Nor Himazian Binti Mohamed

Comparison of arch form between ethnic Malays and Malaysian Aborigines in Peninsular Malaysia

Objective To determine and compare the frequency distribution of various arch shapes in ethnic Malays and Malaysian Aborigines in Peninsular Malaysia and to investigate the morphological differences of arch form between these two ethnic groups. Methods We examined 120 ethnic Malay study models (60 maxillary, 60 mandibular) and 129 Malaysian Aboriginal study models (66 maxillary, 63 mandibular). We marked 18 buccal tips and incisor line angles on each model, and digitized them using 2-dimensional coordinate system. Dental arches were classified as square, ovoid, or tapered by printing the scanned images and superimposing Orthoform arch templates on them. Results The most common maxillary arch shape in both ethnic groups was ovoid, as was the most common mandibular arch shape among ethnic Malay females. The rarest arch shape was square. Chi-square tests, indicated that only the distribution of the mandibular arch shape was significantly different between groups (p = 0.040). However, when compared using independent t-tests, there was no difference in the mean value of arch width between groups. Arch shape distribution was not different between genders of either ethnic group, except for the mandibular arch of ethnic Malays. Conclusions Ethnic Malays and Malaysian Aborigines have similar dental arch dimensions and shapes.

The antimicrobial effect of 0.1 ppm ozonated water on 24-hour plaque microorganisms in situ

Ozone is a known oxidant present in the atmosphere and is commercially produced by simple ozonizer machines. It is a powerful antimicrobial agent in its gaseous and aqueous forms. Ozone readily dissolves in water and retains its antimicrobial property even in the dissolved state. In this study, the effect of 0.1 ppm ozonated water was analyzed on 24-hour supragingival plaque (SP) samples in situ. SP was collected from the two most posterior teeth in the contra-lateral quadrants before and after a 30-second rinse with either distilled water (control group) or 0.1 ppm ozonated water (test group). The plaque was used to count the number of total bacteria, total anaerobic bacteria, Streptococcus mutans, and Candida albicans on selective agar media. The statistical analysis of the number of colony forming units (CFUs) obtained demonstrated a significant antimicrobial effect of ozonated water on the total bacteria (p = 0.01) and anaerobes (p = 0.02). A reduction in the post-rinse CFU count for Streptococcus mutans was also observed, but the effect was not statistically significant (p = 0.07). The Candida species was only grown from one sample. Ozonated water at the 0.1 ppm concentration was effective in reducing the load of 24-hour plaque bacteria, but it did not eliminate them completely.

Quantification of the Dental Morphology of Orangutans

Orangutans are believed to have close biological affinities to humans. Teeth being the hardest tissue provide useful information on primate evolution. Furthermore, knowledge of the pulp chamber and root canal morphology is important for dental treatment. A female Bornean orangutan and a Sumatran male orangutan skull were available for this study. Both of their dentitions, comprising 50 teeth, were scanned employing the cone-beam computed tomography for both metrical and nonmetrical analyses. Measurements included tooth and crown length, root length, enamel covered crown height, root canal length (posterior teeth), length of pulpal space (anterior teeth), and root canal width. Nonmetrical parameters included number of canals per root, number of foramina in each root, and root canal morphology according to Vertuccis classification. It was found that the enamel covered crown height was the longest in the upper central incisors although the canine was the longest amongst the anterior teeth. Both the upper premolars were three-rooted while the lower second premolar of the Sumatran orangutan was two-rooted, with two foramina. The mandibular lateral incisors of the Bornean orangutan were longer than the central incisors, a feature similar to humans. In addition, secondary dentine deposition was noticed, a feature consistent with aged humans.

Validation of cone beam CT scan for measurement of palatal depth in study casts

The purpose of this study was to validate the use of digital dental study casts obtained from Cone beam CT Scan (CBCT) against gold standard; that is traditional dental study cast measured with digital caliper.

Unusual Dental Morphology in a Chimpanzee: A Case Report Utilizing Cone-Beam Computed Tomography

This case report illustrates the teeth morphology of a chimpanzee and its anatomical variations. A well-preserved skull of a male Pan troglodytes troglodyte chimpanzee was scanned using a cone-beam computed tomography machine. Measurements included tooth and crown height, root length, root canal length and width (posterior teeth), and pulp cavity length (anterior teeth). Nonmetrical parameters included number of canals and foramina per root of every root. Interestingly, the mandibular central incisor was longer than the lateral incisor, and all the mandibular anterior teeth presented with a solitary flame-shaped or conical-calcified structure in their pulp cavity. The premolars are usually dual rooted except for the first maxillary premolar that displayed 3 roots. Other unusual discoveries were the presence of bilateral radicular dens invaginatus in the mandibular first premolars and the possibility of having 2 canals and 2 foramina in the roots of the posterior teeth. The presence of conical stone mineralizations at the pulp cavity and the presence of dens invaginatus were of particular interest.

Qualitative analyses of the antimicrobial effect of ozonated water on supragingival plaque and salivary microbes.

Background: Ozone is an unstable gas, capable of oxidizing any biological entity. It is an effective bactericide in its gaseous as well as aqueous form. Aims: The objective of this study was to determine the in-situ antimicrobial effect of 0.1 ppm ozonated water on plaque and salivary microorganisms. Subjects and Methods: 24 h old supragingival plaque (SP) was collected from the two most posterior teeth in the contralateral quadrants before and after a 30 s rinse with either distilled water (control group) or 0.1 ppm ozonated water (test group). Simultaneously stimulated whole saliva (SWS) was collected for both groups. The SP and SWS were stained with LIVE/DEAD Baclight Bacteria Viability fluorescent kit to visualize live and dead microbes. The salivary flow rate, calcium and protein level were also determined in the pre- and post-rinsed samples. The data obtained was subjected to One Way ANOVA test using Minitab 14 statistical software (PA, USA). Results: 0.1 ppm ozonated water was found effective in reducing the bacterial load in both the 24 h plaque and SWS samples, but it did not eliminate them completely. In addition, there was no statistically significant effect of the ozonated water rinse on the salivary flow rate, salivary calcium and protein concentration. Conclusions: 0.1 ppm ozonated water rinse can be an effective adjunct to tooth brushing and flossing to maintain plaque and salivary bacterial load.