en تخصصي Special گزارش مورد case report <span style="font-size:11pt"><span style="line-height:200%"><span style="font-family:&quot;Calibri&quot;,sans-serif"><b><span lang="EN" style="font-size:12.0pt"><span style="line-height:200%"><span style="font-family:&quot;Times New Roman&quot;,serif"></span></span></span></b></span></span></span><br> <span style="font-size:11pt"><span style="line-height:200%"><span style="font-family:&quot;Calibri&quot;,sans-serif"><span lang="EN" style="font-size:12.0pt"><span style="line-height:200%"><span style="font-family:&quot;Times New Roman&quot;,serif">Multiple Endocrine Neoplasia Type 2B (MEN2B) is a rare RET-associated syndrome characterized by mucosal neuromas, craniofacial anomalies, and life-threatening endocrine tumors. Reports of orthognathic surgery in the MEN2B population are extremely limited, despite the functional and aesthetic burden of skeletal deformities. This case highlights intraosseous neural hyperplasia of the jaws in MEN2B, a rare finding with direct implications for surgical planning and outcomes. A 20-year-old Iranian woman with genetically confirmed MEN2B, previously treated with thyroidectomy, presented for correction of severe craniofacial deformities. Clinical findings included double lips, mucosal neuromas, and hypertrophic eyelids. Cephalometric analysis revealed vertical maxillary excess, maxillary prognathism, and a Class II skeletal pattern. Following multidisciplinary evaluation, she underwent Le Fort I osteotomy, bilateral sagittal split osteotomy, and genioplasty. Intraoperatively, unusually dense cortical bone, cortical cracking, and intraosseous neural hyperplasia complicated fixation, requiring modified techniques. Orthognathic surgery in MEN2B patients may be complicated by dense, brittle cortical bone, intraosseous neural hyperplasia, and abundant submucosal soft tissue, which can affect osteotomy and fixation. Multidisciplinary preoperative evaluation, careful surgical planning, and flexible intraoperative techniques are essential to optimize outcomes in this rare population. </span></span></span></span></span></span><br> &nbsp; Multiple endocrine neoplasia type 2b, Orthognathic Surgery, Osteotomy, Le Fort 0 0 http://wjps.ir/browse.php?a_code=A-10-466-91&slc_lang=en&sid=1 Ali Moradi 100319475328460018290 100319475328460018290 No 1. Department of Oral and Maxillofacial Surgery, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran Kimia Jafarpour 100319475328460018291 100319475328460018291 No 2. Dental Research Center, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran Sara Pilehvar 100319475328460018292 100319475328460018292 No 1. Department of Oral and Maxillofacial Surgery, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran Ricardo Grillo 100319475328460018293 100319475328460018293 No 3. Department of Oral & Maxillofacial Surgery, Faculdade São Leopoldo Mandic, Campinas, Brazil Sahand Samieirad samieerads@mums.ac.ir 100319475328460018294 100319475328460018294 Yes 1. Department of Oral and Maxillofacial Surgery, School of Dentistry, Mashhad University of Medical Sciences, Mashhad, Iran