查看更多>>摘要：? 2022 American Association of OrthodontistsIntroduction: The objective was to evaluate the effect of a fluoride mouth rinse and a high-fluoride toothpaste on caries incidence in patients undergoing orthodontic treatment with fixed appliances. Methods: In this 3-armed, parallel-group, randomized controlled trial, patients referred to the Specialist Clinic of Orthodontics, M?lndal, Sweden, were randomly allocated to 1 of the 3 groups. (1) Fluoride mouth rinse (FMR) group: 0.2 % sodium fluoride (NaF) mouth rinse plus 1450 ppm fluoride (F) toothpaste; (2) High-fluoride tootpaste (HFT) group: 5000 ppm F toothpaste; and (3) Control (CTR) group: 1450 ppm F toothpaste. The generation of a randomization sequence was performed in blocks of 30. Inclusion criteria included patients scheduled for treatment with fixed appliances in the maxillary and mandibular arch aged 12-20 years. The primary outcome variable was the change in Decayed Initial Filled Surfaces (ΔDiFS) based on radiographs taken before and after the treatment. For statistical comparisons between groups, the Kruskal–Wallis test were used for continuous variables, whereas the Mann-Whitney U-test was used for pairwise group comparisons. Furthermore, the risk ratio (RR) and 95% confidence interval (CI) based on clinically relevant cutoffs (DiFS ≥2) were calculated to compare the increase of caries during orthodontic treatment between 2 groups. The Cochran-Mantel-Haenszel method was used to adjust RR for baseline values. Blinding was employed during the caries registration and the data analysis. Results: In total, 270 participants were randomized, with 15 patients dropping out, such that 255 patients were included in the statistical analyses. Recruitment was from October 2010 to December 2012. An increase in DiFS (≥1 DiFS) during treatment was observed in 48.3% of the FMR group, 42.0% of the HFT group, and 35.6% of the CTR group. There was no significant difference between the groups regarding increased DiFS (P = 0.17). The risk of increase in DiFS ≥2 during orthodontic treatment was 31.0% in the FMR group, 25.9% in the HFT group, and 18.4% in the CTR group. The RR for an increase of ≥2 DiFS during orthodontic treatment was 1.38 (95% CI, 0.81-2.34; P = 0.23) for FMR vs CTR, 1.21 (95% CI, 0.70-2.10; P = 0.51) for HFT vs CTR, and 0.93 (95% CI, 0.57-1.49; P = 0.76) for HFT vs FMR. Conclusions: In patients who demonstrate a low prevalence of caries and are undergoing orthodontic treatment, daily use of high-fluoride toothpaste or fluoride mouth rinse in combination with regular toothpaste does not appear to significantly alter the caries incidence compared with the use of regular toothpaste. Trial Registration: The trial was registered in the FoU i Sverige research database (http://www.fou.nu/is/sverige), with registration no. 236251. Protocol: The protocol was not published before trial commencement. Funding: Local Research and Development Board for Gothenburg and South Bohusl?n (grant no. 768531); and The Swedish Patent Revenue Fund (grant number EKF-780/19).
Cardinal L.da Rosa Zimermann G.Mendes F.M.Oliveira D.D....
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查看更多>>摘要：? 2022 American Association of OrthodontistsIntroduction: The present study aimed to evaluate the consequences of rapid maxillary expansion in the buccal bone thickness and dehiscence of subjects with unilateral cleft lip and palate. Methods: This prospective cohort study consisted of 30 participants, 20 males and 10 females, between 8 and 15 years old. Participants were allocated into 3 groups, according to the type of maxillary constriction, and were treated with different types of expanders: G1, hyrax; G2, fan-type; G3, inverted mini-hyrax. Cone-beam computed tomography scans were performed immediately before treatment and after 90 days of retention. Linear measurements were obtained by the same calibrated and blinded examiner. Results: An average of 0.8 mm decrease in buccal bone thickness (P <0.001) and a 0.5 mm increase in dehiscence (P <0.001) were observed. There was no significant difference between the cleft and noncleft side for all variables (P >0.05), as there was no significant difference between groups (P >0.05). Conclusion: The findings in this study allow the conclusion that the orthopedic forces of rapid maxillary expansion lead to a decrease in the posterior buccal bone volume in unilateral cleft lip and palate patients.
查看更多>>摘要：? 2022Introduction: The extraction of maxillary first premolars is usually the treatment of choice to resolve crowding, alveolar protrusion, or Class II malocclusion. The demand for a lingual orthodontic treatment is increasing because of its esthetic value; therefore, understanding lingual biomechanics is essential to every clinician. This study compared the 3-dimensional (3D) effects of sliding mechanics in labial and lingual orthodontics using the finite element method. Methods: Twelve 3D finite element models were created with different power arm heights and miniscrew positions. A 150 g of retraction force was applied from the head of the miniscrew to the power arm. The 3D displacement of the original nodes was measured, and the stress distribution on defined element zones of the periodontal ligament. Results: Different force directions led to different movement patterns and stress distribution. The lingual models showed a more important lingual crown tipping, extrusion, and higher stress values than the labial models. Results were not affected by the vertical position of the miniscrew. Conclusions: Bodily en-masse retraction was not achieved in all models. Adding extra torque to the archwires is essential to prevent excessive lingual crown tipping. The lingual appliance induced more lingual tipping and extrusion of the anterior teeth. Expanding the archwire is important to minimize the risk of intercanine width reduction. The vertical position of the miniscrew does not affect the results of en-masse retraction.
查看更多>>摘要：? 2022 American Association of OrthodontistsIntroduction: The objective of this study was to analyze the effects of aligner overtreatment on torque control and intrusion of incisors for anterior retraction with clear aligners. Methods: Models including a maxillary dentition without first premolars, maxilla, periodontal ligaments, attachments, and aligners were constructed and imported to finite-element software. Two groups of models were created: (1) without canine attachment and (2) with canine attachment. Overtreatment degrees (0°, 1°, 2°, 3°, 4°, and 5°) were applied for both groups. Results: Clear aligner therapy caused lingual tipping and extrusion of incisors, distal tipping and extrusion of canines, and mesial tipping and intrusion of posterior teeth, which was more significant with canine attachments except for second premolars. Aligner overtreatment produced palatal root torquing and intrusion of incisors, distal tipping of canines, and mesial tipping of second premolars, with more significant in the condition with canine attachments. With canine attachments, 1.2° overtreatment could cause bodily retraction of central incisors. Without overtreatment, stress was concentrated on apical and cervical area of both labial and lingual surfaces of periodontal ligaments. The stress value was higher with canine attachments. However, when overtreatment was added, the stress was distributed more evenly. Conclusions: Clear aligner therapy produced lingual tipping and extrusion of incisors during anterior retraction. Overtreatment can achieve incisor intrusion and palatal root torquing, and the effect could be augmented by adding attachments on canines, which required more anchorage from posterior teeth. Appropriate overtreatment with placing attachments on canines should be designed to ensure bodily retraction and the least root resorption.
查看更多>>摘要：? 2022Introduction: The study aimed to evaluate the morphologic changes in the pharyngeal airway after bimaxillary surgery in skeletal Class III malocclusion patients with or without asymmetry. We also analyzed the correlation between positional changes in the menton, hyoid bone, and changes in the dimensions of the pharyngeal airway. Methods: We included 32 patients with skeletal Class III malocclusion who underwent bimaxillary surgery. There were 16 subjects in the symmetry group (10 male, 6 female; mean age, 22.44 ± 5.14 years), and 16 in the asymmetry group (10 male, 6 female; mean age, 21.38 ± 4.62 years). Preoperative and postoperative (2 months after surgery) cone-beam computed tomography scans were taken and then analyzed by comparing postoperative changes in each group. Results: The anteroposterior lengths at the uvula level (P2L) and epiglottis level (P3L) were significantly decreased in the symmetry group. The P2L was also significantly decreased in the asymmetry group, and a difference in the P3L was observed. However, there was no significant change in the width at the uvula level (P2W) and epiglottis level (P3W) in the symmetry group. In contrast, in the asymmetry group, P2W and P3W were significantly decreased. The cross-sectional ratio was significantly decreased P2 (P2L/P2W) and P3 (P3L/P3W) in the symmetry group. However, a statistically significant decrease occurred only at P3 in the asymmetry group. Anteroposterior positional changes of the menton and P2L (r = ?0.370; P <.05), P3L (r = ?0.414; P <0.05), and P3L/P3W (r = ?0.361; P <0.05) were correlated. Conclusions: Differences in the morphologic features of the pharyngeal airway after bimaxillary surgery was observed in both the symmetry and asymmetry groups. Bimaxillary surgery with a mandibular setback in patients with skeletal Class III malocclusion worsened morbidity of the elliptical structure of the pharyngeal airway. However, it worsened less in the asymmetry group than in the symmetry group.
查看更多>>摘要：? 2022 American Association of OrthodontistsIntroduction: This study aimed to survey retention protocols and retainer characteristics among orthodontists practicing in Canada. Methods: An online questionnaire was distributed to 576 orthodontists registered with the Canadian Association of Orthodontists. It included respondents’ demographic details, preferred orthodontic retainers and prescribed wear protocol, adjunctive retention procedures, the timing of retention follow-ups, retainer choice in specific situations, and retainer characteristics. Chi-square tests and Fisher's exact tests were used to test the associations between variables. Results: An 18% response rate was recorded (n = 101). Vacuum-formed retainers were the most commonly used retainers in the maxilla (50.5%), whereas bonded retainers were preferred in the mandible (54.5%). An initial full-time removable retainer wear period was commonly prescribed (63.0%-67.0%). Retainer checks were carried out by 85.1%-89.1% of orthodontists for 1 or 2 years after the end of active orthodontic treatment. Only 44.6%-56.4% were comfortable with general dentists continuing retainer checks. Most (72.5%-84.1%) retainers were fabricated in the orthodontists’ office laboratory. Indefinite retainer wear was commonly suggested and was significantly influenced by the number of years in practice. Conclusions: Most orthodontists’ preferred retainer was the vacuum-formed retainers in the maxilla and the bonded retainers in the mandible. A variety of retention protocols and retainer characteristics was evident among orthodontists that reflect the considerable variation in malocclusion traits we face day-to-day. There seems to be a potential dichotomy between orthodontists being uncomfortable about allowing general dental practitioners to manage retention and orthodontists unwilling to provide retention care indefinitely.
NSTL
Elsevier