Morphological evaluation of rat incisor enamel and dentin induced by pregnancy and lactation using a scanning electron microscope.

This study assessed the effects of pregnancy and lactation on the morphology of the dentine tubules and external enamel surface of rat incisor teeth using a scanning electron microscope (SEM) equipped with an energy dispersive x-ray (EDX) system. Twenty-four female Wistar rats were divided into three groups; group A rats were at the end of pregnancy, group B rats were in the post-lactation period and group C rats, the control group, were unmated. The outer enamel surface and openings of the dentine tubules at the neck regions of the incisors were observed under the SEM and photographed. Examination of the incisor teeth of pregnant and post-lactation rats revealed scratches on the enamel surface. There were few eroded areas and slight changes and the dentine tubules of the pregnant group were fully or partially occluded on the entire surface of the enamel in the lactating rats. Almost all dentine tubules of the rats in this group were open. During the study, EDX analysis of calcium, phosphate and magnesium was also performed at 20 kV and 0 degree tilt. The results of EDX analyses of magnesium were significantly lower in the pregnant group compared with the lactation and control groups for the dentine in the neck region (p<0.05). The calcium values increased in the lactation group compared with those of the rats in the other two groups (p<0.05). These results might indicate that changes during pregnancy and lactation affect the content and morphology of mineralized dental hard tissue.

The relationships between dental age, chronological age and bone age in Turkish adolescents with constitutional delay of growth.

The aim of this study was to investigate the relationships between dental age and bone age in Turkish adolescents with constitutional delay of growth and compare them with a group of normal, healthy adolescents. Left hand and wrist radiographs and dental panaromic radiographs of 33 adolescents (25 boys and 8 girls) aged between 10 and 16 years with constitutionally delayed growth were assessed. The control group comprised 41 healthy adolescents (24 boys, 17 girls) aged between 10 and 16 years. Bone age was determined according to Greulich and Pyle; dental age was assessed using the Demirjian method. In the control group, no statistical difference was found between chronological, bone and dental ages. In the group of adolescents with constitutional growth delay, there was no significant difference between chronological age and dental age, but the differences between dental age and bone age and between chronological age and bone age were found to be statistically significant. It was found that Demirjian's dental age assessment is a valid method for scoring dental age in Turkish adolescents. Adolescents with constitutional delay of growth had dental maturation appropriate for chronological age, but not for bone age.

Validation of micro-computed tomography for occlusal caries detection: an in vitro study.

Conventional methods of caries detection, including the gold standard of histological examination, have certain disadvantages that must be addressed prior to validating any other diagnostic technique-current or new. Here we evaluated the validity of micro-computed tomography (micro-CT) as an alternative gold-standard technique for caries detection. Sixty teeth with suspected occlusal caries were chosen from a pool of teeth extracted for orthodontic, periodontal, or surgical reasons. Identical reference points were marked on photographs taken for teeth and were used to evaluate each method. Dimensions of caries were assessed by two calibrated examiners using the ICDAS-II visual examination system, bitewing radiographs, and micro-CT. The teeth included in the study were selected randomly from solution before all measurements. For micro-CT, the device was set to 50 kV, 800 µA, pixel size 15 µm (at 1024 × 1024 resolution), and 1° rotation step. NRecon software (SkyScan) was used to obtain reconstructed images. For each diagnostic method, results were compared with histology results using the McNemar test. Receiver operator characteristic (ROC) analysis was also performed for each method (Z-test; p < 0.05). Besides showing a high correlation with histology results, micro-CT yielded the greatest values at the D3 threshold; moreover, accuracy and area under the ROC curve (AUC) values were greatest at the D1threshold. Our results indicate that micro-CT performs as well as or better than histological examination for the purpose of comparing methods for caries detection.

Effects of pregnancy and lactation on the microhardness of rat incisor dentine and enamel.

Pregnancy and lactation affect the rate of maternal dentine apposition and mineralization in the rat. In this study we have measured the effects of pregnancy and lactation on the degree of mineralization of dentine and enamel by using the microhardness method in rat incisors. At incisal sections, pregnant and lactation group enamel values were increased compared to that of a control group; the pregnancy and post-lactation period dentine values decreased slightly compared to the control group. At neck sections, pregnant and lactation group enamel values were decreased compared to that of the control group; the pregnancy and post-lactation period dentine values were also decreased slightly compared to the control group. At the post-lactation period neck section dentine mineralization was decreased compared with the incisal section. As a result, enamel and dentine layers of rat incisors are affected to varying degrees by these changes in mineralization levels during the maternal period.

Evaluation of diagnostic tests using information theory for multi-class diagnostic problems and its application for the detection of occlusal caries lesions.

BACKGROUND: Several methods are available to evaluate the performance of the tests when the purpose of the diagnostic test is to discriminate between two possible disease states. However multi-class diagnostic problems frequently appear in many areas of medical science. Hence, there is a need for methods which will enable us to characterize the accuracy of diagnostic tests when there are more than two possible disease states. AIMS: To show that two information theory measures, information content (IC) and proportional reduction in diagnostic uncertainty (PRDU), can be used for the evaluation of the performance of diagnostic tests for multi-class diagnostic problems that may appear in different areas of medical science. STUDY DESIGN: Diagnostic accuracy study. METHODS: Sixty freshly extracted permanent human molar and pre-molar teeth suspected to have occlusal caries lesions were selected for the study and were assessed by two experienced examiners. Each examiner performed two evaluations. Histological examination was used as the gold standard. The scores of the histological examination were defined as sound (n=11), enamel caries (n=22) and dentin caries (n=27). Diagnostic performance of i) visual inspection, ii) radiography, iii) laser fluorescence (LF) and iv) micro-computed tomography (M-CT) caries detection methods was evaluated by calculating IC and PRDU. RESULTS: Micro-computed tomography examination was the best method among the diagnostic techniques for the diagnosis of occlusal caries in terms of both IC and PRDU. M-CT examination supplied the maximum diagnostic information about the diagnosis of occlusal caries in the first (IC: 1.056; p<0.05), (PRDU: 70.5%) and second evaluation (IC: 1.105; p<0.05), (PRDU: 73.8%) for the first examiner. M-CT examination was the best method among the diagnostic techniques for the second examiner in both the first (IC:1.105; p<0.05), (PRDU:73.8%) and second evaluation (IC:1.061; p<0.05), (PRDU:70.8%). IC and PRDU were lowest for visual inspection. CONCLUSION: The present study demonstrates that IC and PRDU can be used to evaluate diagnostic test performance when multiple disease states are being evaluated.

Validation of micro-computed tomography for occlusal caries detection: an in vitro study

Conventional methods of caries detection, including the gold standard of histological examination, have certain disadvantages that must be addressed prior to validating any other diagnostic technique—current or new. Here we evaluated the validity of micro-computed tomography (micro-CT) as an alternative gold-standard technique for caries detection. Sixty teeth with suspected occlusal caries were chosen from a pool of teeth extracted for orthodontic, periodontal, or surgical reasons. Identical reference points were marked on photographs taken for teeth and were used to evaluate each method. Dimensions of caries were assessed by two calibrated examiners using the ICDAS-II visual examination system, bitewing radiographs, and micro-CT. The teeth included in the study were selected randomly from solution before all measurements. For micro-CT, the device was set to 50 kV, 800 µA, pixel size 15 µm (at 1024 × 1024 resolution), and 1° rotation step. NRecon software (SkyScan) was used to obtain reconstructed images. For each diagnostic method, results were compared with histology results using the McNemar test. Receiver operator characteristic (ROC) analysis was also performed for each method (Z-test; p < 0.05). Besides showing a high correlation with histology results, micro-CT yielded the greatest values at the D3 threshold; moreover, accuracy and area under the ROC curve (AUC) values were greatest at the D1threshold. Our results indicate that micro-CT performs as well as or better than histological examination for the purpose of comparing methods for caries detection.

Effects of oral health behaviors and socioeconomic factors on a group of Turkish adolescents.

OBJECTIVE: To investigate the effects of socioeconomic factors and oral health behaviors on adolescents in Turkey. METHOD AND MATERIALS: Data were collected through a self-administered questionnaire. The sample consisted of 582 randomly selected adolescents, 309 boys and 273 girls, who presented over a 3-month period with various complaints to the Hacettepe University Medical Faculty Adolescent Clinic. RESULTS: Halitosis complaints were higher in the 11-, 12-, and 13-year-old groups than in other age groups (P < .05). When the sex factor was examined, prevalence of dental fear was found to be higher among girls, while irregular toothbrushing was seen more among boys. In parallel to the increase in the education levels of the parents, an increase was seen in the regular dental visits by the adolescents (P < .05). As the socioeconomic status of the family increased, frequency of dental visits, rate of dental floss usage, and number of teeth with restorations increased. In parallel with the dental visit increase, the rate of restored teeth increased. Of those who did not have regular dental visits because of financial difficulties, however, the rate of teeth with restorations was low. CONCLUSION: A strong correlation exists between the oral health behaviors, socioeconomic and sociodemographic factors, and the oral health status of Turkish adolescents.

Oral candidosis, denture cleanliness and hygiene habits in an elderly population.

BACKGROUND AND AIMS: Poor denture hygiene and Candida infections are very common among elderly denture wearers. Candida species are usually innocuous, but they can cause disease when conditions are favorable. Oral hygiene habits have been found to be poor among the elderly. This may be due to decreasing manual abilities due to advanced age. Dentures act as a reservoir for yeasts, and this may be aggravated by poorly fitting and old dentures. The purpose of this study was to determine oral hygiene habits, denture cleanliness and presence of yeasts in elderly complete denture wearers. METHODS: 42 subjects who had worn complete upper dentures for at least six months were surveyed. The mean age of the subjects was 74 years. Information about denture age, denture hygiene and hygiene habits of subjects was obtained through a structured interview. Clinical examination was conducted by one author. Denture cleanliness was assessed by using the Schubert and Schubert index. For cytological examination, palatal swabs were taken. A chi-square test was used to analyze the results. RESULTS: A significant correlation was seen between oral candidosis and frequency of denture cleaning, and also between candidosis and denture cleanliness. There was no statistically significant correlation between denture cleaning methods and candidosis. The relationship between denture age and the presence of Candida was not significant. There was a significant correlation between denture cleanliness and denture age, cleaning method or frequency of cleaning. CONCLUSIONS: Only 16.7% of dentures worn by the elderly are properly cleaned. Older dentures tended to be dirtier than newer ones. There was a significant correlation between poor denture hygiene and prevalence of Candida.

Evaluation of mandibular bone density to predict osteoporosis in adolescents with constitutional delayed growth.

OBJECTIVE: The aim of this study is to evaluate the correlation between constitutional delayed growth (CDG) and mandibular bone trabeculation as well as bone density on panoramic radiographs using a computer software program. METHODS: Panoramic radiographs obtained from 25 patients with CDG and 25 healthy adolescents were evaluated for this study. Patients were selected from admission to Hacettepe University, Faculty of Medicine, Section of Adolescent Medicine in the first half of the year 2002. All panoramic radiographs were taken under standard conditions, and were randomized and then converted to digital images for density analysis using a scanner. The images were transferred to Osiris computer software program for the evaluation of bone density from 4 different regions on the mandible (right and left mandibular angle and condyle). RESULTS: The CDG group had higher values for the risk of osteoporosis considering the right (t=3.360, p=0.002) and the left condyle (t=3.620, p=0.001) (t-test for independent samples). It was also seen that the CDG group was again at higher risk in comparison to the control group when left mandibular angle values were measured (z=-2.447, p=0.014) (Mann Whitney-U test). CONCLUSION: We suggest that panoramic radiographs, which are transformed into digital format, can be valuable and economic tools for detecting the risk of osteoporosis in adolescents with CDG.