Dental arch morphology and factors associated with dental crowding: a systematic review

Introduction: Dental crowding is considered the most common type of malocclusion, ranking third among the most prevalent oral pathologies. Several genetic and environmental factors are associated with dental crowding. Dental arch dimensions are essential for determining the degree of crowding in the dentition. This review aims to assess the influence of dental arch dimensions on the prevalence of crowding. Material and methods: A study was conducted in accordance with PRISMA guidelines and registered in PROSPERO (CRD420251082613). An electronic literature search from 2010 to 2025 was conducted, selecting articles in English and Spanish. PubMed, Web of Science, and Scopus were used as data sources; all keywords were included as MeSH terms. Results: Based on 14 articles, 10 cross-sectional and 4 longitudinal studies, of medium and high quality according to the risk of bias analysis. Conclusions: Arch dimensions are associated with the occurrence and severity of dental crowding. There is no unanimity in the results on whether it is more frequent in males or females. The combination of larger tooth size and reduced arch dimensions is consistently associated with dental crowding. With increasing age, arch length tends to decrease, often associated with anteroinferior crowding. However, the relative contribution of these factors remains insufficiently quantified, highlighting the need for longitudinal studies with standardized methodologies. These findings may support a more comprehensive and individualized approach to the assessment and management of dental crowding. Clinical significance: Understanding the relationship between arch dimensions and crowding is essential for orthodontists. It supports diagnostic decision-making based on individualized morphometric assessment and may improve early identification of patients at risk of developing crowding.