Is There a Difference in Volumetric Change and Effectiveness Comparing Pedicled Buccal Fat Pad and Abdominal Fat When Used as Interpositional Arthroplasty in the Treatment of Temporomandibular Joint Ankylosis?

Abstract

There is limited evidence in the literature about fat grafting in the management of temporomandibular joint ankylosis (TMJA). The purpose was to investigate which interpositional fat grafting technique is superior in the operative management of TMJA. The specific aim was to compare the volumetric change and maximal mouth opening (MIO) when pedicled buccal fat or abdominal fat is interposed in patients being treated for TMJA. A randomized controlled trial was conducted on TMJA patients divided into 2 groups: Pedicled buccal fat pad was used for interposition in group A, whereas abdominal fat was used in group B. At the end of 1year, the volumetric change in fat was analyzed by comparing immediate postoperative and 1-year follow-up magnetic resonance imaging (MRI). MIO and re-ankylosis were recorded. Categorical variables were analyzed by the χ2 test or Fisher exact test. Continuous variables were compared using the t test and Wilcoxon signed rank test. Linear regression analysis was performed. A total of 36 patients (51 joints [15 bilateral and 21 unilateral]) were included, comprising 18 in group A and 18 in group B. The mean preoperative MIO measured 6.8mm in group A and 4.2mm in group B. The mean immediate postoperative MRI fat volume was 4.3cm3 in group A and 10.8cm3 in group B. One-year follow-up MRI showed a fat retention rate of 32.44% in group A and 58.17% in group B. The rate of volumetric shrinkage was 67.5% in group A and 41.9% in group B (P<.001). Analysis of variance showed a statistically significant difference between volumetric shrinkage and both treatment groups (P<.001). MIO improved to 30.6mm in the pedicled buccal fat pad group (group A) and 41.9mm in the abdominal fat group (group B) (P<.001). No re-ankylosis occurred in either group at 1-year follow-up. Our study results suggest that the percentage of retention of interposed abdominal fat at 1year is more than that of pedicled buccal fat pad. Volumetric shrinkage is greater with buccal fat pad, which is a paradox considering the pedicled blood supply. Abdominal fat is better than pedicled buccal fat pad when used for interposition in TMJA treatment.