Occlusal features of 5-year-old Greek children: a cross-sectional national study.

BACKGROUND: Occlusal characteristics of the primary dentition are crucial in predicting and determining permanent tooth alignment and occlusion. The aim of our study was to determine the occlusal characteristics of the primary dentition of 5-year-old children in Greece through a national pathfinder survey. METHODS: A stratified cluster sample of 1222 5-year-old children was selected according to the WHO guidelines for national pathfinder surveys. Five occlusal traits were registered clinically in centric occlusion, separately for the left and right sides: sagittal relationships of the second primary molars and primary canines, overjet, overbite, crossbite, and maxillary and mandibular spacing. RESULTS: Most children showed a flush terminal plane of primary second molars (44.8%), a class I primary canine relationship (52.2%) and normal overjet (46.4%), but a high prevalence of Class II canine relationship (25.6%) and overjet (37.8%) were also observed. A normal overbite was found in 40% of the children and 40% had a deep overbite. Spacing was apparent in both maxilla (71.1% of children) and mandible (56.4%). The prevalence of open bite and distal step molar relationship significantly rose in children with non-nutritive sucking habits. CONCLUSIONS: Νon-nutritive habits were associated to altered occlusal features. No sex significant differences were found in either the sagittal relationships of second primary molars and primary canines, or overjet, overbite, crossbite and spacing.

Prevalence of Orthodontic Malocclusions in Healthy Children and Adolescents: A Systematic Review.

The purpose of this study was to systematically review the literature regarding the prevalence of malocclusion and different orthodontic features in children and adolescents. METHODS: The digital databases PubMed, Cochrane, Embase, Open Grey, and Web of Science were searched from inception to November 2021. Epidemiological studies, randomized controlled trials, clinical trials, and comparative studies involving subjects ≤ 18 years old and focusing on the prevalence of malocclusion and different orthodontic features were selected. Articles written in English, Dutch, French, German, Spanish, and Portuguese were included. Three authors independently assessed the eligibility, extracted the data from, and ascertained the quality of the studies. Since all of the included articles were non-randomized, the MINORS tool was used to score the risk of bias. RESULTS: The initial electronic database search identified a total of 6775 articles. After the removal of duplicates, 4646 articles were screened using the title and abstract. A total of 415 full-text articles were assessed, and 123 articles were finally included for qualitative analysis. The range of prevalence of Angle Class I, Class II, and Class III malocclusion was very large, with a mean prevalence of 51.9% (SD 20.7), 23.8% (SD 14.6), and 6.5% (SD 6.5), respectively. As for the prevalence of overjet, reversed overjet, overbite, and open bite, no means were calculated due to the large variation in the definitions, measurements, methodologies, and cut-off points among the studies. The prevalence of anterior crossbite, posterior crossbite, and crossbite with functional shift were 7.8% (SD 6.5), 9.0% (SD 7.34), and 12.2% (SD 7.8), respectively. The prevalence of hypodontia and hyperdontia were reported to be 6.8% (SD 4.2) and 1.8% (SD 1.3), respectively. For impacted teeth, ectopic eruption, and transposition, means of 4.9% (SD 3.7), 5.4% (SD 3.8), and 0.5% (SD 0.5) were found, respectively. CONCLUSIONS: There is an urgent need to clearly define orthodontic features and malocclusion traits as well as to reach consensus on the protocols used to quantify them. The large variety in methodological approaches found in the literature makes the data regarding prevalence of malocclusion unreliable.

Prevalence and Etiological Factors of Dental Trauma among 12- and 15-Year-Old Schoolchildren of Lebanon: A National Study.

BACKGROUND: Traumatic dental injuries represent nearly 5% of children and adolescents' injuries leading to serious medical and psychological issues. This current study aims to evaluate the prevalence of dental trauma and its potential association with different predisposing factors among 12-and 15-year-old schoolchildren in Lebanon. MATERIALS AND METHODS: 7902 schoolchildren, 3806 male and 4096 female aged 12 years (n = 3985) and 15 years (n = 3917), were recruited by a stratified multistaged randomized cluster sampling method from public and private schools and were clinically examined in a national cross-sectional study. WHO criteria were used to assess anterior permanent teeth; the nature of trauma, the tooth involved, the size of the incisal overjet, and the type of the lip coverage were furthermore assessed. Data regarding age, sex, and causes of TDI were recorded through a structured questionnaire. RESULTS: The prevalence of dental trauma to anterior teeth was 10.9%. Maxillary central incisors (83.7%) were commonly affected. The most common type of injury was enamel fracture (68.3%), falls being the main reason (52.5%). Increased overjet (OR = 2.32, p = 0.034), deficient lip coverage (OR = 5.73, p = 0.019), and gender (OR = 5.36, p ≤ 0.001) were significant predisposing factors for dental trauma. CONCLUSION: This research highlighted many predisposing factors for dental trauma that affect commonly the anterior teeth. Based on these results, the implementation of strategic preventive measurements targeting especially the identified risk groups remains crucial.

Assessing the risk factors for injuries to maxillary permanent incisors and soft tissues among school children - A cross-sectional study.

Aim: The present study aimed to determine the risk factors related to permanent maxillary incisors and soft tissue injuries along with providing information about the age distribution of trauma, overjet, lip competence and physical activity. Methods and Materials: The sample consisted of 2100 school children aged 8-14 years from 15 schools in the Nellore district. The sample was selected adopting a stratified random sampling method and screened applying WHO criteria for the oral examination. The screening was done in classrooms to obtain demographic data, including name, age, gender and children's experience to the maxillary incisor and soft tissue injuries. The injuries were categorized according to Andreasen classification. Overjet and lip competences were recorded, and physical activity was assessed using a questionnaire (PAQ-C). Results: Of the 2100 children, 228 (10.8%) had suffered traumatic injuries. Boys were 1.6 fold more prone to trauma than girls. Enamel fractures were a common type of trauma, and the commonly involved were maxillary central incisors. The relative risk for trauma is 1.215 times higher in increased overjet when compared to normal overjet. Incompetent lips showed 1.189 times greater risk of trauma. The high physical activity showed 1.692 times higher risk for trauma when compared to low physical activity. Conclusion: The prevalence of traumatic dental injuries among 8-14 year children was 10.8%. Boys were more commonly injured than girls. Increased overjet incompetent lips and high physical activities are risk factors for trauma. Enamel fracture was the most common type, and maxillary central incisors were the most common teeth having traumatic injuries.

Prevalence of malocclusion and non-physiological oral habits in primary school children from Ercilla, Chile / Prevalencia de maloclusión y hábitos bucales no fisiológicos en niños de primaria de Ercilla, Chile

Introduction: Dentomaxillary Anomalies (DMA) affect the growth and morphology of the stomatognathic system of individuals, representing a public health problem. Few studies have described its prevalence among vulnerable populations in Chile. The aim of the study was to explore the prevalence of DMA and its association to non-physiological habits (NFH) and sociodemographic characteristics among primary school children living in Ercilla, Chile. Material and Methods: A convenience sample of 327 primary school students from six schools in Ercilla, were assessed through an intraoral and extraoral evaluation. Overjet, overbite, molar relationship, presence of DMAs, and NFHs were measured. Descriptive statistics, analysis of association between DMAs and studied factors, and logistic regression models were done and odds ratio with 95% confidence intervals presented. Results: A total of 61.5% of students presented at least one DMA. Chi-square test showed no significant association between DMA prevalence and NHFs, however, after adjusting for sociodemographic factors, children with NFH were 1.69 (95%CI 1.02-2.78) times more likely to have DMAs. Gender and area of residence were not significantly associated with DMAs. Conclusion: In children from Ercilla, DMAs were associated with NFHs, however, sociodemographic characteristics did not have a significant role in the presence of DMA, suggesting that sociodemographic factors might not strongly influence orthodontic needs among children from this geographical area.

Introducción: Las anomalías dentomaxilares (ADM) afectan el crecimiento y la morfología del sistema estomatognático de los individuos, lo que representa un problema de salud pública. Pocos estudios han descrito su prevalencia en poblaciones vulnerables en Chile. El objetivo del estudio fue explorar la prevalencia de ADM y su asociación con hábitos no fisiológicos (HNF) y características sociodemográficas en niños de escuela primaria que viven en Ercilla, Chile. Material y Métodos:Se evaluó una muestra de conveniencia de 327 estudiantes de educación básica de seis escuelas de Ercilla mediante una evaluación intraoral y extraoral. Se midieron el resalte, la sobremordida, la relación molar, la presencia de DMA y HNF. Se realizó estadística descriptiva, análisis de asociación entre ADMs y los factores estudiados, y modelos de regresión logística y se presentaron odds ratio con intervalos de confianza del 95%. Resultados: El 61,5% de los alumnos presentó al menos una ADM. La prueba de chi-cuadrado no mostróuna asociación significativa entre la prevalencia de ADM y HNF, sin embargo, después de ajustar de acuerdo a factores sociodemográficos, los niños con HNF tenían 1,69 (IC del 95%: 1,02 a 2,78) veces más probabilidades de tener ADMs. El género y el área de residencia no se asociaron significativamente con las ADMs. Conclusión: En los niños de Ercilla, las DMA se asociaron con NFH, sin embargo, las características sociodemográficas no tuvieron un papel significativo en la presencia de DMA, lo que sugiere que los factores sociodemográficos podrían no influir fuertemente en las necesidades de ortodoncia entre los niños de esta área geográfica.

The mean overjet in libyan children and the relationship between increased overjet and incisors trauma.

AIMS AND OBJECTIVES: The aim of this study was to assess the mean overjet in school-going Libyan children and to examine the relationship between increased overjet and permanent incisor's trauma. MATERIALS AND METHODS: This study is a part of a cross-sectional investigation of aspects of dental health of 2015 school going Libyan children aged between 6 and 16 years old of both genders from both rural and urban areas. Overjet was measured as the horizontal distance in millimetres between the upper and lower incisors. Trauma to permanent incisors was assessed according to Elli's Classification. RESULTS: SPSS version 20.0 for percentages was used for statistical analysis. The relationship between increased overjet and incisor trauma was tested using the Chi-square test at 0.05 significance level. The overjet measurement ranged from -2 mm to 8 mm with the mean overjet of 3.062 (1.23, SD). The prevalence of incisor trauma was statistically significantly higher in children with increased overjet (P < 0.0001). CONCLUSION: The average mean overjet value in Libyan children is between 2 mm and 3 mm and below or above these values, considered decreased or increased, respectively. Traumatic injuries to permanent incisors significantly increased with increased overjet.

Malocclusions in primary and early mixed dentition in very preterm children.

Objective: To compare the prevalence of malocclusions in the primary and early mixed dentition of very preterm and full-term children.Material and methods: Study subjects consisted of 205 very preterm (90 girls and 115 boys), and 205 age- and gender-matched full-term children. Data were collected from the register of Turku University Hospital (children born before the 37th week of pregnancy with a birth weight of less than 1500 g, and all infants born before the 32nd week of pregnancy) and from public health centre dental registers.Results: In primary dentition, case children had a higher odds of dental crowding (OR = 2.94, 95% CI 1.17-7.35, p = .021), a tendency toward increased overbite (OR = 1.55, 95% CI 0.93-2.59, p = .096), and a lower odds of increased overjet (OR = 0.19, 95% CI 0.07-0.57, p = .003) compared to control children. In early mixed dentition, there were no statistically significant differences in occlusal traits; however, case children were significantly more likely to have received orthodontic treatment (OR = 2.80, 95% CI 1.50-5.23, p = .001) compared to controls.Conclusions: The results indicate that in primary dentition, the prevalence of malocclusion varies between very preterm and full-term children. In early mixed dentition, the distribution of occlusal traits is more similar.

Oral Habits: Prevalence and Effects on Occlusion Among 7 to 13 Years Old School Children in Aseer, Saudi Arabia

Abstract Objective: To evaluate the prevalence of deleterious oral habits and its effect on occlusion in school going children from 7 to 13 years old, in Aseer region of Saudi Arabia. Material and Methods: A cross-sectional study was conducted by clinical examination for the total sample of 750, who were attending private/ government schools in Aseer region school. Students were selected by stratified cluster random sampling. Clinical findings of each oral habits, including assessment of malocclusion, were examined involving the following parameters, i.e., crowding, spacing, open bite, crossbite and deep bite. Logistic regression analysis was conducted. Results: Boys had 26.2 % of crowded teeth, while 16.3% of girls were found to have crowded teeth; the difference was found to be significant (p=0.002). Spacing was present in 26.4% of boys and 16.7% girls; a significant difference was found between the two (p=0.002). Sleep bruxism was observed more among male subjects than females with a statistically significant difference in detrimental habits (p<0.001). Those subjects having tongue thrusting are 1.264 times at more risk of having crowded teeth than those with no tongue thrusting. Conclusion: There was a high prevalence of malocclusion associated with harmful oral habits in children. This highlighted the need to implement programs of oral care and health education for preventive orthodontic treatment at an early age.

[Epidemiological survey of malocclusion in 8-9 year-old children in Qingdao Laoshan district].

PURPOSE: To investigate the prevalence of malocclusion and the correlation between caries and malocclusion in mixed dentition of primary students in Laoshan district of Qingdao city, to provide a scientific basis for early orthodontic treatment. METHODS: According to WHO's oral health survey (basic methods), a survey concerning oral health was performed in 1803 children aged 8-9 years old. SPSS 17.0 software package was used for statistical analysis . RESULTS: 1322 of 1803 pupils suffered from malocclusion, the prevalence of malocclusion in children surveyed was (73.32%). There were 519 cases(39.26%) of Class I malocclusion, 374 cases(28.29%) of Class II malocclusion, 357(27.00%) cases of Class III malocclusion, 72 cases (5.45%) with asymmetric malformation. As regard to clinical manifestations, deep overbite accounted for(37.67%) ,followed by deep overjet(29.19%), dental crowding (16.94%) and crossbite(16.03%). The prevalence of caries was 64.23%. Among them, there were 625 males (34.66%) and 532 females(29.51%). CONCLUSIONS: The prevalence rate of malocclusion in mixed dentition of primary students in Laoshan district of Qingdao district is not optimistic, the incidence of malocclusion is closely related to caries.

The effects of playing wind musical instruments on the occlusal characteristics in a Northern Nigerian Population.

INTRODUCTION: Dentists are often questioned on whether playing a wind musical instrument can adversely affect dental occlusion. This study compared the occlusal characteristics in wind instrument players (WIPs) and non-WIPs. MATERIALS AND METHODS: This was a cross-sectional comparative study comprising a group of fifty males aged 18-45 years that had been playing wind instruments for a minimum of 2 years, whereas the control group were non-WIPs in the same environment. All the participants had full complement of dentition. The occlusal characteristics of overjet, overbite, anterior open bite and Little's irregularity were assessed for both groups. Excellent intra-examiner reliability was observed (Cronbach's alpha - 0.997). The Statistical Package for Social Sciences (SPSS Inc., Chicago, IL, USA) version 17 was used for data analysis, and statistical significance level was set at P < 0.05. RESULTS: The number of years of playing wind musical instrument ranged from 2 to 25 years. The mean overjet was 3.46 ± 1.49 mm and 3.18 ± 1.27 mm in the WIP and non-WIP groups, respectively (P > 0.05). The maxillary anterior segment showed statistically significantly higher Little's Irregularity Index score in the WIP group (3.18 ± 3.73 mm) than that in the non-WIP group (1.87 ± 2.21 mm) (P < 0.05). The maxillary Little's Irregularity Index score in trumpet and trombone players (3.55 ± 3.93 mm) was significantly higher than that in saxophone and clarinet players (1.69 ± 2.39 mm). Both the maxillary and mandibular anterior-segment alignments were neither influenced by the number of years nor the frequency of play. CONCLUSIONS: Playing wind musical instruments significantly affects the maxillary anterior-segment alignment.

Dentoskeletal morphology in adults with Class I, Class II Division 1, or Class II Division 2 malocclusion with increased overbite.

INTRODUCTION: The treatment options for adults with increased overbite are limited to dentoalveolar changes that camouflage the condition. Because of high relapse tendency, defining the problem area is important when creating a treatment plan. This study aimed to evaluate dentoskeletal morphology in skeletal Class I and II anomalies associated with Angle Class I, Class II Division 1 (Class II/1), and Class II Division 2 (Class II/2) malocclusions with increased overbite compared with normal occlusion. METHODS: Pretreatment cephalograms of 306 patients (131 men, 175 women; overall ages 18-45 years) were evaluated. Four groups were constructed. Three groups had increased overbite (>4.5 mm): group 1 (n = 96) skeletal Class I (ANB = 0.5°-4°), group 2 (n = 85) skeletal Class II (ANB >4.5°) with Class II/1; and group 3 (n = 79) skeletal Class II with Class II/2 malocclusion. Group 4 as a control (n = 46) skeletal Class I normal overbite. Dental and skeletal characteristics of the groups were compared by sex. For statistical evaluations, analysis of variance followed by Tukey post hoc, Mann-Whitney U, and Kruskall-Wallis tests were used. Additionally correlation coefficients between overbite and skeletal/dental parameters were calculated. RESULTS: Between sexes, with regard to skeletal parameters, the men had greater values in millimetric measurements, and the women had higher SN/GoGn values. Maxillary/mandibular molar heights and the mandibular incisor heights were higher in men. In group 1, decreased lower anterior facial height (LAFH), retrusive mandibular incisors, and increased interincisal degree were determined. The maxillary molars were intrusive, whereas the vertical position of the mandibular molars and incisors in both jaws were normal. In group 2, retrognathic mandible, increased LAFH and mandibular plane angle, extrusive maxillary/mandibular incisors, protrusive mandibular incisors, and decreased interincisal degree were found. In group 3, decreased LAFH, increased interincisal degree, and retrusive incisors in both jaws were determined. There were significant negative correlations between SN/GoGN, palatal plane, and overbite in group 2 and between ANS-SN and overbite in group 3, and positive correlation between interinsical angle and overbite in all increased overbite groups. CONCLUSIONS: Dental morphology seems to be the main factor of increased overbite. Differences between groups were related primarily to inclinations and vertical positions of the incisors, rather than molar positions.

Prevalence and patterns of tooth agenesis in Angle class II division 2 malocclusion in Italy: A case-control study.

OBJECTIVE: The aim of this case-control retrospective study was to assess the prevalence and pattern of tooth agenesis in a group of Italian Caucasian test subjects with Class II division 2 malocclusion. The findings were then compared with an Italian control group of orthodontic patients and with previous studies performed in other countries. MATERIAL AND METHOD: Six hundred patients (37 subjects with Angle Class II division 2 malocclusion and 563 orthodontic patients with other malocclusions), aged 7 or older, from the Orthodontic Department of University of Padua Dental Clinic were collected. For this investigation, two expert operators evaluated the Angle Class from dental casts, intraoral photographs and lateral cephalograms. Inclusion criteria for Class II division 2 were: U1-SN less than 90° and overbite>3mm. Tooth agenesis were assessed with digital panoramic radiographs. Third molars were excluded from the analysis. Descriptive analysis using absolute and relative frequencies were performed to check out the prevalence and pattern of tooth agenesis in the sample considered. The relative frequencies in each table were calculated as a percentage based from column total. RESULTS: The prevalence of tooth agenesis in the Angle Class II division 2 group was 18.92%, while in the general population was 8.35%. This result was sufficient to demonstrate a significant difference between the two groups concerning the tooth agenesis prevalence (P-value<0.05). CONCLUSION: Prevalence of permanent tooth agenesis was more than 2 times higher in the Class II division 2 group rather than in the control group. No agenesis of maxillary lateral incisors was found in Class II division 2 group.

Traumatic dental injuries in preschool-age children: Prevalence and risk factors.

This study examined the prevalence, socio-demographic correlates, and clinical predictors of traumatic dental injuries (TDIs) in the primary dentition among a community-based sample of preschool-age children. The sample comprised 1,546 preschool-age children (mean age 49 [range: 24-71] months) in North Carolina public preschools, enrolled in a population-based investigation among young children and their parents in North Carolina. Information on socio-demographic, extraoral, and intraoral characteristics was collected and analyzed with bivariate and multivariate methods, including logistic regression modeling and marginal effects estimation. The prevalence of dental trauma was 47% and 8% of TDI cases were "severe" (pulp exposure, tooth displacement, discolored or necrotic tooth, or tooth loss). In bivariate analyses, overjet and lip incompetence were significantly associated with TDI. Overjet remained positively associated with severe trauma in multivariate analysis, OR = 1.4, 95% confidence interval (CI) [1.2, 1.6], corresponding to an absolute 1.3%, 95% CI [0.7, 1.8], increase in the likelihood of severe trauma, per millimeter of overjet. Children with increased overjet (>3 mm) were 3.8, 95% CI [2.0, 7.4], times as likely to have experienced severe TDI compared with those with ≤3 mm. Overjet is a strong risk factor for TDIs in the primary dentition. Incorporating and operationalizing this information may help TDI prevention and related anticipatory guidance for families of preschool-age children.

Human sound systems are shaped by post-Neolithic changes in bite configuration.

Linguistic diversity, now and in the past, is widely regarded to be independent of biological changes that took place after the emergence of Homo sapiens We show converging evidence from paleoanthropology, speech biomechanics, ethnography, and historical linguistics that labiodental sounds (such as "f" and "v") were innovated after the Neolithic. Changes in diet attributable to food-processing technologies modified the human bite from an edge-to-edge configuration to one that preserves adolescent overbite and overjet into adulthood. This change favored the emergence and maintenance of labiodentals. Our findings suggest that language is shaped not only by the contingencies of its history, but also by culturally induced changes in human biology.

The association of overjet with traumatic dental injuries: a systematic review protocol.

REVIEW QUESTION: The objective of this review of association (etiology) is to identify the relationship between different overjet measurements and developing a traumatic dental injury (TDI) across different dentition stages. Specifically, the review will elucidate the critical level, in millimetres, at which an overjet will place an individual at an increased risk of developing a TDI within each specific dentition stage. The specific review questions are.

Palate shape and size and palatal rugae morphology of children with anterior open bite and normal vertical overbite.

PURPOSE: To determine differences between open bite and normal vertical overbite regarding distribution, size and clinical appearance of palatal rugae, depth and length of the palate, intercanine and intermolar widths and arch perimeter. METHODS: A cross-sectional study was performed in 264 superior models were studied with a 3D analysis system. A total of 132 individuals with AOB and 132 individuals with normal vertical overbite were evaluated, chosen from public schools with ages between 8 and 16 years. Palatal anthropometric features were evaluated. Qualitative analysis of palatal rugae was performed, exploring the shape, direction, unification and sensitivity of the palate. The Mann Whitney and Chi Square tests were used for statistical analyses. RESULTS: The average age was 11.37 ± 2.27 years for normal overbite and 11.87 for anterior open bite, with 54.9% of women. No significant differences were found between subjects with AOB and subjects with normal vertical overbite regarding intermolar or intercanine width. The maxillary length and depth and the height and width of palatal rugae were lower in the AOB group. The most common rugae shapes were curved and wavy, predominating in the horizontal direction with a parallel distribution. CONCLUSION: Qualitative evaluation demonstrated asymmetry in the shape, direction and unification of rugae in both groups. Most arch measurements were greater in individuals with AOB.

Agenesis of the upper lateral incisors: Study of an orthodontic population and clinical illustration.

In his daily practice, the orthodontist is regularly asked to treat patients with one or more missing teeth. Considering their functional and esthetic specificities, and the relatively high frequency of agenesia, our interest was to focus on the permanent lateral upper incisors. Our study, based on an orthodontic population including 1000 patients, shows that about 7.8% of these patients present agenesis of at least one permanent tooth (out of which 3.6% are agenesis of the upper lateral incisor). Treatment options for these cases are multiple with several decisional factors to consider: the solutions often lead to compromises, and require a multidisciplinary coordination. Therefore, the purpose of this article, was to describe the prevalence of these agenesia based on a retrospective study, and to present two clinical cases: the first case is a bilateral agenesis of the maxillary lateral incisors treated with space opening in order to place two implant-supported restorations. The second case is an agenesis of tooth 12 treated with space reopening and the placement of a cantilever bridge. These clinical cases are presented to illustrate the multidisciplinary approach involving orthodontics, prosthodontics, and periodontology, in order to achieve the most esthetic and functional results possible.

Characteristic of Malocclusion among Saudi Special Need Group Children.

INTRODUCTION: The present study analyzed the characteristics of malocclusions, occlusal traits among Special Health care Needs (SHCN) children with Down syndrome (DS) and autism disorder (AD) in Riyadh City, Kingdom of Saudi Arabia. MATERIALS AND METHODS: A total of 100 DS and 100 AD children from five rehabilitation centers in and around Riyadh, Kingdom of Saudi Arabia, were included in the study. Any children with history of ongoing medical treatment, extraction, or orthodontic treatment were excluded from the study. Out of the 200 patients examined, 131 were males and 69 were females and the age of the children ranged from 6 to 14 years. The children were examined for malocclusion characteristics using the Angle's classification of malocclusion, and also other occlusal traits, such as overjet, overbite, cross bite, and open bite were also determined. The data obtained were analyzed using Statistical Package for the Social Sciences, version 16 to generate descriptive statistics for each variable. RESULTS: The analyzed data of the right and left permanent molar relation showed higher incidence of class III malocclusion (66%) in DS children as compared with (3-4%) AD children. The AD children presented with higher percentage of class I malocclu-sion (40-41%) as compared with (10-14%) DS children. During examination of the primary molars, the analyzed data showed that left primary molar had more mesial shift in AD children as compared with DS children. CONCLUSION: Down syndrome children had high incidence of class III malocclusion and autistic children had high incidence of class I malocclusion. Overall, the DS children were more prone to malocclusion. CLINICAL SIGNIFICANCE: This study provides database for health professionals in Saudi Arabia in regard to malocclusion of autis-tics and DS patients.

The Prevalence of Major Types of Occlusal Anomalies among Saudi Middle School Students.

INTRODUCTION: Malocclusion is the most common dental anomaly among children and adolescents. Accordingly, this study was conducted to investigate the prevalence of major types of occlusal anomalies in permanent dentition among Saudi Arabian middle school adolescent students seeking orthodontic treatment in Jeddah. MATERIALS AND METHODS: The sample comprised 150 males and 150 females with mean age of 14.25 (±1.09) for both males and females. Data were registered using the Bjork method. RESULTS: The results of the study showed that postnormal occlusion, prenormal occlusion, and bimaxillary protrusion represented 22, 14.7, and 8.3% of the studied sample respectively. Moderate and severe overjet accounted for 24.7 and 5.7% and for overbite 28 and 13% respectively. Midline deviation was detected in 25.3% of the sample. Mild, moderate, and severe maxillary and mandibular crowding represented 10, 27.3, and 10% and 13, 40, and 9.7% respectively. CONCLUSION: The prevalence of occlusal anomalies was 90% and some occlusal anomalies were higher in females. CLINICAL SIGNIFICANCE: The prevalence of occlusal anomalies in Saudi Arabian middle school students necessitates the demand for obtaining baseline data for planning orthodontic services.

Cross-sectional Study of Dental Trauma and Associated Factors Among 9- to 14-year-old Schoolchildren in Isfahan, Iran.

PURPOSE: To assess the prevalence of dental trauma (DT) and its associated factors in 9- to 14-year-olds. SUBJECTS AND METHODS: A cross-sectional survey was carried out through clinical examination of the permanent incisors and canines of 907 schoolchildren (9 to 14 years old, average age = 11 ± 0.5 [SD] years, 55% female and 45% male) enrolled in 20 public schools in Isfahan, Iran. The demographic data, history and cause of trauma were recorded during patient interviews and with a structured questionnaire filled in by their parents. The overjet, lip coverage, and visible signs of DT (permanent incisors only, similar to the classification used by the US National Health and Nutrition Examination Survey 1988-1994, NHANES III) were recorded. DT in permanent canines were also recorded. RESULTS: Approximately 36% (n = 325) recalled the occurrence of dental trauma, but only 23.8% (n = 216) of children had visible signs of dental trauma to the permanent incisors (girls [18.8%], boys [29.9%], OR = 0.54; 95% CI 0.40- 0.74; p = 0.000). The maxillary central incisors were commonly injured (69.5%). The most frequent types of injuries were the enamel fracture (59.0%), craze lines (16.3%), and enamel and dentin fracture (13.4%). Tooth avulsion was seen in 0.7%. No significant association was found between dental trauma and increased overjet of > 3 mm (p = 0.328), but a tendency was identified for overjet > 5 mm (OR = 1.51; 95% CI 0.89-2.58; p = 0.060). The relationship between DT and lip coverage was statistically significant (OR = 1.63; 95% CI 1.18-2.25; p = 0.003). Violence (30%) and fall (22.7%) were the main causes of DT. CONCLUSION: The prevalence of DT in permanent incisors was high (23.8%) and significantly lower in girls. The association between DT and lip coverage was significant. There was no association between DT and increased overjet of > 3 mm.