Comparison between basal arch width in normal occlusions and class Ⅱ malocclusions by using cone-beam computed...

Area of Science:

• Orthodontics
• Dental Anatomy
• Cephalometrics

Background:

• Accurate assessment of dental arch dimensions is vital for orthodontic diagnosis and treatment planning.
• Understanding basal arch width differences between normal occlusion and Class II malocclusion is essential for effective intervention.

Purpose of the Study:

• To investigate maxillary and mandibular basal arch width measurements in males and females with normal occlusion.
• To compare dental arch width differences between normal occlusion and Class II malocclusion groups.

Main Methods:

• Cone-beam computed tomography (CBCT) images from 197 individuals (101 males, 96 females) were analyzed.
• Measurements included basal arch widths (BAW) between canines, first molars, and second molars, as well as WALA distance.
• Cephalometric analysis included Sella-nasion-A point (SNA) and Sella-nasion-B point (SNB) angles.

Main Results:

• Significant sex-based differences were observed in maxillary and mandibular transverse widths.
• The normal range for maxilla and mandible basal bone width differences was -2 mm to 2 mm.
• Class II malocclusion groups showed significant differences in intercanine and first molar widths compared to normal occlusion.
• SNA and SNB angles in Class II males correlated positively with maxillary intercanine width.

Conclusions:

• Measuring basal bone width from the first molar's center of resistance is a feasible and repeatable clinical method.
• The findings provide a reference for orthodontic treatment planning, highlighting the importance of horizontal dental issues in Class II patients.
• Mandibular second molar width is greater than maxillary width in normal occlusions, requiring specific attention during treatment.