Costochondral Graft Reconstruction of the Temporomandibular Joint: Long-Term Functional Outcomes and Growth-Related Complications

BACKGROUND: Long-term outcomes of autogenous costochondral graft (CCG) reconstruction of the temporomandibular joint (TMJ) remain poorly characterized because most published series truncate follow-up at ≤10 years and pool heterogeneous indications. We aimed to evaluate sustained functional improvement and growth-related complications over up to 3 decades of follow-up. METHODS: This single-center retrospective cohort included 12 consecutive patients (3 skeletally immature, 9 mature; ages 12-71) who underwent CCG-TMJ reconstruction between January 1996 and December 2011, with chart and imaging review through January 2025. The primary endpoint was maximum mouth opening (MMO; mm) measured at preoperative baseline (T0), immediate postoperative (T1), and final follow-up (T3). Secondary endpoints were operated-side ramus-condyle unit (RCU) length change and surgical complications. MMO trajectories were analyzed using a linear mixed-effects model with random patient intercepts and time as a fixed effect, with Bonferroni-adjusted pairwise contrasts. RCU change was compared between growth subgroups using the exact two-sided Mann-Whitney U test, with a Hodges-Lehmann (HL) point estimate and rank-biserial r as effect size. Given small subgroup sizes, RCU comparisons are presented as descriptive-exploratory. RESULTS: Mean follow-up was 11.1±7.8 years (range 3-31). Mean MMO improved from 15.8±6.3 mm at T0 to 34.6±6.3 mm at T1 (Δ+18.8 mm, 95% CI 14.5-23.1; P <0.001; Cohen d=2.18) and 38.8±6.9 mm at T3 (Δ+23.0 mm, 95% CI 17.9-28.1; P <0.001; Cohen d=3.04); the T1 to T3 contrast was non-significant (P=0.08), indicating durable retention of early gain. Ten of twelve patients (83%) reached the normal range (≥35 mm). Among patients with available radiographic follow-up, operated-side RCU height increased by a median of +4.0 mm (range 3.5-4.0; n=2 of 3) in growing recipients versus a median 0 mm (range -2.0 to +2.0; n=6 of 9) in mature recipients (HL difference +3.25 mm; rank-biserial r=1.0; exact two-sided P=0.071). Two of three growing patients developed graft overgrowth with re-ankylosis, both successfully revised; no donor-site morbidity, infection, or graft displacement occurred in any patient. CONCLUSION: CCG reconstruction provides clinically meaningful and durable improvement in mouth opening that is retained for up to 3 decades. In skeletally immature recipients, residual growth potential coexists with a substantial risk of overgrowth requiring revision. Findings support continued use of CCG when biologic reconstruction is preferred, but mandate structured long-term surveillance until growth completion.