Estimated Time of Biomineralization in Developing Rat Incisors

Abstract

The aim of this study was to estimate time of biomineralization in developmental stages of rat lower incisors. Eruption length was measured. Four stages of incisor development were identified on histologic and microscopic computerized tomography (micro-CT) sections: (1) preodontoblast, (2) dentin matrix secretion, (3) enamel matrix secretion, and (4) enamel calcification. The overall eruption rate of the rat lower incisor was 600 ± 70 µm/day (mean ± SD; n = 12). The length of the enamel secretion was 4.59 ± 0.75 mm in histologic section, was 3.64 ± 0.63 mm in radiographic section, which converts to 180.4 ± 30.0 hours, 145 ± 25 hours respectively (n = 24). These findings suggested that the four biomineralizing developmental stages of the rat incisor took only several days. The significance of this animal study was to provide understanding for the rapid biomineralization process of developing rat tooth germ by analysis of tooth forming period.

Nitrogen isotopes in tooth enamel record diet and trophic level enrichment: Results from a controlled feeding experiment

“…Mean total tooth length for rats was 21.8 ± 0.7 mm while guinea pig incisors were slightly longer at 25.5 ± 1.0 mm. Mandibular incisors have been documented to grow at a rate of 0.4-0.6 mm/day in rats and 0.3 mm/day in guinea pigs (Park et al 2017;Müller et al 2015). The experimental duration was 54 days (after a 5-day acclimatization period during which the animals also received the experimental food).…”

An Investigation of the Wild Rat Crown Incisor as an Indicator of Lead (Pb) Exposure Using Inductively Couple Plasma Mass Spectrometry (ICP-MS) and Laser Ablation ICP-MS

“…Similarly, for lower incisors, the root (L1) part is anchored in the mandibular bone, and the crown (L2) part of the tooth is seen externally. ( B ) Illustrated schematic longitudinal section modified from Park et al [ 31 ] of lower incisor tooth as was sectioned for direct LA-ICP-MS analysis. Furthermore, the three major parts of the incisor tooth are seen—(a) dental pulp, (b) dentine, and (c) enamel running only in the front part of the tooth.…”

Paleodietary reconstruction of endemic rodents from the precolumbian Dominican Republic: Discriminating wild feeding behavior from diets linked to human niche construction activities

“…Extracting adequate amounts of enamel from incisors is more easily accomplished than with molariform teeth of hutias which have thin enamel folds that disintegrate easily under a handheld rotary drill. Mandibular incisors are continually growing in all rodents, within rats at a rate of 0.4–0.6 mm per day, and within guinea pigs at 0.3 mm per day (Müller et al, 2015 ; Park et al, 2017 ). However, for many species of Capromyinae, molariform teeth are open‐rooted and continuously regenerating, which is a useful adaptation for diets that often include tough material such as tree bark (Borroto‐Páez & Woods, 2012 ; Hermanson & Woods, 2012 ).…”