Cureus. 2026 Jul 16;18(7):e112791. doi: 10.7759/cureus.112791. eCollection 2026 Jul.
ABSTRACT
Introduction The association between mandibular third molars and mandibular anterior crowding remains controversial. Although several studies have investigated the relationship between third molar characteristics and lower anterior crowding, the relative influence of third molar position and angulation remains inconclusive. This study aimed to evaluate the association between lower third molar position, angulation, and mandibular anterior crowding in a Chhattisgarh population using panoramic radiographs and mandibular study models. Materials and methods This retrospective observational study included 234 pretreatment orthodontic records comprising panoramic radiographs and mandibular study models. Subjects aged 16-23 years with Angle’s Class I molar relationship and bilaterally present mandibular third molars were allocated into a crowded group (n = 117) and a non-crowded group (n = 117). Mandibular anterior crowding was assessed using pretreatment mandibular study models. Third molar position was evaluated using the retromolar space-to-third molar crown width ratio (Ganss ratio), while third molar angulation was assessed using the inclination between the mandibular second and third molars (Angle A) and the angulation of the mandibular third molar relative to the mandibular base (Angle B). Intergroup comparisons were performed using the independent Student’s t-test, and a p-value of <0.05 was considered statistically significant. Results The crowded group demonstrated significantly lower Ganss ratios than the non-crowded group on both the right (p = 0.0003) and left (p = 0.0031) sides. Angles B were significantly lower in both tails (right: p = 0.030; left: p = 0.038), but Angle A was only significant on the left (p = 0.0006). The right-sided Angle A had no statistically significant difference (p = 0.349). In general, the third molar position showed a more reliable relationship with mandibular anterior crowding compared to angular measurements. Conclusion Lower third molar position and angulation were both associated with mandibular anterior crowding. One of the radiographic measures, the Ganss ratio, showed the lowest variance of association, implying that the available retromolar space measure may offer more diagnostic utility than the angular measurements. These radiograph parameters can be used as helpful adjuncts, but not to be the basis of the prophylaxis of the mandibular third molar extraction in orthodontic diagnoses, as well as treatment planning.
PMID:42604409 | PMC:PMC13477424 | DOI:10.7759/cureus.112791
