In reply

Abstract

We appreciate the interest expressed by Dr de Lange and Dr Baas in the practical aspects of this procedure and present the following responses to their objections. 1Bilateral sagittal split osteotomy (BSSO) and distraction osteogenesis (DO) are associated with their respective advantages and disadvantages. However, in this technique, it is not the disadvantages but rather the advantages of BSSO and DO that are combined, especially in terms of stability, soft tissue manipulation, and a lower relapse potential. Differential growth and conventional orthognathic procedures become more difficult and less predictable when correcting severe mandibular deficiencies requiring lengthening more than 8 to 10 mm, as described by many investigators. 1 American Association of OralMaxillofacial Surgeons (AAOMS)Statements by the American Association of Oral and Maxillofacial Surgeons Concerning the Management of Selected Clinical Conditions and Associated Clinical Procedures. AAOMS, Rosemont, IL2003 Google Scholar , 2 Schreuder W.H. Jansma J. Bierman M.W. et al. Distraction osteogenesis versus bilateral sagittal split osteotomy for advancement of the retrognathic mandible: A review of the literature. Int J Oral Maxillofac Surg. 2007; 36: 103 Abstract Full Text Full Text PDF PubMed Scopus (55) Google Scholar When advancement is more than 10 mm, the area of contact between the fragments is significantly smaller. In BSSO, a larger amount of callus is generated while the fragments are still in close proximity, thus contributing to the stability of fragments even during DO. 3 Choi J.Y. Hwang K.G. Lee S.B.J. et al. Original sagittal split osteotomy revisited for mandibular distraction. J Craniomaxillofac Surg. 2001; 29: 165 Abstract Full Text PDF PubMed Scopus (21) Google Scholar Hence, when advancing the mandible farther than 15 mm, as in some of our cases, there could have been minimal contact between the fragments, which is detrimental for healing and the final outcome. 2We prefer not to mix the procedures together because an osteotomy cut is better planned in a healed socket rather than in an empty socket. Moreover, a partly erupted impacted third molar leaves a gingival pedicle parallel to the vestibular incision, leading to postoperative dehiscence that is detrimental to the healing process. 4 Mehra P. Castro V. Freitas R.Z. et al. Complications of the mandibular sagittal split ramus osteotomy associated with the presence or absence of third molars. J Oral Maxillofac Surg. 2001; 59: 854 Abstract Full Text Full Text PDF PubMed Scopus (68) Google Scholar An empty socket also leads to a large dead space on the osteotomy site that delays healing. Other rare complications are tearing of the soft tissue, a bad split, an unfavorable fracture of the buccal cortical plate, 5 Precious D.S. Lung K.E. Pynn B.R. et al. Presence of impacted teeth as a determining factor of unfavorable splits in 1256 sagittal-split osteotomies. Oral Surg Oral Med Oral Pathol Oral Radiol Endod. 1998; 85: 362 Abstract Full Text PDF PubMed Scopus (58) Google Scholar and a gap in the superior margin. 3Our study was not a randomized controlled study but a prospective study. In our institution, we routinely perform DO with vertical body osteotomy for the last one decade. Inspired by an article by Choi et al, 3 Choi J.Y. Hwang K.G. Lee S.B.J. et al. Original sagittal split osteotomy revisited for mandibular distraction. J Craniomaxillofac Surg. 2001; 29: 165 Abstract Full Text PDF PubMed Scopus (21) Google Scholar we performed the procedure in 10 consecutive patients. We agree that the sample is small. The 29 patients treated so far with this procedure are in various stages of follow-up. Only the 10 patients who completed the follow-up period of 2 years were reported in the study. 4The risk of nerve disturbance in BSSO is similar regardless of the procedure. Paresthesia of the inferior alveolar nerve (sensory function) was evaluated by 2-point discrimination, response to a painful stimulus and moving brush-stroke identification. 6 Whitesides L.M. Meyer R.A. Effect of distraction osteogenesis on the severely hypoplastic mandible and inferior alveolar nerve function. J Oral Maxillofac Surg. 2004; 62: 292 Abstract Full Text Full Text PDF PubMed Scopus (32) Google Scholar Comparative Evaluation of Vertical Body Osteotomy and Sagittal Split Osteotomy for Mandibular Corpus Distraction: Is There a Rationale for the New Technique?Journal of Oral and Maxillofacial SurgeryVol. 69Issue 9PreviewWe read with interest the article by Sahoo and Rangarajan1 regarding distraction osteogenesis (DO) to lengthen the mandible. Since the 1990s, DO has been advocated as an alternative for bilateral sagittal split osteotomy (BSSO), with probably fewer disturbances of the inferior alveolar nerve and better stability. However, more recent research has indicated that the 2 treatment modalities are more or less equal in these aspects.2-5 The risk of nerve damage in the BSSO procedure is related to the identification of the mandibular foramen and to the sagittal splitting itself,6-8 with the probability of the nerve being in the wrong (proximal) bone fragment after the split. Full-Text PDF