Prevalence of dental anomalies in different facial patterns and malocclusions in a Saudi sub-population: a radiograph–based retrospective study

Dental anomalies may complicate orthodontic diagnosis and treatment, but their relationship with malocclusion and facial morphology remains unclear, and prevalence estimates for impaction depend on whether third molars are counted. This study assessed the prevalence and distribution of dental anomalies among orthodontic patients in Qassim, Saudi Arabia, and explored associations with age, sex, sagittal skeletal pattern, and vertical facial pattern, analysing impaction with and without third molars. This retrospective single-centre study evaluated panoramic and lateral cephalometric radiographs of 371 consecutive orthodontic patients aged 16–49 years. Fifteen dental anomalies were recorded. Sagittal skeletal pattern was classified by the ANB angle and vertical pattern by the Jarabak facial height ratio (FHR) and the maxillomandibular plane angle (MMPA). Associations were examined with χ² or exact tests and multivariable logistic regression adjusted for age and sex. Skeletal-pattern analyses were treated as exploratory, and the p -values of the unadjusted skeletal-pattern comparisons were corrected for multiple comparisons (Benjamini–Hochberg). At least one anomaly was present in 198 patients (53.4%). Impaction was the most common anomaly (45.0% including third molars; 17.8% excluding them), followed by hypodontia and ectopic eruption (3.5% each). Sex was not associated with any anomaly. Older age was associated with lower odds of impaction including third molars (adjusted OR 0.90 per year; 95% CI 0.86–0.95) and excluding them (OR 0.92; 95% CI 0.86–0.98). Non-third-molar impaction differed by sagittal class (Class II 13.5%, Class I 22.0%, Class III 27.5%; p = 0.035), and impaction including third molars was less frequent in patients with hyperdivergent FHR (adjusted OR 0.38 vs. neutral; 95% CI 0.19–0.79). These associations were small (Cramér’s V ≤ 0.14); neither unadjusted comparison remained significant after false discovery rate correction ( q = 0.62), and the adjusted regression estimates are exploratory and uncorrected for multiplicity. MMPA was not associated with any anomaly. Dental anomalies, mainly impactions, were common in this Qassim orthodontic sample, and counting third molars more than doubled the prevalence of impaction. Associations with sagittal and vertical skeletal patterns were weak, exploratory, and dependent on how impaction and vertical pattern were defined. These findings do not establish skeletal classification as a reliable predictor of dental anomalies; imaging decisions should follow individual clinical assessment and applicable guidelines.