Mechanical loading leads to osteoarthritis-like changes in the hypofunctional temporomandibular joint in rats |
| |
| Institution: | 1. Orthodontic Science, Department of Orofacial Development and Function, Division of Oral Health Sciences, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan;2. Maxillofacial Anatomy, Department of Maxillofacial Biology, Division of Maxillofacial/Neck Reconstruction, Graduate School, Tokyo Medical and Dental University, Tokyo, Japan;1. State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu, China;2. Department of Oral and Maxillofacial Surgery, Second Hospital of Lanzhou University, Lanzhou, China;3. Pathology Department, Medical School, University of Michigan, MI, USA;1. Stomatology Hospital Affiliated to Medical College, Zhejiang University, China;2. The First Affiliated Hospital,Guangzhou University of Chinese Medicine, China;2. Department of Orthodontics, Hospital of Stomatology, Zhejiang University, 395 Yan''an Road, Hangzhou 310006, China;3. School of Stomatology, Zhejiang Chinese Medical University, 548 Binwen Road, Hangzhou 310053, China;1. Central Laboratory, Peking University School and Hospital of Stomatology, Beijing, China;2. Center for TMD & Orofacial Pain, Peking University School and Hospital of Stomatology, Beijing, 100081, China;1. Institute and Hospital of Stomatology, Medical School of Nanjing University, Nanjing 210008, China;2. Department of Orthodontics, Guanghua School of Stomatology, Sun Yat-sen University, Guangzhou, Guangdong, China;3. Department of Orthodontics, West China College of Stomatology, Sichuan University, Chengdu, Sichuan, China;4. Department of Orthodontics, The Affiliated Hospital of Medical School, Nanjing Medical University, Nanjing, Jiangsu, China |
| |
| Abstract: | ObjectivesTemporomandibular joint (TMJ) hypofunction secondary to feeding a liquid diet in the growing period leads to morphological hypoplasia. However, few studies have evaluated the results of mechanical loading on the hypoplastic TMJ. This study investigated whether TMJ hypofunction in rats causes osteoarthritis (OA)-like changes when exposed to mechanical loading.DesignMale 21-day-old Wistar rats were divided into four groups. The first group (C) served as the control. In the second group (W), mechanical loading was applied to the TMJ by continuous steady mouth opening (3 h/day for 5 days) from 63 days of age. A jaw-opening device was used to hold the mandible open in the maximal mouth-opening position with a cobalt–chromium (Co–Cr) wire (φ: 0.9 mm). Groups C and W both received a normal hard diet. The third group (L) and fourth group (LW) were fed a liquid diet and group LW were subjected to the same loading as group W. We evaluated the TMJ using micro-CT, toluidine blue staining and immunohistochemistry of matrix metalloproteinase (MMP)-13.ResultsIn group LW in the superior and posterior regions of the condyle, bone volume fraction, trabecular thickness and trabecular number were significantly decreased and trabecular spacing was significantly increased. The ratio of MMP-13 immunopositive cells was significantly higher than in the other groups. OA-like changes were also observed, including reduced thickness of the cartilage, irregularities in the chondrocytic layer, and cell-free areas.ConclusionsTMJ hypofunction in rats is likely to lead to OA-like changes when exposed to mechanical loading. |
| |
| Keywords: | Temporomandibular joint hypofunction TMJ-osteoarthritis Growth Mechanical loading Matrix metalloproteinase-13 |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
