Denervation resulting in dento-alveolar ankylosis associated with decreased Malassez epithelium.
Inferior alveolar nerve denervation causes appreciable decreases in the distribution of epithelial rests of Malassez. To explore roles of the Malassez epithelium, we attempted to evaluate possible changes in dento-alveolar tissues surrounding this epithelium by experimental denervation. We found that denervation led to dento-alveolar ankylosis with a decrease in the width of the periodontal spaces. Interestingly, with regeneration of the Malassez epithelium 10 weeks after the denervation, the periodontal space width showed a correspondingly significant increase. These findings suggest that the Malassez epithelium may be involved in the maintenance of periodontal space and that sensory innervation might be indirectly associated with it. In addition, it is of interest that denervation activated root resorption of the coronal root surface and that the consequently resorbed lacunae were repaired by cellular cementum. It is suggested that Malassez epithelium may negatively regulate root resorption and induce acellular cementum formation.
Department of Orthodontics and Dentofacial Orthopedics, Graduate School of Medicine and Dentistry, Okayama University, 2-5-1 Shikata-cho, Okayama 700-8525, Japan.
K
K
Fujiyama
T
T
Yamashiro
T
T
Fukunaga
T A
TA
Balam
L
L
Zheng
T
T
Takano-Yamamoto
D000135:Acid Phosphatase / Q000378:metabolism*; D000818:Animals; D003714:Denervation / Q000009:adverse effects*; D003739:Dental Cementum / Q000378:metabolism / Q000473:pathology; D004848:Epithelium / Q000378:metabolism / Q000473:pathology; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism*; D008297:Male; D008340:Mandibular Nerve / Q000601:surgery*; D010513:Periodontal Ligament / Q000378:metabolism / Q000473:pathology*; D051381:Rats; D017208:Rats, Wistar; D020917:Receptor, trkA / Q000378:metabolism; D000071681:Tartrate-Resistant Acid Phosphatase; D020254:Tooth Ankylosis / Q000209:etiology* / Q000473:pathology / Q000503:physiopathology
D007527:Isoenzymes; D020917:Receptor, trkA; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase