Skeletal anterior open bite is one of the most difficult cases to treat in orthodontics.1 It can result from lack of eruption of anterior teeth, but it is most often caused by rotation of the jaws or excessive eruption of posterior teeth.2 The morphological pattern is characterized by a longer vertical dimension, an increase in development of the maxillary posterior dentoalveolar structure, and a steep mandibular plane.3 In cephalometric analysis, skeletal anterior open bite exhibits a short mandibular ramus and downward rotation of the posterior maxilla; this tends to produce a downward and backward rotation of the mandible that increases anterior facial height and separates the upper and lower anterior teeth.
Successful treatment of skeletal open bite in growing patients requires controlling the downward growth of the maxilla and the eruption of posterior teeth to prevent mandibular rotation. This can be extremely difficult to accomplish.
In adult patients, treatment of severe skeletal anterior open bite consists mainly of surgically repositioning both the maxilla and the mandible. However, some patients fear the surgical risks.4 Thus, various alternative orthodontic therapies can be used, such as high-pull head gear,5 tooth extraction,6 and multiple-loop edgewise arch wire (MEAW).7 These techniques provide acceptable interincisal relationships and increase overbite; however, skeletal improvements are often minimal because it is difficult to establish an absolute anchorage for molar intrusion through traditional orthodontic mechanics. Therefore, implants8 and temporary anchorage devices, including miniscrews9,10 and miniplates,11,12 have been used to attain absolute orthodontic anchorage. These devices can provide absolute anchorage for molar intrusion without active patient participation, but patients must understand the risks and complications associated with 1) miniscrew loosening and fracture, 2) screw–root proximity, and 3) soft tissue impingement and damage.13,14 Relapse of the orthodontic molar intrusion is another unavoidable complication, which is a major harassment in an anterior open bite case.15
This article reports the successful treatment of severe skeletal anterior open bite through maxillary posterior subapical osteotomy (PSO) surgery combined with orthodontic treatment. Common orthognathic surgery in skeletal anterior open bite treatment is either superior repositioning of the maxilla through LeFort I osteotomy to correct face height or mandibular ramus osteotomy to adjust the anteroposterior positioning of the mandible if it does not rotate into the correct position after the maxilla is impacted.16 However, PSO is a simpler procedure than these jaw surgery methods. It can correct anterior open bite through maxillary posterior intrusion and autorotation of the mandible.