Clinical Paper Cleft Lip and Palate Mandibular effects of maxillary distraction osteogenesis in cleft lip and palate § J.-C. Doucet, C. Herlin, M. Bigorre, C. Ba ¨umler, G. Subsol, G. Captier: Mandibular effects of maxillary distraction osteogenesis in cleft lip and palate. Int. J. Oral Maxillofac. Surg. 2014; 43: 702–707. # 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. J.-C. Doucet 1,2 , C. Herlin 1 , M. Bigorre 1 , C. Ba ¨umler 1 , G. Subsol 3 , G. Captier 1,4 1 De ´partement de Chirurgie Orthope ´ dique et Plastique Pe ´ diatrique, Ho ˆ pital Lapeyronie, CHRU Montpellier, France; 2 Department of Oral and Maxillofacial Surgery, Dalhousie University, Halifax, Canada; 3 Equipe ICAR- CNRS, LIRMM, Montpellier, France; 4 Laboratoire d’Anatomie de Montpellier, UFR Me ´ decine, Universite ´ Montpellier 1, France Abstract. Maxillary distraction osteogenesis (DO) is a reliable treatment for severe maxillary deficiency in cleft lip and palate (CLP). The objective was to analyze its long-term effects on the mandible. A retrospective study of 24 CLP treated with maxillary DO using the Polley and Figueroa technique was done; patients were followed for more than 4 years. Preoperative (T0), 6–12 months postoperative (T1), and 4 years postoperative (T2) cephalometric radiographs were evaluated. A classical cephalometric analysis was used to assess treatment stability, and a Procrustes superimposition method was used to assess local changes in the shape of the mandible. The mean age of patients at T0 was 15.4  4.1 years. SNA increased at T1 and T2 (P < 0.001), with no significant relapse between T1 and T2, indicating stability at 1 year after treatment (T0 = 72.4  5.38; T1 = 81.3  6.28; T2 = 79.9  6.18). SNB, facial angle, gonial angle, and symphyseal angle remained stable. Long-term analysis of the mandible demonstrated a minimal counter- clockwise rotation of the body (mandibular plane = 0.2  3.28) and ramus (0.6  4.38). Maxillary DO in CLP had no significant effect on the shape or rotation of the mandible. The maxillary advancement remained stable after 1 year. Key words: cleft palate; cleft lip; growth; distraction; mandible; maxilla. Accepted for publication 31 January 2014 Available online 13 March 2014 Maxillary retrusion is a common problem affecting children with cleft lip and palate (CLP). The prevalence of this skeletal class III relationship requiring surgery has been estimated to be around 25%. 1,2 The aetiol- ogy is multifactorial, and includes the severity of the initial deformity and the iatrogenic effects of the primary surgical treatment. These patients were initially treated with conventional orthognathic sur- gery, but the introduction of distraction osteogenesis (DO) 3,4 allowed the cleft sur- geon to treat severe maxillary hypoplasia with other modalities. 5,6 Maxillary DO has been used successfully in CLP for many years. This reliable treat- ment of severe maxillary deficiency has been proven to have good long-term stabi- lity. 7–13 When this technique is used for significant maxillary advancement, some studies have reported a mandibular auto- rotation (clockwise), due to the forward and downward movement of the maxilla and/or due to the counter-clockwise rotation of the palatal plane, increasing the posterior ver- tical dimensions. 7,11,12,14,15 Despite this initial mandibular movement, to the best of our knowledge no published studies have focused directly on the long-term mandib- ular effects of maxillary DO in CLP. The purpose of our study was to eval- uate the long-term effects on the mandible of external maxillary DO in CLP. Specific aims were to evaluate the mandibular shape, rotation, and position. We hypothe- sized that the effects would be minimal. Int. J. Oral Maxillofac. Surg. 2014; 43: 702–707 http://dx.doi.org/10.1016/j.ijom.2014.01.017, available online at http://www.sciencedirect.com § Presented at the 1 er Congre `s de l’Associa- tion Franc ¸aise des Chirurgiens de la Face (37 e Congre `s de l’Association Franc ¸aise des Chir- urgiens Maxillo-Faciaux), Avignon, France, 2012. 0901-5027/060702 + 06 $36.00/0 # 2014 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.