To evaluate the bisphenol release of different brands of clear aligner materials. Six different clear aligner materials were used in this study: Duran (Scheu-Dental GmbH, Iserlohn, Germany), Zendura Flx (Bay Materials LLC, Fremont, CA, USA), Zendura A (Bay Materials), Essix (Raintree Essix Inc., Metairie, LA, USA), Taglus Premium (Laxmi Dental Export Pvt. Ltd, Mumbai, India), and Smart Track (Align Technology, San Jose, CA, USA). The samples were kept in saline solution for 8 weeks in airtight test tubes at 37°C. The ratio between the weights of the samples and the volumes of the dilutions was prepared as 0.1 g/mL as suggested by International Standards Organization parameters. To evaluate the bisphenol release of materials, liquid chromatography-mass spectrometry/mass spectrometry analysis was performed. Data were analyzed with the Kruskal-Wallis test (α = 0.05). Bisphenol A (BPA) values in Smart Track were found to be significantly higher than the Zendura A and Zendura Flx groups (P = .02, P = .03, respectively). There was no statistically significant difference among the samples in terms of Bisphenol F (BPF) values (P = .108). In terms of Bisphenol S (BPS) values, a statistically significant difference was found (P = .002) indicating that Smart Track released significantly more BPS than Zendura A (P = .001). Under the test conditions, the amounts of leached BPA, BPF, and BPS were less than the reference dose for daily intake. However, the cumulative effect of these appliances should not be underestimated.

To investigate three-dimensional (3D) morphologic changes in the alveolar bone around the maxillary central incisors of patients who underwent premolar extraction and subsequent anterior tooth retraction using temporary anchorage devices (TADs). The subjects consisted of 16 patients with bimaxillary protrusion. The maxillary anterior teeth were retracted using sliding or loop mechanics and TADs for anchorage reinforcement. Cephalograms and computed tomography scans taken pretreatment and posttreatment were registered with respect to the palatal structures. The movement of the maxillary central incisors and morphologic changes in the anterior alveolar bone were evaluated quantitatively. Displacement in the palatal direction was observed in the alveolar bone around the incisors and the interdental septum. The displacement and bone remodeling/tooth movement ratio were larger on the labial side than the palatal side, and decreased progressively from the crest to apex level. The bone thickness was significantly increased on the labial side and decreased on the palatal side. Regional differences exist in morphologic changes of the alveolar bone during anterior tooth retraction using TADs. Attention should be paid to the crest region of the palatal alveolar bone because of its small original thickness and low remodeling activity.

To evaluate whether the quality of orthodontic finishing influences long-term stability of anterior tooth alignment. This retrospective study evaluated 38 patients. Data were obtained at the beginning of treatment (T0), at the end (T1), and at least 5 years after T1 (T2). At this point, the individuals were no longer wearing retainers. Anterior tooth alignment was measured using Little's index (LI). Effect on alignment stability was tested with multiple linear regression using LI-T0, LI-T1, intercanine width difference T1-T0, overbite (T1), overjet (T1), age, gender, time without retention, and presence of third molars as predictor variables. Well-aligned (LI < 1.5 mm) and misaligned (LI > 1.5 mm) cases were compared at T2. At T2, the alignment stability in the upper arch was inversely associated with the alignment quality (R2 = 0.378, P < .001) and directly associated with overbite (R2 = 0.113, P = .008) at T1. Posttreatment changes caused cases finished with poor alignment to become similar to those finished with excellent alignment (P = .917). In the mandible, posttreatment changes were directly associated only with overjet (R2 = 0.152, P = .015) and well-finished cases displayed better alignment than poorly finished cases (P = .011). Other variables showed no significant association. In arches without retention, better quality of orthodontic finishing does not guarantee the stability of anterior alignment. In the maxilla, long-term changes were more significant the greater the overbite and the better the quality of alignment at end of treatment. In the mandible, changes were not dependent on the quality of finishing but were associated with greater overbite at T2.

To compare efficacy of aloe vera and probiotic mouthwashes vs fluoride mouthwash on Streptococcus mutans (S. mutans) in the plaque of orthodontic patients and to assess patient-reported outcomes and compliance. This prospective randomized clinical trial included 90 patients aged 12-35 years and in permanent dentition, who were randomly allocated in a 1:1:1 ratio to three mouthwash groups: aloe vera, probiotic, or fluoride. Smartphone-based applications were used to improve patient compliance. The primary outcome was the change in S. mutans levels in plaque between two times: pre-intervention and after 30 days using real-time polymerase chain reaction (Q-PCR). Secondary outcomes were the evaluation of patient-reported outcomes and compliance. Mean differences between aloe vera vs probiotic: -0.53 (95% CI: -3.57 to 2.51), aloe vera vs fluoride: -1.99 (95% CI, -4.8 to 0.82), and probiotic vs fluoride: -1.46 (95% CI: -4.74 to 1.82) were not significant, P = .467. Intragroup comparison demonstrated a significant mean difference in all three groups of -0.67 (95% CI: -0.79 to -0.55), -1.27 (95% CI: -1.57 to -0.97), and -2.23 (95% CI: -2.44 to -2.00) respectively, P < .001. Adherence was above 95% in all groups. No significant differences in frequency of responses to patient-reported outcomes were found among groups. No significant difference in efficacy among the three mouthwashes in reducing S. mutans level in plaque was found. Patient-reported assessments concerning burning sensation, taste, and tooth staining found no significant differences among mouthwashes. Smartphone-based applications can help improve patient compliance.

To evaluate swallowing function in relation to oropharyngeal dysphagia (OD) in adolescents who had transverse maxillary deficiency with posterior crossbite and high-arched palate, before, and after rapid maxillary expansion (RME). Twenty patients (mean age: 13.0 ± 3.1) with bilateral posterior crossbite and high-arched palate (RME group: RMEG) and 20 volunteers (mean age: 13.4 ± 2.6) with Class I crowding without posterior crossbite or high-arched palate (control group: CG) were recruited. OD signs and symptoms were evaluated using the Eating Assessment Tool-10 (EAT-10) questionnaire, patient complaints, and physical examination of swallowing function before (T1) and 7 months after (T2) RME. Additionally, fiberoptic endoscopic evaluation of swallowing (FEES) with water, yogurt, and cracker was performed. In CG, evaluation of swallowing was performed only once, corresponding to T1 of RMEG. Prevalence of OD signs and symptoms based on patient complaints and physical examination of swallowing was low (5%-15%), and nonsignificant differences were observed between CG and RMEG at T1 for these parameters as well as for EAT-10 scores. Total post-swallow pharyngeal residue with yogurt was significantly different between CG and RMEG at T1, with a prevalence of 60% in RMEG (P < .05). There was no significant difference regarding residue with yogurt between T1 and T2 in RMEG (P > .05). Patients with a maxillary transverse deficiency were affected by pharyngeal residue as indicated by FEES, but it did not appear to improve in short-term follow-up in patients treated with RME.

To investigate the validity and reliability of marginal bone level measurements on cone-beam computed tomography (CBCT) images of thin bony structures using various reconstruction techniques, two image resolutions, and two viewing modes. CBCT and histologic measurements of the buccal and lingual aspects of 16 anterior mandibular teeth from 6 human specimens were compared. Multiplanar (MPR) and three-dimensional (3D) reconstructions, standard and high resolutions, and gray scale and inverted gray scale viewing modes were assessed. Validity of radiologic and histologic comparisons were highest using the standard protocol, MPR, and the inverted gray scale viewing mode (mean difference = 0.02 mm) and lowest using a high-resolution protocol and 3D-rendered images (mean difference = 1.10 mm). Mean differences were significant (P < .05) at the lingual surfaces for both reconstructions, viewing modes (MPR windows), and resolutions. Varying the reconstruction technique and viewing mode does not improve the observer's ability to visualize thin bony structures in the anterior mandibular region. The use of 3D-reconstructed images should be avoided when thin cortical borders are suspected. The small difference when using a high-resolution protocol is unjustified due to the higher radiation dose required. Previous studies have focused on technical parameters; the present study explores the next link in the imaging chain.

To investigate the volumetric changes of the lower incisor roots in skeletal Class III orthodontic patients with anterior crossbite after premolar extraction therapy. Thirty-six adults, aged 18-28 years, had four-premolar extraction treatment. Pre- and posttreatment cone-beam computed tomography (CBCT) images were used to assess the thickness and height of alveolar bone, root volume, and length. A paired t-test was used to detect changes in root volume and length before and after treatment. Pearson's correlation analysis was applied to estimate the correlation between root volume and dentoskeletal morphology. Both the central and lateral incisors had intrusion and tipping movement after treatment. Compared with pretreatment data, root length decreased significantly. The lingual root volume of root cervical, apical third, and the labial root volume of the root apical third decreased significantly (P < .05), among which the percentage of tooth loss at the tip volume was the highest. The pretreatment height of the alveolar ridge crest, thickness of the alveolar bone, and type of incisor movement were related to the volume and length loss. Volume and length loss in the apical third of the lower incisor roots in skeletal Class III patients treated with a Class III bicuspid extraction pattern is common. The pretreatment height of the alveolar ridge crest, thickness of the alveolar bone, and type of tooth movement are related to the loss.

To create an orthodontic anchor screw (OAS)-loosening model and to investigate whether filling the bone hole with beta-tricalcium phosphate (β-TCP) can fix the OAS against orthodontic force. Bone holes with different diameters (1.6, 2.1, or 2.5 mm) were drilled in the tibias of 11-week-old male Wistar rats, and an OAS (3.0 mm in length and 1.2 mm in diameter) was inserted. After a healing period of 2 or 4 weeks, orthodontic force was applied, and the diameter of the bone hole appropriate for the loosening model was determined. Subsequently, under the loosening model, the bone hole was filled with β-TCP, orthodontic force was applied, and movement of the OAS and surrounding tissue changes were evaluated by micro-computed tomography images and histological specimen analysis. The bone hole of 1.6 mm in diameter was employed as the OAS-loosening model. When β-TCP was inserted into the bone hole, the linear distance and mesial tipping angle of the OAS movement decreased markedly. Furthermore, the values of bone morphometry significantly increased with β-TCP filling. An OAS-loosening model was established in rats and demonstrated that the loosening OAS was stabilized by β-TCP filling through bone formation. β-TCP may be useful for fixation of a loosening OAS.

To compare the changes of palatal volume and area in patients treated with tooth-tissue-borne palatal expanders (conventional Haas) and miniscrew-supported palatal expanders (modified Haas). The sample included casts of 22 patients treated as part of a clinical study at the Department of Orthodontics, Al-Azhar University, to correct their crossbite malocclusion. Patients were divided equally into two groups upon arrival. The first group, with a mean age of 12 years and 6 months, received the miniscrew-supported palatal expander. The second group, with a mean age of 12 years and 2 months, received the Haas design-palatal expansion appliance. Pre- and post-expansion dental casts were cone beam computed tomography scanned and the slices were constructed into 3D volumes. Fully automated superimposition was done for pre- and post-expansion 3D models. Palatal volume and area were determined, and all measurements were carried out blindly. Paired t-test was used to assess the mean differences within each group and Welch's t-test was applied to assess the mean changes between the two groups. Shapiro-Wilk test was used to test for the normality of the data. There were no statistical differences in volume changes either within each group or between the groups. Although area changes were statistically significant within each group, the difference between the groups was not significant. Changes that result from the use of either method to expand the upper arch occur primarily in the shape of the palate, but not in its size.

To compare a novel body mandibular horizontal plane (mental foramen-protuberance menti; Body-MHP) with the conventional border mandibular horizontal plane (gonion-menton [Me]; Border-MHP) to assess mandibular body inclination and dental compensation of skeletal Class III patients with and without facial asymmetry. Retrospective data obtained from diagnostic cone-beam computed tomography of 90 skeletal Class III patients (mean age, 21.67 ± 2.93 years; range, 15.0-30.6 years) were divided into symmetry (n = 30) and asymmetry groups (n = 60). The asymmetry group was subdivided into roll (n = 30) and non-roll types (n = 30). The differences in body inclination and dental measurements (distance and angle) according to two mandibular planes (Body-MHP and Border-MHP) were assessed in the groups and subgroups. Mandibular body inclinations relative to the Body-MHP were not different in the roll-type asymmetric mandible between the sides, while those relative to the Border-MHP were different (P < .001). For the mandibular first molar positions relative to the Border-MHP, the differences in vertical distance between the sides were undermeasured and the inclination differences were overmeasured when compared relative to the Body-MHP. The Body-MHP demonstrated better bilateral similarity in body inclination compared with the Border-MHP in patients with roll-type facial asymmetry. The novel body mandibular plane ensures an accurate diagnosis for tooth movement and jaw surgery, particularly in the roll-type asymmetric mandible.