This retrospective clinical study, using cone-beam computed tomography (CBCT), examined the presence of fenestration and dehiscence in anterior teeth following non-extraction clear aligner therapy, along with the associated risk factors. The study included 224 adult patients who underwent non-extraction clear aligner treatment. CBCT scans taken before (T1) and after treatment (T2) were analyzed to detect the presence of fenestration and dehiscence. Patient-related and treatment design-related variables were collected, with the latter from the planned tooth movements specified in the aligner software. The exact McNemar test was used to compare the occurrence of alveolar bone defects between T1 and T2. Univariate and multivariate logistic regression analyses were performed to evaluate the associations between posttreatment alveolar bone defects and various factors. From T1 to T2, the occurrence of fenestration and dehiscence increased on most maxillary and mandibular anterior root surfaces. At T2, the presence of alveolar bone defects at different tooth positions was influenced by multiple factors, including crowding, curve of Spee depth, alveolar bone thickness, gingival thickness, sagittal skeletal pattern, magnitude and type of intrusion, amount of retraction, molar distalization, and number of attachments. Specifically, labial fenestration of the maxillary lateral incisors and canines, as well as the mandibular central incisors and canines, and lingual dehiscence of the mandibular central incisors were significantly associated with the amount of intrusion (P < 0.05). Labial dehiscence of the mandibular central and lateral incisors was significantly associated with the number of attachments (P < 0.05). No significant associations were found between alveolar bone defects and factors such as age, gender, vertical skeletal pattern, changes in arch width, use of miniscrews, the amount of interproximal enamel reduction, attachment type, or treatment duration. In patients undergoing non-extraction clear aligner therapy, factors such as crowding, curve of Spee depth, alveolar bone thickness, gingival thickness, sagittal skeletal pattern, amount and type of intrusion, amount of retraction, molar distalization, and number of attachments were significantly associated with the presence of fenestration and dehiscence at T2. Orthodontists should assess these factors, conduct thorough pretreatment evaluations of individual oral conditions, and develop tailored treatment plans accordingly.
Song et al. (Wed,) studied this question.