Angle Class Research Articles

Comparison of clinical efficiency between pendulum and distal jet appliance - A randomized control trial

The study was to compare the clinical efficiency of Pendulum and distal jet appliances using both cephalometric parameters as well as dental cast analysis at two-time intervals T1-pre-treatment and T2-post-distalization. 10 patients with Angle's Class II malocclusion were enrolled in the study. The patients were divided into two groups: pendulum group & distal jet group (n = 5) for intra oral molar distalization. Lateral cephalogram and dental cast were obtained at T1 and T2. Molar distalization of 4.4 ± 1.1 mm in 4.68 ± 0.67 months in pendulum group and of 3.8 ± 0.4 mm in 5.84 ± 0.7 months in distal jet group. Relative intrusion of upper incisors was found to be more in pendulum group as compared to distal jet group. Mesial tipping of premolars and distal tipping of first molar was observed with both the groups. The transverse expansion at the level of first molars was significantly more in distal jet group as compared to pendulum group. Thus, Pendulum and distal jet appliances were found to be equally effective clinically in distalizing the maxillary molars, although the distalization period was shorter in pendulum group as compared to distal jet group owing to more distal tipping of maxillary first molars in pendulum group. The expansion was significantly more in distal jet group compared to the pendulum group which could be beneficial for patients who have Class II malocclusion with mild posterior crossbite.

Effect of Salvadora persica chewing sticks on maxillary central incisors crown-root angulation in Western-Asian population & correlation with Collum angle on 3D CBCT images

The main aim of the study was to identify the Collum angle classification for maxillary central incisors among individuals use vs not-use chewing sticks which could have beneficial role for immediate implant placement in respective individuals. Additionally, to identify the root-crown positioning and angulation in the Western Asian Saudi Arabian population for chewing sticks user’s vs non-users in order to develop guideline for the prosthetic procedures using Cone beam computed tompography (CBCT). A total number of 380 CBCT scans were included in the study for both of the groups based on the inclusion criterion of the patients reporting to the Dental OPD of Riyadh Elm University. The data was analyzed using 3D planner dental imaging software. Initially the teeth were classified based on root position in relation to facial plate of alveolar bone using Jung et al. classification. Additionally, the Collum angle and the root angulation of the maxillary central incisors was evaluated. The data was analyzed using one-way Anova with post-hoc Tuckey-Kramer test for pair-wise comparison. As per the Jung et al. classification, majority of the roots were observed with buccal placement. Based on the Collum angle classification majority of the maxillary central incisors were observed with facial placement (n=170), specially subtype I (n=78). But the root angulation was observed to be independent of Collum angle. Thus, it can be concluded, unlike root angulation, Collum angle has a correlation with root positioning. The angle for the individuals using chewing sticks of Salvadora Persica was similar to the individuals not using the miswak. Collum angle is correlated in all classified position of root. But the root angulation is independent of classification varies between miswak and non-miswak users.

Evaluation of Rate of Space Closure Between Platelet Rich Plasma (Prp) Injection and Piezocision in Bimaxillary Protrusion Cases

Aim: Reducing orthodontic treatment duration is a significant concern for both patients and clinicians, as prolonged treatments can lead to complications like dental caries, root resorption, and decreased patient compliance. This study aims to compare the effectiveness of two minimally invasive techniques—Piezocision and platelet-rich plasma (PRP) injection—in accelerating orthodontic tooth movement during space closure in patients with bimaxillary protrusion. Methods: Sixteen patients diagnosed with Angle's Class I bimaxillary protrusion requiring extraction of first premolars were randomly assigned to two groups. Group A (n = 8) underwent Piezocision-assisted orthodontic treatment, while Group B (n = 8) received submucosal PRP injections. In both groups, one side of the maxillary arch served as the experimental side, and the contralateral side served as the control. Measurements of space closure were taken at the initiation of retraction (T₀) and after 90 days (T₁). Results: Both Piezocision and PRP significantly enhanced the rate of space closure compared to their control sides. However, Piezocision demonstrated a statistically faster rate of tooth movement than PRP injection. The mean difference in space closure between the Piezocision and PRP groups at T₁ was significant (p < 0.001). Conclusion: While both Piezocision and PRP injections effectively accelerated orthodontic tooth movement, Piezocision proved to be more efficient in reducing treatment time. Clinicians may consider Piezocision as a preferred method for patients seeking expedited orthodontic treatment.

The Influence of Wind Musical Instruments on the Orofacial System.

The main objective of this study was to assess whether there are differences in the muscular and occlusal levels between wind players and the general population, in addition to assessing the different repercussions depending on the embouchure type. Two cohorts were chosen: one of them comprised intermediate students related to the practice of a wind instrument (n = 39), and the other one, harmonized with the former, comprised secondary students that served as a control group (n = 19). Overjet, overbite, presence of lip abrasion and/or erosion, Angle's molar class, Little's irregularity index, dental abrasion, presence of labial herpes, presence of tooth sensitivity, and presence of articular noises muscle pain were evaluated. Significant statistical differences between the groups were found regarding overjet, overcrowding of teeth, lower lip erosion, and dental abrasion, which was higher in musicians. Lastly, within the group of musicians, it was proven that tooth sensitivity was higher in the group of brass musicians. Wind instrument practice may be a risk factor for developing some orofacial involvement, and there are no differences among the various existing mouthpieces.

Evaluation of four machine learning methods in predicting orthodontic extraction decision from clinical examination data and analysis of feature contribution.

The study aims to predict tooth extraction decision based on four machine learning methods and analyze the feature contribution, so as to shed light on the important basis for experts of tooth extraction planning, providing reference for orthodontic treatment planning. This study collected clinical information of 192 patients with malocclusion diagnosis and treatment plans. This study used four machine learning strategies, including decision tree, random forest, support vector machine (SVM) and multilayer perceptron (MLP) to predict orthodontic extraction decisions on clinical examination data acquired during initial consultant containing Angle classification, skeletal classification, maxillary and mandibular crowding, overjet, overbite, upper and lower incisor inclination, vertical growth pattern, lateral facial profile. Among them, 30% of the samples were randomly selected as testing sets. We used five-fold cross-validation to evaluate the generalization performance of the model and avoid over-fitting. The accuracy of the four models was calculated for the training set and cross-validation set. The confusion matrix was plotted for the testing set, and 6 indicators were calculated to evaluate the performance of the model. For the decision tree and random forest models, we observed the feature contribution. The accuracy of the four models in the training set ranges from 82% to 90%, and in the cross-validation set, the decision tree and random forest had higher accuracy. In the confusion matrix analysis, decision tree tops the four models with highest accuracy, specificity, precision and F1-score and the other three models tended to classify too many samples as extraction cases. In the feature contribution analysis, crowding, lateral facial profile, and lower incisor inclination ranked at the top in the decision tree model. Among the machine learning models that only use clinical data for tooth extraction prediction, decision tree has the best overall performance. For tooth extraction decisions, specifically, crowding, lateral facial profile, and lower incisor inclination have the greatest contribution.

Observation of dynamic position and morphological changes of temporomandibular joint discs under Angle's classification

Objective: To observe the dynamic changes of the temporomandibular joint (TMJ) disc in joint movement under different Angle's classification, providing reference for understanding joint functional movement and providing a basis for more accurate clinical imaging diagnosis. Methods: A total of 30 patients (13 males and 17 females) with temporomandibular disorders who were admitted to Beijing Friendship Hospital, Capital Medical University and General Hospital of the People's Liberation Army from January 2022 to April 2024 were enrolled. Thirty adults (13 males and 17 females) with different Angle's classification, with an average age of (34.4±8.5) years, were subjected to dynamic imaging of their TMJ from the closed position to the maximum opening position, and then to the closed position using MRI. The position and morphological changes of the articular discs were observed. Results: The results showed that volunteers with no displacement of the articular disc in class Ⅰ, Ⅱ, and Ⅲ relationships had different shapes of the articular disc during open and closed mouth movements. However, in the maximum opening position, the articular disc were all located directly below the maxillary nodules, and their shape is double concave. In terms of irreversible anterior displacement of the articular disc, in class Ⅰ Angle, the posterior zone of the disc contacts the anterior inclined plane of condyle from the maximum opening position back to the front of the closing position. In class Ⅱ, the posterior zone of the disc contacts the anterior inclined plane of condyle from the beginning of opening position to maximum opening position. In class Ⅲ, the posterior zone of the disc is always in contact with the anterior inclined plane of condyle throughout the entire movement process. And among them, the articular disc presents a forward displacement state at the closing position, its morphology undergoes folding phenomenon. When the openness is 2.5 cm, the articular disc moves up to a certain extent, and is closer to the anterior inclined plane of condyle, and its shape is also partially changed. When the openness is 4.3 cm, the shape of the articular disc, located between the anterior inclined plane of the joint node and the posterior inclined plane of the condyle, is typical double concave, which is sufficient to show that the articular disc is reversible when maximum opening position is reached. In terms of reversible anterior disc displacement, in class Ⅰ Angle, the posterior zone of the disc contact with the anterior inclined plane of condyle at the beginning of the opening position and the end of the closing position. In classⅡ Angle, the posterior zone of the articular disc is not in contact with the anterior inclined plane of condyle. In class Ⅲ Angle, the posterior zone of the articular disc contact with the anterior inclined plane of condyle at the end of the closing position. Conclusions: Multi level dynamic MR imaging data of the temporomandibular joint can dynamically observe the movement of the temporomandibular joint, intuitively and accurately display the position and shape of the articular disc during movement, and can serve as a useful supplement to static conventional MR imaging of the TMJ. The patient's TMJ needs to reach the maximum opening position in order to determine whether the joint disc displacement can be reversible or not.

A Comparison of Arch Length, Intercanine Width, Intermolar Width, and Interalveolar Width in Patients With Angle's Class II Division I Malocclusion With Shallow and Deep Palates.

Background and objective Palatal depth is significant as it impacts the intra-arch dimensions in patients with Angle's Class II Division 1 malocclusion. Hence, understanding this relationship is crucial for developing targeted orthodontic treatment plans, to optimize dental alignment and overall facial aesthetics. This study aimed to compare the arch length, intercanine width, intermolar width, and interalveolar width in patients with Class II Division 1 malocclusion with deep palates and those with shallow palates. Methods The study involved 88 patients aged 18-30 years, categorized into two groups based on palatal depth: Group A (deep palates) and Group B (shallow palates). Measurements were taken for arch length, intercanine width, intermolar width, and interalveolar width. An independent samples t-test was used to compare these measurements between the groups, with statistical significance set at p<0.05. Results The analysis revealed significant differences in intermolar and interalveolar widths between the two groups. Group B, with shallow palates, showed larger intermolar and interalveolar widths compared to Group A, with deep palates (p = 0.001 and p = 0.017, respectively). However, no significant differences were observed in arch length and intercanine width between the groups. Conclusions Our findings suggest that palatal depth is significantly associated with certain intra-arch transverse dimensions, particularly intermolar and interalveolar widths. These differences underline the importance of considering palatal morphology in the orthodontic treatment of patients with Class II Division 1 malocclusion.

Assessment of Thermal Influence on an Orthodontic System by Means of the Finite Element Method.

The development of the finite element method (FEM) combined block polynomial interpolation with the concepts of finite difference formats and the variation principle. Because of this combination, the FEM overcomes the shortcomings of traditional variation methods while maintaining the benefits of current variation methods and the flexibility of the finite difference method. As a result, the FEM is an advancement above the traditional variation methods. The purpose of this study is to experimentally highlight the thermal behavior of two stomatognathic systems, one a control and the other presenting orthodontic treatment by means of a fixed metallic orthodontic appliance, both being subjected to several thermal regimes. In order to sustain this experimental research, we examined the case of a female subject, who was diagnosed with Angle class I malocclusion. The patient underwent a bimaxillary CBCT investigation before initiating the orthodontic treatment. A three-dimensional model with fully closed surfaces was obtained by using the InVesalius and Geomagic programs. Like the tissues examined in the patient, bracket and tube-type elements as well as orthodontic wires can be included to the virtual models. Once it is finished and geometrically accurate, the model is exported to an FEM-using program, such as Ansys Workbench. The intention was to study the behavior of two stomatognathic systems (with and without a fixed metallic orthodontic appliance) subjected to very hot food (70 °C) and very cold food (-18 °C). From the analysis of the obtained data, it was concluded that, following the simulations carried out in the presence of the fixed metallic orthodontic appliance, significantly higher temperatures were generated in the dental pulp.

Soft Tissue Facial Morphology in Growing Patients with Different Occlusal Classes.

The study of facial profiles in the dental field is very important for the diagnosis and the dental and orthodontic treatment plan. The aim of this study is to analyze the three-dimensional morphology of the faces of 269 growing patients with Class I and II occlusions, focusing on children aged between 6 and 9 years old. The analysis was conducted using a non-invasive computerized system, which allowed for the automatic collection of facial landmarks and the subsequent reconstruction of three-dimensional coordinates. The sample comprised 269 children within the specified age range. Each child's facial features were captured using the non-invasive computerized system, which utilized two infrared CCD cameras, real-time hardware for label recognition, and software for three-dimensional landmark reconstruction. Sixteen cutaneous facial landmarks were automatically collected for each participant. From these landmarks, 10 angular and 15 linear measurements, as well as five direct distance rates, were derived. The mean values for each age class were calculated separately for children with bilateral Angle Class I occlusion and compared with those for children with bilateral Class II occlusion. In all children, the left and right occlusal classes were measured as suggested by Katz. The analysis revealed notable differences, primarily in the three-dimensional angular measurements between children with Class I and II occlusions. Specifically, Class II children exhibited more convex faces in the sagittal plane and a less prominent lower jaw compared to Class I children. However, no significant differences were observed in linear measurements, except for the lower facial height rate, which varied inconsistently across age groups between the two occlusion types. the findings of this research highlight distinct three-dimensional facial morphological differences between children with Class I and II occlusions. While Class II children tended to have more convex facial profiles and less prominent lower jaws, linear measurements showed minimal variation between the two occlusion types. These results underscore the importance of three-dimensional analysis in understanding facial morphology in growing patients with different occlusal patterns.

Developing of a multi-angle and varied walking conditions dataset for human gait recognition

The field of Human Gait Recognition (HGR) leverages unique walking patterns for non-invasive, discreet biometric identification. This study highlights the importance of comprehensive datasets in the development, testing, and validation of HGR algorithms. While current datasets, such as those from Carnegie Mellon University Motion of Body (CMU MoBo), Southampton (SOTON), Chinese Academic of Science Institute of Automation (CASIA B), and Osaka University Institute of Scientific Industrial Research (OU-ISIR), have advanced in scale and complexity, they often lack diversity and comprehensive sample representation. To address this gap, we introduce the TecNM Gait-DS dataset (Tecnologico Nacional de Mexico), specifically designed for Latin American populations, featuring 13 viewing angles and five walking variations. Utilizing a Self-Supervised Vision Transformer DINO (Deeper Into Neural Networks) model for view angle classification, our evaluation demonstrates significant improvements in classification accuracy. This dataset not only enhances sample diversity but also supports the development of more robust HGR systems. Our results underscore the potential for improved accuracy and ethical considerations in HGR, advocating for ongoing refinement of datasets to achieve optimal performance and societal acceptance.

On Boundary Discontinuity in Angle Regression Based Arbitrary Oriented Object Detection.

With vigorous development e.g., in autonomous driving and remote sensing, oriented object detection has gradually been featured. The majority of existing methods directly perform regression on the rotation angle, which we argue has fundamental limitations of boundary discontinuity (even if using Gaussian or RotatedIoU-based losses). In this paper, a novel angle coder named phase-shifting coder (PSC) is proposed to address this issue. Different from another well-explored alternative i.e., angle classification, PSC achieves boundary-discontinuity-free in a continuous and differentiable manner and thus can work together with Gaussian or RotatedIoU-based methods to further boost their performance. Moreover, by rethinking the boundary discontinuity of elongated and square-like objects as rotational symmetry of different cycles, a dual-frequency version (PSCD) is proposed to accurately predict the orientation of both types of objects. Visual analysis and extensive experiments on several popular backbone detectors and datasets demonstrate the effectiveness and the potentiality of our approach. When facing scenarios requiring high-quality bounding boxes, the proposed methods are expected to give a competitive performance.

Evaluating anchorage and torque control in adolescent patients with Class II Division 1 malocclusion among 3 appliances

The objective of this study was to compare the differences in anchorage and torque control among the Tweed edgewise, Roth, and physiological anchorage Spee-wire systems (PASS) appliances (Zhejiang Xinya Technology Co, Ltd, Hangzhou, China). A sample of 90 adolescent patients with Angle Class II Division 1 malocclusion (30 Tweed edgewise appliances, 30 Roth appliances, and 30 PASS appliances) with maximum anchorage requirements in the maxilla were collected for this study. The pretreatment baseline levels of the 3 groups were compared initially, and then the differences between the 3 appliances in anchorage and torque control were analyzed after superimposing the pretreatment and posttreatment lateral cephalograms and maxillary 3-dimensional (3D) digital models, respectively. There was no statistical difference in the pretreatment baseline levels of 3 groups, including gender, age, sagittal skeletal types (ANB), vertical skeletal types (SN-GoGn), anchorage requirements, and occlusal plane inclination (SN-OP). After superimposing the pretreatment and posttreatment lateral cephalograms and 3D digital models, respectively, no statistical differences were observed between the measurement results obtained from lateral cephalograms and 3D digital models. Among the measurement variables assessed in this study, statistical differences were observed in the mesial displacement of maxillary first molars, the incisor retraction, and the torque variation of maxillary central incisors among the 3 groups. Specifically, the Tweed group exhibited lower mesial displacement of maxillary first molars compared with the PASS and Roth groups. Furthermore, the Tweed group exhibited the greatest amount of incisor retraction and torque variation of maxillary central incisors, followed by the Roth group and then the PASS group. The remaining measurement variables for the 3 groups showed no statistical differences, including vertical variation of maxillary first molars and central incisors, torque variation of maxillary first molars and canines, mesiodistal inclination variation of maxillary first molars and canines, width variation between maxillary first molars, and width variation between maxillary canines. Compared with contemporary preadjusted straight wire appliances, the Tweed edgewise appliance has superiority in molar anchorage control. In contrast, compared with the Roth appliances, the PASS appliances without any auxiliary anchorage devices could make full use of physiological anchorage to achieve adequate control of molar anchorage. Clinical orthodontists may need to pay extra attention to physiological anchorage. The difference in torque control varies depending on the respective characteristics of bracket designs.

Evaluation of the diagnostic ability of the Fränkel manoeuvre to detect the contributing jaw in angle class II division 1 malocclusion

BackgroundA correct diagnosis of patients with an Angle Class II malocclusion is needed to guide treatment decisions toward the contributing jaw and to achieve better treatment outcomes. The aim of the study is to evaluate the diagnostic potential of the Fränkel manoeuvre (FM) for detecting the components determining sagittal discrepancy in Angle Class II division 1.Materials and methodsAnonymous questionnaires containing photographs were distributed totwo groups: general practitioner (GP) dentists and orthodontists. The level of the patient’s profile aesthetics before (T0) and after (T1) the manoeuvre was determined using a 100 mm visual analog scale, and the ‘profile improvement’ score was defined as T1 minus T0. The diagnostic ability of the FM was calculated by comparison with lateral cephalometry as a reference standard using receiver operating characteristic (ROC) curve analysis.ResultsA total of 102 respondents participated in the survey; 40 were orthodontists, and 62 were GP dentists. According to the post-FM images, the “profile improvement” score (T1-T0) was significantly greater in patients with mandibular retrusion than in those with maxillary protrusion (p < 0.05). The predictive power of FM, coinciding with the area under the ROC curve, was 0.62 for GPs and 0.78 for orthodontists.ConclusionsThe FM method is a useful and accurate tool for diagnosing skeletal Angle Class II malocclusion etiology (mandibular retrusion or maxillary protrusion), especially when used by orthodontists.

Determination of orthodontic anomaly patterns in patients in the Thrace region and assessment of the relationship between orthodontic anomalies and DMFT indices: a retrospective study

OBJECTIVE: The aim of this study was to investigate the prevalence of dental and skeletal anomalies that could be a cause of malocclusion and their relationship with caries distribution in the western region of Türkiye. MATERIALS AND METHOD: A retrospective study was conducted with 1815 digital panoramic and lateral cephalometric radiographs taken from patients, age ranging between 6 and 47 years, who applied for orthodontic treatment. The lateral cephalometric radiographs, panoramic radiographs, and dental records were reviewed according to skeletal anomaly, dental malocclusion (Angle classification), and decay-missing- filling teeth (DMFT) index. Kruskal Wallis test was used in intergroup comparisons of variables that did not show normal distribution, and Dunn’s multiple comparison test was used in subgroup comparisons. The chi-square test and Yates correction were used in comparisons of qualitative data. RESULTS: The mean DMFT of the dental Class I malocclusion group was statistically and significantly lower than Class II division 1 and Class III malocclusion groups (p &amp;lt; 0.05). The mean DMFT index of Class II subdivision malocclusion group was statistically and significantly lower than that of Class III malocclusion group (p &amp;lt; 0.05). The DMFT index was significantly lower in the skeletal Class I group compared to the skeletal Class II and Class III anomaly groups (p &amp;lt; 0.05). CONCLUSION: There is a correlation between DMFT indices and dental malocclusions as well as skeletal anomalies. By correcting dental malocclusions and skeletal anomalies with orthodontic treatment and providing ideal occlusion, it becomes easier for patients to maintain oral hygiene and DMFT indices might decrease.

Prevalence of Malocclusion among School aged Children and Adolescents in Kabul, Afghanistan

One of the major public health concerns is the prevalence of malocclusion among school-aged children. Malaligned teeth and incorrect jaw posture are referred to as malocclusion, and they can cause a number of functional and cosmetic problems. The aim of this study was to investigate the prevalence of malocclusion in school-aged children and adolescents in Kabul, Afghanistan. This descriptive cross-sectional study was conducted at the Faculty of Dentistry, Kabul University of Medical Sciences “Abu Ali Ibn Sina” (KUMS). The data were collected from High schools in Kabul, Afghanistan during 2019 and 2020. A sample of 479 children and adolescents, 236 females (49.3%) and 243 males (50.7%) 8-18 years old (mean age 14.16±2.8) were randomly selected from four high schools of different districts of Kabul city. We used the angle classification for sagittal plane malocclusion; open bite and deep bite for vertical plane malocclusions; cross bites for transverse plane malocclusion; midline diastema, spacing and crowding show the tooth material and arch length discrepancies. This study demonstrated that only 41 (8.6%) of subjects had normal occlusion while 92.4% of subjects had different types of malocclusions. Class I malocclusion was found in 275 subjects ( (57.4%, class II Division 1 in 63 subjects (13.1%), Class II Division 2 in 64 subjects (13.4%), Class III malocclusion in 36 subjects (7.5%), moreover, crowding in 183 (38.2%), spacing in 79 (16.5%), midline diastema in 54 (11.3%), crossbite in 77 subjects (16.1%), open bite in 23 subjects (4.8%) and deep overbite in 44 subjects (9.2%) were found. According to Angle’s classification of malocclusion class I malocclusion was the most prevalent malocclusion and class III was the least prevalent malocclusion in school-aged children and adolescents in Kabul city.

Association Between ABO Blood Group, Dental Caries, Gingivitis, Impacted Teeth and Malocclusion Among Saudi Adults: A Cross-Sectional Study.

Whether there is a relationship between blood group and the likelihood of acquiring oral diseases. Therefore, the present study investigated the potential association between ABO blood groups and various dental conditions, including dental caries, gingivitis, malocclusion, and impacted teeth, in Saudi adults aged 18 years and older. A cross-sectional study was conducted on 300 participants who met the inclusion criteria. Data collection included assessment of dental caries status using the decayed missing filled teeth (DMFT) and decayed missing filled surfaces (DMFS) indices, evaluation of gingivitis using the Gingival Index, classification of malocclusion according to Angle's classification system, and recording the presence or absence of impacted teeth. The AB blood group had the significantly highest mean DMFS score (8.58±6.63), while the O blood group had the lowest mean DMFS score (6.37±4.43). Additionally, blood group O showed a slightly higher prevalence of gingivitis (51.92%) than the other blood groups. Blood group A demonstrated a higher prevalence of both Class II (34.2%) and Class III (19%) malocclusions, with statistically significant differences. Regarding impacted teeth, blood group AB (48.8%) had the highest occurrence. There exists an association between oral disease and ABO blood group in Saudi adults. The results of this study indicate that individuals with specific blood types may be more prone to oral diseases, which can aid in the early diagnosis and prevention of these conditions.

Malocclusion and Deleterious Oral Habits in Vietnamese Children Between the Ages of 8 and 12 years: A Cross Sectional Study

Abstract Aim: This study aimed to determine the relationship between malocclusion and deleterious oral habits in the Vietnamese children aged 8–12 years. Materials and Methods: A cross-sectional descriptive analysis was undertaken on a total of 434 children (8–12 years old, 208 males and 226 females), separated into five age groups: 8 years old (16.8%), 9 years old (18.5%), 10 years old (20.7%), 11 years old (21.4%), and 12 years old (22.6%), with all four first permanent molars erupted, no previous orthodontic treatment, loss of the second primary molar or presence of the second primary molar root or decay, loss of surface material on the second primary molar, and underfilling of the second primary molar size in the mesiodistal direction. The deleterious oral habits and malocclusion were assessed through a clinical examination and questionnaires for parents. The descriptive statistical analysis revealed the following findings: mean and standard deviation. The chi-squared test and Fisher’s exact test were used to compare categorical variables. The data were considered significant at P &lt; 0.05. Result: Deleterious oral habits were found to have a significant relationship with malocclusion. Mouth breathing habits were associated with anterior open bites (P &lt; 0.05). The tongue thrusting habit was associated with anterior open bite (P &lt; 0.05), posterior crossbite (P &lt; 0.01), overbite greater than 4 mm (P &lt; 0.01), and angle class I malocclusion (P &lt; 0.05). Chewing habits on one side were associated with posterior crossbite (P &lt; 0.01) and posterior open bite (P &lt; 0.05). The habit of pen/pencil/nail biting was associated with midline deviation (P &lt; 0.05). As children got older, there was a greater need for orthodontic treatment for dental healthcare, according to the index of orthodontic treatment need. In the 8-year-old patient group, the need was 4.1%; in the 9-year-old patient group, it was 5%; in the 10-year-old patient group, it was 9%; in the 11-year-old patient group, it was 19.4%; and in the 12-year-old patient group, it was 22.4%. The distribution of orthodontic treatment needs for dental health was significantly different based on the number of deleterious oral habits children had (P &lt; 0.01). Conclusion: Abnormal oral habits were prevalent in about 30.6% of the study participants. Mouth breathing, tongue thrusting, pen/pencil/nail biting, and one-side chewing had a significant impact on malocclusion.

Association of Malocclusion with Temporomandibular Disorders: A Cross-Sectional Study.

Background/Objectives: Temporomandibular disorders (TMD) encompass a range of musculoskeletal and neuromuscular conditions affecting the temporomandibular joint (TMJ) and associated structures. This cross-sectional study, conducted in a Portuguese TMD department, aimed to assess the relationship between malocclusion and TMD severity. Methods: Data on demographic variables, TMD clinical symptoms, and malocclusion classes were collected using the EUROTMJ database. The Chi-square test (χ2) identified associations, with their intensity measured by Cramér's V (φc). Results: The study included 1170 patients (932 females and 238 males), with a mean age of 41.73 ± 16.80 years. Most patients exhibited Angle Class I malocclusion (85.5%), followed by Angle Class II (13.5%) and Angle Class III (1.1%). Class II malocclusion was associated with increased TMD severity (p < 0.001), higher myalgia levels (p = 0.002), more frequent disc displacement without reduction (p = 0.002) and lower maximum mouth opening values (Class II: 38.13 ± 7.78 mm, Class I: 39.93 ± 8.67 mm). Significant associations were also found between malocclusion type and arthralgia (p = 0.021), mouth-opening limitation (p = 0.016), and TMJ crepitus (p = 0.017). In cases of malocclusion, the presence of oral signs of bruxism explained the degree of myalgia, disc displacement, and severity (p = 0.003; p = 0.048; p = 0.045). Conclusions: This study highlights that (1) the most common type of dental malocclusion in TMD patients was Class I; (2) Class II malocclusion was associated with increased TMD severity and oral signs of bruxism; and (3) Class III was rarely observed in TMD consultation. The findings suggest that bruxism behavior in cases of malocclusion may be significant in TMD.

A preliminary investigation into the impact of soft tissue augmentation-based periodontal phenotype modification therapy for patients exhibiting class III decompensation

BackgroundPatients with skeletal angle Class III malocclusion usually have inadequate hard and soft tissue volume at the mandibular anterior teeth. The labial proclination at the teeth may lead to gingival recession. The purpose of this study was to explore whether periodontal phenotype modification therapy with soft tissue augmentation (PhMT-s) can prevent gingival recession in these patients.MethodsFour patients with skeletal Class III malocclusion and a thin periodontal phenotype underwent surgical-orthodontic treatment. Prior to tooth movement, they underwent a minimally invasive vestibular incision with subperiosteal tunnel access combined with autogenous connective tissue grafts for periodontal phenotype modification with soft tissue augmentation (PhMT-s). The labial gingival thickness of the anterior mandibular teeth was measured at three distinct levels: at the cementoenamel junction (GT0), 3 mm apical to the CEJ (GT3), and 6 mm apical to the CEJ (GT6). These measurements were taken at baseline, three months following PhMT-s, and after tooth decompensation. Additionally, a biopsy sample was obtained from the PhMT-s site of one patient. All sections were subsequently stained using hematoxylin and eosin, Masson trichrome, Sirius Red, and immunohistochemistry.ResultsThe thickness of the labial gingiva was increased about 0.42 to 2.00 mm after PhMT-s. At the end of pre-orthognathic surgical orthodontic treatment, the thickness of the labial gingiva was increased about − 0.14 to 1.32 mm compared to the baseline and no gingival recession occurred after the pre-orthognathic surgical orthodontic treatment. The histologic results demonstrated that the grafts obtained from the PhMT-s site exhibited increased deposition of collagen fibers. Moreover, the proportion of type III collagen increased and the grafts displayed significantly reduced positive expression of CD31 and OCN.ConclusionsPhMT-s increased the thickness of the soft tissue, stabilizing the gingival margin for teeth exhibiting a thin periodontal phenotype and undergoing labial movement. This is attributed to the increased deposition of collagen fibers.

Effect of mandibular third molar tooth germ extraction on mandibular development: a retrospective study

Objective: To investigatethe effect of extraction of mandibular third molar (M3) tooth germon the development of the mandible in orthodontic patients, with a view to providing a reference for clinical M3 tooth germ extraction. Methods: One hundred and twenty-nine Angel class Ⅰ patients aged 10-16 years who attended the Department of Orthodontics Division 1, School & Hospital of Stomatology, Wuhan University from 1 January 2013 to 30 December 2021 and fulfilled the criteria for nativity were included. Those who had their M3 extracted in the Department of Oral and Maxillofacial Surgery were included in the study group, with a total of 66 cases; and those who did not have their M3 extracted were included in the control group, with a total of 63 cases. The average annual growth was calculated by tracing point measurements on cephalometric films before and after orthodontic treatment according to the Jarabak and McNamara methods, with measurements of the mandibular ramus height (Ar-Go'), mandibular body length (Go'-Me), and overall mandibular length (Co-Gn) values, respectively. The average annual growth of Ar-Go', Go'-Me, and Co-Gn were compared between the two groups for the overall sample of patients, patients of the same sex (male/female), patients of the same age group (A, B, and C), and patients of the same cervical vertebral maturation stage (stages Ⅱ, Ⅲ, and Ⅳ), respectively, to see if there was any difference in the average annual growth of Ar-Go', Go'-Me, and Co-Gn. Results: There was no statistically significant difference in the average annual growth of Ar-Go', Go'-Me, and Co-Gn between the study group [0.88 (0.40, 1.80), 0.67 (0.15, 1.18), and 0.86 (0.40, 1.90) mm, respectively] and the control group [1.08 (0.45, 1.60), 0.53 (0.25, 1.13), and 1.20 (0.46, 2.28) mm, respectively] (P>0.05). In addition, there was no significant difference in the average annual growth in the Ar-Go', Go'-Me, and Co-Gn between the groups for patients of the same sex group (male/female), patients of the same age group (A, B, and C), and patients of the same cervical vertebral maturation stage group (stages Ⅱ, Ⅲ, and Ⅳ) (P>0.05). Conclusions: Extraction of the mandibular third molar tooth germ has no significant effect on the development of the mandible in Angle class Ⅰ orthodontic patients.