Malocclusion Complexity in Patients with Dental Anomalies—A Case–Control Study

<b>Background/Objectives</b>: This study aimed to evaluate the impacts of various dental anomalies on the complexity of malocclusion. <b>Methods</b>: This retrospective cross-sectional study employed a case-control design. The sample comprised 140 patients, 59 cases, and 81 controls. The Index of Complexity Outcome and Need (ICON) was used to calculate a score indicating the complexity of the malocclusion. According to the ICON score, the level of malocclusion complexity was classified into easy, mild, moderate, difficult, and very difficult. The cases were subdivided into three groups based on their dental anomaly type (number, shape, or eruption anomalies). A chi-square test was used to compare the distribution of cases and controls across the ICON levels (<i>p</i> < 0.05). A <i>t</i>-test and an ANOVA with Tukey's post hoc test were used to evaluate the differences in the ICON scores among groups (<i>p</i> < 0.05). <b>Results</b>: The mean values of the ICON score were 56.77 ± 17.1 for the cases and 47.44 ± 17.54 for the controls (<i>p</i> = 0.002). Most patients in the case group were within the highest three ICON levels, while most controls were in the lowest three (<i>p</i> = 0.022). Patients with eruption anomalies had a higher ICON score, compared to the controls and those in other dental anomaly groups (<i>p</i> = 0.001). <b>Conclusions</b>: The presence of dental anomalies increases the complexity of malocclusion. Eruption anomalies are more complex to resolve than number and shape anomalies, due to their impact on occlusion and aesthetics.