Methods: The initial records of orthodontic patients were obtained retrospectively from private orthodontic practices. We identified 44 study subjects with clinical posterior crossbites and 86 control subjects who had no posterior crossbite or any evidence of maxillary constriction. Lateral cephalograms were constructed from CBCT scans and traced using imaging software (Vistadent Version 4.3.12). Independent t-test was used to compare the means of the two groups.
Results: There was a statistically significant difference in mandibular plane angle (p <0.01), lower facial height (p<0.01), palatal plane to mandibular plane angle (p <0.01), gonial angle (p<0.05), Y-axis (p <0.01), anterior face height (p <0.01), and decreased mandibular arc (p <0.05) and facial axis (p<0.01) between the crossbite and non crossbite groups. Furthermore, there was a decrease in ratio of anterior face height to posterior face height (p<0.01) and upper to lower face height (p<0.01) in the crossbite group. On the other hand, there was no statistically significant difference in the measurements of ramus height (p>0.05) and occlusal plane to Frankfort angle (P>0.05) between the two groups.
Conclusion: The presence of clinical posterior crossbite is associated with an increased lower facial height as well as many other vertical measurements. Further studies are needed to evaluate whether resolution of dental crossbite will normalize the dentoalveolar dimensions.