Treatment modalities in bone-borne maxillary protraction in children with maxillary retrognathism: a systematic review and meta-analysis.

Objectives: The aim of the systematic review and meta-analysis is to compare the efficacy of 4 different bone-anchored maxillary protraction techniques: 1) bone-anchored maxillary elastics (BAMP), 2) maxillary bone anchors combined with facemask (BAFM), 3) hybrid hyrax combined with facemask (HHFM) and 4) hybrid hyrax combined with mandibular bone anchors (HH-BAMP).

Search methods: The search was performed in four electronic databases: Pubmed, Embase, Scopus and Web of Science. In addition, the reference lists of eligible articles have been hand-searched.

Selection criteria: Study designs included: randomized controlled trials, non-randomized controlled trials, case-control studies including more than 4 patients.

Data collection and analysis: Qualitative and quantitative information were extracted for each study including author, year of publication, study type, sample size, chronological age of patient group pretreatment (years), skeletal maturity stage, gender (female/male), treatment duration (months), treatment type, type of skeletal anchorage, force magnitude (grams), duration of protraction (hours), RME or Alt-RAMEC and cephalometric measurements.Statistical heterogeneity was assessed by a stratified analysis for mean difference (MD) and a graphical display of the estimated treatment effects. A meta-analysis comparing treatment effects for the four groups were only made if two or more outcomes were reported.

Results: 653 articles were initially screened, 25 full-text articles satisfied the inclusion criteria including 6 randomized controlled trials. Comparing the four maxillary protraction protocols, SNA improved significantly more in group 4 compared to the other groups including group 1 (mean difference 1.9, 95% confidence interval [CI] 1.6-2.1; p < 0.001).Treatment with facemask (group 2) seemed to increase the lingual inclination of the lower incisors (IMPA) while in the other groups, proclination of the lower incisors were evident.

Conclusions: The level of evidence in the selected articles ranged from low to moderate. The current evidence suggests that skeletally anchored rapid maxillary expansion combined with maxillary protraction with mandibular bone anchors yields the greatest maxillary advancement in cl.III patients.

Registration: The study has been registered at PROSPERO with registration number CRD42023380964.