A new experimental mouse model of periodontitis using an orthodontic ligature wire

Abstract

Periodontitis is characterized by alveolar bone resorption and loss of attachment. Recently, many induced periodontitis animal models have been developed to mimic alveolar bone resorption, but each model has a number of disadvantages. Periodontitis-inducing procedures should be simple and reproducible. Therefore, with the aim of establishing an experimental mouse model of periodontitis, we induced subgingival plaque accumulation in eight-week-old male C57BL/6 wild-type mice by placing an orthodontic ligature wire around the contact point between the left maxillary first and second molars. Maxillae were collected at four and eight weeks after ligature placement, and alveolar bone between the left molars (test maxillae) was compared with that between the right molars (control maxillae). Micro-computed tomography and pathological analysis were then performed to examine the degree of alveolar bone resorption. Alveolar bone resorption was significant in the test maxillae compared with the controls. In addition, the ligature wire was not found to affect the periodontal tissue. The induction of alveolar bone resorption was likely due to the direct mechanical impact (mechanical irritation of gingiva) of the wire ligature. These findings suggest that placement of the ligature wire around the contact point between teeth successfully induced alveolar bone resorption. Furthermore, use of the ligature wire removed the need to induce alveolar bone resorption by using an impacted wire ligature to create mechanical stress. Therefore, the present report provides a new animal model of periodontitis. © 2014 The Hard Tissue Biology Network Association Printed in Japan, All rights reserved.