Marcia Spinelli Casanova

Dental maturity as an indicator of chronological age: radiographic assessment of dental age in a brazilian population

Objective: The purpose of this investigation was to evaluate the applicability of the methods proposed by Nolla and by Nicodemo and colleagues for assessing dental age and its correlation to chronological age. Methods: Panoramic radiographs of 360 patients from the city of Fortaleza (CE, Brazil) aged 7-15 years were used to assess the associations between dental and chronological age. Data were submitted to statistical analysis using the BioEstat 2.0 (2000) software. Student-Neuman-Keuls test was performed and Pearsons correlation coefficients were calculated at 5% significance level. Results: When the Nolla method was applied, the mean difference between true and estimated age for males and females was underestimated. The use of the method proposed by Nicodemo and colleagues also resulted in underestimation, although it was more evident in male subjects. The correlation coefficients between chronological age and estimated dental age were high, with mean values ranging between 0.87 and 0.91 for males and between 0.84 and 0.93 for females. Conclusion: Although both methods proved to be reliable in estimating age, the use of correction factors is recommended.

Task-specific enhancement filters in storage phosphor images from the Vistascan system for detection of proximal caries lesions of known size

OBJECTIVE The aim was to compare original 8-bit images from the Vistascan storage phosphor plate system with images enhanced with specific filters for detection of proximal caries lesions and, further, to analyze the mutual sensitivity of the filtered images for different lesion sizes. STUDY DESIGN One hundred sixty approximal noncavitated surfaces were radiographed using the Vistascan storage phosphor plate system. Original and enhanced (Fine, Caries1, and Caries2 filters) images were assessed by 6 observers who recorded the presence/absence of proximal carious lesions. Microscopy served to detect and measure true lesion size. RESULTS One hundred one surfaces were sound, and 59 had lesions. The sensitivity of the Fine filter images was significantly higher than the Caries1 and Caries2 filter modalities (P < .005). The original images did not differ significantly from the Caries1 and Caries2 modalities. Both the Fine filter and the original images had a significantly higher specificity than the Caries2 modality (P < .005). The overall accuracies for the Fine filter and the original images were significantly higher than for the Caries2 modality (P < .005). The Fine filter images also had higher accuracy than the Caries1 modality (P < .05). The mutual sensitivity of the filters varied little with lesion size. CONCLUSION Fine filter may be a promising enhancement tool for images used for detection of shallow carious lesion, because it showed less observer variability. The task-specific enhancement filters, Caries1 and Caries2, were less accurate than the original and Fine filter images and cannot be recommended for detection of the lesion sizes included in this study.

Comparison of TW2 and TW3 skeletal age differences in a Brazilian population

Objective: The aim of this study was to determine the differences between the skeletal ages estimated by TW2 and TW3 methods through their RUS and Carpal systems. Material and Methods: A sample of two hundred and forty hand and wrist radiographs of male and female Brazilian children aged 84-199 months was evaluated by five observers. The Dunnet test was performed for statistical analysis. Results: Results showed higher skeletal ages estimated by TW2RUS than TW3RUS and Carpal for both genders. For girls a statistically significant difference (p<0.05) was observed between TW2RUS and TW3RUS over the entire age range. For boys this difference was observed from 108 months onwards. In general RUS skeletal ages were higher than the chronological age and Carpal skeletal ages for both genders. The overestimation of chronological age was smaller for TW3RUS than for TW2RUS, and this last system showed a statistically significant difference regarding chronological age over the entire age range for girls, whereas for boys this difference was seen from 132 months onwards. For girls TW3 RUS and Carpal showed a significant difference regarding chronological age in the oldest age groups; in boys TW3RUS did not show a significant difference regarding chronological age. For Carpal, these results were more variable. Conclusion: It seems reasonable to recommend the use of the TW3 system for the studied Brazilian population.

Sensitometric comparisons of Insight and Ektaspeed Plus films: effects of chemical developer depletion

The aim of this study was to compare the sensitometric properties of Insight and Ektaspeed Plus radiographic films manually and automatically processed using fresh and depleted chemical solutions. Ten sets of each type of film were obtained (1 set = 5 films), 5 sets being manually processed and 5 sets being automatically processed. A total of 100 films (50 Ektaspeed Plus and 50 Insight film) were exposed and developed. The first two sets of each film type were developed in fresh chemicals (one set per each type of processing), on the first day of the experiment. The other sets were processed in the same progressively depleted solutions once a week until the end of experiment, which was completed within 4 weeks. Characteristic curves were constructed to compare the sensitometric properties of the films: contrast, latitude and speed. Processing solution depletion had different effects on manually and automatically developed films, which was confirmed by the changes in the form of the characteristic curves in the third week of the automatic processing and fourth week of the manual processing. Ektaspeed Plus showed 11% reduction in contrast values for manual processing and 53% for automatic processing, while Insight contrast values showed a reduction of 25% and 59%, respectively. Insight film, however, showed lesser loss of speed and lesser increase of latitude than Ektaspeed Plus. In conclusion, chemical depletion in automatic film processing was faster than in manual developing. In depleted chemicals, both types of films had an increase in latitude values and a decrease in speed and contrast. Insight was more resistant than Ektaspeed Plus to decrease in speed and latitude when processed using older chemicals, whereas contrast in Ektaspeed Plus was comparatively more stable.

Telerradiografias obtidas em posição natural da cabeça alteram as grandezas cefalométricas

AIM: the aim of this study was to quantify the real variation of cephalometric measurements obtained from lateral cephalometric radiographs using a natural head posture (NHP) and a conventional technique, positioning Frankfurt Horizontal Plane parallel to the horizontal. A facial analysis was performed in order to compare postural measurements, facial profile and antero-posterior measurements. METHODS: fifty lateral cephalometric radiographs from 25 females and 25 males composed the sample, mean aged 21 years. The cephalometric measurements were divided into three groups: 4 postural measurements, 3 profile measurements, and 9 antero-posterior measurements. RESULTS AND CONCLUSION: no statistically significant differences were found for females, while males showed statistically significant differences for sella-nasion (SN), Frankfurt, and mandibular planes in relation to true vertical line (T). For antero-posterior and facial profile measurements, no statistically significant differences were found in both groups. A correlation of the SN/V (sella-nasion/true vertical line) plane with the palatal and Frankfurt planes was found for both techniques, except when conventional lateral cephalometric radiographs were taken from males. No correlation was found between the SN/V base of the skull plane and the mandibular plane in both positions.