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1.
J Orofac Orthop ; 84(Suppl 1): 19-25, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36723622

ABSTRACT

OBJECTIVES: The aims of this study were to determine the frequency of oral health-related quality of life (OHRQoL) impairment in a national representative sample of 8 to 9 year olds in Germany and to evaluate the impact of orthodontic treatment need. METHODS: Data were collected in the Sixth German Oral Health Study (Sechste Deutsche Mundgesundheitsstudie, DMS 6) and subjects were sampled using a multistage sampling technique. OHRQoL was measured with a modified version of the 5­item Oral Health Impact Profile (OHIP-5) which was administered in a computer-assisted personal interview. Children were also examined for malocclusion and orthodontic treatment need. RESULTS: In all, 1892 children aged 8-9 years were invited to take part. Finally, data of 705 children (48.6% female) could be included in the analysis. The OHIP­5 mean was 1.3 (±2.0). There was no relevant influence from age and gender on the OHIP­5 summary scores (r < 0.10), but the summary scores differed when analyzed separately regarding orthodontic treatment need or no orthodontic treatment need (1.5 ± 2.0 vs. 1.2 ± 1.9, p = 0.020). Nevertheless, the level appears to be low. CONCLUSIONS: Malocclusions with orthodontic treatment need have an influence on OHRQoL.


Subject(s)
Malocclusion dentaire , Qualité de vie , Enfant , Humains , Femelle , Mâle , Santé buccodentaire , Malocclusion dentaire/diagnostic , Malocclusion dentaire/épidémiologie , Malocclusion dentaire/thérapie , Enquêtes et questionnaires , Allemagne/épidémiologie
2.
J Orofac Orthop ; 84(Suppl 1): 26-35, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36723623

ABSTRACT

PURPOSE: The aim of the present study was to compare the malocclusion indices KIG (Kieferorthopädische Indikationsgruppen, Orthodontic Indication Groups), ICON (Index of Complexity, Outcome and Need), and mIOTN (modified Index of Orthodontic Treatment Need) regarding differences in malocclusion prevalence and their assessment of orthodontic treatment need in German 8­ to 9­year-old children of the Sixth German Oral Health Study (Deutsche Mundgesundheitsstudie, DMS 6). METHODS: The necessary data for the calculation of the KIG, mIOTN, and ICON were collected by a dentist as part of a clinical orthodontic examination during the field phase of the DMS 6 and by a subsequent digital orthodontic model-analytical evaluation of intraoral scans of the dental arches and the occlusal situation in habitual occlusion. RESULTS: Prevalence, severity, and treatment need of tooth and jaw misalignments differed in part considerably depending on the index used for assessment. On the other hand, there were several outcomes which yielded quite similar results for the different indices used, such as orthodontic treatment need, which ranged from 40.4% (KIG) over 41.6% (ICON) to 44.2% (mIOTN). Interestingly, orthodontic treatment need for the individual subject could differ considerably, when assessed using different indices. CONCLUSIONS: In general, the results show that the mIOTN is much more conservative in assessing malocclusion prevalences often being smaller than those derived by KIG or ICON. In contrast, KIG and ICON often yield similar prevalences with certain distinct differences due to discrepancies in the respective definitions and also clearly differentiate between treatment possibility and arbitrarily determined treatment need.


Subject(s)
Malocclusion dentaire , Santé buccodentaire , Humains , Enfant , Prévalence , Malocclusion dentaire/diagnostic , Malocclusion dentaire/épidémiologie , Malocclusion dentaire/thérapie , Indice de besoin de traitement orthodontique , Évaluation des besoins , Orthodontie correctrice
3.
J Orofac Orthop ; 84(Suppl 1): 1-9, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36723620

ABSTRACT

PURPOSE: Current population-wide data on the prevalence of malocclusions in 8­ and 9­year-old children in Germany are not available. Therefore, the primary objective of this study was to collect data on the prevalence of malocclusions in 8­ and 9­year-old children in Germany. The secondary objective of this study was to use this information to derive the need for orthodontic care provision. METHODS: This is an oral-epidemiological investigation and social science survey at the national level with a focus on tooth and jaw misalignment. The investigation took place between January and March 2021 at 16 study centers across Germany. All relevant data were available for the 705 study participants and were included in the statistical analysis. RESULTS: Overbite was the most common finding with 88.9%. Also widespread were crowding, with at least 60.9%, and lack of space, with a share of 30.9%. All other indication groups had a share below 10%. Rare (< 1%) were buccal and lingual occlusions and craniofacial abnormalities. The most severe forms of disease (Orthodontic Indication Group [Kieferorthopädische Indikationsgruppen, KIG] grade 5) were overbite (3.2%), open bite malocclusion (1.0%), undershot (0.6%), and craniofacial abnormalities (0.4%). The proportion of study participants who required orthodontic treatment, in accordance with statutory health insurance provider guidelines, was 40.4%. The proportion of study participants in principle requiring orthodontic treatment for medical reasons was 97.5%. Systemic differences in the need for orthodontic care provision relating to gender, region, or social status were not identified. CONCLUSION: In general, the need for care provision identified in the orthodontic indication groups corresponds to that shown in previous studies. This suggests that the need for orthodontic treatment in Germany has remained stable over the years.


Subject(s)
Malocclusion de classe II , Malocclusion dentaire , Surocclusion , Humains , Enfant , Santé buccodentaire , Prévalence , Malocclusion dentaire/diagnostic , Malocclusion dentaire/épidémiologie , Malocclusion dentaire/thérapie , Malocclusion de classe II/épidémiologie , Allemagne/épidémiologie
4.
J Clin Pediatr Dent ; 47(1): 1-8, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36627214

ABSTRACT

A great emphasis is currently given to the early correction of malocclusions to prevent further complications if left untreated. Interceptive orthodontics not only simplifies but also eliminates the need for later procedures. The 2 × 4 appliance is an orthodontic treatment modality applied during the mixed dentition period, particularly for malpositioned permanent upper incisors. This scoping review was aimed to examine the breadth and depth of the published literature on this clinical topic, as well as knowledge gaps, about this fixed appliance during mixed dentition, for the correction of incipient anterior malocclusions (incisor crowdings, midline diastemas, or crossbites). PubMed, Cochrane Library, Google Scholar, Dentistry & Oral Sciences Source, and two grey literature databases were explored; under a structured PICO question (Patient, Intervention, Comparison, Outcome) and eligibility criteria, for relevant clinical trials, observational studies, and case reports/series (in English or Spanish), using different searching terms. Titles and abstracts were screened. Full-text articles were critically reviewed for bias risk and a data charting table was constructed. 161 references were identified, after which 115 titles remained after removing duplicates. After the abstract screening, 18 potential full-text articles were reviewed. Finally, 16 studies were included, according to the performed critical appraisal. The 2 × 4 appliance is suitable for mixed dentition patients with mild or severe malocclusions, particularly when removable appliance usage is a critical problem.


Subject(s)
Denture mixte , Malocclusion dentaire , Humains , Malocclusion dentaire/thérapie , Appareils dentaires fixes , Orthodontie interceptive , Incisive
5.
J Clin Pediatr Dent ; 47(1): 67-73, 2023 Jan.
Article in English | MEDLINE | ID: mdl-36627222

ABSTRACT

This study aimed to identify the frequency of complications during the diagnosis, observation, and treatment of supernumerary teeth or odontomas and evaluate the relationship between complications and the timing of surgical intervention. This study was conducted based on data from the Korea Health Insurance Review and Assessment Service between January 2008 and December 2019. A 2-year washout period was applied, and a follow-up period of at least 2 years was also included. During the observation period, the age at diagnosis of supernumerary teeth and odontomas was analyzed using major diagnostic codes, and the treatment codes were used to determine the interval between diagnosis and surgical intervention. The incidence rates of supernumerary teeth (1.21%) and odontomas (0.36%) were comparable to that reported in previous studies. The frequency of supernumerary teeth was the highest in the anterior region, followed by the premolar and molar regions. The average ages at diagnosis according to the location of the supernumerary teeth were 7.25, 13.98, and 16.11 years in the anterior, premolar, and molar regions, respectively. The age at diagnosis correlated with the maturity period of the teeth at the corresponding location. For the supernumerary tooth group, surgical intervention was more likely to occur when malocclusion (p < 0.0001) or tooth eruption disturbances (p < 0.0001) were present or dentigerous cysts were absent (p = 0.006). For the odontoma group, malocclusion (p = 0.251) was not correlated with surgical intervention. When tooth eruption disturbances (p = 0.002) and dentigerous cysts (p < 0.0001) were present, surgical intervention was more likely to occur. Pediatric dentists should conduct timely clinical checks and periodic follow-ups to prevent complications and unnecessary orthodontic treatments in patients with supernumerary teeth or odontomas.


Subject(s)
Kyste dentigère , Malocclusion dentaire , Odontome , Dent enclavée , Dent surnuméraire , Enfant , Humains , Dent surnuméraire/épidémiologie , Dent surnuméraire/chirurgie , Dent enclavée/thérapie , Odontome/épidémiologie , Odontome/chirurgie , Kyste dentigère/complications , Malocclusion dentaire/complications , Assurance maladie , République de Corée/épidémiologie
6.
Article in English | MEDLINE | ID: mdl-36674407

ABSTRACT

BACKGROUND: There is still an ongoing debate about the role of the craniomandibular system, including occlusal conditions, on postural stability. This study aims to assess the role of antero-posterior malocclusion on postural control and plantar pressure distribution during standing and walking. METHODS: 90 healthy volunteers (aged 19 to 35) were qualified for the study. The subjects were assigned to three groups, depending on the occlusion type. Each group (Angle Class I, II and III) consisted of 30 people. The research procedure included a clinical occlusal assessment performed by a dentist. Postural control measurements were carried out using a force platform by measuring plantar pressure distribution during standing (six trials with and without visual control) and walking test conditions. RESULTS: The tendency to shift the CoP forward is demonstrated by Angle Class II subjects and backwards by Class I and III subjects (p < 0.001). Individuals with a malocclusion demonstrated significantly higher selected stabilographic parameters while standing on both feet (with eyes open and closed) and during the single-leg test with eyes open (p < 0.05). The analysis of the dynamic test results showed no significant correlations between Angle Classes and the selected gait parameters. CONCLUSIONS: Analyses conducted among individuals with malocclusions showed the impact of occlusion on static postural stability. In order to diagnose and effectively treat malocclusion, a multidisciplinary approach with the participation of dentists and physiotherapy specialists is necessary, with the use of stabilometric and kinematic posture assessments.


Subject(s)
Occlusion dentaire , Malocclusion dentaire , Humains , Adulte , Démarche , Posture , Position debout , Équilibre postural
7.
Gen Dent ; 71(1): 66-70, 2023.
Article in English | MEDLINE | ID: mdl-36592362

ABSTRACT

The goal of this study was to describe a series of orthognathic surgery cases in which a clear aligner system was used for orthodontic treatment. A total of 16 cases were undertaken. A majority of the patients were female (68.75%), and the mean age of the patients was 26.78 years (SD 10.85 years). The most frequent malocclusion was Class II (56.25%), mainly caused by mandibular retrognathism (80.00%). Most of the patients were treated with single-jaw surgeries (56.15%). Orthodontic buttons and elastics were used for maxillomandibular fixation in 81.25% of the patients. The mean (SD) treatment period was 19.00 (1.11) months, and the postsurgical follow-up varied from 6 months to 10 years. Good results were achieved with orthognathic surgery and the adjunctive use of clear aligners, and no damage was noted during the orthosurgical treatment. Since clear aligners provide an esthetic, removable appliance and may be more acceptable to patients than conventional orthodontic appliances, the use of clear aligners in orthognathic surgery is a promising alternative to traditional orthodontics.


Subject(s)
Malocclusion dentaire , Appareils orthodontiques amovibles , Chirurgie orthognathique , Procédures de chirurgie orthognathique , Humains , Mâle , Femelle , Adulte , Appareils orthodontiques , Mouvement dentaire/méthodes
8.
BMC Oral Health ; 23(1): 18, 2023 01 13.
Article in English | MEDLINE | ID: mdl-36639670

ABSTRACT

BACKGROUND: Three-dimensional (3D) detailed evaluations of the mandibular mediolateral position, mandibular condylar position, and temporomandibular joint (TMJ) spaces following stabilization splints (SS) therapy in patients with temporomandibular joint disorders (TMD) and mandibular deviation (MD) have not been reported in the available literature. Accordingly, this study aimed to three-dimensionally analyze the skeletal and bony temporomandibular joint changes following stabilization splint therapy in adult patients with temporomandibular joint disorders and mandibular deviation. METHODS: This study is a retrospective clinical study that enrolled 26 adult patients with TMD and MD with a mean age of 24.86 years. The Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) was used to diagnose TMD. SS was adjusted weekly until occlusal contact stabilization occurred, and then adjusted monthly, patients were instructed to wear it at night for at least 10 h. The SS was removed after the elimination of TMD symptoms (TMJ/muscle pain on palpation, muscle spasm, and clicking) and having both condyles completely seated in a musculoskeletally stable position. Pre- and post-therapeutic Cone Beam Computed Tomography (CBCT) was analyzed. Mandibular mediolateral position, TMJ spaces, and mandibular condyle position were analyzed three-dimensionally using Mimics 21.0 software. Paired t-test or Wilcoxon rank-sum test was performed, and the significance level was considered at P < 0.05. RESULTS: The treatment period with SS therapy was 10.07 ± 3.1 months. The deviated chin was improved in 69.23% of the sample; the range of improvement was > 0 mm ≤ 3.9 mm. The mandibular rotation was significantly decreased from 3.58 ± 2.02° to 3.17 ± 1.60. The deviated side's superior and posterior joint TMJ spaces were significantly increased from 2.49 ± 0.88 mm and 1.25 ± 0.79 mm to 2.98 ± 1.02 mm and 1.86 ± 0.72 mm, respectively. The value of the difference from the bilateral condyle head position to the X and Z axes significantly decreased from 2.50 ± 1.56 mm and 2.30 ± 1.57 mm to 1.64 ± 1.58 mm and 1.82 ± 1.11 mm, respectively. CONCLUSION: The main positional effect of the stabilization splint treatment in TMD patients with MD includes considerable correction of mandibular deviation, improving facial asymmetry, and moving the condyle into a stable condylar position; these were done by promoting the mandible to rotate around the Z (roll) and Y (yaw) axes and by forward, downward, and outward condylar movement on the deviated side, respectively.


Subject(s)
Malocclusion dentaire , Gouttières occlusales , Troubles de l'articulation temporomandibulaire , Adulte , Humains , Jeune adulte , Malocclusion dentaire/imagerie diagnostique , Malocclusion dentaire/thérapie , Condyle mandibulaire/imagerie diagnostique , Études rétrospectives , Attelles , Articulation temporomandibulaire/imagerie diagnostique , Troubles de l'articulation temporomandibulaire/imagerie diagnostique , Troubles de l'articulation temporomandibulaire/thérapie
9.
BMC Oral Health ; 23(1): 28, 2023 01 17.
Article in English | MEDLINE | ID: mdl-36650491

ABSTRACT

BACKGROUND: It is difficult for orthodontists to accurately predict the growth trend of the mandible in children with anterior crossbite. This study aims to develop a deep learning model to automatically predict the mandibular growth result into normal or overdeveloped using cephalometric radiographs. METHODS: A deep convolutional neural network (CNN) model was constructed based on the algorithm ResNet50 and trained on the basis of 256 cephalometric radiographs. The prediction behavior of the model was tested on 40 cephalograms and visualized by equipped with Grad-CAM. The prediction performance of the CNN model was compared with that of three junior orthodontists. RESULTS: The deep-learning model showed a good prediction accuracy about 85%, much higher when compared with the 54.2% of the junior orthodontists. The sensitivity and specificity of the model was 0.95 and 0.75 respectively, higher than that of the junior orthodontists (0.62 and 0.47 respectively). The area under the curve value of the deep-learning model was 0.9775. Visual inspection showed that the model mainly focused on the characteristics of special regions including chin, lower edge of the mandible, incisor teeth, airway and condyle to conduct the prediction. CONCLUSIONS: The deep-learning CNN model could predict the growth trend of the mandible in anterior crossbite children with relatively high accuracy using cephalometric images. The deep learning model made the prediction decision mainly by identifying the characteristics of the regions of chin, lower edge of the mandible, incisor teeth area, airway and condyle in cephalometric images.


Subject(s)
Apprentissage profond , Malocclusion dentaire , Humains , Enfant , Mandibule/imagerie diagnostique , , Radiographie , Malocclusion dentaire/imagerie diagnostique
10.
BMC Oral Health ; 23(1): 37, 2023 Jan 23.
Article in English | MEDLINE | ID: mdl-36691053

ABSTRACT

BACKGROUND: Sex dimorphism has been implicated in oral health differences and the pathogenesis of oral diseases, such as tooth agenesis, periodontal disease, dental caries, and tooth loss. Tooth agenesis (TA) is one of the most common developmental anomalies in humans, and its prevalence and patterns are different across ethnic groups. The aim of this study was to investigate the phenotypes and sex-associated patterns of nonsyndromic tooth agenesis (TA) in Thai dental patients. METHODS: One thousand ninety panoramic radiographs were examined. One hundred and one subjects (37 males, 64 females, 15-20 years-old) with nonsyndromic TA were evaluated. Differences in TA prevalence between groups were analyzed using the chi-square or Fisher exact test. RESULTS: The TA prevalence, excluding third molars, was 9.3% and more frequently found in the mandible compared with the maxilla. The maxilla demonstrated a higher prevalence of first premolar agenesis than the mandible (P = 0.012), while the mandible had a higher prevalence of second premolar agenesis than the maxilla (P = 0.031). There were significantly more males missing one tooth than females, however, there were more females missing two or more teeth than males (P = 0.042). A missing maxillary left lateral incisor was significantly more frequent in males (P = 0.019), while a missing mandibular right lateral incisor was more frequent in females (P = 0.025). In females, the pattern of two mandibular lateral incisors agenesis was the most common and significantly present in females more than males (P = 0.015). In contrast, the pattern of one mandibular left lateral incisor agenesis was only observed in males and significantly found in males more than females (P = 0.047). CONCLUSIONS: We demonstrate sex-associated differences in nonsyndromic tooth agenesis. The prevalence of single tooth agenesis was higher in males, while that of two or more teeth agenesis was higher in females. We found different patterns of lateral incisor agenesis between males and females.


Subject(s)
Anodontie , Caries dentaires , Malformations dentaires , Adolescent , Adulte , Femelle , Humains , Mâle , Jeune adulte , Anodontie/épidémiologie , Caries dentaires/anatomopathologie , Denture permanente , Maxillaire/anatomopathologie , Prévalence , Caractères sexuels , Malformations dentaires/épidémiologie , Malocclusion dentaire
12.
BMC Oral Health ; 22(1): 557, 2022 Dec 01.
Article in English | MEDLINE | ID: mdl-36456929

ABSTRACT

OBJECTIVE: Additively manufactured (3D-printed) titanium meshes have been adopted in the dental field as non-resorbable membranes for guided bone regeneration (GBR) surgery. However, according to previous studies, inaccuracies between planned and created bone volume and contour are common, and many reasons have been speculated to affect its accuracy. The size of the alveolar bone defect can significantly increase patient-specific titanium mesh design and surgical difficulty. Therefore, this study aimed to analyze and investigate the effect of bone defect size on the 3D accuracy of alveolar bone augmentation performed with additively manufactured patient-specific titanium meshes. METHODS: Twenty 3D-printed patient-specific titanium mesh GBR surgery cases were enrolled, in which 10 cases were minor bone defect/augmentation (the planned bone augmentation surface area is less than or equal to 150 mm2 or one tooth missing or two adjacent front-teeth/premolars missing) and another 10 cases were significant bone defect/augmentation (the planned bone augmentation surface area is greater than 150 mm2 or missing adjacent teeth are more than two (i.e. ≥ three teeth) or missing adjacent molars are ≥ two teeth). 3D digital reconstruction/superposition technology was employed to investigate the bone augmentation accuracy of 3D-printed patient-specific titanium meshes. RESULTS: There was no significant difference in the 3D deviation distance of bone augmentation between the minor bone defect/augmentation group and the major one. The contour lines of planned-CAD models in two groups were basically consistent with the contour lines after GBR surgery, and both covered the preoperative contour lines. Moreover, the exposure rate of titanium mesh in the minor bone defect/augmentation group was slightly lower than the major one. CONCLUSION: It can be concluded that the size of the bone defect has no significant effect on the 3D accuracy of alveolar bone augmentation performed with the additively manufactured patient-specific titanium mesh.


Subject(s)
Anodontie , Implants dentaires , Malocclusion dentaire , Perte dentaire , Humains , Titane , Filet chirurgical
13.
Front Public Health ; 10: 1045815, 2022.
Article in English | MEDLINE | ID: mdl-36466455

ABSTRACT

Objective: This study aims to develop a new category scheme for the profile morphology of temporomandibular disorders (TMDs) based on lateral cephalometric morphology. Methods: Five hundred and one adult patients (91 males and 410 females) with TMD were enrolled in this study. Cluster tendency analysis, principal component analysis and cluster analysis were performed using 36 lateral cephalometric measurements. Classification and regression tree (CART) algorithm was used to construct a binary decision tree based on the clustering results. Results: Twelve principal components were discovered in the TMD patients and were responsible for 91.2% of the variability. Cluster tendency of cephalometric data from TMD patients were confirmed and three subgroups were revealed by cluster analysis: (a) cluster 1: skeletal class I malocclusion; (b) cluster 2: skeletal class I malocclusion with increased facial height; (c) cluster 3: skeletal class II malocclusion with clockwise rotation of the mandible. Besides, CART model was built and the eight key morphological indicators from the decision tree model were convenient for clinical application, with the prediction accuracy up to 85.4%. Conclusion: Our study proposed a novel category system for the profile morphology of TMDs with three subgroups according to the cephalometric morphology, which may supplement the morphological understanding of TMD and benefit the management of the categorical treatment of TMD.


Subject(s)
Malocclusion dentaire , Troubles de l'articulation temporomandibulaire , Adulte , Femelle , Mâle , Humains , Analyse de regroupements , Analyse en composantes principales , Algorithmes
14.
Eur J Paediatr Dent ; 23(4): 275-280, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36511914

ABSTRACT

AIM: The aim of the present prospective study was to evaluate the effectiveness of elastodontic appliance (EAs) in the treatment of subjects presenting Class II sagittal discrepancy in mixed dentition, and to evaluate palatal morphological development during treatment. MATERIALS: The study group, composed of 19 subjects, received treatment with EA for 1 year. The control group consisted of 17 untreated subjects. INCLUSION CRITERIA: age between 6 and 11 years, mixed deciduous dentition and skeletal and/or dental Class II malocclusion. EXCLUSION CRITERIA: previous orthodontic therapy, systemic diseases and signs of temporal dysfunction. Skeletal and dentoalveolar parameters were compared between T0 and T1. A 3D imaging technology was used to compare palatal morphology obtained from intra-oral digital scans between T0 (pre-treatment) and T1 (post-treatment). CONCLUSION: EAs can successfully mitigate early signs of malocclusion in Class II subjects as well as contribute to the harmonious development of the palate.


Subject(s)
Malocclusion de classe II , Malocclusion dentaire , Humains , Enfant , Denture mixte , Études prospectives , Céphalométrie/méthodes , Maxillaire , Malocclusion de classe II/imagerie diagnostique , Malocclusion de classe II/thérapie , Palais , Malocclusion dentaire/thérapie
15.
Niger J Clin Pract ; 25(12): 1955-1962, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36537450

ABSTRACT

Background and Aim: Four premolars extractions are routine procedures for correction of malocclusion, but will inevitably lead to a reduction of tongue space, whether this will weaken the pharyngeal airway remains a controversy. Patients and Methods: Cone-beam computed tomography (CBCT) radiographs of 80 patients who completed four premolar extraction orthodontic treatments were collected and divided into three anteroposterior skeletal groups according to the ANB (angle subspinale to nasion to supramentale) value. Linear, angular, cross-sectional area, and volumetric dimensions of the pharyngeal airway were measured using Dolphin Imaging 11.9 software. One-way analysis of variance and Pearson's correlation coefficient test were performed to assess the intergroup comparisons. Treatment changes were evaluated with two-sample t-tests. Results: In intergroup comparisons, vertical linear and cross-sectional area differences were identified in S-Go/N-Me, VD1, VD1/N-Me, VD2/N-Me, AA, OAA and OMINI (p<0.05), while other measurements showed no significant differences. Angle2, the tilting degree of the pharyngeal airway, showed a positive correlation with ANB (p<0.05). As for the treatment changes, a significant increase was found in the pharyngeal airway in the Class I group (OUA p<0.05, VD1 p<0.001, VD2 p<0.05) and Class II group (VD1 p<0.001. VD2, p<0.05), and inversely, a significant decrease was found in the pharyngeal airway in the Class III group (OAA p<0.05, OMINI p<0.05, OUA p<0.05). No volumetric difference was identified. Interestingly, regarding the preoperative pharyngeal airway size, values trended to the mean value significantly. Conclusion: Four premolar extraction orthodontic treatments did not affect the pharyngeal airway volume except for the vertical liner and cross-sectional area dimensions. The trend of the gold standard suggested a positive influence of four premolar extraction orthodontic treatments.


Subject(s)
Malocclusion de classe III , Malocclusion dentaire , Tomodensitométrie hélicoïdale à faisceau conique , Humains , Prémolaire/chirurgie , Mandibule , Pharynx , Tomodensitométrie à faisceau conique/méthodes , Céphalométrie/méthodes , Imagerie tridimensionnelle/méthodes
16.
Article in English | MEDLINE | ID: mdl-36554314

ABSTRACT

Urban rail transit (URT) is a key mode of public transport, which serves for greatest user demand. Short-term passenger flow prediction aims to improve management validity and avoid extravagance of public transport resources. In order to anticipate passenger flow for URT, managing nonlinearity, correlation, and periodicity of data series in a single model is difficult. This paper offers a short-term passenger flow prediction combination model based on complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) and long-short term memory neural network (LSTM) in order to more accurately anticipate the short-period passenger flow of URT. In the meantime, the hyperparameters of LSTM were calculated using the improved particle swarm optimization (IPSO). First, CEEMDAN-IPSO-LSTM model performed the CEEMDAN decomposition of passenger flow data and obtained uncoupled intrinsic mode functions and a residual sequence after removing noisy data. Second, we built a CEEMDAN-IPSO-LSTM passenger flow prediction model for each decomposed component and extracted prediction values. Third, the experimental results showed that compared with the single LSTM model, CEEMDAN-IPSO-LSTM model reduced by 40 persons/35 persons, 44 persons/35 persons, 37 persons/31 persons, and 46.89%/35.1% in SD, RMSE, MAE, and MAPE, and increase by 2.32%/3.63% and 2.19%/1.67% in R and R2, respectively. This model can reduce the risks of public health security due to excessive crowding of passengers (especially in the period of COVID-19), as well as reduce the negative impact on the environment through the optimization of traffic flows, and develop low-carbon transportation.


Subject(s)
, Malocclusion dentaire , Humains , Transports/méthodes , , Santé publique
17.
Prog Orthod ; 23(1): 56, 2022 Dec 28.
Article in English | MEDLINE | ID: mdl-36575336

ABSTRACT

BACKGROUND: It is thought that achieving a normal overjet may help to stabilise the alignment of the maxillary anterior dentition. Little's Irregularity Index is limited in assessing discrete post-orthodontic changes, fails to account for reciprocal rotations and is not sensitive to dental changes in three planes. A more holistic tool for the assessment of post-treatment change is therefore required. AIM: To compare the post-treatment stability of maxillary anterior dental alignment in subjects treated either to a Class I incisor relationship or an increased overjet (> 4 mm) following fixed appliance-based orthodontics using a novel measurement tool. MATERIALS AND METHODS: The Orthodontic Alignment Index (OAI) was developed and validated using a panel of 63 raters. The new index accounts for a range of weighted features including contact point displacement, spacing, reciprocal rotations, inclination, angulation and vertical discrepancy. A retrospective cohort study was undertaken at the Institute of Dentistry, Queen Mary University of London. Recruitment took place over a 4-year period. All participants had removable retainers in the maxillary arch only. The stability of maxillary anterior teeth was assessed using Little's Irregularity Index (LII) and the OAI. Subjects were recruited at least 12 months following completion of dual-arch fixed appliance-based treatment. RESULTS: Eighty-two participants were included with a positive correlation observed between LII and OAI at the 12-month post-treatment review with a 1-mm increase in LII associated with a 2-point increase in the OAI (P < 0.001). Limited relapse was observed in both groups: normal overjet group (OAI = 1.28; LII = 0.52); residual overjet group (OAI = 0.88; LII = 0.47). Median regression analysis failed to identify a significant association between an increased overjet at debond and the alignment of the maxillary anterior segment when assessed with OAI (P = 0.389) and LII (P = 0.577). Furthermore, age, gender, extraction protocols and retention regime were not predictive of post-treatment change. CONCLUSIONS: Using a novel index (OAI) and LII, there was limited post-treatment relapse in alignment of the maxillary anterior dentition over a 12-month period. Based on this retrospective evaluation, achieving a normal overjet at the end of treatment may have little bearing on the post-treatment stability of maxillary anterior alignment at 12 months.


Subject(s)
Malocclusion de classe II , Malocclusion dentaire , Surocclusion , Humains , Études rétrospectives , Denture , Malocclusion dentaire/thérapie , Surocclusion/thérapie , Récidive , Appareils de contention orthodontiques , Orthodontie correctrice/méthodes
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