Prevalence of numeric anomalies in the permanent dentition of patients with Down syndrome

The purpose of this study was to evaluate the prevalence of numeric anomalies in the permanent dentition of patients with Down syndrome by means of panoramic radiographs. The sample consisted of panoramic radiographs from 70 subjects. We examiend the radiographs to detect hypodontia as well as supernumerary teeth. Our results confirm the high prevalence of hypodontia among patients with Down syndrome (60%), mostly with mild expression. The teeth most often missing were the upper lateral incisors, usually bilaterally, followed by the lower second premolars and upper second premolars. Supernumerary teeth were seen in 6% of the subjects, and the concomitant occurrence of hypodontia and supernumerary teeth occurred in one patient.     

Exploring taste hyposensitivity in Japanese senior high school students

Aim: The main objective of this study was to investigate the prevalence of taste hyposensitivity and the relationships between sex, oral health status, and eating habits with taste hyposensitivity in Japanese senior high school students. Methods: Oral examinations, sweet and salt whole‐mouth taste tests, and a questionnaire about eating habits were conducted on 234 senior high school students. Factors affecting taste hyposensitivity were investigated using a multivariate analysis. Results: Sweet‐taste hyposensitivity was observed in 7.3% of the students, and salt‐taste hyposensitivity in 22.2%. Approximately 3% of the students had both sweet‐ and salt‐taste hyposensitivity, and 22.6% had either sweet‐ or salt‐taste hyposensitivity. In total, 26% had a taste hyposensitivity. There were significant relationships between the intake of instant noodles with sweet‐taste hyposensitivity, and the intake of vegetables or isotonic drinks with salt‐taste hyposensitivity. Conclusions: There was a significant association between eating habits and taste hyposensitivity in Japanese senior high school students. Taste tests would be a helpful adjunct for students to recognize variations in taste sensitivity, and a questionnaire about their eating habits might provide an effective self‐review of their eating habits, and therefore, provide motivation to change.     

Prevalence of congenital hypodontia in the permanent dentition and its treatment

Congenital aplasia (agenesis) is an important development dental anomaly. There is a big discrepancy between the data on the prevalence of aplasia in dental literature. The authors analyzed orthopantomograms of 1875 children and adolescents at the Department of Dentistry for Children and Orthodontics of Semmelweis University. The prevalence of congenital aplasia was found 15.68% (294 subjects). There was no difference between the sexes. The most frequently missing teeth were the upper lateral incisors, the lower second premolars, the upper second premolars and the lower central incisors. The highest number of aplasia was detected in the second premolars (330 teeth). The frequency of aplasia of the molars was 0.74%. Oligodontia was found in 1.12%. The authors present two patients with aplasia and the successful treatment of the cases.     

Dental anomalies in the primary dentition and their repetition in the permanent dentition: a diagnostic performance study

This study investigated the recurrence in the permanent dentition of dental anomalies of the primary dentition. A sample of 189 subjects (100 males, 89 females, mean age of 5 years and 7 months) with anomalies of primary teeth (tooth hypodontia, supernumerary teeth, geminated teeth, and fused teeth) was selected and re-analyzed at a mean age of 11 years and 2 months for the recurrence of the dental anomalies in the permanent dentition. As a control group, 271 subjects (123 males, 148 females) without dental anomalies in the primary dentition were selected. The recurrence in the permanent dentition of the dental anomalies in the primary dentition was evaluated by measures of diagnostic performance. The results showed high values for the repetition of hypodontia (positive likelihood ratio = 102.0); low score for the repetition of hyperdontia (positive likelihood ratio = 6.5); low positive likelihood ratio (9.1) for gemination of primary teeth resulting in supernumerary permanent teeth; high positive likelihood ratio (47.0) for fusion of primary teeth followed by missing permanent teeth. Dental anomalies in the primary dentition are associated with an increased likelihood of anomalies of the succedaneous permanent.     

Prevalence of temporomandibular dysfunction in Turkish children with mixed and permanent dentition

This study was carried out to determine the prevalence of temporomandibular joint (TMJ) dysfunction in mixed and permanent dentition and to evaluate the sex distribution in Turkish children. One hundred and eighty-two children with mixed dentition and 212 with permanent dentition were selected for the study, which used a questionnaire and clinical examination. Children with one or more signs (TMJ sounds, TMJ tenderness, muscle tenderness, restricted mouth opening) and/or symptoms (TMJ pain during mastication and mouth opening, restriction of the jaw opening and TMJ sounds) met the criterion of TMJ dysfunction. The total prevalence of signs and symptoms of TMJ dysfunction in the studied population was 68% (68% in girls and 68% in boys) in mixed dentition and 58% (61% in girls and 56% in boys) in permanent dentition. The Z-test and analysis of variance (ANOVA) were used for statistical analysis of the difference between the results. The total prevalence of signs and symptoms of TMJ dysfunction in mixed dentition was found to be higher than in permanent dentition (P < 0.05). No statistically significant difference was found in the total prevalence of TMJ dysfunction between girls and boys.     

Comparison of normal permanent and primary dentition sagittal tooth-crown inclinations of Japanese females

The purpose of this study was to clarify the characteristics of permanent and primary tooth-crown inclinations. Landmark points from cephalograms and dental casts of two groups; 23 women (mean 20.3 +/- 3.3 years) and 11 girls (mean 5.2 +/- 0.1 years) were digitized, and the coordinates were integrated and transformed to a standardized plane. The 3-dimensional crown inclinations were projected on the sagittal plane, and the angles between the tooth vectors and the FH plane were calculated. An independent-group t-test was used to test for group differences of each tooth inclination, and correlation coefficients were generated for the inclination angles among the permanent and primary teeth. Most maxillary tooth-crown inclinations showed significant age-related differences, while only the second premolar and primary second molar differed significantly in the mandible. The maxillary molars were parallel to the corresponding mandibular molars and correlated with each other, but the primary molars were not. Significant correlations were found between inclinations of most permanent teeth, but not the primary teeth. Maxillary tooth-crown inclinations change during growth, but tooth-crown inclinations of the mandibular teeth do not.     

Prevalence of malocclusion in high school students in Japan according to the Dental Aesthetic Index

Abstract – The Dental Aesthetic Index (DAI) was used to evaluate malocclusion in Japanese high school students ( n = 409, ages 15–18 yr). The purpose of this study was to obtain basic data concerning malocclusion in Japanese high school students. This study used a sample of students from randomly selected urban and rural high schools in Japan's Kyushu district. The DAI scores for urban and rural high school students, as well as the total DAI scores from these two areas were significantly higher than that of American high school students. These results showed that the number of students with an acceptable dental appearance among Japanese high school students is significantly lower than among American high school students. This indicates a higher need for orthodontic treatment among Japanese high school students.     

Prevalence of malocclusions and demand for orthodontic treatment among students at a women's high school

Prevalences of malocclusions were investigated in a sample of 3,520 girls recorded between 1984 and 1986 at a private high school. Also, proportions of students who had received and were under treatment were surveyed for 3,501 students in 1989. In addition, ratios of a number of those who were judged to reveal maxillary protrusion with respect to that of the whole sample examined were evaluated as a function of overjet. The results of the surveys are as follows. SURVEY I) A total prevalence of malocclusion was 57.9% in the Grade 7 (G7) and 56.4% in the Grade 10 (G10). Among malocclusions surveyed, maxillary protrusion was found in 8.1% of the G7 and in 7.8% of the G10. Deep overbite was determined in 7.9% of the G7 and in 7.6% of the G10, mandibular protrusion was found in 2.4% of the G7 and in 2.7% of the G10. Edge-to-edge incisor relationships were determined in 6.4% of the G7 and in 7.6% of the G10. Anterior open bite was found in 2.4% of the G7 and in 2.9% of the G10. Crowding was found in 37.3% of the G7 and in 33.9% of the G10. SURVEY II) Prevalence of students who had orthodontic treatment at the time of survey, was 6.4% in the G7, 7.0% in the G8, 6.0% in the G9, 6.0% in the G10, 5.4% in the G11, and 3.6% in the G12. Those who had had orthodontic treatment revealed proportions of 8.1% in the G7, 8.0% in the G8, 7.7% in the G9, 11.3% in the G10, 12.2% in the G11, and 13.7% in the G12 students. SURVEY III) A proportion of 73.5% of those who had overjets more than 6 mm were judged to have maxillary protrusion.     

Prevalence of dental erosion and related factors in the deciduous dentition of Japanese children

ObjectivesThe objectives of this study were to clarify the prevalence of dental erosion in the deciduous dentition of child patients, and to identify dietary habits and other factors related to dental erosion.MethodsA total of 116 weaned child patients (67 boys, 49 girls) aged 2–6 years who attended the outpatient pediatric dental clinic of a university hospital for treatment or a periodic checkup were included in the study. A questionnaire survey of the patients' dietary habits and a clinical examination were performed. Dentition was divided into four areas, and responses to erosion-related questions were evaluated for each area using multiple logistic regression analysis.ResultsThe prevalence of subjects with erosion, including pre-erosion lesions without tooth surface defects, was 86%; the prevalence of advanced erosion accompanied by tooth surface defects was 34%. Some food- and drink-related items were found to be significantly associated with erosion of the maxillary anterior teeth but not the mandibular teeth. Medication, use of fluoride, and past dental or medical history did not have any significant effect on erosion in any of the four areas.ConclusionsThe occurrence of dental erosion in deciduous dentition and factors related to its appearance were clarified for each area. An epidemiological survey is required to further reveal the state of deciduous dental erosion in Japanese children and to investigate the necessity of, and, if necessary, establish relevant guidelines for the prevention of dental erosion.     

Possible periodontal pathogens associated with clinical symptoms of periodontal disease in Japanese high school students

BACKGROUND: The purpose of this study is to investigate how the components of biofilm and clinical oral status change in adolescents and to identify specific periodontal pathogens as risk markers for the onset of periodontitis. METHODS: One hundred seven high school students (72 boys and 35 girls, all 15 years old) were recruited. The mesio-lingual site of the left lower first molar was selected as the examined site. Probing depth (PD), bleeding on probing (BOP), the presence of subgingival calculus, and Community Periodontal Index (CPI) were determined by examination with a WHO probe. The prevalence and proportion of seven selected periodontal pathogens (Porphyromonas gingivalis, Tannerella forsythensis, Prevotella intermedia, Campylobacter rectus, Eikenella corrodens, and Actinobacillus actinomycetemcomitans serotypes b and c) were determined by indirect immunofluorescent technique, and the prevalence and proportion of spirochetes were determined by their morphology under dark-field microscopy. The relationship between the periodontal status and the bacterial condition was statistically analyzed. RESULTS: The mean proportion of T. forsythensis was significantly higher in BOP (+) sites compared with BOP (-) sites (3.47% +/- 5.35% versus 0.83% +/- 1.95%) and in CPI 3 sites compared with CPI 0 sites (3.29% +/- 5.28% versus 0.68% +/- 1.37%). The mean proportion of C. rectus was significantly increased in BOP (+) compared with BOP (-) (2.01% +/- 2.48% versus 0.79% +/- 0.91%) and in CPI 3 sites compared with CPI 0 sites (2.04% +/- 2.64% versus 0.80% +/- 0.79%). CONCLUSION: The results indicated that T. forsythensis and C. rectus might be able to be used as risk markers for the onset of periodontitis.     

Prevalence pattern of dental caries in the primary dentition among school children.

The purpose of the study was to assess the pattern of prevalence of dental caries in the primary dentition among 5 year old children. The area of study was urban Pondicherry and the study population consisted of 1009 school children of both sexes (527 boys and 482 girls). A simple random sampling method was used to select the schools. Dental caries was assessed by the Dentition status and Treatment Need (WHO 1997). Statistical analysis was done using the Proportion test. The prevalence of caries was 44.4% among the study population, being higher in the boys (P < 0.05); In Mandibular arch in both the sexes (boys P < 0.05, girls P < 0.01); in posterior teeth (both sex wise & arch wise). Comparison of caries among anterior teeth (Boys vs Girls) [corrected] and posterior teeth (upper vs. lower) revealed higher caries prevalence in Maxillary anterior teeth (P < 0.001) and Mandibular posterior teeth (P < 0.001). In both the sexes and arches, primary second molars showed higher caries prevalence.