Prediction model for miniscrew-assisted rapid palatal expansion failures in late adolescent and adult patients

Introduction The objective of this study was to develop an exploratory prognostic model for predicting the failure of miniscrew-assisted rapid palatal expansion (MARPE) in late adolescent and adult patients.Methods This was a prognostic model study based on a case series analysis from multicenter cohorts. The sample included 69 late adolescent and adult patients with maxillary transverse deficiency who were treated with a bone-borne MARPE appliance anchored by 4 miniscrews across 4 private practices. Only skeletal baseline characteristics were used as potential predictors. The primary outcome was the failure of MARPE, defined as the clinically observable absence of midpalatal suture opening despite the application of adequate and continuous orthopedic forces from a bone-borne appliance. Bivariate logistic regression analyses were performed on all potential predictors of expansion failure. Variables with a P value Results A total of 15 univariate logistic regressions were performed, 1 for each predictor variable. Only the variable gender was found to be significant, with an odds ratio of 6.75. Specifically, the failure rate was 19 of 38 patients (50%) among males and 4 of 31 patients (13%) among females. The failure rate was higher in males and increased with age, whereas this trend was not observed in females. Specifically, for males, the probability of failure was approximately 50% at 22 years, whereas for females, it remained below 20% across the entire age range considered.Conclusions The effectiveness of MARPE decreased with increasing age in late adolescent and adult patients. Failure was more frequent in male patients, with a failure rate of approximately 50% after the age of 22 years, increasing with age. Bone characteristics evaluated in this study do not show a significant correlation with MARPE failure.