree of maxillary incisor intrusion, the posterior occlusal plane must be altered through a leveled or canted intrusion. Unfortunately, superior displacement of the maxillary occlusal plane is not possible in an adult patient without surgery, unless adjuncts such as skeletal anchorage are used.