Histochemical Analysis Of Root Resorption In Rats By Jiggling Forces
Objectives: Root resorption is a severe side effect of orthodontic treatment. Jiggling force is one of the risk factors of root resorption, however, there has been no report in the literature about the influence of jiggling force on apical root resorption in experimental animal models. The purpose of this study was to clarify whether the jiggling force is one of the key determinants for root resorption during orthodontic tooth movement.
Methods: In this study, 72 Wistar strain male rats of 12-week-old were used. The upper first molars were moved alternately to the buccal lingual directions using an experimental appliance to produce jiggling forces of 10g and 50g. Among 72 rats, 48 rats underwent changes in force direction every 1, 2 and 4weeks with a force of 10g and 50g. After 8 weeks, the appliances were removed and the animals were scarified. For the remaining 24 rats, the force direction was changed every one week with a force of 10g, and after 3, 7,10,14,17 and 21 days, the animals were scarified. Then, the maxillae were resected and subjected to histochemical analyses. The resorption area was quantified morphohistologically. The number of TRAP-positive cells on the root surface was also counted.
Results: The amount of root resorption and the number of TRAP-positive cells were significantly greater in rats with jiggling forces in different directions once a week than in other rats. However, there were no significant differences in resorption area between rats with 10g and 50g forces. The amount of root resorption area and TRAP-positive cells increased with a lapse of experiment.
Conclusions: It is shown that jiggling force, applied alternatively in different directions with a short interval, is one of the critical factors for severe root resorption.
Division: Japanese Division Meeting
Meeting:2010 Japanese Division Meeting (Kitakyushi City, Japan) Location: Kitakyushi City, Japan
Year: 2010 Final Presentation ID: Abstract Category|Abstract Category(s):Scientific Groups
Authors
Matsuda, Yayoi
( Hiroshima University, Hiroshima, N/A, Japan
)
Hayashi, Hidetaka
( Hiroshima University, Hiroshima, N/A, Japan
)
Terao, Akiko
( Hiroshima University, Hiroshima, N/A, Japan
)
Kojima, Shunichi
( Hiroshima University, Hiroshima, N/A, Japan
)
Tsubamoto, Noriko
( Hiroshima University, Hiroshima, N/A, Japan
)
Ishikawa, Emi
( Hiroshima University, Hiroshima, N/A, Japan
)
Tanne, Kazuo
( Hiroshima University, Hiroshima, N/A, Japan
)
Motokawa, Masahide
( Hiroshima University, Hiroshima, N/A, Japan
)
Kaku, Masato
( Hiroshima University, Hiroshima, N/A, Japan
)
Kawata, Toshitsugu
( Hiroshima University, Hiroshima, N/A, Japan
)
Fujita, Tadashi
( Hiroshima University, Hiroshima, N/A, Japan
)
Ohtani, Junji
( Hiroshima University, Hiroshima, N/A, Japan
)
Sunagawa, Hiroko
( Hiroshima University, Hiroshima, N/A, Japan
)
Koseki, Hiroyuki
( Hiroshima University, Hiroshima, N/A, Japan
)
Abedini, Sara
( Hiroshima University, Hiroshima, N/A, Japan
)