Use of Micro-CT Imaging to Assess Ventral Mandibular Cortical Thickness and Volume in an Experimental Rodent Model With Chronic High-Phosphorus Intake.

Vladimir Jekl,Tomas Zikmund,Adam Brinek,Josef Kaiser,Edita Jeklova

doi:10.3389/fvets.2021.759093

Abstract

Adverse effects of high dietary phosphorus on bone health have been observed in both animal and human studies. The aim of the investigation was to examine chronic effects of high phosphorus diet on the apical mandibular cortical thickness and volume in a hystricomorph rodent (Octodon degus) using microcomputed tomography. Male degus were randomly divided into two groups fed by different mineral contents from the age of 12 weeks till the age of 17 months. The micro-CT scanning and wall thickness analysis were applied on the region of the mandible exactly under the apices of the 4th premolar tooth, first molar tooth, and second molar tooth in two animals from each group. General overview and mapping of the ventral mandibular bone thickness revealed pronounced bony mandibular protrusions in all the animals fed a high-phosphorus diet with obvious bone thinning apically to the 4th premolar and first and second molar tooth apices. Mandibular bone volume and thickness located apically to the premolar and molars were statistically significantly smaller/thinner in the group fed by a high phosphorus diet. The thinnest bone measured 0.004 mm, where the mandibular 4th premolar tooth almost perforated the mandibular cortex. Similar studies of metabolic bone disease and its influence on alveolar bone were also published in rats and mice. The influence of different environmental, infectious, or metabolic factors on the growing tooth, alveolar bone formation, and bone pathologies must be done experimentally on growing animals. In contrast, degus have continuously growing dentition, and the effect of any of the above listed factors can be studied in this animal model at any age and for longer time periods.

Highlights

Metabolic bone diseases are a diverse group of diseases that result in abnormalities of bone mass, mineral homeostasis, bone turnover, or growth in man and in animals [1]
The aim of the present investigation was to examine the chronic effect of high-phosphorus diet on the mandibular apical alveolar bone thickness in a hystricomorph rodent—Octodon degu—using microcomputed tomography
The aim of the present investigation was to examine the chronic effect of high-phosphorus diet on the mandibular apical alveolar bone thickness in a hystricomorph rodent— Octodon degu—using microcomputed tomography in four randomly selected animals

Summary

Introduction

Metabolic bone diseases are a diverse group of diseases that result in abnormalities of bone mass, mineral homeostasis, bone turnover, or growth in man and in animals [1]. Apart from osteoporosis, the most commonly encountered metabolic bone diseases in humans are associated with impaired metabolism of phosphorus [2]. Excessive dietary phosphorus intake is observed in most age groups in the US [1, 3, 4]. Adverse effects of high dietary phosphorus on bone health have been observed in both animal and human studies. A high-phosphorus diet produces a higher level of plasma phosphate, which reduces urine calcium loss, reduces renal synthesis of 1.25dihydroxycholecalciferol, reduces serum-ionized calcium, and leads to increases in parathormone and osteopontin release with subsequent secondary hyperparathyroidism and increased bone resorption [1, 2, 5, 6]

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Results

Conclusion