Type Of Malocclusion Research Articles

Casuística de maloclusiones Clase I, Clase II y Clase III, según Angle en el Departamento de Ortodoncia de la UNAM

Se estudió el caso de 428 pacientes que recibieron tratamiento en la División de Estudios de Posgrado e Investigación (DEPeI). Este estudio se realizó a partir del levantamiento del índice de maloclusiones, de acuerdo con la clasificación de Angle, en una muestra proveniente de expendientes de los pacientes atendidos en el Departamento de Ortodoncia de la División de Estudios de Posgrado e Investigación de la Facultad de Odontología de la UNAM, durante los años 1998 al 2004. Se seleccionaron personas entre 8 y 40 años de edad, y se obtuvo una base de datos en Excel que contiene el expediente con la historia clínica de cada paciente, con el análisis de los modelos de estudio para determinar el tipo de oclusión según Angle. Los resultados reflejan que 226 pacientes presentan Clase I dental según Angle, que representan el 52.8% del total de la muestra, 145 pacientes padecen Clase II que representa el 33.9% y, 57 pacientes se encuentran en Clase III, que representa el 13.3%. No se encontraron asociaciones significativas entre la edad, el sexo y el tipo de maloclusión. Lo anterior, a través de un análisis descriptivo, transversal y retrospectivo de la información para identificar el tipo de maloclusiones existentes.

Multi-Loop Edge Wise Arch Wire Technique (MEAW) – A Review

Anterior open bite treatment is considered to be a complex treatment in the field of orthodontics. Orthognathic surgery is often the treatment of choice for these types of malocclusions and prognosis of the results are still questionable. With the introduction of Multiloop edgewise archwire therapy, treatment of open bite has started showing efficient results. Moreover, MEAW is versatile as it is capable of correcting various malocclusions as well such as Class II, Class III, deep overbite, and malocclusions with marked midline deviations. Since the advent of the MEAW, its treatment modality has been used worldwide and numerous reports of successful results have been published. Some orthodontists have described the MEAW technique as “magical” or “unbelievable,” but it certainly is not. The diagnosis and treatment plan must be correct and construction of the MEAW must be precise to deliver the necessary forces to move the teeth to an optimal, stable relationship.Hence this article aims to review the multiloop edge wise arch wire technique in detail along with its biomechanics.

CLINICAL, SOCIO-DEMOGRAPHIC AND BEHAVIORAL FACTORS AFFECTING THE ORAL-HEALTH RELATED QUALITY OF LIFE IN PRE-SCHOOL CHILDREN WITH MALOCCLUSION

Amaç: Bu kesitsel çalışmanın amacı, maloklüzyonu olan okul öncesi çocukların ağız sağlığına bağlı yaşam kalitesini etkileyen sosyo-demografik, klinik ve davranışsal faktörlerin incelenmesidir. Gereç ve Yöntemler: Çalışmaya İstanbul Üniversitesi Diş Hekimliği Fakültesi Pedodonti Anabilim Dalı Kliniği’ne başvuran 113 çocuk (30-71 ay yaş aralığında) ve ebeveyni dahil edildi. Çalışma verileri, klinik muayeneler ile Erken Çocukluk Çağı Ağız Sağlığı Etki Ölçeği’nin (ECOHIS) Türkçe versiyonu, sosyo-demografik ve davranışsal faktörleri içeren bir anket aracılığı ile toplandı. Verilerin analizinde tanımlayıcı istatistik, Mann-Whitney-U testi, Spearman’ın sıralı korelasyon katsayısı ve çoklu doğrusal regresyon analizi kullanıldı. Bulgular: İkili analizlerde, çürük ve dolgulu diş sayısı ile ECOHIS-toplam, çocuk ve aile alt boyutları skorları arasında anlamlı pozitif korelasyonlar bulundu. Distal basamak ve derin örtülü kapanış maloklüzyon tipi olan çocuklar ile beslenme dışı emme alışkanlığı olanların ağız sağlığına bağlı yaşam kaliteleri olmayanlara göre daha iyi bulundu. Regresyon analizinde, maloklüzyonla alakalı bir alışkanlığın olması, diş çürüğünün olması ve çocuk yaşının artması çocuğa bağlı yaşam kalitesini azaltan ve toplam varyansın %17,1’ini açıklayan faktörler olarak saptandı. Sonuç: Çocuklarda periodontal durumun ve maloklüzyon tipinin ağız sağlığına bağlı yaşam kalitesini olumsuz etkilemediği saptandı. Diş çürükleri, dolgulu diş sayısı, parafonksiyonel alışkanlıklar, çocuğun yaşı ve eğitim kurumuna devamı ağız sağlığına bağlı yaşam kalitesini etkileyen önemli belirleyenler olarak tespit edildi.

Can malocclusion provide clinicians with information for differential diagnosis of temporomandibular joint diseases?: A review.

The aim of this literature review was to summarize the clinical characteristics and symptoms of temporomandibular joint diseases, and to discuss the associations between temporomandibular joint diseases and categorization of malocclusion. Electronic literature searches were performed using the PubMed database. The authors established a differential diagnostic method for temporomandibular joint diseases related to malocclusion. A literature search using PubMed yielded 213 texts, of which based on exclusion criteria, 28 were included in this study. Malocclusions were categorized into 5 types. The authors suggested a diagnostic tree of temporomandibular joint diseases based on the types of malocclusion and 4 variables in clinical characteristics and symptoms. Clinicians treating malocclusions must attempt to clarify the cause of the occlusal condition. If caused by temporomandibular joint disease, it is important to make a proper differential diagnosis at first, and not to overlook the causative disease. Further clinical knowledge of associations between temporomandibular joint diseases and malocclusions should be accumulated, and the diagnostic tree should be improved based on new information.

The effect of orthodontic treatment on facial attractiveness: a systematic review and meta-analysis.

Facial and smile attractiveness are significant motivating factor for patients to seek orthodontic treatment. Although there is a general belief that orthodontic treatment improves facial appearance, this has yet not been systematically evaluated. The objective of this study was to assess the current evidence on the effect of orthodontic treatment on facial attractiveness. Systematic and unrestricted search of nine databases were performed up to January 2022. Studies evaluating facial attractiveness before and after orthodontic treatment. Extracted data included study design and setting, sample size and demographics, malocclusion type, treatment modality, and method for outcome assessment. Risk of bias was assessed with the ROBINS-I tool for non-randomized studies and with RoB-2 for randomized controlled trials (RCTs). Random-effects meta-analyses of mean differences and their 95% confidence intervals (CIs) were performed. Twenty studies were included in data synthesis; three randomized controlled clinical trials and 17 non-randomized clinical studies of retrospective or prospective design. One of the RCTs was found to have low risk of bias, one presented some concerns and the third showed a high risk of bias. All non-randomized studies showed either unclear or high risk of bias. Data syntheses showed that orthodontic treatment improved facial attractiveness ratings by 9% when compared with untreated controls (MD: 9.05/95% CI: 4.71; 13.39). A combination of orthodontics and orthognathic surgery also showed a positive effect of 5.5% (MD: 5.51/95% CI: 1.55; 9.47) when compared with orthodontic treatment alone. There was no difference in effect between extraction and non-extraction treatments (MD: -0.89/ 95% CI: -8.72; 6.94) or between different types of Class II correctors (MD: 2.21/95% CI: -16.51; 20.93). With the exception of two RCTs, included studies were of unclear or low quality. Orthodontic treatment has a clinically weak effect on facial attractiveness when compared to no treatment. The same is true when a combined orthodontic/surgical treatment is compared to orthodontics alone. PROSPERO #: CRD42020169904.

Early orthodontic treatment of malocclusion in the mixed dentition

Children in the mixed dentition grow rapidly, and various types of malocclusion often appear in this period. At the same time, there are many environmental factors affecting the development of the occlusion at this stage. Functional abnormalities related to lip, tongue, articulation and breathing, and impacted teeth should be actively intervened and blocked to avoid the continued development of the deformity. Appropriate orthopedic devices should be used in patients with skeletal malocclusion, if necessary, for growth modification and the influence of congenital factors and the prognosis of treatment should be fully evaluated. Over-intervention of the temporary malocclusions in the mixed dentition should be avoided. In conclusion, early orthodontic treatment in the mixed dentition requires a comprehensive assessment of the treatment need, risks, timing, cost and the ultimate benefit of the patient. The timing of orthodontic treatment is not the sooner the better. The indications must be strictly controlled, and the necessity and limitations must be carefully considered.

Common dental anomalies in Korean orthodontic patients: An update.

ObjectiveThe aim of this study was 1) to investigate the prevalence and pattern of dental anomalies (DAs), 2) to compare DAs according to the type of malocclusion, and 3) to investigate the correlation between tooth impaction and other DAs in the Korean orthodontic population.MethodsA total of 3,240 orthodontic patients were classified as Class I, Class II, or Class III malocclusion groups. The presence and location of common DAs, including impaction, microdontia, agenesis, supernumerary tooth, transposition, and fusion, were identified by examining diagnostic records. Furthermore, samples were classified as Group 1 without impaction or Group 2 with impaction. The prevalence of other DAs concurrent with impaction was investigated and compared to Group 1.ResultsImpaction was the most prevalent DA, followed by microdontia, agenesis, and supernumerary. Class I and Class III groups showed the same order of prevalence, but agenesis was more frequent than microdontia in the Class II group. The prevalence of the four DAs was lowest in the Class III group. Overall, 8.6% of patients were classified into Group 2. The incidence of DAs other than impaction and the prevalence of multiple concurrent DAs were significantly higher in Group 2. Impaction showed a significant relationship with supernumerary tooth, transposition, and fusion.ConclusionsThe prevalence and pattern of DAs varied depending on the type of malocclusion. As there was a higher risk of other DAs in patients with impacted teeth, early detection of the impacted tooth and a detailed diagnosis of other possible DAs may be essential.

Prevalence of dental anomalies in different facial patterns and malocclusions in an Iranian population

ObjectiveThis study aimed to evaluate the prevalence and association of dental anomalies with different types of malocclusions and facial patterns. MethodsIn this cross-sectional study, the records of patients referred to the Orthodontics Department at 12–20 years of age were collected. The patients were classified into four types of malocclusion: Cl I, Cl II div 1, Cl II div 2, and Cl III, and three types of facial patterns: normal, long, and short. Fifteen dental anomalies were searched within the documents. The statistical analysis of data was performed with chi-squared and Fisher's exact test. ResultsAmong 602 patients evaluated in this study, 28.6% were males, and 71.4% were females. The prevalence of Cl I, Cl II div1, Cl II div 2, and Cl III was 58.3%, 28.7%, 5.5%, and 7.5%, respectively. The normal facial pattern was most prevalent (47.2%), followed by the long facial pattern (41.4%) and short facial pattern (11.5%); 60.7% of the study population had at least one dental anomaly. Dilaceration was the most common anomaly (27.7%), followed by impaction (21.8%) and hypodontia (18.9%). Most dental anomalies were found in females, Cl II malocclusion, and long face samples. A statistically significant association was found between transposition and male gender (P = 0.006) and between short roots and Cl II malocclusion (P = 0.047). No significant association was found between dental anomalies and facial patterns. ConclusionSignificant associations were reported between transposition and male gender and between short roots and Cl II malocclusion. In our population, dilaceration was the most common dental anomaly.

Calcification of the Atlanto-Occipital Ligament (Ponticulus Posticus) in Orthodontic Patients: A Retrospective Study.

Background: Ponticlus Posticus (PP) is a rare anomaly of the first cervical vertebra easily identifiable in lateral cephalometric radiograph and typically required for orthodontic diagnosis. The aim of this study is to evaluate the PP prevalence in lateral Cephalograms in a cohort of orthodontic patients treated at the Dental School of the University of Bari ‘Aldo Moro’, Italy, and to find possible connection between PP and other dental anomalies, as well as the patient’s cephalometric characteristics. Methods: A total of 150 panoramic radiographs and 150 lateral Cephalograms, obtained for orthodontic use only, were evaluated. No patients were referred to for congenital syndromes or disease, or a history of previously occurred maxillofacial trauma. A detailed cephalometric study was performed for each patient, and the whole cohort was divided according to the common three dental malocclusion classes. The values obtained were analyzed using the Chi-Square Test. Results: PP prevalence was 8% (12 of 150 cases), where the complete and partial forms observed 4.7% and 3.3%, respectively. Although females were more affected (9.6%), no statistically significant sex-related difference was found. Furthermore, no statistically significant relationship regarding age or dental anomalies (dental agenesis/palatal impacted canines) among the groups was observed either. Cephalometric analyses revealed that half of the subjects with PP were sagittal skeletal class I and had vertical hyper-divergence. Conclusions: PP is a frequent anatomical variation of the cervical vertebra, apparently unrelated to the skeletal malocclusion type or dental anomalies. The current study needs to further confirm the congenital hypothesis of PP’s origin already reported in literature.

Accuracy of Patient-specific Soft-tissue Prediction Algorithms for Maxillomandibular Surgery in Class III Patients.

Context:Improved esthetics is an important factor for most patients undergoing orthognathic surgery. Thus, a treatment simulation that can provide patients with a realistic view of the esthetic outcome after surgery is important in clinical practice.Aims:To evaluate the accuracy of simulations generated using algorithms specific for patient's type of malocclusion and surgical procedure compared to nonspecific algorithms.Settings and Design:A total of 36 patients (average age 18.41 years) who had undergone maxillary advancement and mandibular setback for Class III malocclusion were included.Subjects and Methods:The presurgical and postsurgical cone-beam computed tomography scans were used to generate the lateral cephalograms and the surgical simulations were created with the patient-specific algorithm (specific for Class III patients) and the nonspecific algorithm (default algorithm not specific for any particular malocclusion or type of surgery) using the treatment simulation feature in Dolphin Imaging software. The accuracy of the simulations was examined by comparing the soft-tissue changes in the surgical simulations with the postsurgical result.Statistical Analysis Used:Statistical analyses were performed with SPSS-software at 0.05 significance level. For the mean difference between the postsurgical and surgical-simulation landmarks, a paired sample t-test (Student's t-test) was performed.Results:Patient-specific algorithms were accurate in vertical prediction of lower lip, B’, tip of nose, upper lip, and horizontal prediction of pogonion’. Whereas the nonspecific algorithm was accurate in the horizontal prediction of the lower lip, pogonion’, and menton’.Conclusions:Patient-specific and nonspecific algorithms for generating surgical simulations showed different accuracy for vertical and horizontal predictions of the parameters.

Bad splits in bilateral sagittal split osteotomy: A retrospective comparative analysis of the use of different tools

This study aims to analyse the relationship between the incidence of bad splits and the surgical tools adopteded to perform bilateral sagittal split ramus osteotomy (BSSRO).BSSROs performed by the same experienced surgeon period were reviewed, retrospectively. The patients were divided into three groups according to the surgical instrument used to perform the osteotomy: a Lindemann burr, reciprocating saw or piezosurgery. Among the 1120 BSSROs performed, 5 bad fractures were detected during the observation period: 3 among patients operated with the Lindemann burr (0.8%) and 2 among those operated with a reciprocating saw (0.5%). There was no significant correlation between the bad split rate and age and gender of the patients, the type of malocclusion or the type of instrument used to perform the osteotomy.Within the limitations of the study it seems that the the choice of the osteotomy tool for BSSRO does not influence the rate of bad fractures and, therefore, the selection of the osteotmy tool should be left to the discretion of the surgeon.

Malocclusion in children with speech sound disorders and motor speech involvement: a cross-sectional clinical study in Swedish children

ObjectivesThe objectives of this study were to investigate the occurrence, types and severity of malocclusions in children with speech sound disorder (SSD) persisting after 6 years of age, and to compare these findings to a control group of children with typical speech development (TSD).MethodsIn total, 105 children were included: 61 with SSD and motor speech involvement (mean age 8:5 ± 2:8 years; range 6:0–16:7 years, 14 girls and 47 boys) and 44 children with TSD (mean age 8:8 ± 1:6; range 6:0–12:2 years, 19 girls and 25 boys). Extra-oral and intra-oral examinations were performed by an orthodontist. The severity of malocclusion was scored using the IOTN-DHC Index.ResultsThere were differences between the SSD and TSD groups with regard to the prevalence, type, and severity of malocclusions; 61% of the children in the SSD group had a malocclusion, as compared to 29% in the TSD group. In addition, the malocclusions in the SSD group were rated as more severe. Functional posterior crossbite and habitual lateral and/or anterior shift appeared more frequently in the SSD group. Class III malocclusion, anterior open bite and scissors bite were found only in the SSD group.ConclusionChildren with SSD and motor speech involvement are more likely to have a higher prevalence of and more severe malocclusions than children with TSD.

Assessment of the relationship between fractal analysis of mandibular bone and orthodontic treatment duration : Aretrospective study.

This retrospective study aimed to determine whether acorrelation exists between the fractal dimension value and overall orthodontic treatment duration in children and young adults. The study included atotal of 643 patients (age: 10-25 years) who received orthodontic treatment between January 2015 and March 2020. Patient records and pretreatment panoramic radiographs were evaluated. The regions of interest selected for calculating fractal dimension were the bilateral mental foramen regions of the mandible. Fractal dimension was set in relation to orthodontic treatment duration using alinear regression model which was also adjusted for potential confounding variables. Total treatment duration was the outcome variable of interest used as acontinuous variable. The predictor variables of interest included age, gender, type of dental and skeletal malocclusion, vertical growth pattern, extraction type, and fractal dimension. The mean age, treatment duration, and fractal dimension were 14.56 years, 27.01 months, and 1.23 mm, respectively. Multiple linear regression analysis showed that the fractal dimension had asignificant influence on overall treatment duration (P < 0.001). From the other variables, Angle classII malocclusion significantly influenced treatment duration (P < 0.01), age showed asignificant negative correlation with treatment duration (P < 0.01), and treatment duration significantly increased for patients with tooth extractions (P < 0.001). There was anegative correlation between fractal dimensions at the mandibular mental region and total orthodontic treatment duration. Fractal dimension analysis may help to understand physiologic features of alveolar bone and predict orthodontic tooth movement.

Study of skeletal changes in individuals with anterior open bite treated with JFO

Anterior Open Bite (AOB) is a type of malocclusion that promotes severe esthetic aesthetic and functional impairment. Its etiology is multifactorial and may involve several etiological factors, such as deleterious oral habits, hypertrophic tonsils, mouth breathing, dental ankylosis and eruption abnormalities either associated with genetic factors or not. AOB is one of the most challenging treatments in any treatment protocol. A retrospective study of 21 patients with anterior open bite treated with Jaw Functional Orthopedics (JFO) with improvement in overbite was conducted with the aim of understanding mandibular behavior during the treatment. Using SPSS 11.0, using Shapiro-Wilk test all variables showed Normal distribution (p&gt; 0.05), in the comparison between the means at T0 and T1, the t-test for paired samples was used. In order to verify whether cooperative patients had better results than the non-cooperative group, a variable was created. For all tests, a significance level of 5 % was used. A weak statistical correlation (P&lt; 0,1) was found for Bimler’s Factor 8. Change resulted from AOB treatment with FOA in a short time. There was no statistical correlation of Bimler’s Factor 8 when cooperative patients were compared with the non-cooperative group. It could be concluded that in the studied sample there was a weak correlation between overbite improvement during AOB treatment with JFO and mandibular rotation. Further studies are necessary to understand the skeletal behavior of the maxillary bones in the treatment of AOB with FOA.

Bimaxillary protrusion: A literature review

Introduction: Bimaxillary protrusion is an occlusal feature characterized by protrusive and proclined upper and lower incisors, associated with increased flattening of the lips and greater than average degree of lip prominence. It is considered one of the malocclusion types that stimulate patients to seek orthodontic treatment to improve facial symmetry. Objective: To conduct a literature review on bimaxillary protrusion with respect to its aetiological factors, morphological features, prevalence, diagnosis, and management. Methods: Relevant sources of information were searched using electronic databases including Google Scholar, PubMed, Elsevier, ResearchGate, and Web of Science. A total of 28 articles were considered and included in the literature review. Results: It was observed that bimaxillary proclination is prevalent among Asian, African, African-American, and the Caribbean regions, but less prevalent in white Caucasian populations. Treatment of patients with bimaxillary protrusion by extraction of four premolars was found to be successful in decreasing the dental and soft tissue procumbency seen in patients with bimaxillary protrusion. Conclusion: Successful treatment of patients with bimaxillary protrusion starts with a good understanding of the patient’s concerns and sometimes, a close collaboration between an orthodontist and an oral surgeon.

Comparison of Malocclusion Prevalence, Type and Severity between Cerebral Palsy and Healthy Subjects: A Prospective Case-Control Study

Background: To analyze the prevalence, type and severity of malocclusions in a group of patients with cerebral palsy (CP) using a facial and occlusal analysis and the Dental Aesthetic Index (DAI). Methods: A prospective, case–control study was made of two groups, a cerebral palsy and a control group, with the determination of the facial and occlusion analysis in the three spatial planes. The Dental Aesthetic Index (DAI) was used to assess the severity of malocclusion. Results: The patients with CP presented a higher prevalence of increased facial lower third height and a greater tendency towards right-side canine and molar class II malocclusion, narrower transverse relationship and crossbite. The DAI scores were statistically significantly higher in the CP group. Increased physical impairment in the CP group was associated to greater DAI scores. Conclusions: The prevalence and severity of malocclusion were significantly greater in the CP group. The type of malocclusion predominantly found in these patients was molar class II, with open bite, increased overjet and a narrow arch. The CP group also presented mixed breathing with higher DAI scores and decreased facial lower third height.

Bolton Analysis on Class I, II, and III Malocclusion Cases

Background: Tooth size discrepancy is defined as an imbalance in size between each tooth. To obtain good occlusion with overbite and overjet, the maxillary and mandibular teeth must be of the appropriate size. One of the causes of malocclusion is the mismatch of the mesiodistal size of the teeth to the arch of the jaw. The relation of teeth with a large maxillary mesiodistal size while the mandibular mesiodistal size is small, it is impossible to get an ideal occlusion. This condition is known as tooth size discrepancy and can be a problem when determining the orthodontic treatment plan and when achieving the final orthodontic treatment outcome. Purpose: this study aimed to describe Bolton's analysis in cases of Class I, II, and III malocclusions. Review(s): The literature sources used in preparing the review were through databases PubMed and Google Scholar with the keywords tooth size discrepancy, Bolton analysis, and Class I, II, and III malocclusions. From the results of the researchers' measurements on malocclusions in the Angle Classification Class I and II, The anterior ratio was different in several cases, while in Class III the results were greater than the Bolton ratio, where the size of the lower jaw teeth was larger than the maxillary teeth, especially in the anterior ratio. Conclusion: Bolton's analysis can be applied to all cases regardless of the type of malocclusion, gender, or race, and remains an important investigation before starting treatment for post-treatment arch stability.

Straight wire and segmented technique in canine retraction-case reports

Correct positioning of the canines after their retraction is of great importance for the function, stability and esthetics. Aim: Two case reports were presented to compare the efficiency of two techniques for canine retraction, segmented mechanics using 0.017 x 0.025 TMA T-loop vs sliding straight-wire mechanics usingelastomeric chains. Material and methods: The first case describes orthodontic treatment with 0.017 x 0.025 TMA T-loop whereas the second case describes a 9 mm canine retraction using elastomeric chains. Results: Depending on the type of malocclusion both techniques for canine retraction can be used. Post treatment results showed canine retraction with good anchorage control and no mesial movement of the molars.Conclusion: Both techniques provide an optimum rate of tooth movement and none of the methods can be considered superior in terms of tooth movement or side effects, including rotation, tipping, root resorption, anchorage loss, as well as associated pain.

Abnormal wear patterns in different types of malocclusions

Relevance. Abnormal tooth wear is a disease characterized by excessive loss of hard tissues of the erupted teeth, unrelated to the physiological process. This disease prevalence appears to have increased in recent decades. The literature often indicates malocclusion as the cause of abnormal tooth wear, though it rarely notes the impact of abnormality type on individual teeth.Purpose. The study aimed to establish the relationship between the abnormality type and the degree and nature of abnormal tooth wear in children at different stages of dentition development.Materials and methods. The study analyzed the examination results of 266 patients aged 8 to 18 years without a history of previous orthodontic treatment. The orthodontic diagnosis was made based on the ICD-10. The patients formed the groups according to the stage of dentition development. The tooth wear index (TWI) (only permanent teeth) evaluated the abnormal tooth wear. The maximum TWI score determined the grade of abnormal tooth wear. The study statistically analyzed the data by StatTech v. 2.5.6, compared the data using the Kruskal – Wallis test (ANOVA) and Pearson chi-square, and made post hoc comparisons using Dunn’s test with Holm adjustment. The prognostic model was developed using the linear regression method.Results. The children and adolescents showed a sufficiently high prevalence of abnormal tooth wear (69.2% had at least one tooth with a tooth wear facet), tooth-wear grade increased with age (correlation coefficient rxy = 0.674, p &lt; 0.001). The risk of abnormal tooth wear in distal and deep occlusion appeared to increase at incisors and canines (p &lt; 0.001), in mesial occlusion - molars and premolars, in open bite – molars (p &lt; 0.001). The combination of distal and deep occlusion led to severe abnormal tooth wear.Conclusion. The study results showed that wear patterns differ in various types of malocclusions. The received data will help to develop effective measures to prevent abnormal tooth wear.

Cone Beam Computerized Tomographic Analysis of Collum Angle of the Maxillary Central Incisors in Different Types of Malocclusion: Comparative Assessment in Saudi, Jordan and Egypt Subpopulation.

Background: The collum angle (CA) is an extremely significant for patients who are undergoing orthodontic, dental implant restoration, prosthodontic and periodontic treatments. Aim and Objectives: To determine and compare the mean CA for maxillary central incisor in different types of malocclusion utilizing 3D Cone Beam Computerized Tomography (CBCT) images. The additional objectives were to determine and compare the mean CA for maxillary central incisor based upon the demographic characteristics among Saudi, Jordan and Egypt subpopulation and to test for significant differences in the CA of maxillary central incisor with different molar malocclusions. Methodology: A total of 400 CBCT images were included from the radiology archive at the College of Dentistry, Jouf University (Sakaka, Saudi Arabia). The CBCT images were divided into four groups based upon molar classifications. The selected records were used for the measurement of CA of maxillary central incisor using the measurement tool built into 3D:OnDemand software. Statistical analysis was done using independent t test and ANOVA to examine the differences between gender and races. Results: The mean CA for Class II div 2 exhibited significantly higher crown-root variation as compared other groups (p < 0.0001). Males sample showed greater value of CA for each group as compared to the females and this difference was statistically significant for all the groups other than for Class I (p < 0.05). The post hoc pairwise comparisons between the races showed statistically insignificant findings (p > 0.05). Significant difference was found on pairwise comparisons among different malocclusion groups other than for group Class I/Class II div 1 (p < 0.05). Conclusion: The CA of Class II div 2 group was the greatest as compared to other malocclusion groups. Males sample showed greater value of CA for each group as compared to the females and this difference was statistically significant for all the groups other than for Class I. Statistically insignificant difference was noted for the mean CA among different races whereas significant difference was found on pairwise comparisons among different malocclusion groups other than for group Class I/Class II div 1.