Evaluation of oro-facial function in young subjects with temporomandibular disorders.

The aim of this study was to evaluate bite force (BF) and oro-facial functions at different dentition phases (initial-mixed, intermediate-mixed, final-mixed and permanent dentition) in children and adolescents diagnosed with temporomandibular disorders (TMDs). The sample was selected from four public schools in Piracicaba, São Paulo, Brazil. Of the 289 participants recruited, aged 8-14 years old, 46 were placed into the TMD group. TMD was diagnosed using Axis I of the Research Diagnostic Criteria for Temporomandibular Disorders (2011). Oro-facial functions were evaluated using the Nordic Orofacial Test-Screening (NOT-S), which involves both an interview and a clinical examination. BF was measured using a digital gnathodynamometer. Age and body mass index (BMI) were also considered. The data were analysed by the following tests: Kolmogorov-Smirnov test, Student's t-test, Spearman and Pearson coefficients, Qui-square test, Fisher's exact or binomial test, as indicated. Moreover, univariate and multivariable logistic regression were applied. For the TMD group, scores associated with NOT-S interview and NOT-S total were higher than for the control group (P = 0.033 and P = 0.0062, respectively). No differences in BF between genders or groups (P > 0.05) were detected. Variables included in the multivariate logistic regression were BMI and NOT-S total. Based on this analysis, NOT-S total was associated with TMDs. Reported sensory function was the specific domain within NOT-S interview that established the significant difference between the groups (P = 0.021). The TMD group also had a greater number of alterations in the face-at-rest domain of the NOT-S exam (P = 0.007). Concluding, it did not detect an association between TMDs and either dentition phase or BF. Instead, BF correlated with age and BMI. Oro-facial dysfunction was associated with TMD in the studied sample, but this association may be bidirectional, requiring further researches.

Changes in the oral-health-related quality of life of Brazilian children after an educational preventive programme: an 1-month longitudinal evaluation.

OBJECTIVE: This 1-month longitudinal study assessed whether the oral status and the oral-health-related quality of life (OHRQoL) of children changed after four sessions of an educational preventive programme. STUDY POPULATION AND METHODS: Fifty Brazilian students (11-12 year old) were examined for signs and symptoms of gingivitis using the Community Periodontal Index and two questions about gingival bleeding. The OHRQoL was measured using the Brazilian Portuguese version of the Child Oral Impacts on Daily Performances (Child-OIDP). Higher scores indicated worse OHRQoL. The results were analysed using the Shapiro-Wilk, Chi-square, Wilcoxon signed-rank and Mann-Whitney tests. The magnitude of the mean change was calculated using the effect size. RESULTS: Twenty-four percentage of children had more than six sites with bleeding at follow-up compared with 58% at baseline. There was a significant decline in the intensity and extension of impacts at follow-up. A significant improvement in the clinical status and oral hygiene was observed for both transitional categories. There was a significant decline in the Child-OIDP scores of those reporting 'much improved'. A significant improvement in the global ratings of oral health was observed at follow-up. CONCLUSIONS: In the studied sample, an improvement occurred with respect to the severity of disease, intensity and extension of impacts and global ratings of oral health after 1-month follow-up. These results suggest that improving the global transition in health by enhancing coping and management skills while inducing slight changes in the clinical status and the specific aspects of health compromised by the disease is possible.

Evaluation of masticatory performance and bite force in children with sleep bruxism.

The aim of this study was to evaluate the association between masticatory performance (MP) and bite force (BF) in children with sleep bruxism (SB) during the mixed dentition stage, considering also the occlusal characteristics. The sample was composed by 52 healthy children of both genders, aged 6-10 years. From those, 22 presented signs and symptoms of SB and 30 were the controls. SB diagnosis consisted of both parental report and presence of tooth wear. MP was evaluated by the individual's ability to communicate an artificial chewable test material for determining the median particle size (X50) and distribution of particles in the different sieves (b). BF was measured using a digital gnathodynamometer with fork strength of 8 mm. The results were submitted to descriptive statistics, Mann-Whitney and chi-square tests, Spearman's correlation and multiple logistic regression. Mean BF and X50 did not differ between groups with and without SB. A significant negative correlation was observed between BF and X50 only in the group of children with SB. Moreover, the logistic regression model showed an association between the presence of SB and higher b index. The other independent variables included in the model showed no association with SB. BF did not differ between children with and without SB. Besides, higher BFs in children with SB meant better MP; however, they were more likely to present chewed particles retained in the larger aperture sieves, consequently requiring more chewing cycles to break down the test material in smaller particles.

Alterations in macrophages after exposure to root canal filling materials.

The process of engulfment of overextended root canal filling materials was investigated in rat peritoneal macrophages in vitro. Root canal filling materials tested were Finapec APC, Sealapex, Canals-N, and Canals. The phagocytosis rate of macrophages for the Finapec APC was significantly (p < 0.05) higher than that for other three root canal filling materials. That for Canals was the lowest. About 95% of the cells exposed to Finapec APC were viable at 60 and 120 min. For Canals the percentage was 74% and 63% at 60 and 120 min, respectively. Ruffle formation in macrophages was observed by scanning electron microscopy after exposure to Finapec APC for 60 or 120 min. Many vacuoles were observed in macrophages exposed to Canals for 60 min. It was concluded that the phagocytic rate of macrophages for Canals that showed a strong cytotoxicity was lowest and that the rate for Finapec APC that showed a low cytotoxicity was the highest.

Lack of correlation between the amount of eugenol released from zinc oxide-eugenol sealer and cytotoxicity of the sealer.

The purpose of this study was to examine a possible correlation between the eugenol released from a zinc oxide-eugenol sealer (Canals) and the degree of cytotoxicity. The cytotoxicity and eugenol release from root canal filling material containing eugenol was examined for test solutions at several experimental periods. No positive correlation was found between eugenol release and cytotoxicity of the root canal filling material.

Transmission of hand-arm vibration to the head.

A "tooth impression" was devised to measure head vibration. The vertical head vibration of four subjects was measured with the tooth impression during exposure of the hand to vertical sinusoidal vibration at acceleration levels of 3.15, 10.0, and 31.5 m/s2 root mean square in the range of 8-200 Hz. While in a standing position, the subjects pulled the vibrating handle upward at a force of 5 kg with the elbow joint stretched during the tests. The measurement was repeated twice. The difference between the two measurements was within 3 dB, a level which suggests that this method has good reproducibility. The vibration transmitted to the head was the greatest in the range of 12.5-16 Hz, and the attenuation was about 20 dB. Head vibration decreased by approximately 15 dB per octave at frequencies above 20 Hz as the frequency increased. When the excitation level was increased by 10 dB, the head vibration increased by about 8 dB.

Detectability of anterior displacement of the articular disk in the temporomandibular joint on helical computed tomography: the value of open mouth position.

OBJECTIVE: The purpose of this study was to establish the diagnostic reliability of anterior displacement of the articular disk in the temporomandibular joint on helical computed tomography. STUDY DESIGN: Ninety-four consecutive patients were examined through use of both computed tomography and magnetic resonance imaging. On axial computed tomography, anterior disk displacement was defined as the presence of an area of soft tissue density that was semilunar in shape and located in front of the mandibular condyle. RESULTS: With magnetic resonance imaging taken as the diagnostic gold standard in evaluation of articular disk position, the sensitivity, specificity, and accuracy for computed tomography were 91%, 100%, and 97%, respectively, in the closed mouth position and 96%, 99%, and 98%, respectively, in the open mouth position. CONCLUSIONS: The detectability on axial helical computed tomography of anterior displacement of the articular disk in the temporomandibular joint in the open mouth position was almost equal to that on magnetic resonance imaging. It is recommended that the open mouth position be added when helical computed tomography is used to evaluate patients with temporomandibular joint disease.

Ozonolysis mechanism of lignin model compounds and microbial treatment of organic acids produced.

Treatment methods comprising ozonolysis and microbial treatment of lignin discharged from the pulp manufacture industries were investigated by using a sulfite pulp wastewater and a lignin model compound, i.e. sodium lignosulfonate. Dynamic behaviors for the formations of intermediate derivatives such as muconic acid, maleic acid, and oxalic acid produced from the ozonolysis of sulfite pulp wastewater were observed from data of UV absorption at 280 nm by a spectrophotometer and at 210 nm by high performance liquid chromatography. The microorganisms that were isolated by the enrichment culture method were used to degrade the organic acids such as oxalic acid and acetic acid. Time courses of biological degradation of these organic acids indicated diauxic growth, which was found in a culture with mixed substrates. In the treatment of sodium lignosulfonate, the ozonolysis and microbial treatment using activated sludge converted sodium lignosulfonate into carbon dioxide and water almost completely.

[Effect of soft laser on pain].

Two kinds of semiconductor laser, STOMA-LASER and Four-Luck, were used for patients having pain in the mouth and their effective rates were compared in 93 patients (133 cases). As a result, the following results were obtained. 1. The effective rate was 70.7% at the stage just after radiation. 2. Age, sex and oral hygiene were not significant for the effective rate. 3. The kinds of diseases were remarkably significant. 4. The kind of apparatus did not play any role in the effective rate as a whole, but was significant for the kinds of disease.

A study of volumetric visualization and quantitative evaluation of bone trabeculae in helical CT.

OBJECTIVES: The aim of this study was to investigate the reliability of quantitative evaluation of bone trabeculae by helical CT. METHODS: Ten specimens of human cadaver mandibular condyles were examined using both micro-CT and helical CT, and volume rendered three-dimensional (3D) images were obtained from the CT data. Micro-CT was used as the reference standard. From the micro-CT data images, bone trabeculae in each condyle were extracted by image processing and their volumes were calculated automatically. From the helical CT data images, the cortical bone was manually removed and bone trabeculae in each condyle were extracted using opacity curve and colour mapping thresholds. The optimal cut-off CT value that resulted in a similar volume of bone trabeculae obtained from helical CT and micro-CT data was investigated. RESULTS: The optimal cut-off CT value to assess the volume of bone trabeculae accurately on 3D images obtained with helical CT data was found to be 200 Hounsfield units. CONCLUSIONS: This study suggests that quantitative evaluation of bone trabeculae using helical CT might be a valid and useful method.

Helicobacter pylori infection among Japanese children.

BACKGROUND: In Japan, there are few reports describing Helicobacter pylori infection among young children. The aim of the present study was to identify risk factors associated with H. pylori in school-aged children. METHODS: Subjects were first-grade students of three elementary schools (n = 310) and second-grade students of a junior high school (n = 300). Personal information, such as student's medical history, parent's history, family size, sibshipsize and household pets, was collected from guardians using a questionnaire. Saliva samples and personal information were collected twice (1995 and 1996). By using the saliva samples, H. pylori IgG antibody was measured using a commercial kit. To analyze the risk factors for H. pylori infection, sex- and age-adjusted odds ratios (OR) were calculated using a multiple logistic model. RESULTS: Among the children, factors related to Helicobacter antibody in saliva included spending a longer period of time in a nursery school or kindergarten (OR = 4.0) and a maternal history of stomach disease (OR = 2.8). Birth order (OR = 2.2), sleeping situation (OR = 2.3) and sibshipsize (OR = 1.6) were not factors that were significantly related to Helicobacter antibody in the saliva. Chewing food for the infant, family size, rooms in the household, sharing a bedroom during childhood, pets, a past history and a paternal history were not related to positivity. CONCLUSIONS: The results indicate that transmission is person-to-person, mainly through close contact with other children and intrafamilial infection. Helicobacter pylori infection seems to occur frequently early in life, probably before 6 years of age.