Double teeth in primary dentition and findings of permanent successors]

Prevalence of double teeth in primary dentition of 0.5% was established in the sample of 2.987 preschool children of Zagreb. Between children with double teeth 60% were female and 40% males. Fusion ocurred in 66.7 percent and germination in 33.3 percent in the sample of children having double teeth. In all children with double teeth orthopantomograms were taken. Analysis of radiographs revealed anomalies of permanent successors in 53.3 percent of all children with double primary teeth. In children with germination in primary dentition anomalies of permanent teeth were present in 20 percent (hyperdontia in all cases), while fusion of deciduous teeth was accompanied by abnormal finding (hypodontia) in permanent dentition in 70 percent. Obtained results pointed out to the need of distinction between type of double teeth in primary dentition, i.e. between fusion and germination because chance of lacking the permanent successors is considerably dependent on the type of anomaly.     

Panoramic radiographic findings of the mandibular growth from deciduous dentition to early permanent dentition

The outlines of mandibular rami, condyles, coronoid process, and corpus in panoramic radiographs of normal children from deciduous to early permanent dentition were traced and digitized. Nine linear and four angular measurements were measured. During the observation period, the lengths for all the linear measurements increased, however, the angles for all the angular measurements decreased. The shape of condyle and gonion significantly correlated with the growth of ramus and corpus.     

Gingivitis in the deciduous and permanent dentition

The present investigation was performed in order to study the reaction of the gingiva in the deciduous and permanent dentition of dogs to 3 weeks of plaque accumulation. The study was carried out in 10 beagles, divided into 2 groups of 5 dogs each; group I and group II. When the dogs of group I were 10 weeks old, a meticulous plaque control regimen was initiated in order to establish clinically healthy gingiva. After 6 weeks of plaque control, the gingivae of the lower deciduous molars was exposed to a clinical examination, and biopsies as well as bacterial plaque samples were harvested from tooth 03P and 02P. A second plaque control regimen was initiated when the same dogs were 15 months old. After 6 weeks of plaque control, the gingiva of the permanent dentition was examined and biopsies sampled from tooth P3 and P4. In the dogs of group II, plaque control regimens of 3 weeks duration were initiated when the animals were 10 weeks and 15 months old. Clinical examinations were performed at the end of each 3-week period. Immediately after the clinical examinations. 3-week periods of plaque accumulation were initiated. Examinations and plaque sampling were performed after each of these 3-week periods and biopsies were sampled from the deciduous and permanent dentition as described for group I. The biopsies were processed for histometric and morphometric measurements. The findings from the experiment showed that careful plaque control resulted in the establishment of clinically healthy gingiva. In both the deciduous and permanent dentition, however, a clinically healthy gingiva was found to contain a small inflammatory cell infiltrate (ICT). 3 weeks of plaque accumulation resulted in both dentitions in the development of clinical signs of gingivitis and in the formation of comparatively large ICT. The large ICT of the permanent gingiva resided in the coronal portion of the free gingival unit, while in the deciduous dentition, the inflammatory lesion occupied a narrow tissue portion along the entire border of the dento-gingival epithelium. The ICT of the permanent gingiva harbored a larger portion of plasma cells than the inflammatory lesion studied in the deciduous dentition.     

Panoramic radiographic findings of the mandibular foramen from deciduous to early permanent dentition

The purpose of this study was to investigate the position of the mandibular foramen from deciduous (Hellman's stage IIA) to early permanent dentition (Hellman's stage IVA). Panoramic radiographs of 311 Taiwanese children were used. The results revealed that the distances between the mandibular foramen and ramus anterior plane were greater than those between the mandibular foramen and ramus posterior plane through all stages. The mean difference between them was the smallest (0.25 mm) in stage IIA and the greatest (1.18 mm) in stage IIIC. The distance from the mandibular foramen to the alveolar crest plane showed a little change from stage IIA (3.99 mm) to IVA (5.26 mm). The gonial angle had a negative correlation with the distances between the mandibular foramen and each mandibular border. Evaluation of the mandibular foramen from the oral aspect can be influenced by the degree of mouth opening.     

Anomalies in the permanent dentition and other oral findings in 29 individuals with Laurence-Moon-Bardet-Biedl syndrome

This paper reports a clinical and roentgenological examination of the teeth, jaws and saliva of 29 Scandinavian individuals with Laurence-Moon-Bardet-Biedl (LMBB) syndrome, whose cardinal signs are retinal dystrophy, polydactyly, obesity, hypogenitalism and mental retardation. All subjects had at least three of these signs, including retinal dystrophy. Compared with normal subjects, the group had statistically significantly higher frequencies of hypodontia. small teeth and short roots. In addition, the saliva showed a buffering capacity higher than normal. In conclusion, there seem to exist disturbances of both dental and skeletal formation in the LMBB syndrome.     

Plaque and gingivitis in the deciduous and permanent dentition

Abstract The aim of the present investigation was to monitor de novo plaque formation and associated alterations of the gingival conditions in the deciduous, mixed and permanent dentition in man. 31 volunteers, divided into 3 study groups participated in the trial. Group 1 was made up of 11 subjects, 4–6 years of age (deciduous dentition), group 2 comprised of 10 subjects, 8–9 years of age (mixed dentition) and group 3 included 10 subjects, 14–16 years of age (permanent dentition). After a screening examination, each participant received detailed instruction in a proper oral hygiene technique and was subjected to professional tooth cleaning. The professional debridement and the oral hygiene instruction were repeated after 1 week. After another week, a given day was termed Day 0 and a baseline examination was performed. This examination included assessments of plaque and gingivitis. Each subject received an additional, comprehensive professional tooth cleaning and was asked to abstain from all mechanical oral hygiene measures. Re-examinations were performed after 3 and 7 days. The findings demonstrated that: (i) during a 7-day period of no active oral hygiene, subjects with a mixed or a permanent dentition formed visible amounts of plaque and developed modest signs of gingivitis; (ii) during the 7 days of the trial, young subjects with a fully erupted deciduous dentition formed less plaque than the older subjects, and failed to respond to de novo plaque formation with enhanced signs of gingivitis; (iii) in subjects with a mixed dentition, the amount of plaque formed during the 7 days of experiment and the matching gingivitis development were similar in the deciduous and permanent tooth segments of the dentition.     

Prevalence of supernumerary teeth in deciduous and mixed dentition

Supernumerary teeth are the extra teeth which may have either erupted or unerupted in addition to normal dentition and are seen both in deciduous as well as permanent dentition. The incidence of supernumerary teeth shows more frequent occurrence in permanent dentition than deciduous dentition, affecting both the sexes. The etiology of supernumerary teeth is still unknown and not well understood, but thought to be the result from disturbance during the initiation and proliferation stages of tooth development. In the present study an attempt has been made to asses, its prevalence in deciduous and mixed dentition phase.     

Prediction of the permanent dentition in deciduous anterior crossbite

Early prospective evaluation for self-correction of deciduous anterior crossbite can enable identification of patients who require early treatment as well as those who do not. The purpose of the present study was to generate an algorithm that can be used to predict self-correction in the transitional dentition in 3-year-old subjects. The subjects were divided into 2 groups. One group comprised 22 subjects whose anterior crossbite self-corrected during the transitional stage (hereafter referred to as group N). The other group was comprised of 22 subjects whose anterior crossbite persisted during the transitional dentition (hereafter referred to as group R). All subjects were examined using lateral cephalometric radiography in order to evaluate differences in occlusion. Fifteen measurements were used for the evaluation. For each measurement, the variance ratio and the difference in the population mean between groups N and R were tested and t-values were derived. Based on the Student's t-test results, only measurements that had statistically significant differences (P < .05) were extracted. Predictor variables that had a partial F value of 5 or greater were selected for stepwise discriminant analysis, and the following equation was obtained: deciduous indicator (DI) = -0.58(cranial length anterior) + 1.31(posterior facial height) - 0.76(porion location) - 2.02(Wits appraisal) - 70.28. The lower the DI value (negative), the higher the probability that the crossbite will self-correct at the transitional dentition. On the other hand, a high (positive) discriminant score strongly suggests that the subject requires treatment in the primary dentition. The result of this analysis showed that the apparent error rate was 95.46% and the Maharanobis' generalized distance was 8.99.     

Aprismatic external layer of deciduous and permanent teeth

The authors verify the presence of an aprismatic layer at the surface of human deciduous and permanent, erupted and non erupted teeth, by means of the polarizing and scanning electron microscope. The results allowed the Authors to conclude that the presence of different extents of aprismatic enamel at the surface of human teeth should be regarded as a constant and normal feature, with some different frequency and organization patterns between different tooth types.     

Caries experience in the deciduous dentition as predictor for caries in the permanent dentition

The present study aims at determining a reliable screening test for the prediction of caries. In order to identify children at risk of caries, individual classifications were recorded for 268 children at the age of 7 years, according to different screening criteria of the caries experience in the deciduous dentition and according to caries increment as validation criterion. In order to determine the best screening criterion, ratios of sensitivity, specificity and false-positive and false-negative ratios were computed and plotted in receiver operating characteristic curves. The best screening criterion at less than or equal to 4 dmft resulted in a sensitivity ratio of 0.69, specificity of 0.72 and diagnostic power of 0.78 for caries increment in the permanent dentition at the age of 7-11 years. The potential of the screening is elucidated with an example, showing that 48% of the expenses needed for a preventive treatment for all children could be saved by selecting children at risk with the aid of a screening test. The disadvantage of this decision making is that 19% of the children who develop caries would not benefit from the preventive treatment.