The maxillary casts of 320 Malaysian children were examined for the occurrence of the Carabelli trait on the maxillary first permanent molars. The total trait frequency was observed to be 52.2 per cent. Statistical analysis showed no sex dimorphism in the occurrence of the trait. Bilateral occurrence with a tendency towards concordance of expression between sides was also observed.
The disinfective and fixative properties of glutaraldehyde are now widely investigated. Glutaraldehyde is effective against micro-organisms and their spores. Recently, studies have shown the effectiveness of glutaraldehyde against the HIV virus. 2% glutaraldehyde is now recommended for the sterilisation of surgical instruments, operating areas, dental impressions and root canals during endodontic therapy. Studies have also shown that glutaraldehyde is an effective fixative with minimum side effects, limited penetration and quick acting. Pulpotomy studies using glutaraldehyde as the fixative agent produce high success rates. The important feature is the vital pulpal tissue at the apical third suggesting its limited penetration. The small amounts that get distributed systemically are quickly metabolised and excreted in the urine or exhaled as carbon dioxide.
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.
Pulpal tissue changes following pulpotomies with 2% w/v buffered glutaraldehyde in primary teeth were observed. A 3 minute single application of 2% w/v buffered glutaraldehyde was able to produce effective surface fixation. Limited penetration of the medicament left the remaining pulp tissue unaffected. The zone of fixation did not proceed apically. With time, macrophages and fibroblasts appear apical to the zone of fixation indicating the onset of replacement resorption.
Nine thousand and six hundred infants delivered in a maternity hospital were examined for the prevalence of natal and neonatal teeth. The prevalence among this group was noted. The teeth were the normal primary incisors that had erupted prematurely. The crown was normal in shape and size with very little root formation. The histological features were that of an immature tooth.
Five hundred and thirty-six patients were examined for the presence of talon cusps. The anomaly was observed in 28 patients (5.2 per cent). There was no sex predilection in the occurrence. Only two patients had a bilateral occurrence, with the maxillary lateral incisors being the most commonly affected. Radiographic evidence of pulpal extension into the cusp was observed in five patients. Many of the affected teeth presented with deep developmental grooves some of which were carious and/or occlusal interference leading to malocclusion.
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.
The medicaments used in this study were buffered glutaraldehyde and formocresol. Schiff's reagent was used in the quantification of aldehyde released into the collecting medium. The results of this study clearly show that formocresol diffused throughout the dentine and cementum within fifteen minutes following a pulpotomy procedure, whereas no diffusion of buffered glutaraldehyde was observed.
Incidence, aetiology, morphology, histology and symptoms of natal or neonatal teeth are presented. The commonly used terminology natal and neonatal teeth is adopted in this article. A case of an 8-week old girl with natal tooth and sublingual ulceration of the tip of the tongue is described.