Growth Outcome and Jaw Functions are Better After Gap Arthroplasty Plus Costochondral Graft Reconstruction Than Gap Arthroplasty Alone in Pediatric Temporomandibular Joint Ankylosis Patients: A Cluster Randomized Controlled Trial.

Abstract PURPOSE It is not known if the muscle matrix that becomes functional after gap arthroplasty (GA) in temporomandibular joint ankylosis (TMJA), induces growth of the mandible or the reconstructive arthroplasty with costochondral graft (CCG) is responsible for growth. The study aimed to evaluate the mandibular growth and functional outcome with the use of CCG/GA in the management of pediatric TMJA. METHODS The investigators designed a cluster randomized controlled trial on pediatric (3-16 years) TMJA patients. Treatment applied (CCG and GA), was the primary predictor variable. Patients were divided into CCG and GA groups. The primary outcome variable was growth. Secondary outcome variables included etiology and duration of ankylosis, maximal incisal opening (MIO), reankylosis, occlusion, laterotrusion, chin deviation, facial asymmetry, occlusal tilt, and complications. The distance condylion (Co) to gnathion (Gn) was used to measure mandibular length. Ramal height was measured from Co- gonion (Go). Lower facial height was measured from the anterior nasal spine (ANS) to Gn. Generalized estimating equations were used to calculate the regression coefficient adjusted for the cluster. The patient was considered as a cluster and the unit of analysis was joint. RESULTS 56 {n=28 in each group, (n=33 joint in CCG and n=31 joints in GA group)} patients were analyzed. The median follow-up was 33-months (31.93±15.24) in CCG and 32-months (32.85±17.84) in the GA group. Intergroup comparison between CCG and GA group showed a statistically significant difference in mandibular length (CCG =77.51±9.31 and GA=66.66 ± 8.32mm, p CONCLUSION The results of the present study concluded that growth and jaw functions were better in reconstructive arthroplasty with CCG than GA in pediatric TMJA.