Human Amniotic Membrane as an Interpositional Material in Temporomandibular Joint Arthroplasty for Intraarticular Pain and Dysfunction: A Randomized Clinical Trial

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• Picked for Plastic and Reconstructive Surgery (top studies of the week, 8 November 2026): HAM interposition improves TMJ arthroplasty outcomes

Abstract

BACKGROUND: Open arthroplasty with discectomy is offered for temporomandibular joint (TMJ) intraarticular pain and dysfunction after failed conservative care. Whether human amniotic membrane (HAM) interposition improves outcomes remains unclear. PURPOSE: To compare pain, mandibular function, and safety between discectomy plus HAM and discectomy alone. STUDY DESIGN, SETTING, AND SAMPLE: Single-center randomized trial (Treviso Regional Hospital, Italy; 2017 to 2024). Adults with TMJ osteoarthrosis on magnetic resonance imaging and symptoms persisting after 5 hyaluronic acid arthrocenteses were randomized at 1:1 ratio (block randomization and concealed allocation). PREDICTOR VARIABLE: Reconstructive technique: discectomy plus HAM versus discectomy alone, randomly assigned. PRIMARY OUTCOME VARIABLES: Peak pain on a 0 to 10 visual analogue scale (VAS) at rest, phonation, and mastication; maximum interincisal opening (MIO, mm); lateral and protrusive excursions. Secondary: complications. Assessed at baseline (T0) and 12 months (T1). COVARIATES: Age, sex, symptom duration, arthrocentesis cycles, unilateral versus bilateral disease, and follow up. ANALYSES: Welch t-test, Mann-Whitney U, Fisher's exact test; ANCOVA adjusting for baseline, age, sex, and laterality; P < .05; intention-to-treat. RESULTS: Sixty-two subjects enrolled: 32 HAM (mean age 48.7 [standard deviation [SD] 17.4] years; 26 [81.3%] female) and 24 controls (mean age 60.3 [SD 11.2]; 14 [58.3%] female; P = .02 and P = .08). At T0, peak VAS was comparable at rest (4.38 [SD 1.18] vs 4.58 [SD 1.14]; P = .51) and phonation (6.47 [SD 1.08] vs 6.58 [SD 1.10]; P = .70); mastication was higher in controls (7.58 [SD 1.06] vs 6.53 [SD 1.29]; P = .002). At T1, peak VAS favored HAM at rest (0.88 [SD 0.83] vs 3.67 [SD 1.09]; P < .001), phonation (1.41 [SD 1.04] vs 5.62 [SD 1.13]; P < .001), and mastication (1.41 [SD 1.13] vs 4.58 [SD 0.83]; P < .001). MIO did not differ (34.34 [SD 4.60] vs 35.88 [SD 1.54] mm; P = .09). Right lateral excursion favored HAM (8.12 [SD 1.48] vs 6.08 [SD 0.78] mm; P < .001). Transient facial nerve weakness: 4 (12.5%) HAM versus 6 (25.0%) controls (P = .29); no other complications. CONCLUSIONS AND RELEVANCE: HAM interposition yielded clinically meaningful pain reduction and superior excursive and masticatory outcomes at 12 months, with no benefit on MIO and no added morbidity.

Abstract as published, via PubMed.