Does the Excision of Overlying Oral Mucosa Reduce the Recurrence Rate in the Treatment of the Keratocystic Odontogenic Tumor? A Systematic Review and Meta-Analysis

Purpose The purpose of this study was to identify whether there is scientific evidence to support excision of the overlying mucosa (EOM) in conjunction with cyst enucleation to decrease the recurrence rate (RR) of keratocystic odontogenic tumors (KOTs). Materials and Methods A systematic review with meta-analysis conforming to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) guidelines was performed. A comprehensive search of 3 major databases through PubMed, EMBASE, and Cochrane CENTRAL was conducted to identify all relevant articles published without date or language restrictions from inception to December 2015. Eligible articles were selected based on the following inclusion criteria: randomized, prospective, or retrospective studies comparing enucleation with EOM to enucleation without EOM for patients with KOTs. The predictor variable was treatment group (enucleation with EOM vs enucleation without EOM). The outcome variables were RR of KOTs, presence of epithelial islands and microcysts in the excised overlying mucosa, and correlation between recurrent cortically perforated KOTs. A weighted RR and odds ratio (OR; using a random- or fixed-effect model) and the Mantel-Haenszel test with 95% confidence interval (CI) were performed using comprehensive meta-analysis software. Results Eleven studies were included in this review. There was no significant difference between enucleation with and without EOM (random; OR = 3.259; 95%, 0.975-10.901, P = 0.055). The weighted event rates for enucleation with Carnoy's solution plus EOM and enucleation without EOM in cortically perforated lesions were 6.2% (random; 95% CI, 2.6-14) and 9.1% (random; 95% CI, 1.6-38.2), respectively. The weighted event rate for the presence of epithelial islands and microcysts in overlying mucosa of KOTs was 68.8% (random; 95% CI, 27.2-92.9). Conclusion The results of this study suggest that enucleation of KOTs plus the use of Carnoy's solution or liquid nitrogen (when indicated) should be combined with EOM to obtain the lowest RR, specifically for retromandibular trigone, posterior maxillary, and cortically perforated lesions. However, the results from this study do not provide sufficient scientific evidence for EOM in combination with enucleation of KOTs.