Postoperative Sequelae and Complications of Alveolar Ridge Augmentation With Simultaneous Implant Placement. A Retrospective Cohort‐Based Predictive Risk Modelling

AIMS: To quantify the incidence and develop predictive models for postoperative sequelae and complications (POSC) and the need for additional grafting after alveolar ridge augmentation with simultaneous implant placement (SARA). METHODS: This longitudinal retrospective cohort included adults with ridge deficiencies who underwent SARA with implant placement from 2019 to 2024 at the University of Michigan Graduate Periodontics Clinic. One site per patient was analysed. Complications were classified according to the severity of consequences and need for further intervention. Univariable and multivariable logistic regression models were performed with stepwise refinement. Firth penalized logistic regression was used when sparse data/separation were present. Model discrimination (area under the curve, AUC) and calibration (Hosmer-Lemeshow, HL) were assessed; ROC-derived thresholds were used to report operating characteristics. RESULTS: Three-hundred and ninety-one patients were included. Systemic comorbidities were documented in 48.6%. Postoperative sequelae occurred in 31.5% of patients, and complications occurred in 25.8%. Membrane exposure was associated with vertical/combined defects (adjusted odds ratio [aOR] 2.52; 95% CI: 1.50-4.23). Microsurgical technique was associated with lower odds of incision-line dehiscence (aOR 0.76; 95% CI: 0.57-1.00; p = 0.049). Prolonged swelling was associated with flap extension (aOR 1.21 per tooth site; 95% CI: 1.04-1.39). Additional grafting occurred in 6.14% and was associated with clinical attachment loss (CAL ≥ 5 mm on adjacent tooth [OR 14.07; 3.79-52.18; p < 0.001]), current smoking (OR 5.11; 1.38-18.95; p = 0.015) and long-term systemic corticosteroid use (OR 1.61; 1.04-2.51; p = 0.035) (AUC 0.744; HL p = 0.5103). CONCLUSION: Postoperative sequelae were more frequent than true complications, and the need for additional grafting was uncommon. Complications were mainly associated with defect morphology and surgical technique rather than systemic comorbidities.