Long-term stability of anterior open bite treatment by intrusion of posterior teeth using temporary anchorage devices: a systematic review and meta-analysis

Objective: Posterior teeth intrusion performed by means of temporary anchorage devices (TADs) offers the possibility of closing anterior open bite, but data on the long-term stability of the treatment effect are lacking. This systematic review and meta-analysis evaluates the post treatment stability of anterior open bite patients performed by posterior teeth intrusion using temporary anchorage devices. Methods: The Pub Med, EMBASE, Web of science, Scopus, and Cochrane library databases were searched comparing effect of temporary anchorage devices on open bite treatment and posttreatment stability in studies performed using lateral cephalograms. No language restriction, authors were contacted and reference list screened. Screening and data extraction were performed by two independent investigators. Outcome measures were amount of changes in cephalometric variables measurement of upper and lower posterior teeth after intrusion using temporary anchorage devices. Standardized mean difference (SMD) and their corresponding 95% confidence intervals (95% CIs) were calculated. Quality and risk of bias were assessed by using Newcastle Ottawa scale and methodological index for non-randomized trials (MINORS) respectively. Results: Studies involving 115 patients; (mean age, 24.8 years) were included. There were significant differences in amount of upper and lower molar intrusion with open bite correction (SMD -1.63, 95% CI -2.68 to -0.57; P = 0.003) and (SMD -2.67, 95% CI -4.33 to -1.00; P = 0.002), respectively. No significant differences existed between upper and lower molar relapse with open bite recurrence for one year (SMD -0.41, 95% CI -1.04 to 0.22; P = 0.02) and more than one year posttreatment (SMD -0.41, 95% CI -0.55to 0.64; P = 0.88). Conclusions: TADs produce greater amount of molar intrusions which results into autorotation of mandible along with open bite correction. Greater percentage of molar and overbite relapse seems to occur during the first year posttreatment than the next subsequent years but doesn’t result in relapse of open bite malocclusion.