Int. J. Oral Maxillofac. Surg. 2000; 29: 167–175 Copyright C Munksgaard 2000 Printed in Denmark . All rights reserved ISSN 0901-5027 Aesthetic and reconstructive surgery Maria J. Troulis, Gerard J. Kearns, David H. Perrott, Leonard B. Kaban Extended genioplasty: Department of Oral and Maxillofacial Surgery, Massachusetts General Hospital, Boston, Massachusetts, USA long-term cephalometric, morphometric and sensory results M. J. Troulis, G. J. Kearns, D. H. Perrott, L. B. Kaban: Extended genioplasty: long-term cephalometric, morphometric and sensory results. Int. J. Oral Maxillofac. Surg. 2000; 29: 167–175. C Munksgaard, 2000 Abstract. The incision, dissection, osteotomy design and fixation are important technical considerations when performing a genioplasty. The purpose of this study was to describe an extended genioplasty technique and to evaluate stability of position, form, surface area of the chin and incidence of postoperative sensory deficit. Records of 15 consecutive adult patients who underwent the extended genioplasty procedure were reviewed. The technique included incision in the labial vestibule from 2nd premolar to 2nd premolar, dissection, mobilization and retraction of the mental nerves, osteotomy parallel to the occlusal plane extending proximally to the antegonial notch and rigid fixation. Lateral cephalograms pre- and postoperatively and at the latest follow-up ( 6 months) were analyzed by linear and computer morphometric measurements to evaluate changes in position, shape and surface area of the chin. Neurosensory data from examination or questionnaire were recorded. Immediately postoperatively (T 1 ), mean advancement in the sagittal plane was π8.7 mm and increase in surface area was π1.1 cm 2 . At the end of follow-up (T 2 ), there were no significant Key words: genioplasty; microgenia; long- changes (T 2 -T 1 ) in chin position or surface area. Inferior border form was rated term follow-up. as smooth in all cases. Neurosensory evaluation revealed that 12/12 patients evaluated had functional sensory return at T 2 . Accepted for publication 1 April 2000 Genioplasty (anterior horizontal man- dibular osteotomy), alone or combined with other orthognathic operations, is a commonly performed procedure. The first description of the sliding advance- ment genioplasty was by H 13 in 1942. He advocated an extraoral, sub- mental approach to the chin. In 1947 G &M 10 reported a jump- ing genioplasty, for a patient with Tre- acher Collins Syndrome, via an external incision. T  &O 33 in 1957 were the first to describe an intra- oral, anterior labial sulcus approach to advance the chin and used circumandi- bular wires for stabilization. During the ensuing years numerous authors have described variations in surgical access, osteotomy design and fixation method for the genioplasty 4,11,12,17,23,25,26,28,38,39 . Concepts and controversies Exposure of the chin and mental nerve dissection Intraoral access, described by T -  &O 33 , is now almost uni- versally used to perform a genioplasty. The incision is made in the depth of the labial sulcus and extended to the bicus- pid areas bilaterally 12,28,39 . Most authors advocate a ‘‘stepped’’ incision, initially perpendicular to the mucosa and then perpendicular to the bone 11,12,28 . The mentalis muscle is di- vided horizontally and the chin is ex- posed in a subperiosteal plane. The ex- tent of dissection, which influences both access for the osteotomy and blood supply to the chin, remains contro- versial. Limited subperiosteal dissection has been advocated by B &G-  4 . They recommended leaving a broad soft tissue pedicle by avoiding