Systematic Review
The prevalence of cleft lip in conjunction with cleft palate is twice that of cleft lip or palate alone. Dental abnormalities are more frequent in patients with cleft lip and palate (CLP) than in non-cleft individuals. The present systematic review aimed to identify studies that examined the prevalence of dental anomalies in unilateral and bilateral clefts. Relevant articles that met the specified inclusion criteria were identified with the use of MEDLINE/PubMed®, Scopus and EBSCOhost databases. The systematic review protocol was formulated using the established PRISMA (Preferred Reporting Items for Systematic Reviews and MetaAnalyses) checklist. The results of the meta-analysis demonstrated a statistically significant difference in the prevalence of supernumerary teeth (ST) in patients with left unilateral CLP (p = 0.021). The difference was statistically insignificant for ST between unilateral and bilateral CLP (p = 0.542). The present analysis demonstrated that the difference between unilateral and bilateral CLP, as well as between right and left unilateral CLP regarding tooth agenesis/missing teeth (A/MT) was statistically insignificant (p = 0.301 and p = 0.130, respectively). However, the black diamond presented in the forest plot indicates that the unilateral CLP and left unilateral CLP groups are in favor, respectively. Consequently, patients with left unilateral CLP exhibited a higher frequency of ST. The analysis suggests a potential association between the type of unilateral CLP and bilateral CLP concerning A/MT and ST in particular.