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Changes in cell density and morphology of selected cells of the ageing human dental pulp

Daud S, Nambiar P, Hossain MZ, Rahman MR, Bakri MM

Gerodontology, 2016 Sep;33(3):315-21.

OBJECTIVES: The aim of this study was to determine the changes in cell density and morphology of selected cells of the ageing human dental pulp.

BACKGROUND: Changes in cell density and morphology of dental pulp cells over time may affect their capability to respond to tooth injury.

MATERIALS AND METHODS: One hundred thirty-one extracted teeth were obtained from individuals between the ages of 6 and 80 years. The apical 1/3 of the root region was removed from all teeth prior to routine processing for producing histological slides. The histology slides were used to study the changes in cell density and morphology of selected pulp cells; odontoblasts, subodontoblasts and fibroblasts in the crown and root regions of the dental pulp. Student's t-test and one-way anova were used for statistical analyses.

RESULTS: In all age groups, the cell density for all types of cells was found to be higher in the crown than in the root (p crown and root regions. However, it was noted that the reduction of coronal odontoblasts occurred later in life (40-49 years) when compared to that of subodontoblasts or fibroblasts (30-39 years).

CONCLUSIONS: The density of the coronal pulp cells reduces and these cells undergo morphological changes with ageing of individuals and this may affect the pulp's ability to resist tooth injury.

Matched MeSH terms: Tooth Crown/pathology

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 Crown/pathology

Validity and reproducibility of ICDAS II in primary teeth

Shoaib L, Deery C, Ricketts DN, Nugent ZJ

Caries Res, 2009;43(6):442-8.

PMID: 19907175 DOI: 10.1159/000258551

The aim of this in vitro study was to assess the validity and reproducibility of the ICDAS II (International Caries Detection and Assessment System) criteria in primary teeth. Three trained examiners independently examined 112 extracted primary molars, ranging from clinically sound to cavitated, set up in groups of 4 to mimic their anatomical positions. The most advanced caries on the occlusal and approximal surfaces was recorded. Subsequently the teeth were serially sectioned and histological validation was undertaken using the Downer and Ekstrand-Ricketts-Kidd (ERK) scoring systems. For occlusal surfaces at the D(1)/ERK(1) threshold, the mean specificity was 90.0%, with a sensitivity of 75.4%. For approximal surfaces, the specificity and sensitivity were 85.4 and 66.4%, respectively. For occlusal surfaces at ICDAS code > or =3 (ERK(3) threshold), the mean specificity and sensitivity were 87.0 and 78.1%, respectively. For approximal surfaces, the equivalent values were 90.6 and 75.3%. At the D(3) threshold for occlusal surfaces, the mean specificity and sensitivity were 92.8 and 63.1%, and for approximal surfaces 94.2 and 58.3%, respectively. Mean intraexaminer reproducibility (Cohen's kappa) ranged from 0.78 to 0.81 at the ICDAS code > or =1 cut-off and at the ICDAS code > or =3 cut-off from 0.74 to 0.76. Interexaminer reproducibility was lower, ranging from 0.68 to 0.70 at the ICDAS code > or =1 cut-off and from 0.66 to 0.73 at the ICDAS code > or =3 cut-off. In conclusion, the validity and reproducibility of the ICDAS II criteria were acceptable when applied to primary molar teeth.

Matched MeSH terms: Tooth Crown/pathology

Experimental determination of optimal force system required for control of anterior tooth movement in sliding mechanics

Sia S, Shibazaki T, Koga Y, Yoshida N

Am J Orthod Dentofacial Orthop, 2009 Jan;135(1):36-41.

PMID: 19121498 DOI: 10.1016/j.ajodo.2007.01.034

This study was designed to determine the optimum vertical height of the retraction force on the power arm that is required for efficient anterior tooth retraction during space closure with sliding mechanics.

Matched MeSH terms: Tooth Crown/pathology

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