Soft Tissue Dehiscence and Survival of Customized CAD/CAM Titanium Subperiosteal Implants: A Systematic Review and Metaanalysis.

PURPOSE: This systematic review and meta-analysis aimed to assess the prevalence of soft tissue dehiscence and survival rates of modern customized titanium subperiosteal implants (CSIs). A secondary objective was to determine whether the anatomical site (maxilla vs. mandible) is a significant predictor of these outcomes.

MATERIALS AND

METHODS

An electronic search was conducted across PubMed, Scopus, and Google Scholar for clinical studies published between January 2010 and April 2026 involving 3D-printed (DMLS) or milled titanium CSIs. Primary outcomes focused on soft tissue dehiscence, while secondary outcomes assessed implant survival. Statistical modeling utilized Kaplan-Meier estimation for time-to-event analysis and Cox Proportional Hazards Regression to evaluate the influence of the surgical site.

RESULTS

Fourteen clinical studies involving 368 implants (276 maxillary, 92 mandibular) were included. The overall incidence of soft tissue dehiscence was 28.6%. While the maxilla exhibited a higher numerical incidence of dehiscence compared to the mandible (31.9% vs. 18.5%), the hazard ratio (HR 1.518) did not reach statistical significance (p=0.116). The overall implant survival rate was 87.8%. However, the surgical site was a statistically significant predictor of failure, though this association may partly reflect differences in case severity between anatomical cohorts; maxillary implants demonstrated a 3.8-fold higher hazard of failure compared to mandibular implants (HR 3.843; 95% CI: 1.157-12.723; p=0.028).

CONCLUSIONS

Modern titanium CSIs are a viable solution for severe alveolar atrophy, yet they possess a distinct, site-specific risk profile. While the mandible appears more "forgiving" of soft-tissue complications, maxillary dehiscence is significantly more likely to result in total implant loss. Long-term clinical monitoring is essential, as failure hazards exhibit bimodal "step-like" increases at approximately 35 and 70 months postoperatively.