Aging is a physiological change that leads to a decline in biological functions from metabolic stress. To investigate the effect of aging on mandibular bone formation, we created SAMP1/Klotho-deficient mice and performed micro-computed tomography (micro-CT) and histology analyses in 4-or 8 week-old SAMP1/kl -/- mice. SAMP1/kl -/- mice exhibited extensive inflammation, tissue calcification, and abnormal mandibular bone development. Using micro-CT analysis, SAMP1/kl -/- mice displayed a loss of incisor roots and irregular dentinal tubule formation, as well as calcification within the pulp root canal. Furthermore, the mandibular ramus showed extensive ground glass appearance in SAMP1/kl -/- mice. In histological analysis, we found calcified skeletal structures and dysplastic bone formation in SAMP1/kl -/- mice. These results provide an understanding of the pathologic alterations of aging-related mandibular bone. SAMP1/kl -/- mice may serve as a novel model for dysosteogenesis in mandibular bone development.

Abstract
Ⅰ. INTRODUCTION
Ⅱ. MATERIALS AND METHODS
    1. Generation of SAMP1/kl Deficient Mice
    2. Micro-computed tomography imaging
    3. Histology
    4. Bone volume analysis
    5. Statistical analysis
Ⅲ. RESULTS
    1. SAMP1/kl-deficient mice displayed severe tooth defects in the proximal incisor region and altered in the mandibular bone
    2. Three-dimensional surface rendering of the head and neck bones of the SAMP1/kl-/-mice using micro-CT
    3. SAMP1/kl-deficient mice exhibited ectopic calcification in mandibular bone
    4. The micro-CT analysis of the trabecular bones in distal femurs
Ⅳ. DISCUSSION
REFERENCES

• 육종인(연세대학교 치과대학 구강병리학교실) | Jong-In Yook (Department of Oral Pathology, College of Dentistry, Yonsei University)
• Nguyen Khanh Toan(조선대학교 치과대학 구강병리학교실)
• 서요섭(조선대학교 치과대학 구강악안면방사선학교실) | Yo-Seob Seo (Department of Oral and Maxillofacial Radiology, School of Dentistry, Chosun University)
• 유상준(조선대학교 치과대학 치주과학교실) | Sang-Joun Yu (Department of Periodontology, School of Dentistry, Chosun University)
• 안상건(조선대학교 치과대학 구강병리학교실) | Sang-Gun Ahn (Department of Oral Pathology, School of Dentistry, Chosun University) Correspondence