Journal of Orthodontic Science最新文献

Correcting skeletal Class III malocclusion in adults can be challenging and may require either orthognathic surgery or orthodontic camouflage, depending on a malocclusion's severity. This case report describes the successful use of mini-screws to distalize the mandibular whole arch in a female patient aged 18 undergoing non-extraction camouflage therapy for skeletal Class III malocclusion. The patient presented with anterior and posterior crossbites, crowding in both upper and lower arches, and the concave profile. After third molar extractions, followed by initial alignment and leveling, two buccal shelf mini-screws and Class III elastics were utilized to first distalize the mandibular molars using a segmented arch wire and subsequently retract the entire mandibular dentition with a continuous arch wire. Treatment resulted in a canine and Class I molar related normally overbite and overjet after 21 months. The treatment outcomes were highly beneficial, leading to stable functional occlusion and improved facial aesthetics. This report also provides a critical evaluation of alternative non-surgical treatments available for patients, who decline orthognathic surgery, emphasizing their benefits, limitations, and long-term stability.

Objectives: Deep bite correction with aligners involves anterior intrusion and posterior extrusion. During lower incisor intrusion with clear aligners (CAs), root disengagement from the alveolar bone can cause complications. Frog staging protocol applies sequential forces, targeting lateral incisors first, then central incisors. This study compares conventional and Frog staging intrusion protocols using attachments for mandibular anterior teeth to optimize clinical practice.

Materials and methods: A 3D finite element (FE) model, including the clear aligner, periodontal ligament (PDL), and mandibular dentition, was established. Four groups were analyzed: Group 1 (Conventional intrusion with attachments), Group 2 (Conventional intrusion without attachments), Group 3 (Frog staging intrusion with attachments), and Group 4 (Frog staging intrusion without attachments). Rectangular molar attachments (4.0 × 2.0 × 0.75 mm) and vertical canine attachments (3.5 × 1.8 × 0.75 mm) provided anchorage. Incisor attachments (3.0 × 1.5 × 0.75 mm) facilitated precise force application. Stress distribution was evaluated using von Mises stress (overall stress), maximum principal stress (tensile), and minimum principal stress (compressive).

Results: Frog staging resulted in balanced stress distribution and reduced adverse effects compared to conventional intrusion. Attachments minimized stress and displacement, enhancing intrusion mechanics. Frog staging better controlled root displacement and stress concentration at the root apex.

Conclusions: Frog staging intrusion with attachments is biomechanically superior for lower incisor intrusion, reducing complications and providing a safer approach for deep bite correction with CAs.

Objectives: The aims of our study were to compare the prevalence of obstructive sleep apnea (OSA) and two-dimensional cephalometric measurements between patients in Boston and Lebanon and to investigate the relationship between high-risk subjects and their underlying respiratory condition.

Materials and methods: A cross-sectional study was conducted among patients enrolled in different dental treatment centers in Boston and Lebanon. Participants' medical history, pediatric sleep questionnaire (PSQ), and lateral cephalograms were collected. Sagittal and vertical dimensions of the cranial base, maxilla, mandible, and hyoid bone position were assessed for each patient.

Results: 463 children with a mean age of 13.8 ± 2.5 years were included in this study. A binary logistic regression was run to predict a high risk for OSA by the predictors mentioned below. Lebanese children were significantly at higher risk of OSA (OR = 0.05; 95% CI: 0.01-0.24, P < .001), with a prevalence of 17.8% compared to only 0.7% among children in Boston. Age and sex, however, did not contribute significantly (P > 0.05). ANB (P = 0.02), GoMe (P < .001), Wits (P = 0.02), and MPh (P < .001) significantly differed between Boston and Lebanon groups, although none could predict a high risk for OSA. Adenoid (P < .001) and tonsil (P = 0.019) hypertrophy and nasal septum deviation (P < .001) were significantly more prevalent among Lebanese, with adenoid (P = 0.015) and tonsil hypertrophy (P = 0.01) being significant OSA predictors.

Conclusions: High-risk for OSA subjects were significantly more prevalent among Lebanese children. Cephalometric measurements differed significantly between both groups; however, none was a risk predictor of OSA. Adenoid and tonsil hypertrophy were major risk factors for OSA, and Lebanese patients showed a higher predisposition to these factors.

Functional asymmetry is often accompanied by a shift in the dental midline and a one-sided crossbite. In this context, occlusal disorders, such as malposition teeth or premature contact, can cause deviation. Therefore, a comprehensive evaluation is required to determine the etiology of asymmetry, distinguishing between dental and skeletal origin. This case report presented a 23-year-old woman with Class I malocclusion, mandibular dental arch midline shift, left-sided scissors bite, and transposition of upper left canine and first premolar (UL3-UL4). Based on observations, upper right lateral incisor (UR2) teeth were peg-shaped. The treatment was administered using the Damon self-ligating system with asymmetric and one-sided cross-elastic. The results showed that the midline shift was corrected and the UR2 peg-shape was reshaped. However, the transposition teeth were not corrected purposely. Asymmetric mechanotherapy was applied, utilizing asymmetric elastic from the initial to the high wire phase, alongside one-sided cross-elastic. In this case, intermaxillary elastic often used symmetrically was formulated asymmetrically, marking a novel aspect of the treatment method.

Misaligned teeth can result in a wide range of physical, psychological, and functional impairments influencing both oral and systemic health. This calls for the need for an early orthodontic intervention, which is crucial to prevent these consequences and improve both functions and cosmetic appearance. The objectives of the current article are to identify the role of orthodontic treatment in maintaining psychological well-being and social health, to ascertain the potential challenges in delivering orthodontic treatment, and propose specific recommendations to overcome identified challenges. Orthodontic treatment plays a defining role in improving the psychological well-being of the person, by augmenting self-confidence as they are more comfortable about their appearance. In conclusion, orthodontic treatment is quite effective in improving the psychological and social well-being of people with misaligned teeth. The need of the hour is to identify the existing challenges and provide effective treatment to aid in improving the quality of life of the affected person.

Objective: To evaluate the predictability of clear aligner treatment in correcting maxillary transverse and anteroposterior movements using cone beam computed tomography (CBCT).

Methods: Thirty orthodontic patients who underwent orthodontic treatment using clear aligners were enrolled. Predicted tooth movements were obtained using digital orthodontic treatment planning software for clear aligners, while actual tooth movements were calculated by measuring the difference between pre- and post-treatment tooth positions using CBCT. Statistical analyses were done using the paired sample t-tests to compare the mean differences between predicted and actual movements at the crown and root levels.

Results: There were significant mean differences in the transverse dimension between the actual and predicted movements at the crown level for the first molars and first premolars and root level, 1.88 mm (±1.6), 0.64 mm (±1.7), 5.50 mm (±3.1), and 3.10 mm (±3.1), respectively (P < 0.05). In contrast, no difference was seen in the canines at crown or root levels (P > 0.05). There was a significant mean difference of 6.4 mm (±5.6) in the anteroposterior movements of incisors between actual and predicted measurements in the proclination group (P < 0.05). In contrast, no difference was seen in the retroclination group (2.02 mm (±6.8)) (P > 0.05).

Conclusion: Orthodontic tooth movement using clear aligners showed that transverse movements at the canines are more predictable than at premolars and molars. Retroclination is more predictable than proclination; however, retrusive movements are less predictable than protrusive movements.

Objective: The objective of this study was to compare the Dental Health Component (DHC) of the Index of Orthodontic Treatment Need (IOTN) with the Dental Aesthetic Index (DAI) in evaluating orthodontic treatment needs among adolescents. In addition, it sought to assess the concordance between adolescents' self-perception of the Aesthetic Component of the IOTN (AC-IOTN) with the evaluations made by orthodontic professionals.

Material and methods: A two-stage stratified cluster sampling method was used to select 248 high school students aged 11-14. Clinical examinations were conducted by specialist orthodontists. DAI, AC-IOTN, and DHC-IOTN were measured based on the students' occlusal morphology. Students also made self-assessments using the AC-IOTN.

Results: In terms of DHC-IOTN, 9.7% of students had severe cases that definitely needed treatment. The DAI assessment identified 5.2% with severe malocclusion and 4% with handicapping malocclusion. Using the AC-IOTN, the students assessed 4.8% of cases as severe, compared with 8.5% according to orthodontists. A comparative analysis of the results of the modified DAI and the DHC-IOTN, using Chi-squared test demonstrated highly significant differences between the two indices.

Conclusions: The study highlights the need for improved orthodontic assessment methods, preventive care, and enhanced dental education to improve students' oral health behaviors.

Background/objectives: Throughout the course of orthodontic treatment, preventive measures are crucial to lower the risk of plaque accumulation, subsequent decalcification, and the development of white-spot lesions. This study was done to assess antibacterial efficacy of orthodontic brackets covered with nanoparticles mixture with silver-copper oxide or zincoxide.

Methodology: This in-vitro study includes three groups of 12 brackets each coated with coated with nanoparticles combined with silver-copper oxide hybrid or zincoxide, and an uncoated group as the control. Physical vapor deposition was used for the coating process. Using the colony-forming unit, the antibacterial efficacy was assessed against Lactobacillus acidophilus and Streptococcus mutans.The antibacterial activity of coated brackets was assessed at just after coating and four months later. The obtained data were statistically evaluated.

Result: The L.acidophilusand S. mutanscount was reduced most effectively by brackets coated with a blend of silver and copper oxide nanoparticles, followed by zinc oxide nanoparticles, and least effectively by control groups. When compared to an unprotected surface, the surface is smoothed out after being covered with nanoparticles.

Conclusion: The strongest antibacterial activity was found in brackets coated with silver-copper oxide hybrid followed by zinc oxide nanoparticle combination and least with uncoated brackets. In order to prevent decalcification, orthodontic bracket antibacterial coating could be further evaluated in clinical settings.

Objective: To retrospectively evaluate the prevalence and positional classification of maxillary and mandibular canine impactions in the Saudi population of Jeddah and Al-Madinah Al-Munawwarah using digital panoramic radiographs, posteroanterior skull views, and cone-beam computed tomography scans.

Methods: This cross-sectional retrospective study was conducted using the radiographic databases" of Jeddah Specialty Dental Center and King Fahad General Hospital. The sample included 177 radiographs from 68 males and 109 females within the age range of 14-40 years. The main extracted data were the frequency and percentage of the utilized radiograph, gender, side distribution of impaction, angulation of the impacted canine to the midsagittal plane, and vertical level of impacted canines about the neighboring adjacent tooth.

Results: The most commonly used radiographs were PD (70.6%), PD-CBCT (21.5%), PD-CBCT-PA (2.3%), PD-PA (1.1%), and CBCT alone (4.5%). Unilateral impaction was more common than bilateral impaction (69.5% had unilateral impaction and only 30.5% had bilateral impaction). Females had a significantly higher prevalence of impaction than males (61.6% and 38.4%, respectively). The most common angulation of the impacted canine was >30°(44.6%), followed by 16-30°(28.2%), and the least common angulation was 0-15 °(27.1%). The vertical level showed that the most common level of impaction was between the cementoenamel junction and halfway up the root of the neighboring adjacent tooth (53.1%).

Conclusion: PD is the most commonly used method to diagnose canine impaction. Unilateral impactions are more common than bilateral impactions. Females had a higher prevalence of impaction than males.