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Measurement of the Force Required to Extract the Mandibular First Molar from Its Socket in the Dissected Jaw of Growing Young Rats
Author(s) -
Komatsu K.,
Ohshima S.,
Chiba M.
Publication year - 1990
Publication title -
gerodontology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.7
H-Index - 54
eISSN - 1741-2358
pISSN - 0734-0664
DOI - 10.1111/j.1741-2358.1990.tb00251.x
Subject(s) - periodontal fiber , medicine , molar , dental alveolus , dentistry , mandibular first molar , mandibular molar , orthodontics , mandibular second molar , mandible (arthropod mouthpart) , biology , botany , genus
Age‐related changes in the mechanical strength of the periodontal ligament have been examined by measuring the force required to extract the mandibular first molar from its socket at an extension rate of 5 mm/min in the dissected jaws of growing young rats from 3 to 32 weeks of age. Almost linear increase in the ultimate loads was found from 3 to 8 weeks of age. However the values from 8 to 32 weeks of age did not show any significant differences. Close correlations were found between the ultimate loads and the weights of animals, mandibles and extracted teeth and between the load and length of the tooth from 3 to 8 weeks of age. It is supposed that a mechanical equilibrium has been established within the periodontal ligament in association with various external and internal factors such as root elongation, alveolar bone growth, turnover and maturation of periodontal ligament and occlusal activity, at about 8 weeks of age in the rat mandibular first molar.