Orthodontics & Craniofacial Research最新文献

{"title":"Using three-dimensional geometric morphometry for facial analysis in patients with the oculo-auriculo-vertebral spectrum","authors":"Petra Poláčková,&nbsp;Jiří Borovec,&nbsp;Jana Vašáková,&nbsp;Matěj Patzelt,&nbsp;Wanda Urbanová,&nbsp;Michaela Mihulová,&nbsp;Milan Macek Jr,&nbsp;Markéta Havlovicová,&nbsp;Veronika Moslerová","doi":"10.1111/ocr.12834","DOIUrl":"10.1111/ocr.12834","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Aim</h3>\u0000 \u0000 <p>To utilize three-dimensional (3D) geometric morphometry for visualization of the level of facial asymmetry in patients with the oculo-auriculo-vertebral spectrum (OAVS).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>Three-dimensional facial scans of 25 Czech patients with OAVS were processed. The patients were divided into subgroups according to Pruzansky classification. For 13 of them, second 3D facial scans were obtained. The 3D facial scans were processed using geometric morphometry. Soft tissue facial asymmetry in the sagittal plane and its changes in two time spots were visualized using colour-coded maps with a thermometre-like scale.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Individual facial asymmetry was visualized in all patients as well as the mean facial asymmetry for every Pruzansky subgroup. The mean colour-coded maps of type I and type IIA subgroups showed no differences in facial asymmetry, more pronounced asymmetry in the middle and the lower facial third was found between type IIA and type IIB (maximum 1.5 mm) and between type IIB and type III (maximum 2 mm). The degree of intensity facial asymmetry in affected middle and lower facial thirds did not change distinctly during the two time spots in all subgroups.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The 3D geometric morphometry in OAVS patients could be a useful tool for objective facial asymmetry assessment in patients with OAVS. The calculated colour-coded maps are illustrative and useful for clinical evaluation.</p>\u0000 </section>\u0000 </div>","PeriodicalId":19652,"journal":{"name":"Orthodontics & Craniofacial Research","volume":"27 6","pages":"917-927"},"PeriodicalIF":2.4,"publicationDate":"2024-07-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/ocr.12834","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141731363","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The morphology of alveolar bone of the mandibular second and third molars in skeletal Class III patients","authors":"Liya Jiang,&nbsp;Luxi Weng,&nbsp;Xin Yu,&nbsp;Jun Lin","doi":"10.1111/ocr.12833","DOIUrl":"10.1111/ocr.12833","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>To investigate the alveolar bone morphology of the mandibular second and third molars in skeletal Class III patients from a buccolingual direction.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Sixty skeletal Class III patients were recruited. The alveolar bone width, buccal cortical bone thickness and lingual cortical bone thickness were measured in five planes from mesial to distal and at five depths from gingival to root. The effects of the gender of the patients, the second molar lingual inclination and the third molar on alveolar bone width and cortical bone thickness were evaluated. To explore the effect of third molar extraction on alveolar bone morphology, the measurements before and after third molar extraction were compared.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The impacted third molar had significantly greater alveolar bone width and thicker buccal cortical bone at the cervical third of the molar, while the erupted third molar had greater alveolar bone width at the apical third. Three weeks after third molar extraction, these advantages would weaken owing to the reconstruction of the alveolar bone. Patients with lingually inclined molar were observed to own thicker lingual cortical bone. Males tended to have greater alveolar bone width, but no significant differences were shown in this study.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The growth of the third molar and the second molar lingual inclination affect the alveolar bone morphology of the mandibular second and third molars significantly, but gender has trivial effects on the morphology. The alveolar bone morphology of the mandibular second and third molars would change 3 weeks after third molar extraction.</p>\u0000 </section>\u0000 </div>","PeriodicalId":19652,"journal":{"name":"Orthodontics & Craniofacial Research","volume":"27 6","pages":"909-916"},"PeriodicalIF":2.4,"publicationDate":"2024-07-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141620646","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Maxillary arch dimensions in bilateral cleft lip and palate in the age 0–5 months","authors":"Adriano Porto Peixoto,&nbsp;Felicia Miranda,&nbsp;Rayane de Oliveira Pinto,&nbsp;Tiago Turri de Castro Ribeiro,&nbsp;Franciele Salazar Somensi Lara,&nbsp;Fabrício Monteiro de Castro Machado,&nbsp;Daniela Garib","doi":"10.1111/ocr.12836","DOIUrl":"10.1111/ocr.12836","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Introduction</h3>\u0000 \u0000 <p>The complete bilateral cleft lip and palate (BCLP) divides the maxillary arch into three segments, separated from each other, resulting in abnormal growth of the alveolar arch. This study evaluated the maxillary arch dimensions in BCLP and compared them with neonates without craniofacial anomalies.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>This retrospective study was conducted in a tertiary cleft centre. Sixty-six neonates aged 0–5 months were divided into two groups: cleft group—children with BCLP (23 boys and 18 girls) and control group—children without craniofacial deformities (15 boys and 10 girls). The dental models were processed by a 3D scanner. Landmarks were marked to achieve inter-canine distance, inter-tuberosity distance and arch length measurements. <i>t</i>-Tests were used for intergroup comparisons (<i>p</i> &lt; .05).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The maxillary cleft arch was demonstrated to be wider and longer in the posterior region compared to the control group. The inter-canine distance did not present differences between the cleft and controls. The inter-canine distance of the control group was the only measurement influenced by the variable sex.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The cleft significantly interfered with the arch posterior width and arch sagittal length, making them larger. There was no statistical difference in the measurements between sex in the cleft group.</p>\u0000 </section>\u0000 </div>","PeriodicalId":19652,"journal":{"name":"Orthodontics & Craniofacial Research","volume":"27 6","pages":"903-908"},"PeriodicalIF":2.4,"publicationDate":"2024-07-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141603974","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Automatic soft-tissue analysis on orthodontic frontal and lateral facial photographs based on deep learning","authors":"Qiao Chang,&nbsp;Yuxing Bai,&nbsp;Shaofeng Wang,&nbsp;Fan Wang,&nbsp;Yajie Wang,&nbsp;Feifei Zuo,&nbsp;Xianju Xie","doi":"10.1111/ocr.12830","DOIUrl":"10.1111/ocr.12830","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Background</h3>\u0000 \u0000 <p>To establish the automatic soft-tissue analysis model based on deep learning that performs landmark detection and measurement calculations on orthodontic facial photographs to achieve a more comprehensive quantitative evaluation of soft tissues.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>A total of 578 frontal photographs and 450 lateral photographs of orthodontic patients were collected to construct datasets. All images were manually annotated by two orthodontists with 43 frontal-image landmarks and 17 lateral-image landmarks. Automatic landmark detection models were established, which consisted of a high-resolution network, a feature fusion module based on depthwise separable convolution, and a prediction model based on pixel shuffle. Ten measurements for frontal images and eight measurements for lateral images were defined. Test sets were used to evaluate the model performance, respectively. The mean radial error of landmarks and measurement error were calculated and statistically analysed to evaluate their reliability.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The mean radial error was 14.44 ± 17.20 pixels for the landmarks in the frontal images and 13.48 ± 17.12 pixels for the landmarks in the lateral images. There was no statistically significant difference between the model prediction and manual annotation measurements except for the mid facial-lower facial height index. A total of 14 measurements had a high consistency.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Based on deep learning, we established automatic soft-tissue analysis models for orthodontic facial photographs that can automatically detect 43 frontal-image landmarks and 17 lateral-image landmarks while performing comprehensive soft-tissue measurements. The models can assist orthodontists in efficient and accurate quantitative soft-tissue evaluation for clinical application.</p>\u0000 </section>\u0000 </div>","PeriodicalId":19652,"journal":{"name":"Orthodontics & Craniofacial Research","volume":"27 6","pages":"893-902"},"PeriodicalIF":2.4,"publicationDate":"2024-07-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141534975","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Assessment of hard and soft tissue thickness at mandibular symphysis in skeletal Class III patients with different vertical patterns","authors":"Jiyoung Oh,&nbsp;Lyun Kwang Ham,&nbsp;Hyemin Shin,&nbsp;Sung-Hoon Han,&nbsp;Yoonji Kim","doi":"10.1111/ocr.12829","DOIUrl":"10.1111/ocr.12829","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Introduction</h3>\u0000 \u0000 <p>This study aimed to assess the bony and soft tissue parameters at mandibular symphysis among skeletal Class III patients with different vertical growth patterns, using cone-beam computed tomography (CBCT).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>CBCT images of 60 skeletal Class III non-growing patients were evaluated (mean age 24.9 ± 8.4 years). Study samples were classified into three facial types based on the mandibular plane angle (SN-MP angle): low, normal, and high angle. The bony and soft tissue parameters at the mandibular symphysis were evaluated.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Among hard tissue variables, symphysis and pogonion width were significantly narrower in the high-angle group (<i>P</i> &lt; .05). The thickness of the buccal cortex at pogonion was also significantly thinner in subjects with high angles (<i>P</i> &lt; .01). Symphysis height showed an increasing tendency from the low-angle to the high-angle group. However, no significant differences were found in chin width and height according to vertical patterns. Across all soft tissue measurements, the low-angle group exhibited the highest thickness, which gradually decreased in the high-angle group. Statistically significant differences in soft tissue thickness were observed at Menton (Me) and Gnathion (Gn) (<i>P</i> &lt; .05). A significant negative correlation was observed between the SN-MP angle and the thickness of both hard and soft tissues.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>In skeletal Class III subjects, significant differences existed in both hard and soft tissues at the mandibular symphysis, depending on the vertical patterns. These results provide a comprehensive evaluation of symphyseal area, which can aid clinicians in identifying appropriate treatment approaches, especially for combined orthognathic and orthodontic treatment.</p>\u0000 </section>\u0000 </div>","PeriodicalId":19652,"journal":{"name":"Orthodontics & Craniofacial Research","volume":"27 6","pages":"886-892"},"PeriodicalIF":2.4,"publicationDate":"2024-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141492929","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effects of orthognathic surgery on respiratory function during sleep: A prospective longitudinal study","authors":"Magnus Ahl,&nbsp;Agneta Marcusson,&nbsp;Anders Magnusson,&nbsp;Jahan Abtahi,&nbsp;Ola Sunnergren,&nbsp;Martin Ulander","doi":"10.1111/ocr.12828","DOIUrl":"10.1111/ocr.12828","url":null,"abstract":"<p>When treating patients with orthognathic surgery, there might be a risk of obstructive sleep apnoea (OSA) due to soft tissue changes in the upper airways, especially in patients treated with isolated mandibular setback or mandibular setback in combination with maxillary advancement. In the present study, we assessed respiratory function during sleep with home cardiorespiratory polygraphy in 62 patients who had not been previously been diagnosed with OSA at three times: prior to orthognathic surgery for aesthetic and functional indications, and then 3 months and 1 year after surgery. We evaluated surgical displacement based on measurements in three dimensions using pre- and post-operative computed tomography. There were only minor changes in the respiratory parameters such as the apnoea-hypopnoea index (AHI), the apnoea-hypopnoea index in the supine position (AHI_sup), the oxygen saturation index (ODI) and the snore index. There was no significant correlation between surgical displacement and the AHI, AHI_sup and ODI. There was a weak but significant correlation between vertical displacement of the anterior mandible and the snore index. Within the limitations of the present study, the risk for iatrogenic obstruction of the upper airways seems to be low in patients without OSA treated with orthognathic surgery.</p>","PeriodicalId":19652,"journal":{"name":"Orthodontics & Craniofacial Research","volume":"27 6","pages":"877-885"},"PeriodicalIF":2.4,"publicationDate":"2024-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/ocr.12828","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141469903","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Tooth movement analysis of maxillary dentition distalization using clear aligners with buccal and palatal mini-screw anchorages: A finite element study","authors":"Runzhi Guo,&nbsp;Linwei Li,&nbsp;Xiang Yao Lam,&nbsp;Qianyi Qin,&nbsp;Yunfei Zheng,&nbsp;Yiping Huang,&nbsp;Yifan Lin,&nbsp;Weiran Li","doi":"10.1111/ocr.12826","DOIUrl":"10.1111/ocr.12826","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>To assess the tooth movement trends during the three stages of maxillary dentition distalization with clear aligners (CA) and to compare the efficacy of different mini-screw anchorage systems.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>Three-dimensional (3D) finite element models of three anchorage systems (A, control group; B, buccal mini-screw anchorage group; C, palatal mini-screw anchorage group) were established. Three stages of simulating maxillary dentition distalization with CA included maxillary molar distalization (stage 1), maxillary premolar distalization (stage 2) and maxillary anterior teeth retraction (stage 3). Therefore, a total of nine models were constructed to analyse the 3D displacement of maxillary teeth during the distalization process.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The displacement pattern of maxillary dentition during distalization was similar across the three groups, but with varying magnitudes. During stage 1, groups B and C exhibited greater amounts of molar distalization compared to group A. Group C also demonstrated the least amount of labial movement of the maxillary central incisor compared to the other two groups. During stage 2, the mesial displacement of the maxillary first molar was less significant in groups B and C than in group A. In the final stage, group C exhibited a greater amount of maxillary anterior retraction compared to groups A and B.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>The palatal mini-screw anchorage system was effective in reducing anchorage loss and improving the efficacy of maxillary dentition distalization with CA.</p>\u0000 </section>\u0000 </div>","PeriodicalId":19652,"journal":{"name":"Orthodontics & Craniofacial Research","volume":"27 6","pages":"868-876"},"PeriodicalIF":2.4,"publicationDate":"2024-06-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141508115","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluation of post-activation mandibular remodelling in children with craniofacial microsomia treated with distraction osteogenesis","authors":"Xiyuan Li,&nbsp;Songxia Xia,&nbsp;Zhifeng Li,&nbsp;Zhiyong Zhang","doi":"10.1111/ocr.12827","DOIUrl":"10.1111/ocr.12827","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objective</h3>\u0000 \u0000 <p>Patients with type IIA craniofacial microsomia (CFM) may benefit from mandibular distraction osteogenesis (MDO) treatment during childhood; however, remodelling of the mandible during the consolidation phase, which may affect the short-term outcomes of MDO, has not yet been quantitatively analysed using computed tomography. Therefore, we aimed to investigate bone remodelling of the mandible in children with type IIA CFM treated with MDO before distractor removal and the factors that influence ramus vertical elongation efficiency.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>Twenty-three children with unilateral CFM were studied between 2020 and 2024. Longitudinal computed tomography data (preoperative, end of active phase and at pre-distractor removal) were analysed. Condyle positions and the mandibular cant were analysed using a paired-sample <i>t</i> test. The relapse rates of vertical lengthening and mandibular cant were calculated. The correlation between distraction efficiency and preoperative craniofacial morphology was analysed.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>The condyle on the affected side moved upwards and backwards by 28.84 ± 4.08 and 2.85 ± 4.33 mm, respectively during the active phase but lost 7.66 ± 2.64 mm of vertical extension during the consolidation phase. The relapse rates for vertical extension of the condyle and occlusal plane were 27% and 35%, respectively. The ratio of mandibular ramus height was positively related to EV.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>In children with CFM, attention should be paid to vertical elongation instability and relapse of mandibular inclination during consolidation. Severe mandibular ramus hypoplasia is a preoperative risk factor for vertical skeletal relapse during consolidation. Further efforts are required to reduce the stress that leads to relapse.</p>\u0000 </section>\u0000 </div>","PeriodicalId":19652,"journal":{"name":"Orthodontics & Craniofacial Research","volume":"27 6","pages":"860-867"},"PeriodicalIF":2.4,"publicationDate":"2024-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141427400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of thermomechanical ageing on force transmission by orthodontic aligners made of different thermoformed materials: An experimental study","authors":"Tarek M. Elshazly,&nbsp;Christoph Bourauel,&nbsp;Ahmed M. Ismail,&nbsp;Omar Ghoraba,&nbsp;Philippe Chavanne,&nbsp;Hanaa Elattar,&nbsp;Abdulaziz Alhotan","doi":"10.1111/ocr.12825","DOIUrl":"10.1111/ocr.12825","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Objectives</h3>\u0000 \u0000 <p>Investigating the impact of thermal and mechanical loading on the force generation of orthodontic aligners made from various thermoplastic materials and different compositions.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Materials and Methods</h3>\u0000 \u0000 <p>Five distinct materials were utilized including, three multi-layer (Zendura FLX, Zendura VIVA, CA Pro) and two single-layer (Zendura A and Duran). A total of 50 thermoformed aligners (n = 10) underwent a 48-hour ageing protocol, which involved mechanical loading resulting from a 0.2 mm facial malalignment of the upper right central incisor (Tooth 11) and thermal ageing through storage in warm distilled water at 37°C. The force exerted on Tooth 11 of a resin model was measured both before and after ageing using pressure-sensitive films and a biomechanical setup.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Before ageing, pressure-sensitive films recorded normal contact forces ranging from 83.1 to 149.7 N, while the biomechanical setup measured resultant forces ranging from 0.1 to 0.5 N, with lingual forces exceeding facial forces. Multi-layer materials exhibited lower force magnitudes compared to single-layer materials. After ageing, a significant reduction in force was observed, with some materials experiencing up to a 50% decrease. Notably, multi-layer materials, especially Zendura VIVA, exhibited lower force decay.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusions</h3>\u0000 \u0000 <p>The force generated by aligners is influenced by both the aligner material and the direction of movement. Multi-layer materials exhibit superior performance compared to single-layer materials, primarily because of their lower initial force, which enhances patient comfort, and their capability to maintain consistent force application even after undergoing ageing.</p>\u0000 </section>\u0000 </div>","PeriodicalId":19652,"journal":{"name":"Orthodontics & Craniofacial Research","volume":"27 S2","pages":"113-119"},"PeriodicalIF":2.4,"publicationDate":"2024-06-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://onlinelibrary.wiley.com/doi/epdf/10.1111/ocr.12825","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141420303","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Is motor-driven insertion of orthodontic miniscrews more advantageous than manual insertion? A micro-CT evaluation of bone miniscrew contact surface area and cortical microcracks in rabbits","authors":"Reem A. Alansari,&nbsp;Khaled H. Zawawi,&nbsp;Nikhillesh Vaiid,&nbsp;Zuhair Natto,&nbsp;Samar M. Adel,&nbsp;Maha R. Alshihri,&nbsp;Mohammed Alsadat,&nbsp;Rania Dause,&nbsp;Shoroog Agou,&nbsp;Ali H. Hassan","doi":"10.1111/ocr.12824","DOIUrl":"10.1111/ocr.12824","url":null,"abstract":"<div>\u0000 \u0000 \u0000 <section>\u0000 \u0000 <h3> Aim</h3>\u0000 \u0000 <p>This in vitro study aimed to evaluate and compare the bone–miniscrew contact surface area (BMC) and the cortical bone microcracks (CM) resulting from manual (hand-driven) and automated (motor-driven) orthodontic miniscrew (OM) insertion methods.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Methods</h3>\u0000 \u0000 <p>Thirty-three OM were inserted in the femurs of nine New Zealand rabbits using manual (n = 16) and automated (n = 17) insertions. After euthanizing the rabbits, bone blocks, each including one OM, were sawed. Micro-CT scanning was performed, and data analysis included reconstruction, binarization and quantification of morphometric parameters of BMC and the number and length of CM. Means and standard deviations for complete BMC, complete BMC proportion, cortical BMC, cortical BMC proportion, and length and number of CM were calculated. Mixed model analysis was used to adjust for more than one sample/CM per animal. A paired <i>t</i>-test was used to compare the number of CM between the two groups.</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Results</h3>\u0000 \u0000 <p>Compared to the automated insertion, manually inserted miniscrews had significantly lower complete BMC (7.54 ± 1.80 mm² vs. 11.99 ± 3.64 mm²), cortical BMC (5.91 ± 1.48 mm² vs. 8.48 ± 1.90 mm²) and cortical BMC proportion (79.44 ± 5.84% vs. 87.94 ± 3.66%). However, it was not statistically significant in complete BMC proportion (<i>p</i> = .052). The automated insertion also resulted in a significantly lower mean number of CM than the manual method (<i>p</i> = .012). However, the length of the cracks was shorter in the manual group but with no significant difference (<i>p</i> = 0.256).</p>\u0000 </section>\u0000 \u0000 <section>\u0000 \u0000 <h3> Conclusion</h3>\u0000 \u0000 <p>Motor-driven OM insertion results in superior BMC and reduction in the number of CM, which may lead to better miniscrew stability.</p>\u0000 </section>\u0000 </div>","PeriodicalId":19652,"journal":{"name":"Orthodontics & Craniofacial Research","volume":"27 6","pages":"853-859"},"PeriodicalIF":2.4,"publicationDate":"2024-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141331453","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}