Prevalence of Tooth Number Anomalies in the Iranian Population: A Systematic Review and Meta-Analysis

Document Type : Original Article

Authors

1 Department of Pediatric Dentistry, Dental School, Qazvin University of Medical Sciences, Qazvin, Iran

2 Non-Communicable Diseases Research Center, Research Institute for Prevention of Non-Communicable Diseases, Qazvin University of Medical Sciences, Qazvin, Iran

3 Student Research Committee, Qazvin University of Medical Sciences, Qazvin, Ira

4 Department of Restorative, School of Dentistry, Dental Research center, Hamadan University of Medical Sciences, Iran

Abstract

Background: Hyperdontia and hypodontia are two tooth number anomalies that often cause esthetic and functional problems. Early detection is the key to more effective treatment. This research set out to estimate the aggregated prevalence of tooth number anomalies in Iran.
Methods: International databases comprising PubMed, Scopus, and ISI Web of Science, and Iranian databases including Magiran (Magiran.com) and Idml.research.ac.ir were systematically searched for cross-sectional studies on the prevalence of hyperdontia and hypodontia until December 2025. The random effects model was used to derive the combined prevalence estimate of each anomaly. Meta-regression and sensitivity analyses were performed to assess the sources of heterogeneity.
Results: The prevalence of each anomaly was estimated by the meta-analysis of 14 eligible studies regarding hyperdontia and 17 studies about hypodontia. The estimated prevalence of hyperdontia and hypodontia was 1.2% and 6.0% in Iran, respectively. Meta-regressions showed a significantly higher prevalence of hyperdontia in males, but hypodontia prevalence showed no association with sex. An insignificant reduction in the prevalence of both anomalies was noted over time. No significant correlation was found between age and hyperdontia, but hypodontia prevalence decreased with advancing age. In both anomalies, the maxilla was more involved than the mandible. Also, most patients with hypodontia had Angle’s class II malocclusion.
Conclusion: The overall prevalence of hyperdontia and hypodontia was 1.2% and 6.0%, respectively, in the Iranian population. Moreover, considerable heterogeneity was observed in the prevalence of both anomalies.

Keywords

Main Subjects


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