Background: Correction of severe anterior open bites is impossible with traditional orthodontic treatment and a conventional Le Fort I impaction osteotomy is often the only alternative. Skeletal anchorage is becoming a popular therapeutic tool in orthodontics and miniplates in the zygomatic buttress area can serve as anchorage for maxillary posterior intrusion.

Aims: The aim of this study was to evaluate the use of a conservative ostectomy associated with zygomatic miniplate anchorage for the closure of a severe anterior open bite case.

Methods: A 13-year-old girl with a severe anterior open bite (−8 mm) was treated by intrusion of the posterior maxillary teeth. Under local anesthesia and IV sedation, a supra-apical posterior ostectomy above the maxillary molars was performed, and a specially designed miniplate was fixed to the zygomatic buttress. A transpalatal arch was used to counteract the buccal molar tipping tendency. An intrusive force of 500 g was applied for 4 months when a positive overbite of 3 mm was achieved. Treatment was continued with traditional orthodontic methods, and was completed after 12 months.

Results: After the end of treatment, optimal occlusion and the correction of the anterior open bite were achieved. The maxillary molars were impacted 5.0 mm, and the mandibular plane showed a counterclockwise autorotation of 4.0×.

Conclusion: This one-stage ostectomy can be done under LA and IV sedation, and can be an effective option to treat posterior maxillary intrusion in severe open bite cases. This method is a safe, quick and less expensive alternative to orthognatic surgery.

Conflict of interest: This case was presented in an intermediate stage of treatment at the Australian and New Zealand Association of Oral and Maxillofacial Surgeons 2010 Conference.