TY - JOUR
T1 - Odontoblast turnover in the impeded and unimpeded rat incisor derived from computerized histomorphometry
AU - Weinreb, M.
AU - Steigman, S.
AU - Zajicek, G.
AU - Michaeli, Y.
PY - 1985/2
Y1 - 1985/2
N2 - A computerized histomorphometric method was devised to estimate the kinetics of odontoblast turnover and dentinogenesis in rat incisors. The method was applied to two groups of rats: one group with lower incisors in impeded eruption and another group with the left lower incisor in the unimpeded state. The teeth were divided into six equal segments, from which consecutive ground sections were obtained. The distance of each ground section from the posterior border of the alveolar bone was calculated. Each section was magnified, traced, and the tracings fed into a computer by a sonic digitizer. The perimeters and areas of dentine and pulp in each ground section were calculated by the computer. The mean odontoblast density along the predentine was evaluated from histological sections taken both from the same tooth segments and from teeth sectioned midsagittally. These served for the estimation of the predentine area occupied by the average odontoblast. In the impeded group, this area was 11% larger than in the unimpeded one. Outer dimensions of teeth, namely the circumference of the dentine, the labiolingual width, and the mesiolateral width remained constant and equal for both groups. Daily rates of dentine apposition were computed and were found to vary according to the age of the odontoblasts. Odontoblasts of impeded teeth started to secrete matrix at a rate of 17 μm/day, which increased slightly to 19 μm/day and later declined to 7 μm/day on the 38th day. Dentine production of unimpeded odontoblasts, on the other hand, started at a rate of 16 μm/day and gradually increased to 34 μm/day on the 17th day. The daily rate of odontoblast cell‐production was 2.29 times greater in the unimpeded teeth (112.9 × 103 cells/day instead of 49.4 × 103 cells/day). The absolute mean daily rate of odontoblast cell loss increased in unimpeded teeth from 33.1 × 103 cells/day to 42.9 × 103 cells/day. On the other hand, the relative daily rate of cell loss decreased from 73.6 cells/day/1μm eruption to 47.7 cells/day/1μm eruption.
AB - A computerized histomorphometric method was devised to estimate the kinetics of odontoblast turnover and dentinogenesis in rat incisors. The method was applied to two groups of rats: one group with lower incisors in impeded eruption and another group with the left lower incisor in the unimpeded state. The teeth were divided into six equal segments, from which consecutive ground sections were obtained. The distance of each ground section from the posterior border of the alveolar bone was calculated. Each section was magnified, traced, and the tracings fed into a computer by a sonic digitizer. The perimeters and areas of dentine and pulp in each ground section were calculated by the computer. The mean odontoblast density along the predentine was evaluated from histological sections taken both from the same tooth segments and from teeth sectioned midsagittally. These served for the estimation of the predentine area occupied by the average odontoblast. In the impeded group, this area was 11% larger than in the unimpeded one. Outer dimensions of teeth, namely the circumference of the dentine, the labiolingual width, and the mesiolateral width remained constant and equal for both groups. Daily rates of dentine apposition were computed and were found to vary according to the age of the odontoblasts. Odontoblasts of impeded teeth started to secrete matrix at a rate of 17 μm/day, which increased slightly to 19 μm/day and later declined to 7 μm/day on the 38th day. Dentine production of unimpeded odontoblasts, on the other hand, started at a rate of 16 μm/day and gradually increased to 34 μm/day on the 17th day. The daily rate of odontoblast cell‐production was 2.29 times greater in the unimpeded teeth (112.9 × 103 cells/day instead of 49.4 × 103 cells/day). The absolute mean daily rate of odontoblast cell loss increased in unimpeded teeth from 33.1 × 103 cells/day to 42.9 × 103 cells/day. On the other hand, the relative daily rate of cell loss decreased from 73.6 cells/day/1μm eruption to 47.7 cells/day/1μm eruption.
UR - http://www.scopus.com/inward/record.url?scp=0022019984&partnerID=8YFLogxK
U2 - 10.1002/ar.1092110215
DO - 10.1002/ar.1092110215
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C2 - 3977090
AN - SCOPUS:0022019984
SN - 0003-276X
VL - 211
SP - 218
EP - 225
JO - Anatomical Record
JF - Anatomical Record
IS - 2
ER -