The prevalence and symmetrical distribution of enamel defects were studied in 218 Malaysian school children aged 11-12 years old. The tooth prevalence of enamel defect was 40.3 per cent. The first permanent molars were the most severely affected, whereas the lower incisors were the least severely affected. Overall there was no sex difference. Distribution of symmetry was assessed between the right and left tooth pairs as well as for upper and lower teeth. A higher proportion of symmetry was observed for the right and left tooth pairs and the lingual surfaces showed a greater percentage of bilateral distribution.
The objectives of this Malaysian study were to investigate the relationship between severity of trauma and interval before treatment, and the effect of delayed treatment on prognosis. A total of 123 traumatized permanent incisors were observed over a 24-month period. Results of this study suggest that the interval between trauma and emergency treatment is directly related to the severity of injury and the level of dental awareness of the patients. However, prognosis of these teeth is greatly influenced by the interval between trauma and initial treatment. Pathological pulp changes in these teeth can occur as late as two years after injury and this justifies the necessity for a long observation period following treatment.
The prevalence and distribution patterns of enamel defects in maxillary incisors was assessed in 194 Singaporean children aged 11-15 years and belonging to three different ethnic groups. All were born and continuously resident in Singapore, which has a tropical climate. The water supply was fluoridated in 1957 at a level of 0.7 ppm. The mouth prevalence of defects was 71.5 per cent and the tooth prevalence was 55.9 per cent; 82 per cent of all affected teeth demonstrated white lesions of various forms. Although there was no sex difference in the prevalence and distribution pattern of defects, some racial differences were observed. The results were compared with data from other studies where the same classification of defects was used.
Calcifying odontogenic cysts (COCs) represent a group of lesions that may be broadly classified into two main entities: cysts and neoplasms. In the present study 30 non-neoplastic cystic COCs were examined by a quantitative histological method in an attempt to calibrate the relative distribution of the type of epithelial lining, intensity of ghost cell formation and the amount of dentinoid present. The results showed that there are two main types of cystic COC: an odontoma-producing type and a non-odontoma-producing variant. Morphologically, tooth-like structures were a valid distinguishing feature, while morphometrically the odontoma-producing variant showed a greater amount of luminal and mural dentinoid as well as luminal ghost cells. Demographic analysis also revealed that the odontoma-producing COC occurred in younger patients and showed an even sex distribution, whereas the non-odontoma-producing type was seen in older patients and showed a predilection for females. Both subtypes were more prevalent in the Chinese population and occurred preferentially in the maxilla.
Little new evidence on the prevalence of injury to the anterior teeth of children has been reported in the past five years and, in South Africa, trauma to the teeth of children in different ethnic groups has not been compared respectively. The purpose of this investigation was to determine the prevalence of dental trauma using well-defined criteria and to sample a specific age-group. Five regions were chosen and 1035 children in the eleven-year age-group were examined. No statistical significance was found between the ethnic groups related to the amount of injury sustained. For all groups, boys received more injuries than girls. The most common injury was fracture of the enamel of the maxillary central incisor. With 15 percent of the children receiving some level of trauma by age eleven years, this is one of the main dental treatment needs for South African children.
The root canal walls of twenty -five deciduous molar teeth with exposed and necrotic pulps were examined using thescanning electronmicroscope. Immediately after extraction, all teeth were fixed in Kamosky's solution. The coronal portion of the tooth was sectioned at about 2mm above the enamel cemental junction.The mesial and distal roots were separat~d and either split in the mesio-distal or bucco-lingual direction. All specimens were prepared for SEM. Obsevations showed that all roots were infected with organisms consisting of cocciand short rods. Some of the coccihad penetrated the dentine layer. However, the distribution of organisms is. not uniform throughout thecanals. Bacterialinvasion ismostinthecoronal region and reduces towards the apical region: Accompanying bacterial invasion is root canal walls deterioration. The odontoblastic processes are the first to deteriorate followed by the predentine layer.
Determining the racial affinity of an unknown individual from dentition for identification is indeed a difficult endeavour. However, there are certain dental characteristics which are predominant in certain racial groups and these contribute important indicators in the identification process. Inherited dental characteristics are modified by prenatal and postnatal environmental and nutritional conditions. They can also become less discernible due to admixture of the various races.
Two hundred and twenty-nine children aged 12-15 years who were continuous residents of Penang island, in the north of Peninsular Malaysia were examined for caries and enamel defects. Caries prevalence was 82.2% with a DMFT score of 3.4 and DMFS score of 4.9; there were very few missing teeth and very little untreated caries in the population examined. Majority of DF (decayed/filled) lesions were pits and fissures with approximal and smooth surfaces relatively caries free. The prevalence of enamel defects was 76.4% with 19.1% of all teeth examined being affected. More posterior than anterior teeth were affected by enamel defects just as there were more maxillary than mandibular teeth affected by enamel defects. Diffuse patchy opacities were the most common defect diagnosed and this was found in 60.2% of the population examined. A bilateral distribution of diffuse patchy opacities was seen in 41.5% of the population examined. Tooth surfaces with enamel defects were no more susceptible to caries than defect-free surfaces.
To date, fluorides has remained to be the best means of controlling dental caries. Fluoride is given either systematically via fluoridated water or topically through other supplements including toothpastes. In recent years increasing prevalence of enamel defects or fluorosis is observed in both populations receiving or not receiving water fluoridation. It is suspected that excessive ingestion of a "standard" 1000 to 1500 ppm fluoride from toothpastes might be a contributing factor to the presence of such defects. In Malaysia, reports of enamel defects occurring amongst 12 to 16 year-old schoolchildren ranged between 67 to 88 percent. Where water fluoridation is available, the amount of fluorides received from the home is between 0.3 to 0.5 ppm F. However, almost all toothpastes sold locally contains fluoride, the content of which is unknown to the consumers. This study reports on the analysis of fluoride levels carried out on 20 toothpaste samples sold locally. Results showed that fluoride levels in all 20 samples ranged between 20 to 1970 ppm F. Only two of the 20 samples analyzed, however, indicated having a level anywhere near the "standard" level. In addition, only two type~ of children's toothpaste with a fluoride concentration of 20 and 450 ppm F were commonly available as compared to adult toothpastes in all the samples studied.
The prevalence of developmental defects of enamel was assessed in 4805 16-year-old schoolchildren in fluoridated and non-fluoridated areas in Malaysia. In this sample, the mouth prevalence was 56.0%; tooth prevalence was 21.8%. There were significant differences between children in fluoridated and non-fluoridated areas, urban and rural areas as well as between the ethnic groups. However, there was no significant gender difference. Prevalences were lower than those reported in most other Asiancountries. However, direct comparisons could not be madedue to differences in indices and methodology used.
Ninety-seven specimens of sympatric monkeys and apes from East Malaysia and 115 monkeys and apes from West Africa are examined in order to evaluate the magnitude and nature of the great ape-monkey linear enamel hypoplasia (LEH) 'dichotomy'. This study demonstrates that great apes from both regions have a higher incidence of LEH and repetitive LEH than do gibbons and monkeys. However, the authors find that the dichotomy is not as clear-cut as previous research suggests, since some monkey samples exhibit high LEH frequencies. The authors evaluate the potential influence of great ape-monkey differences in crown height on this dichotomy. They show that canine crown height variation is weakly associated with LEH variation. Differences between monkeys and great apes in their crown formation spans and in their experience of environmental stress may be more likely causes of the dichotomy.
The estimation of age of human foetal remains is of great medico-legal importance. When the remains are intact and fresh, various morphological features such as crown-heel length, weight, appearance of ossification centres particularly around the ankles and knees and other parameters could be used to make a reasonable estimation of the period of gestation. In cases of criminal abortion, infanticide and child murder the question of age of the foetus, viability, live birth and a separate existence become very important. In practice, often at the time of detection, the remains are decomposed or skeletonised. In such a situation the examination of developing teeth will provide a reliable answer pertaining to the foetal age, the possibility of a separate existence and even the period of survival after birth. The.age determination from dental examination is possible from approximately 10 weeks intrauterine up to old age. The presence of neonatal line (birth line) in both dentine and enamel indicates live birth and a separate existence. It is possible that the time period of survival can be estimated by measuring postnatal deposition of these hard tissues. An intact human foetus that has undergone mild to moderate putrefaction was studied. The study of the morphological features and the ossification centres suggested that its approximate age was around nine months intrauterine. It was not possible to decide whether it was a live birth and had a separate existence. The examination of the developing first deciduous molar of the mandible suggested the approximate age was around 30-32 weeks intrauterine. The importance of examination of developing teeth in foetal remains (including neonates), particularly associated with putrefaction or skeletonisation is emphasized.
The paradental cyst is an odontogenic cyst occurring near to the cervical margin of the lateral aspect of a root as a consequence of an inflammatory process in a periodontal pocket. A distinct form of the paradental cyst occurs not infrequently on the buccal aspects of erupted mandibular third molar, where there is an associated history of pericoronitis. A search of the literature revealed that these cysts had all been reported in relation to partially, newly or fully erupted molars. This report presents one case in which the cyst was noticed to be associated with an unerupted third molar. The histological appearance of the cyst and the gross relationship to the cemento-enamel junction is similar to those typical of paradental cysts reported in the literature. However, the radiographic and clinical appearance of the tooth being unerupted do not tally with paradental cyst and yet exclude the diagnosis of dentigerous cyst. The diagnosis of dental follicular tissue was excluded based on the histopathological presentation. The authors suggested that this case may represent an early form of paradental cyst which in the past may have been dismissed as dental follicular residues and thus, the prevalence of paradental cyst may have been under reported in the literature.
Sex determination of livestock is performed to achieve the objectives of livestock breeding programmes. Techniques for sex determination have evolved from karyotyping to detecting Y-specific antigens and recently to the polymerase chain reaction (PCR), which appears to be the most sensitive, accurate, rapid and reliable method to date. In this study, a PCR-based sex determination method for potential application in goat breeding programmes was developed. Primers were designed to amplify a portion of the X amelogenin gene (Aml-X) on the X chromosome to give a 300 bp product and Sry gene on the Y chromosome to give a 116 bp product. PCR optimization was performed using DNA template extracted from a whole blood sample of Jermasia goats (German Fawn x Katjang) of both sexes. It was possible to identify the sex chromosomes by amplifying both male- and female-specific genes simultaneously in a duplex reaction with males yielding two bands and females yielding one band. The Aml-X primer set, which served as an internal control primer, did not interfere with amplification of the Y-specific sequence even when a low amount of DNA (1 ng) was used. The duplex reaction subjected to a blind test showed 100% (14/14) concordance, proving its accuracy and reliability. The primer sets used were found to be highly specific and were suitable for gender selection of goats.
The human sex test in forensic multiplexes is based on the amelogenin gene on both the X and Y chromosomes commonly used in sex genotyping. In this study of 338 male individuals in a Malaysian population comprising Malays, Chinese and Indians, using the AmpFlSTR Profiler Plus kit, the amelogenin test gave a significant proportion of null alleles in the Indian ethnic group (3.6% frequency) and 0.88% frequency in the Malay ethnic group due to a deletion of the gene on the Y chromosome. This sex test also failed in a forensic casework sample. Failure of the amelogenin test highlights the need for more reliable sex determination than is offered by the amelogenin locus in the Malay and Indian populations. The gender of the Indian-Malay amelogenin nulls was confirmed by the presence of three Y-STR alleles (DYS438, DYS390 and DYS439). For the Indian ethnic group, one of the Y-STR forms a stable haplotype with the amelogenin null. The amelogenin-deletion individuals also showed a null with a male-specific minisatellite MSY1, indicating that a very large deletion was involved that included the amelogenin and the MSY1 loci on the short arm of the Y chromosomes (Yp).
This study is conducted to compare two resin luting cements (Rely XTMARC,3M and Compolute™ESPE) on their microleakage with one composite inlay system (Filtek™ Z250 Universal Restorative Materials, 3M). Thirty conventional inlays, Class II MOIDO cavity with gingival margin I mm above the cementoenamel junction, were prepared in premolar teeth. The composite inlays were fabricated directly on the prepared teeth using layering technique. Fifteen of the inlays were cemented with RelyTMX ARC and fifteen with Compolute™ (ESPE). The specimens were kept at 370 C for 10 days before thermocycling and immersed in methylene blue 2% solution for 24 hours. The teeth were sectioned mesio-distally. The site and degree of leakage of each section was scored using a visual scoring system under a stereomicroscope at a magnification of 1.5X. Results showed that there was no significant difference in'leakage extent (p>O.05), between Rely X™ARC and Compolute™. For both materials, leakage occurred most commonly within the enamel surface and between the cement-tooth interfaces. None of the leakage occurred between inlay - cement interface. There is no significant difference in the extent of leakage between Rely XTMARC compared to Compolute™.
Decalcified permanent teeth were sectioned and stained with Van Gieson and Gomori trichome dyes. Sections dyed with the Van Gieson dye did not produce any zones in dentine but with the Gomori trichome dye, four different zones of dentine were produced. Zone 1 begins at the predentine-dentine junction while zone 4 ends at the enamel - dentine junction. In zone 1, the intertubular dentine was stained clearly while in zone 3 intense staining of the peritubular dentine was observed. The result of this study supports the previous findings reported by other workers that the formation of intertubular dentine takes place in zone 1 while peritubular dentine occurs in zone 3.
The aim of this study was to investigate the prevalence and psychosocial impact of enamel defects among 16-year-old school children on the island of Penang. The data were collected through a self-administered questionnaire survey and an oral examination, using the Modified Developmental Defects of Enamel Index (FDI, 1992). In all, 1024 subjects were selected using a multistage random sampling technique. About two-thirds of the sample (67.1%) had at least one tooth affected by enamel defects. Enamel opacities accounted for 85.6% of the total condition. Diffuse-type opacity predominated (63.5%). Among subjects who expressed dissatisfaction, 18.8% reported covering their mouths when smiling, 8.7% avoided going out with friends and 39.1% had consulted their dentists. About 17% of the subjects reported that their parents had complained about the color of their front teeth but only 5.7% had experienced being teased by their friends about the problem. Two-thirds of the subjects were affected by enamel defects involving at least one tooth; however, the esthetic perception and psychosocial impact of those affected were minor.
The aim of the present study was to determine the oral health status of 16-year-old Malaysian school children. The prevalence of caries was 75.5%. More than 60% of subjects had caries experience by teeth (DMFT) scores of 0-3. The largest component of the DMFT and caries experience by surface index was the filled component. Females had higher caries prevalence and caries scores than males. The mouth and tooth prevalences of enamel defects were 56% and 21.8%, respectively. The most common type of enamel defects observed were diffuse opacities, affecting 95.5% of affected subjects and 92.1% of affected teeth. One-third of subjects had healthy gingival conditions, 8.6% had bleeding gingivae, 55.1% had calculus and 3% had pockets. Less than 1% of subjects wore or required dentures. Cleft lip and/or palate was uncommon. This study shows that the prevalence of caries and DMFT scores have declined over the last 30 years.
Amelogenesis imperfecta (AI) is a hereditary disorder resulting in generalized defects in the enamel. The case reported here is of a seven-year-old male child with yellow color of all his teeth. Two of his primary molars were extracted due to dental abscess with advanced root resorption. Histologically hypoplastic enamel layer, positively birefringent, generalized pitting, roughness with irregular general cracked borders were observed. Scanning electron microscope, revealed extensive irregular, disorganized rough superficial enamel layer. The enamel was irregularly decussate with filamentous prisms accompanied by small rounded formations. The morphological and histological examination of the tooth revealed that this patient has the features of AI. For genetic study blood sample were collected from the patient and PCR analysis revealed that there is no mutation in exons 1-7 of AMELX gene on the X chromosome of the patient. Hence, it is probable that the AI of this patient is not X-linked. It is more likely to be an autosomal mutation.