Evaluation of mandibular range of motion in Brazilian children and its correlation to age, height, weight, and gender

This study aimed to measure the active mandibular range of motion (ROM) (mouth opening: MO; right and left lateral movements: RL and LL; protrusion: P) in Brazilian children of both genders and of various ages, weights, and heights, and to establish correlations among such variables. Study subjects (n = 303) were healthy boys and girls, with ages ranging between 6 and 14 years, who were regular students of a public school in the state of S?o Paulo. Analysis of variance and intra-class correlation coefficients were considered significant for p < 0.05. Weak significant correlations were observed between mandibular ROM and age, height, and weight. No statistically significant differences (p > 0.05) were observed regarding mandibular ROM between gender groups. Mean mandibular ROM values showed significant increases (p < 0.05) in relation to age, height, and weight, except for RL (p > 0.05), in the studied age range. Significantly smaller (p < 0.05) mean mandibular ROM values were observed for the intervals of 6 and 7 years of age, 1.15-1.35 m, and 17.30-26.50 kg, in relation to the other ranges. Nonetheless, no differences were observed among mean mandibular ROM values in the ranges 8 to 12-14 years, 1.36-1.75 m, and 47-85 kg. Thus, it is suggested that weight, height, and age variables be considered when obtaining mandibular ROM values, particularly in children aged 6 to 7 years, measuring 1.15-1.35 m, and weighing between 17.3-46.5 kg.     

The influence of 30-day-old Streptococcus mutans biofilm on the surface of esthetic restorative materials--an in vitro study

OBJECTIVE: To evaluate the effects of Streptococcus mutans biofilm/restorative materials interaction on surface roughness, hardness and morphology of materials tested. METHODS: Empress 2 (E2), Filtek Supreme (FS), Vitremer (V) and Ketac Molar Easymix (KM) were tested. Twenty-five disks of each material were made and divided into three storage groups: (1) 100% relative humidity (n=5); (2) growth medium (BHI and 1% sucrose) (n=5); (3) S. mutans biofilm-growth medium (n=15). Before storage, hardness measurements were immediately obtained from group 1 specimens. After 30 days of storage, the specimens were cleaned in order to obtain the surface roughness and hardness values, besides morphology analysis by scanning electron microscopy. RESULTS: The surface roughness and hardness values obtained from E2 and FS specimens did not present statistically significant differences among the groups 1, 2 and 3 and between immediate and 30-day-old specimens of each material. However, group 3 specimens of V and KM showed statistically significant higher surface roughness means than other groups. Group 1 specimens of V and KM also showed higher hardness values than the immediate values. Group 3 specimens of V presented decreased hardness values compared with other groups. The scanning electron micrographs showed an increase in surface degradation from group 1 to group 3 for FS, V and KM. CONCLUSIONS: Thirty-day-old biofilm promotes a negative effect on the surface morphology of FS, V and KM, on the surface roughness of V and KM and on the hardness of V.     

The application of microscopic surgery in dentistry

The use of the microscope as a tool for practising Medicine, especially in surgical specialisations, has been established for decades. The microscope was first used in OdontologyDentistry back to the 1970s and 1980s, and was introduced more widely (although it was still far from being in general use) during 1990s. The purpose of this article is to describe the main applications of the microscope in OdontologyDentistry today, as well as providing odontologists and stomatologists, whether specialists or in general practice, with information about microscopic OdontologyDentistry for better patient care. This work also gives particular importance to matters needed to achieve the necessary manual dexterity to work in a magnified operating field using a surgical microscope (SM).     

Treatment of a second maxillary molar with six canals

Variations in the dental anatomy are found in all teeth. Knowledge of these variations, particularly concerning the location and treatment of all canals, is very important for the success of the endodontic therapy. The purpose of this study is to present a clinical case of a maxillary second molar with three palatal canals, two mesio-buccal and one disto-buccal canal. This report serves to remind clinicians that such anatomical variations should be taken into account during endodontic treatment of the maxillary molars.     

Solitary fibrous tumour of the oral cavity with histological features of aggressiveness

We operated on a 65-year-old woman and removed a solitary fibrous tumour from her oral mucosa. Microscopically we found marked atypia, abundant necrosis, increased number of mitotic figures (>4 in 10 high-power fields) and hypercellularity. The tumour cells were strongly stained for CD34. There has been no recurrence after 18 months.     

Caries increment in the permanent dentition of Mexican children in relation to prior caries experience on permanent and primary dentitions

OBJECTIVE: To evaluate the likelihood of caries increment in schoolchildren, based on their prior caries experience. MATERIAL AND METHODS: We undertook a longitudinal study in 452 six-to-nine year olds between 1999 and 2001 in Mexico, with dental exams conducted by two standardized examiners (kappa>0.85). The dependent variable was the DMFT increment, dichotomized as without increment, and at least one unit of increment. Independent variables estimated caries experience at baseline. Data were analyzed using non-parametric tests and generalized linear models (log-binomial) to calculate relative risk (RR) adjusted for age and sex. RESULTS: The percentage of caries-free children diminished by 20.5% from 1999 to 2001. DMFT index increased two-fold, from 0.25+/-0.70 in 1999 to 0.77+/-1.30 in 2001 (p<0.001). The overall risk for this sample was 24%. The DMFT increment was higher (p<0.001) in children with DMFT>0 and dmft>0 in 1999 (RR=1.89, 95% CI=1.37-2.62; RR=2.71, 95% CI=1.94-3.76, respectively). The likelihood for DMFT increment from the 1999 levels was: (1) 2.78 times higher (95% CI=2.06-3.76) if schoolchildren had caries in any of the first permanent molars and (2) 1.62 times higher (95% CI=1.20-2.19) if schoolchildren were affected by high severity caries at baseline. CONCLUSIONS: Both caries prevalence and mean DMFT had significant increments in 18 months. Dental caries in the primary (dmft) and permanent (DMFT) dentitions at baseline are goods indicators of subsequent caries development in this group of children in a medium income country. This relationship became stronger when the occurrence of caries in the first permanent molars was included.     

Multiple hyperdontia: Report of an unusual case

Supernumerary teeth are an infrequent developmental anomaly that can appear in any area of the dental arch and can affect any dental organ. Multiple supernumerary teeth, or hyperdontia, is rare in people with no other associated diseases or syndromes. Conditions commonly associated with hyperdontia include cleft lip and palate, trichorhinophalangeal syndrome, cleidocranial dysplasia, and Gardner's syndrome. A black girl, aged 11 years 8 months, came for consultation; radiographs showed 81 teeth: 18 deciduous, 32 permanent, and 31 supernumerary. The main concern initially was to determine whether she was syndromic, and she was referred to a geneticist. G banding analysis showed pericentric inversion of chromosome 9; the chromosome formula was 46, XX, inv (9) (p13q21). Orthodontic treatment for this patient will be a clinical challenge because of the great number of teeth to be extracted and the alterations in the shapes of the teeth. Treatment goals should be established by a multidisciplinary team, where oral surgeon, orthodontist, periodontist, and prosthodontist come together to solve a medical and dental puzzle, eliminating the pieces that do not fit and searching for new ones to obtain an occlusion that will give the patient physiologic conditions of normality and esthetic satisfaction.