The fate of autogenous free fat grafts in the human temporomandibular joint using magnetic resonance imaging

Abstract Objective Autologous fat grafts in the temporomandibular joint (TMJ) has achieved positive clinical effects in preventing adhesion after surgery. However it still remains indeterminate about the survival rate of grafted fat. The purpose of this study was to evaluate the long-term survival rate of free fat grafts in the TMJ using magnetic resonance imaging (MRI). Materials and methods 89 patients (117 joints) with free fat grafts placed into TMJs following modified TMJ disc anchor were included in our study. They were divided into the following groups according to the time lapse between TMJ surgery and the latest MRI investigation: 1–3 months, 4–6 months, 7–12 months, 13–24 months, and >24 months. The signal intensity changes and volume retention were evaluated by MRI. Results The volume retention rate of grafted free fat showed that the size was hovering right around 50% although it reduced very slowly with a long-term follow-up. Nearly half joints showed lower signal intensity of the grafted fat on MRI within 6 months and it recovered to normal compared with that of the day after surgery 6 months later. Conclusions Free fat grafted into TMJ cavity could be alive for a long time with the survival rate about 48.44%. However the survival mechanism has still been unknown, which need us to explore and study in the future.