Macroscopic and histologic analysis of abdominal dermis-fat grafts retrieved from human temporomandibular joints

The purpose of the present study was to examine the fate of the abdominal dermis-fat grafts that were implanted into human temporomandibular joints (TMJ) at the macroscopic and histologic levels.

The clinical records of 123 patients who underwent TMJ discectomy with dermis-fat grafting during a 10-year period (2000 to 2009) were reviewed, and 8 patients were identified who had had the dermis-fat graft surgically removed from their TMJ at a subsequent operation. The retrieved grafts were assessed at the macroscopic and histologic levels for size, consistency, and cellular composition. The dermis-fat grafts were retrieved after a period of 8 to 46 months (mean, 22.3) after initial implantation into the TMJ.

The graft material was a rubbery consistency and filled the entire joint space between the condylar head and glenoid fossa/articular eminence. The average size of the retrieved grafts was 16 mm × 14 mm × 7 mm, with a mean volumetric dimension of 1.57 ± 0.38 cm(3). The interpositional tissue retrieved from all joints demonstrated clear histologic evidence of mature adipose tissue interspersed with dermal elements such as sweat glands and hair follicles that were atrophied. The ratio of fat/nonfat tissue was significantly (P < .01) less (mean, 31.3% ± 5.7%) than in the original (mean, 90.2% ± 6.3%) graft. No evidence was found of dermoid cysts or necrotic fat in any of the specimens examined.

The results of the present study showed that abdominal dermis-fat grafts transplanted to the TMJ do thrive and adapt well to the confines of the joint cavity, allowing functional movement of the joint. However, in the present study, the dermis-fat graft failed to protect the condyle against additional deterioration in 6.5% of patients who went on to have total joint replacements.