An 18-year-old female patient presented with complaint of swelling on the lower right side of the face since six months. Swelling was initially small but gradually increased in size up to the present dimension within four months. Since two months there was no increase in the size of the swelling. There was no history of trauma, paresthesia, pain or fever. Patient was having difficulty in mastication. On general physical examination, the patient was well nourished and her vital signs were normal. The past medical history was non-contributory. Extraoral examination revealed facial asymmetry due to swelling on the right body of the mandible which measured about 8cm X 6cm extending antero-posteriorly from right parasymphysis to the angle of mandible and inferiorly involving the inferior cortex and extending into the submandibular region crossing the midline. Skin over the swelling was normal and surface was smooth [Table/Fig-1]. On palpation, site, size and extent of swelling was confirmed. Swelling was firm in consistency and was tender on palpation. [Table/Fig-1]: Extraoral photograph showing swelling on the right side of the body of the mandible crossing the midline and extending to the submandibular region. On intraoral examination, the right mandibular region showed a swelling extending from tooth # 43 to tooth # 47. It measured about 6cm X 2cm, obliterating the buccal sulcus. It was firm in consistency and was tender on palpation. The mucosa overlying the area was intact. On the lingual side too, there was swelling in the premolar and molar region which was firm and smooth [Table/Fig-2]. Teeth # 43 to 48 and # 33 to 38 tested positive for pulp vitality. Provisional diagnosis of benign odontogenic tumor was given. Patient was advised hematological and biochemical laboratory tests, panoramic radiograph, mandibular right lateral occlusal radiograph and CT scan. Hematological and biochemical laboratory tests were within normal limits. [Table/Fig-2]: Intraoral photograph of the mandibular right quadrant showing buccal and lingual swelling / cortical expansion in the premolar and molar region. A mandibular right lateral occlusal radiograph revealed single large multilocular radiolucent lesion extending from distal surface of lower right lateral incisor to the lower right third molar extending to involve buccal and lingual cortices. Multiple thin straight septae were seen in the molar region and curved septae were seen in the anterior region [Table/Fig-3]. [Table/Fig-3]: Right mandibular lateral occlusal view shows single large multilocular radiolucent lesion extending from distal surface of lower right lateral incisor to the lower right third molar involving buccal and lingual cortices. Panoramic radiograph revealed single large multilocular osteolytic radiolucent lesion involving the right body and inferior half of the ramus extending from midline. Superiorly extending to involve the crestal bone and inferiorly closely approximating the inferior cortex. The lesion was not well defined. The internal structure was radiolucent with thick radiopaque curved septae seen in the body region and thin straight septae seen in the crestal bone. Widening of periodontal space was seen uniformly, involving first, second and third molar. Root resorption was seen till apical third of mesial root of first molar and distal root of second molar. There was marked resorption of the inferior cortex with Sunburst Periosteal reaction in relation to right mandibular body [Table/Fig-4]. [Table/Fig-4]: Panoramic radiograph shows single large multilocular radiolucent osteolytic lesion extending from the midline involving the right body and inferior half of the ramus with a marked scalloped shaped resorption of the inferior cortex that presents a sunburst ... CT scan of mandible and neck showed that there was destruction of the right body and ramus of the mandible with associated soft tissue component containing bony spicules within the mass extending medially, displacing the mylohyoid muscle and the tongue towards the opposite side [Table/Fig-5]. Anteriorly the mass extended into the soft tissue of the cheek. Periosteal reaction was observed with sunburst appearance [Table/Fig-6]. [Table/Fig-5]: CT Scan of the mandible shows an osteolytic lesion on the right side involving the body and ramus with mild expansion and destruction of the medial cortex. [Table/Fig-6]: CT Scan of the mandible shows a sunburst periosteal reaction. The differential diagnosis considered was osteosarcoma, ameloblastoma and odontogenic myxoma. Incisional biopsy was performed under local anesthesia and subjected to histopathological examination. On microscopic examination, the stained H & E section showed a loose myxomatous stroma. The stroma made up of stellate shaped cells with long cytoplasmic processess anastomosing with each other. Each cell has a prominent darkly staining nucleus. A few fibroblasts and collagen fibers were seen in between the myxoid stroma. The histopathology report was suggestive of a diagnosis of odontogenic myxoma [Table/Fig-7]. [Table/Fig-7]: H & E section shows a loose myxomatous stroma. The patient was admitted for surgery. Hemi-mandibulectomy of the right side was done preserving the condyle and coronoid process of the mandible and primary reconstruction was done by taking graft from the fibular region. Maxillomandibular fixation was maintained for 45 days [Table/Fig-8,​,9].9]. Microscopic examination of the surgical specimen confirmed the diagnosis of Odontogenic Myxoma. During the one year post-surgical follow up, there was no evidence of any recurrence. [Table/Fig-8]: Post-operative intraoral photograph shows Vicryl sutures placed over the surgical site of the hemisected right half of the mandible with intermaxillary fixation done on the left side. [Table/Fig-9]: Post-operative radiograph shows resection of mandible on the right side with preservation of condyle and coronoid process and placement of an ‘L’ shaped reconstruction graft fixed with three bone plates one in the anterior region and two ...