The Angle orthodontist最新文献

Objective: To assess the corrosion products and cytotoxicity of generic and proprietary fixed lingual retainers (FLRs).

Materials and methods: Seven FLRs were investigated. Wires were submersed in solution for 34 days, at 37°C, under constant agitation. A proportion of this solution was analyzed to determine the concentration of metallic ions leaching off the wires. The remainder was diluted to 5%, 10% and 20% followed by exposure to human gingival fibroblasts and analysis of cytotoxicity of the wires.

Results: Three wires (Dentaflex, Universal, and AZDent) released excessive concentrations of lead, two wires (MeshMark and Orthoflex) released excessive concentrations of nickel, and one wire (Universal) released excessive concentrations of molybdenum into solution. No statistically significant difference was found between the wires analyzed (P = .24). Slight cytotoxicity was noted in only one wire (Dentaflex) at a 20% dilution of eluent. This was also the wire which released the highest concentration of lead into solution. All other wires, at all concentrations, were deemed noncytotoxic, but five samples overall were deemed statistically significant (P < .0024). A statistically significant difference existed between wires (P = .013) and concentrations analyzed (P < .001).

Conclusions: Metals were released in differing quantities from all wires, with some elemental concentrations measuring more than that deemed acceptable in drinking water in Australia. A trend toward increased cell viability across samples was found with only one demonstrating cytotoxicity. There was no indication that generic FLRs were more or less biocompatible than their proprietary counterparts.

Objectives: To compare the transfer accuracy of two different indirect bonding (IDB) trays.

Materials and methods: Digital IDB was performed on a total of 30 patients using one of two designs: shell and bar trays, with 15 patients in each group. Trays were designed with the Appliance Designer software (3Shape A/S, Copenhagen, Denmark). Angular (torque, tip, angulation) and linear (mesiodistal, buccolingual, occlusogingival) differences were compared between the bonded intraoral scans taken immediately after IDB and the virtually bracketed model prepared in Ortho Analyzer software (3Shape A/S) using open source GOM inspect software (GOM GmbH, Braunschweig, Germany).

Results: There were no significant differences found between the bar and shell groups. Within the groups, significant tip differences were found between the incisors, canines, and premolars in both groups (P = .0001). Additionally, a statistically significant torque difference was found in the canines and incisors in the shell group. The percentage of values that deviated from the clinical acceptance limit was relatively higher in the bar group.

Conclusions: Although there was no statistical difference between groups, the shell tray showed better results according to clinical acceptability limits. This study is important as it is the first clinical study to compare directly printed transfer trays with different designs.

Objectives: To evaluate the incidence and pattern of unexpected/excessive condylar displacement after comprehensive orthodontic treatment in adults.

Materials and methods: Adult patients (age ≥18 years) who underwent comprehensive orthodontic treatment with pre-(T1) and post-treatment (T2) cone beam computed tomography scans were consecutively collected within an orthodontic cohort (N = 291). T1 and T2 CBCTs were superimposed three-dimensionally (3D) and condylar displacement was estimated by the 3D changes of condylar neck point (CdN) between T1 and T2 (ΔCdN). Participants with excessive condylar displacement (ΔCdN >1 mm) were classified as condylar displacement (+) and otherwise as displacement (-). The incidence and pattern of condylar displacement, association with factors such as sex, age, skeletal relationship, extraction pattern, treatment duration, history of temporomandibular joint disorder, and presence of condylar resorption with the final occlusal outcome were investigated.

Results: The incidence of unexpected condylar displacement >1 mm in the adult orthodontic cohort was 6.2%. Females (vs males; OR: 9.07; [95% CI: 1.19-69.23]) and Skeletal Class II (vs Classes I and III; OR: 4.57 [95% CI: 1.58-13.20]) demonstrated significantly higher odds of unexpected condylar displacement (P < .05). Condylar resorption was not evident in participants with condylar displacement and did not interfere with the final orthodontic outcome.

Conclusions: Unexpected 3D condylar displacement exceeding 1 mm was noted in approximately 6% of the adult orthodontic patient cohort. However, the condylar displacement per se was not associated with condylar resorption and did not cause clinical concerns.

Class III malocclusion due to a retrognathic maxilla is common in patients with cleft lip and palate. Skeletally anchored maxillary protraction using screw-anchored mini-plates combined with intraoral elastics has shown promising results in achieving orthopedic changes and maintaining the outcome until the completion of the growth. This case report presents the course of treatment in a patient with unilateral cleft lip and palate and multiple congenitally missing teeth treated with bone-anchored maxillary protraction until the end of growth. Four mini-plates (Bollard plates) were used during comprehensive fixed orthodontic treatment to protract the dentition and close the space where teeth were missing, extrude the canine, and force eruption of the second premolar using extension arms and cantilevers. A 2-year follow-up at age 17 showed stable occlusion and maintenance of soft tissue results. Bone-anchored maxillary protraction treatment in a patient with cleft lip and palate demonstrates proper orthopedic results and could be a viable alternative to orthognathic surgery.

Managing orthodontic treatment for adults with missing permanent teeth can be intricate, especially when dealing with a posterior scissor bite and an impacted tooth. This case report presents successful treatment of a female patient with dental and skeletal Class II malocclusion, high mandibular plane angle, missing maxillary left lateral incisor and mandibular right first molar, as well as right posterior scissor bite, and a deeply impacted mandibular left second premolar. In the maxilla, the right second molar and right lateral incisor were strategically extracted to eliminate the scissor bite and enhance frontal esthetic balance. In the mandible, the edentulous space caused by early loss of the first molar was successfully closed and the impacted second premolar was guided into its proper position after surgical exposure. Finally, symmetric frontal esthetics, well-aligned dentition with ideal intercuspation and an improved profile were achieved, which remained stable in the 17 month follow-up.

Adequate and transparent reporting is necessary for critically appraising published research, yet ample evidence suggests that the design, conduct, analysis, interpretation, and reporting of oral health research could be greatly improved. Accordingly, the Task Force on Design and Analysis in Oral Health Research, statisticians and trialists from academia and industry, identified the minimum information needed to report and evaluate observational studies and clinical trials in oral health: the OHStat guidelines. Drafts were circulated to the editors of 85 oral health journals and to Task Force members and sponsors and discussed at a December 2020 workshop attended by 49 researchers. The guidelines were subsequently revised by the Task Force writing group. The guidelines draw heavily from the Consolidated Standards for Reporting Trials (CONSORT), Strengthening the Reporting of Observational Studies in Epidemiology, and CONSORT harms guidelines, and incorporate the SAMPL guidelines for reporting statistics, the CLIP principles for documenting images, and the GRADE indicating the quality of evidence. The guidelines also recommend reporting estimates in clinically meaningful units using confidence intervals, rather than relying on P values. In addition, OHStat introduces seven new guidelines that concern the text itself, such as checking the congruence between abstract and text, structuring the discussion, and listing conclusions to make them more specific. OHStat does not replace other reporting guidelines; it incorporates those most relevant to dental research into a single document. Manuscripts using the OHStat guidelines will provide more information specific to oral health research.

Objectives: To examine dentoalveolar changes following intrusion of maxillary incisors with one or two anterior miniscrews in subjects with gummy smile and deep bite.

Materials and methods: Forty-three subjects were selected and divided into two groups: group I (22 subjects: 15 women, 7 men; mean age 30 ± 10 years) received one miniscrew between the upper central incisors, and group II (21 subjects: 16 women, 5 men; mean age 30 ± 10 years) received two miniscrews between the canines and lateral incisors. Dentoalveolar parameters, including amount of intrusion, root resorption, incisor inclination, alveolar bone thickness, and buccal alveolar crest height (cementoenamel junction to labial alveolar crest), were evaluated using cone-beam computed tomography scans obtained before and after intrusion. The intergroup comparison was analyzed using a paired t-test and unpaired t-test to determine significant changes within and between groups.

Results: The amount of intrusion was significantly greater in group II than in group I (P < .05). No statistically significant differences were found between groups I and II for changes in incisor inclination, labial bone thickness, and buccal alveolar crest height (P > .05).

Conclusions: Maxillary central and lateral incisor intrusion was significantly greater in subjects treated with two miniscrews. Root resorption of the maxillary central incisors was notably greater in subjects with one miniscrew, while maxillary lateral incisor resorption was greater in subjects treated with two miniscrews.

This case report describes correction of maxillary constriction using a maxillary skeletal expander (MSE) in a 15-year-old female with a skeletal Class III pattern and asymmetry. The maxillary expansion device with four mini-implants was used to correct the constricted maxilla, bilateral crossbite of the posterior teeth, and crowding of the dentition. Comparison of cone-beam computed tomography scans before and after treatment showed that the majority of maxillary expansion was orthopedic, with minimal alveolar bone bending and tooth tipping. Fixed appliances were used to correct the crowding and malocclusion. Stable and satisfactory maxillary expansion was obtained by using MSE non-urgically.

In this case report, we describe the successful camouflage treatment of a 53-year-old female with dental and skeletal Class III malocclusion combined with anterior crossbite, gingival recession, and mobility of the lower incisors, using clear aligners. The treatment involved periodontal debridement followed by orthodontic treatment. The mandibular posterior teeth were distalized to correct the anterior crossbite and to establish Class I molar relationships. During treatment, the mandibular incisors were intruded, and the mandibular occlusal plane underwent a clockwise rotation due to slight extrusion of the maxillary buccal segments and distalization of the mandibular posterior teeth. Following treatment, all objectives were achieved, including resolution of the anterior crossbite, significant reduction of gingival recession and tooth mobility, and improved functional occlusion. The dental and skeletal Class III malocclusion was corrected, and the marginal alveolar bone dehiscence was significantly reduced. The results remained stable over a 3-year retention period, with enhanced molar intercuspation and gingival growth progression. This case adds to the evidence supporting the adaptability and effectiveness of clear aligners in treating orthodontic patients with compromised periodontium. The treatment outcomes support that orthodontic treatment using clear aligners, combined with periodontal monitoring, can assist in managing alveolar bone defects, gingival recession, and tooth mobility.

This case report describes the nonsurgical management of a patient with a Class II skeletal pattern, retrognathic mandible, steep mandibular angle, maxillary vertical excess, and lip incompetence. The treatment approach involved orthodontic mechanics supported with skeletal anchorage to achieve maximal intrusion and retraction of the dentition. A novel elastic hanging rack appliance, supported by midpalatal miniscrews, was used. A maximal anchorage setup for active vertical control on both arches was illustrated. Significant improvement in the facial profile was achieved with optimal occlusion. Cephalometric analysis revealed successful incisor retraction and intrusion, as well as a forward rotation of the mandible. The treatment outcome illustrates the impact of active vertical control on orthodontic camouflage treatment for severe protrusion.