“FREE FIBULA OSTEOCUTANEOUS FLAP FOR RECONSTRUCTION OF MANDIBLE IN A RARE CASE OF AMELOBLASTIC CARCINOMA”. PRESENTED BY: DR. PRAMOD SUBASH MAXILLOFACIAL SURGERY UNIT DEPT OF HEAD & NECK SURGEY AIMS KOCHI

CASE HISTORY 54 yr old man chief complaint –Swelling on lower jaw mobility of lower front tooth x 1 year HOPI -since 2 years gradually increasing in size no h/o of pain, bleeding, anesthesia/paresthesia of lip no h/o of trauma to the mandible no h/o tooth ache in relation to the lower teeth. No deleterious habits

PAST MEDICAL HISTORY Known case of CAD – Inferior wall MI in 1998 Developed APD Stopped cardiac medications Started APD treatment Now not on any drugs RTA 1 year back – Fractured both bones - left leg Closed reduction done.

EXAMINATION Symmetrical face Good mouth opening - 3 finger’s breadth Poor oral hygiene – few missing teeth. Single swelling in the lingual aspect of mandible on the left side (continuous with the bony contour of mandible), extending from left lower incisor to second premolar Measuring 2 ½ x 2 cms, the swelling was firm, non-fluctuant and non-tender A small ulcerated area was seen on the swelling which measured around 0.5 cms in diameter

Expansion of buccal cortex of mandible was palpable though clinically not visible There were no palpable neck nodes Tooth vitality test - the involved teeth & contra lateral incisors and canines were also non-vital

INVESTIGATIONS Orthopantomogram ( OPG)

CT Scan

DIFFERENTIAL DIAGNOSIS Ameloblastoma Odontogenic keratocyst Solitary (traumatic) bone cyst

BIOPSY Incisional biopsy HISTOPATHOLOGY REPORT Diagnosis: Ameloblastic carcinoma [As long standing history of ameloblastoma is absent, ameloblastic carcinoma could have arisen de novo from epithelial cell rests of mandible]

AMELOBLASTOMA PATHOGENESIS Dental embryonic remnants i. Epithelial lining of odontogenic cyst ii. Dental lamina or enamel organ iii. Stratified squamous epithelium of oral cavity iv. Displaced epithelial remnants Odontogenic tumor Locally invasive Tends to recur Rarely behaves aggressively or shows metastatic dissemination

MALIGNANCY IN AMELOBLASTOMA ? Malignant Ameloblastoma Ameloblastomas that metastasize despite benign histological features in both primary and metastatic lesions Ameloblastic carcinoma - Show histologic features of both ameloblastoma and carcinoma - Both primary and secondaries show histologic signs of malignancy

AMELOBLASTIC CARCINOMA No definite sex / age/ race predilection Mandible most commonly involved area. Usually asymptomatic perforates bone extends into soft tissue tends to recur Metastasis to regional lymph nodes Most common distant metastasis to lungs

TREATMENT PLAN Wide excision (segmental mandibulectomy) ? Neck dissection (Clinically N0 neck) RECONSTRUCTION

WHY RECONSTRUCTION? Functional impairment - difficulty in chewing - difficulty in speech - TMJ problems Disfigurement “ Two piece mandible”

OPTIONS FOR RECONSTRUCTION Common Mandibular Reconstruction Plate Reconstruction plate and bone graft e.g. Ileac crest Contoured titanium trays with bone chips Other Micro-vascular free Flaps

A.Scapula B. Ilium C. Radius D. Fibula OPTIONS – FREE FLAPS

ADVANTAGES OF FREE FIBULAR FLAP Long thin non weight bearing bone Initially used to reconstruct long bones Distant from head and neck region 22 to 25 cms of bone can be harvested Segmental multiple nutrient arteries to the bone ( bone can be osteotomised into smaller fragments by keeping the periosteum intact) Relative ease of harvest

FREE FIBULA OSTEO-CUTANEOUS FLAP Based on Peroneal artery and vein Skin flap receives supply from septo- cutaneous or musculo- cutaneous perforators from the Peroneal artery

Anterior view – Lt. leg Posterior view – Lt. leg