Maxillary Canine Morphological Patterns In Class ⅱ Division 1 Adults

This study aimed to investigate crown-root and alveolar bone morphological characteristics of maxillary canines in Angle's Class II division 1 malocclusion adults. Cone-beam computed tomography (CBCT) scans of 150 eligible patients (26.30±5.65 years) were analyzed and stratified into hyperdivergent (n=50), normodivergent (n=50), and hypodivergent (n=50) groups based on vertical skeletal morphology. The crown root angle (CRA), labial surface angle (LSA) and labial alveolar bone fenestration/dehiscence of maxillary canines measurement and analysis were performed on reconstructed CBCT volumes. CRA (mean=181.31±3.48°) showed significant intergroup differences (hyperdivergent >normodivergent>hypodivergent, P<0.05), while LSA (mean=21.83±2.52°) exhibited no skeletal variation (P>0.05). Alveolar fenestration (length <2/3 root length) incidence was highest in hyperdivergent group (P<0.05), with dehiscence length (mostly 2-4mm) being comparable across groups. Maxillary canines in Angle's Class II division 1 adults demonstrate significant root labial deviation (particularly in hyperdivergent cases), suggesting an increased risk of labial alveolar fenestration/dehiscence during distalization.