The present study attempted to describe the distribution of the mineralized tissues that compose the cemento-enamel junction, with respect to both the different types of permanent premolars of males and females and the various surfaces of individual teeth. The cervical region of ground sections of 67 premolars that had been extracted for orthodontic reasons were analyzed using transmitted light microscopy to identify which of the following tissue interrelationships was present at the cemento-enamel junction: cementum overlapping enamel; enamel overlapping cementum; edge-to-edge relationship between cementum and enamel; or the presence of gaps between the enamel and cementum with exposed dentin. An edge-to-edge interrelation between root cementum and enamel was predominant (55.1%). In approximately one-third of the sample, gaps between cementum and enamel with exposed dentin were observed. Cementum overlapping enamel was less prevalent than previously reported, and enamel overlapping cementum was seen in a very small proportion of the sample. In any one tooth, the distribution of mineralized tissues at the cemento-enamel junction was irregular and unpredictable. The frequency of gaps between enamel and cementum with exposure of dentin was higher than previously reported, which suggests that this region is fragile and strongly predisposed to pathological changes. Hence, this region should be protected and carefully managed during routine clinical procedures such as dental bleaching, orthodontic treatment, and placement of restorative materials.

No abstract

The present study was conducted to investigate the prevalence of external cervical resorption (ECR) in different tooth surfaces of maxillary first premolars in a Sri Lankan population. A sample of 59 (15 males, 44 females) permanent maxillary first premolars (age range: 11-18 years) were used. The teeth had been extracted for orthodontic reasons and were stored in 10% formalin. Morphologically, sound teeth were selected for the study. The teeth were stained with carbol fuchsin. The cervical regions of the stained teeth were observed under 10× magnifications using a dissecting microscope (Olympus SZ) to identify any resorption areas. The resorption areas present on buccal, lingual, mesial and distal aspects of all teeth were recorded. Fifteen (25.4%) [4 males (26.7%), 11 females (25.0%)] permanent maxillary first premolars showed areas of resorption on buccal, lingual, mesial or distal surfaces. Mesial (33.3%) and distal (33.3%) surfaces exhibited areas of resorption more frequently than buccal (20.0%) and lingual (13.3%) aspects. The difference was not statistically significant. It can be speculated that the ECR of root surfaces of these young premolar teeth could have been triggered by the excess pressure exerted on their proximal surfaces by the crowding of teeth. How to cite this article Arambawatta K, Peiris R, Ihalagedara D, Abeysundara A, Nanayakkara D. External Root Resorption of Young Premolar Teeth in Dentition with Crowding. World J Dent 2013;4(4):224-227.

No abstract

Introduction: Sexual dimorphism is one of the most important implications in forensic investigations and anthropological studies. Teeth are becoming a good source of material for gender determination. The canine is the most preferred tooth for gender determination because the canine is the strongest tooth in the oral cavity. Objectives: To investigate sexual dimorphism in permanent mandibular and maxillary canines of a Sri Lankan Sinhalese population, and to ascertain the most suitable dimension (labiolingual, mesiodistal and crown height) to determine the sex of an individual. Materials & Methods : The study was conducted using 384 dental casts (Males 192, Females 192) aged between 18 and 25 years in a sample of the Sri Lankan population. According to a selection criterion, casts were selected using a convenient random sampling technique. Mesio-distal, Bucco-lingual and Crown height of all the canines in the casts were measured using a digital vernier caliper accurate to 0.01 mm. Results : Statistical analysis was performed using Minitab 17 and SPSS (Version 21). Unpaired sample t-test, paired sample t-test and point-biserial correlation were used for data analysis. The present study revealed that males show larger mean dimensions of canine teeth than females. Out of all four canines, mandibular canines show highly consistent results for sexual dimorphism. Further, crown height is the best measurement to evaluate sexual dimorphism. Conclusion : It can be concluded that out of all the four canines, mandibular canines show highly consistent results for sexual dimorphism. Moreover, crown height is the best measurement to evaluate sexual dimorphism, in identifying an unknown .