Effects of Bisphosphonate on the Endochondral Bone Formation of the Mandibular Condyle

Authors

  • M. S. Kim,

    1. Addresses of authors: Dental Science Research Institute, 2nd stage Brain Korea, School of Dentistry, Chonnam National University, Gwangju, South Korea 500-757
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  • S. Y. Jung,

    1. Addresses of authors: Dental Science Research Institute, 2nd stage Brain Korea, School of Dentistry, Chonnam National University, Gwangju, South Korea 500-757
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  • J. H. Kang,

    1. Addresses of authors: Dental Science Research Institute, 2nd stage Brain Korea, School of Dentistry, Chonnam National University, Gwangju, South Korea 500-757
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  • H. J. Kim,

    1. Department of Oral Anatomy, School of Dentistry, Wonkwang University, Iksan, South Korea 570-749
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  • H. M. Ko,

    1. Addresses of authors: Dental Science Research Institute, 2nd stage Brain Korea, School of Dentistry, Chonnam National University, Gwangju, South Korea 500-757
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  • J. Y. Jung,

    1. Addresses of authors: Dental Science Research Institute, 2nd stage Brain Korea, School of Dentistry, Chonnam National University, Gwangju, South Korea 500-757
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  • J. T. Koh,

    1. Addresses of authors: Dental Science Research Institute, 2nd stage Brain Korea, School of Dentistry, Chonnam National University, Gwangju, South Korea 500-757
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  • W. J. Kim,

    1. Addresses of authors: Dental Science Research Institute, 2nd stage Brain Korea, School of Dentistry, Chonnam National University, Gwangju, South Korea 500-757
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  • S. M. Kim,

    1. Addresses of authors: Dental Science Research Institute, 2nd stage Brain Korea, School of Dentistry, Chonnam National University, Gwangju, South Korea 500-757
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  • E. J. Lee,

    1. Addresses of authors: Dental Science Research Institute, 2nd stage Brain Korea, School of Dentistry, Chonnam National University, Gwangju, South Korea 500-757
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  • S. H. Kim

    1. Addresses of authors: Dental Science Research Institute, 2nd stage Brain Korea, School of Dentistry, Chonnam National University, Gwangju, South Korea 500-757
    2. Corresponding author: Tel.: 82 62 530 4822; fax: 82 62 530 4829; e-mail: ksh@chonnam.ac.kr
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Dental Science Research Institute, School of Dentistry, Chonnam National University, Yongbongdong, Gwangju, South Korea

Summary

The development of the mandibular condylar cartilage is important for the overall growth of the mandible. However, there have been a few researches into medical approaches aimed at controlling condylar growth. This study examined the effects of bisphosphonate on the growth of the condylar cartilage. Alendronate (3.5 mg/kg/week) was administered to postnatal day 1 SD rats for 7 and 10 days. The thickness of each chondrocyte layer and the level of MMP-9 expression were measured. The anteroposterior diameter of the developing condyle was unaffected by the alendronate treatment for 7 days (P > 0.05). The total thickness of the cartilage layers was also unaffected by the treatment for 7 days (P > 0.05). In particular, there was no change in the thickness of the perichondrium and reserve cell layer at the measured condylar regions (P > 0.05). However, the thickness of the proliferating cell layer was reduced significantly, whereas the thickness of hypertrophied cartilage layer was increased (P < 0.05). The number of chondroclasts engaged in hypertrophied cartilage resorption was reduced significantly by the alendronate treatment (P < 0.05). The level of MMP-9 expression was reduced at both the transcription and translation levels by the alendronate treatment for 7 and 10 days. These results indicate that alendronate (>3.5 mg/kg/week) inhibits the longitudinal growth of the mandibular condyle by inhibiting chondrocyte proliferation and the resorption of hypertrophied cartilage for ossification.

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