Orthodontic treatment of traumatically avulsed maxillary central incisors with bimaxillary dentoalveolar protrusion in an adult female: a case report.

BACKGROUND: Clinicians agree that obtaining and retaining good treatment results for missing maxillary central incisors owing to trauma is not easy. Management of adult patients with permanent maxillary central incisor loss who visit the clinic with high expectations for aesthetics and function pose a significant diagnostic dilemma. Therefore, esthetic and functional outcomes should be taken into consideration when deciding the proper treatment method. The treatment described in this study aimed to reestablish smile esthetics by proposing an effective multidisciplinary clinical approach that includes orthodontic-prosthetic-periodontal procedures, optimally reduced lip protrusion, center dental midlines, and establishment of stable occlusion. CASE PRESENTATION: The patient was a 19-year-old adult female with bimaxillary arch protrusion who had been wearing removable dentures for several years since the loss of her maxillary central permanent incisors. A multidisciplinary treatment including the extraction of two mandibular primary premolars was adopted. The treatment plan consisted of orthodontic space closure by shifting the adjacent teeth towards the central incisor spaces combined with appropriate morphologic remodeling and gingival reshaping to obtain good aesthetic and functional results. The duration to complete the orthodontic treatment was 35 months. Clinical and radiographic results after treatment suggested smile harmony with an improvement in the facial profile, good function of the occlusion, and a positive effect on bone remodeling in the area of the missing incisors during orthodontic tooth movement. CONCLUSIONS: This clinical case illustrated the necessity for using multidisciplinary methods involving orthodontic, prosthodontic, and periodontic procedures to treat an adult female patient with bimaxillary arch protrusion and long-term absence of anterior teeth due to severe trauma.

[Characteristics of condylography during masticatory movement in patients with Class â ¡ division 1 malocclusion and temporomandibular disorders].

PURPOSE: To investigate the characteristics of condylography of masticatory movement in patients of Class Ⅱ division 1 malocclusion with temporomandibular disorders (TMD), and the effects of TMD and Angle Ⅱ1 malocclusion factors on the condylography of masticatory movement. METHODS: According to the inclusion criteria of the experiment, ten normal occlusion subjects without TMD（nTMD-N）, ten Angle Ⅱ1 patients without TMD（nTMD-Ⅱ1）and 14 Angle Ⅱ1 patients with TMD（TMD-Ⅱ1）were included. Cadiax IV was used to record the condylography of the subjects during mastication, and the data of condylography was measured and analyzed by GDSW software. The results were analyzed with SPSS 26.0 software package. RESULTS: The characteristics of condylography in nTMD-Ⅱ1 and TMD-Ⅱ1 groups were different from those of nTMD-N group. During unilateral mastication on the left or right side, there was no significant difference among nTMD-N group, nTMD-Ⅱ1 group and TMD-Ⅱ1 group. During bilateral mastication, the SCI value of nTMD-Ⅱ1 group was significantly higher than that of nTMD-N group, and the S value of nTMD-N group was significantly higher than that of nTMD-Ⅱ1 group (P<0.05). CONCLUSIONS: During unilateral masticatory movement, TMD and Angle Ⅱ1 malocclusion has little effect on the masticatory movement trajectory. Angle Ⅱ1 malocclusion has influence on bilateral masticatory movement, and the amplitude of condylar movement in patients with ClassⅡdivision 1 malocclusion is smaller than that in normal mastication. TMD has no significant effect on the masticatory movement condylography of the patients.

The Optimal Energy Density of Photobiomodulation Therapy in Decreasing Orthodontic-Related Pain: A Systematic Review and Network Meta-Analysis.

Objective: The aim of this network meta-analysis (NMA) was to explore the optimal energy density (ED) for relief of orthodontic-related pain by photobiomodulation therapy. Background: Orthodontic treatment corrects the deformity of teeth, dental arch, jaw, and face using various orthodontic devices under the action of biomechanics. Materials and methods: A computerized literature search was conducted within the MEDLINE, EMBASE, Scopus, Cochrane Library, Web of Science, CNKI, Wanfang, VIP, and CBM databases to identify randomized controlled trials (RCTs) that used photobiomodulation therapy to relieve pain during orthodontic treatment. Particular inclusion and exclusion criteria were connected to recognize relevant articles. The information was extricated autonomously by two reviewers, and a quality assessment was carried out by utilizing the Cochrane Collaboration "risk of bias" tool. The RevMan 5.4 software and STATA 15.0 were utilized for data analysis. Also, the NMA was performed with mvmeta commands in Stata (StataCorp, TX). Results: Of the 1024 recognized articles, 21 RCTs were at long last included. Within the risk-of-bias assessments, 2 studies displayed a high risk, 17 an unclear risk, and 2 a low risk. The global and local inconsistency of the NMA in 1 and 2 days was not significant; however, the NMA in 3 days showed a significant inconsistency. Laser with lower ED (0-10 J/cm2) appeared to be the most noteworthy possibility to become the optimal intervention, and it also had the highest mean rank in the rankogram and the biggest value of surface under the cumulative ranking in all three NMA structures. Conclusions: On account of the limited evidence of included trials, laser with lower ED (0-10 J/cm2) appeared to be more valid than the remaining treatment modalities (laser with higher ED, placebo, and control) for pain reduction in 1, 2, and 3 days after orthodontic procedures were applied. In the future, more high-quality research with consistency in research design is needed for further evaluation.

Viability of Photobiomodulaton Therapy in Decreasing Orthodontic-Related Pain: A Systematic Review and Meta-Analysis.

Objective: To assess the viability of photobiomodulation therapy (PBMT) in decreasing orthodontic-related pain after different orthodontic procedures. Methods: A computerized literature search was conducted within the MEDLINE, EMBASE, Scopus, Cochrane Library, Web of Science, CNKI, WanFang, VIP, and CBM databases to identify randomized controlled trials (RCTs), which used PBMT to relieve pain during orthodontic treatment. Particular inclusion and exclusion criteria were connected to recognize relevant articles. The information was extricated autonomously by two reviewers, and a quality assessment was carried out by utilizing the Cochrane Collaboration "risk of bias" tool. Meta-analysis was conducted with fixed- or random-effects models as suitable. Statistical heterogeneity was also examined. The RevMan 5.4 software was utilized for data analysis. Results: Of 1024 recognized articles, 25 RCT were at long last included. Within the risk-of-bias assessments, 1 study displayed a high risk, 22 an unclear risk, and 2 a low risk. The meta-analysis appeared that in patients treated with photobiomodulation (PBM) versus control there was a distinction in support of PBMT in placement of elastomeric separators, canine retraction, and archwire placement during 1 week. Conclusions: PBMT demonstrated to be effective in advancing a reduction pain after elastomeric separators placement, canine retraction, and archwire placement within 1 week. In the future, more high-quality research with consistency in research design is needed for further evaluation.

Study of Deformation Behavior and Microstructural Evolution in Multiphase Steel.

In the present work, the tensile deformation characteristics of the high performance multiphase steel with complex microstructures are investigated. A mixture of ferrite, bainite, and 14.4 vol% retained austenite (RA) with an average grain size of less than 3 µm of the matrix is obtained after specific heat treatment. Tensile tests are performed with increasing strain, i.e., 0%, 5%, 10%, 15%, and 20%. Then X-ray diffraction, transmission electron microscope and electron backscatter diffraction are utilized to analyze the deformation-transformation behaviors of the complex microstructures. Phase transformation of the RA, which is controlled by its morphology and distribution, contributes to high strain hardening capacity of the steel. The blocky-type RA that locates in ferrite grain boundaries shows less stability and transforms easily at early deformation stage, while the film-like RA that distributes between bainitic ferrite shows higher stability and transforms continuously throughout plastic deformation. Moreover, the substructure formation by dislocation configuration in ferrite grains begins with randomly distributed dislocations and ends up with cellular structures, resulting in ferrite subdivision during deformation and also grain refinement strengthening. As a result, the experimental steel is reinforced not only by the martensite transformation of RA, but also ferrite refinement.