Quality of occlusal outcome in adult patients with posterior crossbite treated with completely customized lingual appliances and CAD/CAM archwires for maxillary expansion and mandibular compression compared to adult Class I patients: A retrospective study.

PURPOSE

There is a lack of evidence regarding whether non-surgical crossbite correction leads to compromised occlusal outcomes. The aim of this study was to objectively evaluate the quality of the occlusal outcome and the transverse correction after non-surgical crossbite correction in adults compared to adult patients with no pretreatment crossbite.

MATERIAL AND METHODS

This retrospective study included 80 adult patients treated consecutively with completely customized lingual appliances (CCLAs) between 2019 and 2021. Crossbite correction was performed with CAD/CAM expansion archwires in the maxilla and compression archwires in the mandible. Occlusal outcome was evaluated using the American Board of Orthodontics (ABO) Model Grading System (MGS), and transverse metric measurements were performed, both on plaster models before treatment (T1), on the set-up models (T2A) and after debonding (T2B).

RESULTS

From a total of 1098 patients debonded during the observation period, 40 patients (f/m 30/10, mean age 33.6±10.9years) with unilateral or bilateral crossbite were enrolled in the crossbite group. The matched non-crossbite control group consisted of 40 Class I patients (f/m 30/10, mean age 30.7±9.1years). No statistically significant difference was observed between the crossbite and non-crossbite groups regarding the total ABO score at T2B (20.7 vs. 18.8, p>0.05), despite the malocclusion being significantly more severe in the crossbite group at T1 (68.1 vs. 41.0, p<0.001). In both groups, 38 out of 40 patients (95%) would have passed the ABO examination (total score at T2B≤25). All crossbites were completely corrected at T2B, with a mean total transverse correction of 6.7±2.3mm (3.2±2.1mm maxillary expansion, 3.5±2.4mm mandibular compression).

CONCLUSION

Non-surgical crossbite correction did not lead to compromised occlusal results. CCLAs in combination with CAD/CAM expansion and compression archwires can correct posterior crossbites successfully in adult patients. The final occlusal outcome can be of a similar high quality in crossbite and non-crossbite patients.