Functional appliance treatment for mandibular fractures: A systematic review with meta-analyses

Objectives Mandibular collum fractures among growing patients can lead to abnormal growth, function, esthetics and ultimately quality of life. Among the proposed treatment alternatives, orthopaedic treatment with functional appliances has been suggested, with encouraging results. Aim of the present systematic review was to critically appraise existing evidence on the outcome of functional appliance treatment among growing patients with mandibular collum fractures. Materials and methods Eight databases were searched up to October 2020 for randomised and non-randomised clinical studies assessing functional appliance treatment outcome for children with mandibular fractures. After duplicate study selection, data extraction and risk of bias assessment, random effects meta-analyses of mean differences (MD) and their 95% confidence intervals (CIs) were performed, followed by assessment of the quality of evidence with GRADE. Results A total of 8 unique studies (one prospective and nine retrospective non-randomised) with 223 children could be identified. Functional appliance treatment was associated with greater anteroposterior condyle dimensions of the injured condyle compared with the contralateral healthy condyle (3 studies; MD = 0.87 mm; 95% CI = 0.30 to 1.45 mm; p = .003). No difference was found in the mesiodistal condyle size between the injured and the contralateral healthy joint (3 studies; MD = -0.05 mm; 95% CI = -1.05 to 0.95 mm; p = .92), but collum length was smaller at the injured side compared with the contralateral one (1 study; MD = -2.89 mm; 95% CI = -5.29 to -0.49 mm; p = .02). Treatment outcome might be influenced by patient age, patient sex and severity/localisation of the fracture, but the quality of evidence for all analyses was very low due to methodological limitations leading to bias. Conclusions While some evidence exists that functional appliances might lead to good clinical rehabilitation of fractured mandibular condyles, including considerable bone remodelling, available studies are small and have methodological weaknesses.