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Fulltext Quantification of the dental morphology of orangutans

Nambiar P, John J, Al-Amery SM, Purmal K, Chai WL, Ngeow WC, et al.

ScientificWorldJournal, 2013;2013:213757.
PMID: 24348143 DOI: 10.1155/2013/213757

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 Vertucci's 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.

Matched MeSH terms: Tooth/anatomy & histology*
A comparative study of evolutionary trends in the upper molar pattern of recent Kodiak Island inhabitants and subrecent Javanese Malayans

Korenhof CA

J Dent Res, 1966 Nov-Dec;45(6):1687-95.
PMID: 5226535
Matched MeSH terms: Tooth/anatomy & histology*
MICAP--a novel system for identification and communication of dental problems

Akram A, Hamid AH, Razak J, Hock TT

Int Dent J, 2011 Feb;61(1):31-6.
PMID: 21382031 DOI: 10.1111/j.1875-595X.2011.00006.x

To design a new tooth notation system to record and communicate dental and periodontal problems around the world.

Matched MeSH terms: Tooth/anatomy & histology*
Overjet, overbite and dental midline shift as predictors of tooth size discrepancy in a Bangladeshi population and a graphical overview of global tooth size ratios

Alam MK, Iida J

Acta Odontol Scand, 2013 Nov;71(6):1520-31.
PMID: 23530813 DOI: 10.3109/00016357.2013.775336

This study aimed to measure and compare tooth size ratios in a Bangladeshi population across the following groups: those with normal occlusion, crowding or spacing; those with normal, increased or decreased overjet; those with normal, increased or decreased overbite; those with or without dental mid-line discrepancy; and those with or without lip competence. It also presents a graphical overview of the anterior and overall ratios from the study and using available global data.

Matched MeSH terms: Tooth/anatomy & histology*
A new black fly species of Simulium (Nevermannia) (Diptera: Simuliidae) from Vietnam

Takaoka H, Low VL, Tan TK, Sofian-Azirun M, Chen CD, Lau KW, et al.

Acta Trop, 2019 Feb;190:320-328.
PMID: 30496721 DOI: 10.1016/j.actatropica.2018.11.025

Simulium pumatense sp. nov. is described from Vietnam, and is placed in the Simulium feuerborni species-group of the subgenus Simulium (Nevermannia) Enderlein. Its morphological characteristics include the relatively smaller numbers of the following three numerical features: inner teeth of the female mandible (15-18), minute conical processes (16) on the female cibarium, and male upper-eye facets (in 15 vertical columns and 16 horizontal rows). Keys are constructed to distinguish this species from four species of the same group in Vietnam. Our molecular analysis of the DNA barcoding COI gene shows that this species is most closely related to cytoform A of the S. feuerborni complex from Thailand.

Matched MeSH terms: Tooth/anatomy & histology*
First discovery of Pleistocene orangutan (Pongo sp.) fossils in Peninsular Malaysia: biogeographic and paleoenvironmental implications

Ibrahim YKh, Tshen LT, Westaway KE, Cranbrook EO, Humphrey L, Muhammad RF, et al.

J Hum Evol, 2013 Dec;65(6):770-97.
PMID: 24210657 DOI: 10.1016/j.jhevol.2013.09.005

Nine isolated fossil Pongo teeth from two cave sites in Peninsular Malaysia are reported. These are the first fossil Pongo specimens recorded in Peninsular Malaysia and represent significant southward extensions of the ancient Southeast Asian continental range of fossil Pongo during two key periods of the Quaternary. These new records from Peninsular Malaysia show that ancestral Pongo successfully passed the major biogeographical divide between mainland continental Southeast Asia and the Sunda subregion before 500 ka (thousand years ago). If the presence of Pongo remains in fossil assemblages indicates prevailing forest habitat, then the persistence of Pongo at Batu Caves until 60 ka implies that during the Last Glacial Phase sufficient forest cover persisted in the west coast plain of what is now Peninsular Malaysia at least ten millennia after a presumed corridor of desiccation had extended to central and east Java. Ultimately, environmental conditions of the peninsula during the Last Glacial Maximum evidently became inhospitable for Pongo, causing local extinction. Following post-glacial climatic amelioration and reforestation, a renewed sea barrier prevented re-colonization from the rainforest refugium in Sumatra, accounting for the present day absence of Pongo in apparently hospitable lowland evergreen rainforest of Peninsular Malaysia. The new teeth provide further evidence that Pongo did not undergo a consistent trend toward dental size reduction over time.

Matched MeSH terms: Tooth/anatomy & histology
Dento-facial relationships in individuals with normal occlusion

Al-Khatib AR, Rajion ZA, Masudi SM, Hassan R, Townsend GC

Homo, 2013 Aug;64(4):296-311.
PMID: 23755965 DOI: 10.1016/j.jchb.2013.04.002

The aim of this study was to evaluate the relationships of selected facial measurements with mesio-distal crown widths and dental arch dimensions in individuals with normal occlusions. A cross-sectional study was conducted on 276 subjects with Angle's Class I normal occlusions. Three-dimensional images of the face and dental casts were captured and analyzed using stereophotogrammetric systems. Significant correlations were found between the sagittal facial variables and both upper and lower dental arch dimensions and to lesser degree with the horizontal and vertical variables. The values of correlation coefficients calculated between facial and dental crown measurements ranged from .01 to .50 for upper teeth and .01 to .49 for lower teeth. The values of correlation coefficients between facial and upper dental arch dimensions ranged from .01 to .55 and those between facial and lower dental arch dimensions ranged from .01 to .60. A principal components analysis showed that the sagittal dimensions, face height, nose, labial fissure, binocular widths were positively associated with dental arch dimensions and mesio-distal crown diameters in males. On the other hand, only the sagittal variables were associated with dental dimensions in females. The results of this study confirm that positive associations exist between facial and dental arch dimensions. These relationships should be taken into consideration when attempts are made to modify dental arch size as part of orthodontic treatment. Moreover, these relationships are also relevant to prosthodontists involved with selecting tooth sizes that display optimal functional balance with the craniofacial structures.

Matched MeSH terms: Tooth/anatomy & histology*
Variations in tooth size and arch dimensions in Malay schoolchildren

Hussein KW, Rajion ZA, Hassan R, Noor SN

Aust Orthod J, 2009 Nov;25(2):163-8.
PMID: 20043553

To compare the mesio-distal tooth sizes and dental arch dimensions in Malay boys and girls with Class I, Class II and Class III malocclusions.

Matched MeSH terms: Tooth/anatomy & histology
Tooth size discrepancies in an orthodontic population

Othman S, Harradine N

Angle Orthod, 2007 Jul;77(4):668-74.
PMID: 17605478

To explore how many millimeters of tooth size discrepancy (TSD) are clinically significant, to determine what percentage of a representative orthodontic population has such a tooth size discrepancy, and to determine the ability of simple visual inspection to detect such a discrepancy.

Matched MeSH terms: Tooth/anatomy & histology*
Assessing agreement in measurements of orthodontic study models: Digital caliper on plaster models vs 3-dimensional software on models scanned by structured-light scanner

Wan Hassan WN, Othman SA, Chan CS, Ahmad R, Ali SN, Abd Rohim A

Am J Orthod Dentofacial Orthop, 2016 Nov;150(5):886-895.
PMID: 27871715 DOI: 10.1016/j.ajodo.2016.04.021

INTRODUCTION: In this study we aimed to compare measurements on plaster models using a digital caliper, and on 3-dimensional (3D) digital models, produced using a structured-light scanner, using 3D software.
METHODS: Fifty digital models were scanned from the same plaster models. Arch and tooth size measurements were made by 2 operators, twice. Calibration was done on 10 sets of models and checked using the Pearson correlation coefficient. Data were analyzed by error variances, repeatability coefficient, repeated-measures analysis of variance, and Bland-Altman plots.
RESULTS: Error variances ranged between 0.001 and 0.044 mm for the digital caliper method, and between 0.002 and 0.054 mm for the 3D software method. Repeated-measures analysis of variance showed small but statistically significant differences (P <0.05) between the repeated measurements in the arch and buccolingual planes (0.011 and 0.008 mm, respectively). There were no statistically significant differences between methods and between operators. Bland-Altman plots showed that the mean biases were close to zero, and the 95% limits of agreement were within ±0.50 mm. Repeatability coefficients for all measurements were similar.
CONCLUSIONS: Measurements made on models scanned by the 3D structured-light scanner were in good agreement with those made on conventional plaster models and were, therefore, clinically acceptable.

Matched MeSH terms: Tooth/anatomy & histology
Dental age estimation in Malaysian adults based on volumetric analysis of pulp/tooth ratio using CBCT data

Asif MK, Nambiar P, Mani SA, Ibrahim NB, Khan IM, Lokman NB

Leg Med (Tokyo), 2019 Feb;36:50-58.
PMID: 30415192 DOI: 10.1016/j.legalmed.2018.10.005

Forensic odontology plays an important role in human identification and dental age estimation is an integral part of this process. The aim of the study was to investigate the association between chronological age and pulp/tooth volume ratio in a Malaysian population (Malays and Chinese) from cone-beam computed tomography (CBCT) scans, enhanced with Mimics software. Three hundred CBCT scans of 153 males and 147 females, aged between 16 and 65 years were divided into 5 age groups. Volumetric analysis of the pulp/tooth ratio was performed in maxillary left canines, maxillary right canines and maxillary right central incisors. Simple linear regression and Pearson correlation analysis indicated the strongest coefficient of correlation (R) values for maxillary right central incisors (0.83) followed by maxillary right canines (0.74) and maxillary left canines (0.73). Fisher's Z test indicated that dental age estimation is gender independent. The derived regression equations were further validated on an independent group of 126 teeth. The results indicated mean absolute error (MAE) values of 6.48 and 8.58 years for maxillary right central incisors and maxillary canines respectively. It was also noticed that MAE values were higher among the age groups ranging from 46 to 65 years. This study showed that a volumetric change in the pulp cavity with age is a valuable assessment method for dental age estimation among Malaysian population.

Matched MeSH terms: Tooth/anatomy & histology
Fulltext Evaluation of dental arch dimensions in 12 year-old Vietnamese children - A cross-sectional study of 4565 subjects

Dung TM, Ngoc VTN, Hiep NH, Khoi TD, Xiem VV, Chu-Dinh T, et al.

Sci Rep, 2019 02 28;9(1):3101.
PMID: 30816230 DOI: 10.1038/s41598-019-39710-4

This study aimed to define the width and length of the dental arch in 12-year-old Vietnamese children, and to elucidate differences between genders and among ethnic groups. A cross-sectional study was conducted in 4565 12 years-old children from the 4 major ethnic groups in Vietnam (Kinh, Muong, Thai, and Tay), with a healthy and full set of 28 permanent teeth that had never had any orthodontic treatment and with no reconstructive materials at the measured points. The mean variables in all subjects were 36.39 mm for upper inter-canine width; 46.88 mm for upper inter-first molar width; 59.43 mm for upper inter-second molar width; 10.41 mm for upper anterior length; 32.15 mm for upper posterior length 1; 45.52 mm for upper posterior length 2; 28.31 mm for lower inter-canine width; 41.63 mm for lower inter-first molar width; 54.57 mm for lower inter-second molar width (LM2W); 7.06 mm for lower anterior length (LAL); 26.87 mm for lower posterior length 1 (LP1L); and 41.29 mm for lower posterior length 2. Significant differences in these parameters between genders were found in all ethnic groups, except for LAL in the Kinh and Thai groups, and LP1L in the Tay group. Significant ethnic differences were also found in almost all parameters except LM2W in both males and females. Taken together, the representative sizes of dental arches of 12-year-old Vietnamese children have been defined. Our data indicate that there are some variations in dental arch dimensions among ethnic groups and between genders.

Matched MeSH terms: Tooth/anatomy & histology*
A new system for classifying tooth, root and canal anomalies

Ahmed HMA, Dummer PMH

Int Endod J, 2018 Apr;51(4):389-404.
PMID: 29023779 DOI: 10.1111/iej.12867

Understanding the normal anatomical features as well as the more unusual developmental anomalies of teeth, roots and root canals is essential for successful root canal treatment. In addition to various types of root canal configuration and accessory canal morphology, a wide range of developmental tooth, root and canal anomalies exists, including C-shaped canals, dens invaginatus, taurodontism, root fusion, dilacerations and palato-gingival grooves. There is a direct association between developmental anomalies and pulp and periradicular diseases that usually require a multidisciplinary treatment approach to achieve a successful outcome. A number of classifications have categorized tooth, root and canal anomalies; however, several important details are often missed making the classifications less than ideal and potentially confusing. Recently, a new coding system for classifying root, root canal and accessory canal morphology has been introduced. The purpose of this article is to introduce a new system for classifying tooth, root and canal anomalies for use in research, clinical practice and training, which can serve as complementary codes to the recently described system for classifying root, as well as main and accessory canal morphology.

Matched MeSH terms: Tooth/anatomy & histology*
Dental perspectives on the population history of Southeast Asia

Matsumura H, Hudson MJ

Am J Phys Anthropol, 2005 Jun;127(2):182-209.
PMID: 15558609

This article uses metric and nonmetric dental data to test the "two-layer" or immigration hypothesis whereby Southeast Asia was initially occupied by an "Australo-Melanesian" population that later underwent substantial genetic admixture with East Asian immigrants associated with the spread of agriculture from the Neolithic period onwards. We examined teeth from 4,002 individuals comprising 42 prehistoric and historic samples from East Asia, Southeast Asia, Australia, and Melanesia. For the odontometric analysis, dental size proportions were compared using factor analysis and Q-mode correlation coefficients, and overall tooth size was also compared between population samples. Nonmetric population affinities were estimated by Smith's distances, using the frequencies of 16 tooth traits. The results of both the metric and nonmetric analyses demonstrate close affinities between recent Australo-Melanesian samples and samples representing early Southeast Asia, such as the Early to Middle Holocene series from Vietnam, Malaysia, and Flores. In contrast, the dental characteristics of most modern Southeast Asians exhibit a mixture of traits associated with East Asians and Australo-Melanesians, suggesting that these populations were genetically influenced by immigrants from East Asia. East Asian metric and/or nonmetric traits are also found in some prehistoric samples from Southeast Asia such as Ban Kao (Thailand), implying that immigration probably began in the early Neolithic. Much clearer influence of East Asian immigration was found in Early Metal Age Vietnamese and Sulawesi samples. Although the results of this study are consistent with the immigration hypothesis, analysis of additional Neolithic samples is needed to determine the exact timing of population dispersals into Southeast Asia.

Matched MeSH terms: Tooth/anatomy & histology*
Fulltext Feasibility of fiber optic displacement sensor scanning system for imaging of dental cavity

Rahman HA, Che Ani AI, Harun SW, Yasin M, Apsari R, Ahmad H

J Biomed Opt, 2012 Jul;17(7):071308.
PMID: 22894469 DOI: 10.1117/1.JBO.17.7.071308

The purpose of this study is to investigate the potential of intensity modulated fiber optic displacement sensor scanning system for the imaging of dental cavity. Here, we discuss our preliminary results in the imaging of cavities on various teeth surfaces, as well as measurement of the diameter of the cavities which are represented by drilled holes on the teeth surfaces. Based on the analysis of displacement measurement, the sensitivities and linear range for the molar, canine, hybrid composite resin, and acrylic surfaces are obtained at 0.09667 mV/mm and 0.45 mm; 0.775 mV/mm and 0.4 mm; 0.5109 mV/mm and 0.5 mm; and 0.25 mV/mm and 0.5 mm, respectively, with a good linearity of more than 99%. The results also show a clear distinction between the cavity and surrounding tooth region. The stability, simplicity of design, and low cost of fabrication make it suitable for restorative dentistry.

Matched MeSH terms: Tooth/anatomy & histology*
Tooth size and dental arch dimensions: a stereophotogrammetric study in Southeast Asian Malays

Al-Khatib AR, Rajion ZA, Masudi SM, Hassan R, Anderson PJ, Townsend GC

Orthod Craniofac Res, 2011 Nov;14(4):243-53.
PMID: 22008304 DOI: 10.1111/j.1601-6343.2011.01529.x

To investigate tooth size and dental arch dimensions in Malays using a stereophotogrammetric system.

Matched MeSH terms: Tooth/anatomy & histology*
Racial characteristics of human teeth with special emphasis on the Mongoloid dentition

Yaacob H, Nambiar P, Naidu MD

Malays J Pathol, 1996 Jun;18(1):1-7.
PMID: 10879216

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.

Matched MeSH terms: Tooth/anatomy & histology*
Fulltext The implications of different lateral wall thicknesses on surgical access to the maxillary sinus

Lim EL, Ngeow WC, Lim D

Braz Oral Res, 2017 Nov 27;31:e97.
PMID: 29185606 DOI: 10.1590/1807-3107bor-2017.vol31.0097

The objective of this study was to measure the topographic thickness of the lateral wall of the maxillary sinus in selected Asian populations. Measurements were made on the lateral walls of maxillary sinuses recorded using CBCT in a convenient sample of patients attending an Asian teaching hospital. The points of measurement were the intersections between the axes along the apices of the canine, first premolar, and second premolar and along the mesiobuccal and distobuccal apices of the first and second molars and horizontal planes 10 mm, 20 mm, 30 mm and 40 mm beneath the orbital floor. The CBCT images of 109 patients were reviewed. The mean age of the patients was 33.0 (SD 14.8) years. Almost three quarters (71.8%) of the patients were male. The mean bone thickness decreased beginning at the 10-mm level and continuing to 40 mm below the orbital floor. Few canine regions showed encroachment of the maxillary sinus. The thickness of the buccal wall gradually increased from the canine region (where sinus encroachment of the canine region was present) to the first molar region, after which it decreased to the thickness observed at the canine region. The buccal wall of the maxillary sinus became thicker anteroposteriorly, except in the region of the second molar, and thinner superoinferiorly. These changes will affect the approach used to osteotomize the lateral sinus wall for oral surgery and for the sinus lift procedure.

Matched MeSH terms: Tooth/anatomy & histology

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