Objectives <p>This study evaluated the relationship between the gonial angle and the impaction patterns of mandibular third molars (M3Ms) using cone-beam computed tomography (CBCT). The secondary aim was to assess the association between the impaction patterns (Pell &amp; Gregory and Winter classifications) and mandibular ramus dimensions, specifically ramus height (RH) and ramus width (RW).</p> Methods <p>A total of 355 impacted M3Ms from 213 patients were retrospectively analyzed. Impaction patterns were classified according to the Pell &amp; Gregory (PG) Ramus/Depth and Winter classification systems. Gonial angle, RH, and RW measurements were performed on standardized panoramic reconstruction images generated from CBCT data. Relationships between morphometric parameters and impaction types were analyzed statistically with a significance level of <i>p</i> &lt; 0.05.</p> Results <p>There was no significant relationship between PG classifications and the gonial angle. However, a significant association was found between Winter classification and the gonial angle (<i>p</i> = 0.044), with the vertical position exhibiting the highest mean values. Multivariable analysis confirmed a significant gender-specific interaction (<i>p</i> = 0.012), with significance occurring exclusively in males (<i>p</i> = 0.005). RH showed statistically significant differences according to both PG Ramus (<i>p</i> &lt; 0.001) and PG Depth (<i>p</i> = 0.037) classifications, whereas RW did not differ significantly across impaction groups. Additionally, a negative correlation was observed between the gonial angle and both ramus height and width.</p> Conclusion <p>Gonial angle and RH are associated with specific M3M impaction patterns, whereas RW is not a determining factor. These morphometric parameters can guide surgeons in estimating extraction difficulty and planning appropriate surgical approaches.</p>