Comparative study of gene expression during tooth eruption and orthodontic tooth movement in mice.
OBJECTIVE
The aim of this study was to understand tooth eruption by comparing the gene expression during tooth eruption and orthodontic tooth movement (OTM).


METHODS
Orthodontic force was applied on maxillary molars for 2, 4, 7 and 14 days to study tooth movement. Mice at PN 0, 7, 10, 15 and 21 were fixed to observe tooth eruption. Comparative study of two procedures was assessed by haematoxylin and eosin, tartrate-resistant acid phosphatase staining and in situ hybridization for matrix metalloproteinase (Mmp)2, 13, bone sialoprotein (Bsp) and osteocalcin (Ocn).


RESULTS
Tartrate-resistant acid phosphatase activity and expression of Mmp2, 13 were obviously detectable in the compression region during OTM. They were also identified in the occlusal and apical region of alveolar bone during tooth eruption. Strong expression of Bsp and Ocn was detectable at the tension side during OTM. These genes were also expressed in the inner lateral region of alveolar bone adjacent to the tooth, but absent in the inner surface of the occlusal and root apical regions during tooth eruption.


CONCLUSIONS
The process of alveolar bone metabolism during developmental eruption and OTM shares the same mechanism. Internal force, as the orthodontic force for OTM, may be initiating factor for tooth eruption.
Huang
X F
XF
Department of Stomatology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong'an Road, Xuanwu District, Beijing 100050, China. hxf1998@hotmail.com
Zhao
Y B
YB
Zhang
F M
FM
Han
P Y
PY
D000135:Acid Phosphatase / Q000235:genetics / Q000378:metabolism; D000539:Alveolar Process / Q000033:anatomy & histology / Q000378:metabolism; D000818:Animals; D016723:Bone Remodeling / Q000235:genetics / Q000502:physiology; D020869:Gene Expression Profiling; D006867:Hydrolases / Q000235:genetics / Q000378:metabolism*; D058574:Integrin-Binding Sialoprotein; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D053509:Matrix Metalloproteinase 13 / Q000235:genetics / Q000378:metabolism; D020778:Matrix Metalloproteinase 2 / Q000235:genetics / Q000378:metabolism; D008437:Maxilla; D051379:Mice; D008810:Mice, Inbred C57BL; D008963:Molar; D015675:Osteocalcin / Q000235:genetics / Q000378:metabolism*; D010519:Periodontium / Q000033:anatomy & histology / Q000378:metabolism*; D012795:Sialoglycoproteins / Q000235:genetics / Q000378:metabolism*; D000071681:Tartrate-Resistant Acid Phosphatase; D013997:Time Factors; D014078:Tooth Eruption / Q000235:genetics / Q000502:physiology*; D014087:Tooth Movement Techniques
C546872:Ibsp protein, mouse; D058574:Integrin-Binding Sialoprotein; D007527:Isoenzymes; D012795:Sialoglycoproteins; D015675:Osteocalcin; D006867:Hydrolases; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase; D053509:Matrix Metalloproteinase 13; D020778:Matrix Metalloproteinase 2