Do Alveolar Bone Dehiscences and Fenestrations Remodel After Adult Non-Extraction Clear Aligner Therapy? A Retrospective Study up to 2 Years in Retention.

Objective: To evaluate the radiographic presence and magnitude of alveolar bone dehiscences (ABDs) and fenestrations (ABFs) in maxillary and mandibular anterior teeth of adults with dental Class II malocclusion, before (T1), immediately after (T2), and up to 2 years after (T3) non-extraction clear aligner therapy (CAT).

Setting And Sample Population: Records from 14 adults with dental Class II malocclusion treated with non-extraction CAT and Class II elastics were retrospectively obtained.

Materials And Methods: A total of 332 labial and lingual anterior root surfaces were assessed using cone beam computed tomography (CBCT) at T1, T2 and T3. Dehiscences were recorded when the linear measurement for dehiscence (LM-D) was more than 2 mm from the cementoenamel junction. The defect was classified as ABF when it did not involve the alveolar crest and the linear measurement for fenestration (LM-F) measured more than 2.2 mm. Changes in incisor inclination and intercanine width were calculated. Binary logistic regression analyses were used to assess the association between CAT and the presence of ABDs/ABFs. Linear regression analyses were used to identify factors affecting the magnitude of LM-Ds/LM-Fs.

Results: Non-extraction CAT was associated with an increased presence of ABDs at T2 compared to T1 [Odds Ratio (OR): 2.69; 95% Confidence Interval (CI): 1.92-3.76]. The association remained significant at T3 (OR: 2.46, 95% CI: 1.76-3.45). Non-extraction CAT was not significantly associated with the presence of ABFs at T2 and T3.

Conclusions: Alveolar bone remodelling during retention did not result in the reduction or resolution of post-treatment radiographic alveolar bone defects.