Computer guided resection and reconstruction of a hybrid odontogenic tumor of the anterior mandible: A case report

Purpose: Hybrid odontogenic tumors are considered to be rare differentiation forms of certain tumors. This study dealt with a case of rare hybrid odontogenic tumor involving a combination of the aggressive clear cell odontogenic carcinoma (CCOC) and the benign granular ameloblastoma (GA) and its computer guided resection and reconstruction.
Patients and methods: A 79 years old male, was referred to the oral and maxillofacial surgery department at the Faculty of Dentistry, Cairo University with a progressively facial swelling at the anterior mandible with palpable and tender submandibular lymph nodes (LN). He had a difficulty in breathing and inability to wear his removable denture. An intra-oral ulceration over the tumor was evident. Radiographic findings revealed a well-defined, multilocular lesion of 60 x 56 mm of size. Surgical resection of the lesion with safety free margins using computer guided 3D printed seating device used as an osteotomy guide with a stabilizing arm to prevent disarticulation of the condyles and collapse of the ramus of both sides. Immediate reconstruction plate and fibula vascularized flap were used.
Results: The excised lesion was sent to the pathology lab for microscopic examination. The specimen revealed a dominating clear cell carcinoma with minor granular ameloblastic appearance. The final diagnosis reached was a Hybrid odontogenic tumor.
Conclusion: Our study uncovered the presence of a rare hybrid tumor of the CCOC and granular ameloblastoma. Wide resection with safe margin is the only documented line of treatment due to its highly aggressive malignant nature with subsequent composite fibula free flap reconstruction.
The use of computer guided 3D printed devices is always beneficial. In this case, it was used as an osteotomy guide and to hold the mandible intra-operatively to prevent its collapse during tumor removal and before mandibular fixation.