187 MAXIMIZING TISSUE RESPONSE IN SELECTED SUBJECTS WITH ANTERIOR OPEN BITES Aim: Open bites are challenging malocclusions with a multifactorial etiology, varying clinical severity, and questionable stability. The aim of this article is to describe a method for maximizing tissue response in the treatment of selected subjects with anterior open bites. Method: Twelve subjects with an anterior open bite and insufficient incisor display underwent a limited corticotomy to augment alveolar bone response by creating an anteroposterior intra-arch anchorage differential. Cephalometric radiographs were taken before treatment (T1) and 1 month after open bite closure (T2). The change in per- ceived smile esthetics was assessed by a visual analog scale. Results: All open bites were closed after a mean of 6 weeks. Radiographic evaluation showed significant maxillary incisor extrusion and retru- sion. There was a notable improvement in smile esthetics after treat- ment. Conclusion: It is possible to close anterior open bites rapidly with significant improvement in smile esthetics in a selected group of anterior open-bite subjects. World J Orthod 2009;10:187–195. Key words: accelerated tooth movement, corticotomy, open bite, smile esthetics, tissue response Yehya A. Mostafa, BDS, FDSRCED, MS, PhD 1 Nagwa Helmy El-Mangoury, BDS, FDSRCED, MS, PhD 2 Amr M. Abou-El-Ezz, BDS, MDSc, PhD 3 Ahmed M. Heider, BDS, MDSc, PhD 4 A nterior open bites are one of the most difficult malocclusions to treat because they are usually a result of an interaction of multiple etiologic factors. 1,2 Anterior open bites can be skeletal or dentoalveolar or have a functional or a habit-related cause. 3 Many therapeutic approaches and appliances have been used for anterior open bite treatment, including habit-therapy, 4,5 vertical chin cups, 6 vertical holding appliances, 7 high- pull headgears, 8,9 posterior bite blocks, 10 spring-loaded bite blocks, 11 active verti- cal correctors, 12 and Fränkel IV appli- ances. 13 Other treatment modalities include orthodontic camouflage using fixed appliances with extractions, 14 elas- tics, 15 extrusion arches, 16 multiloop edgewise archwires, 17 and reverse/ accentuated curve of Spee Ni-Ti arch- wires. 18 Plates 19 and microimplants 20 have also been used for the treatment of anterior open bites. Subjects with severe open bites require a combined surgical- orthodontic approach. 21 Orthodontists are also faced with the challenge of retaining successfully treated open bites. In a review article on anterior open bite stability, Huang concluded that the level of evidence provided by current literature is not conclusive. 22 For decades, tooth movement has largely been attributed to a resorption- apposition process occurring within the periodontal ligament. Attempts to acceler- ate tooth movement include physical agents, 23–26 local and systemic drug administrations, 27–32 and combining orthodontics with alveolar surgery. 33–35 Alveolar corticotomies accelerate tooth movements, resulting in a shorter ortho- dontic treatment. 36–38 This acceleration is believed to be due to bony block move- ment. 39 However, it should be considered a combination of conventional tooth movement and bony block movement. 1 Professor and former Chair, Depart- ment of Orthodontics,Cairo Univer- sity Faculty of Dentistry, Cairo, Egypt. 2 Professor and Chair, Department of Orthodontics, Cairo University Fac- ulty of Dentistry, Cairo, Egypt. 3 Professor, Department of Orthodon- tics, Cairo University Faculty of Den- tistry, Cairo, Egypt. 4 Lecturer, Department of Orthodon- tics, Cairo University Faculty of Den- tistry, Cairo, Egypt. CORRESPONDENCE Dr Nagwa Helmy El-Mangoury PO Box 60 Mina Garden Post Office October City, Cairo 12582 Egypt Email: mangoury@usa.net © 2009 BY QUINTESSENCE PUBLISHING CO, INC. PRINTING OF THIS DOCUMENT IS RESTRICTED TO PERSONAL USE ONLY. NO PART OF THIS ARTICLE MAY BE REPRODUCED OR TRANSMITTED IN ANY FORM WITHOUT WRITTEN PERMISSION FROM THE PUBLISHER.