Extracellular matrix-mediated tissue remodeling following axial movement of teeth.
Tooth eruption is a multifactorial process involving movement of existing tissues and formation of new tissues coordinated by a complex set of genetic events. We have used the model of the unopposed rodent molar to study morphological and genetic mechanisms involved in axial movement of teeth. Following extraction of opposing upper molars, lower molars supererupted by 0.13 mm. Labeled tissue sections revealed significant amounts of new bone and cementum apposition at the root apex of the unopposed side following supereruption for 12 days. Newly apposited cementum and alveolar bone layers were approximately 3-fold thicker in the experimental vs the control group, whereas periodontal ligament width was maintained. Tartrate-resistant acid phosphatase staining indicated bone resorption at the mesial alveolar walls of unopposed molars and provided in tandem with new bone formation at the distal alveolar walls an explanation for the distal drift of molars in this model. Microarray analysis and semiquantitative RT-PCR demonstrated a significant increase in collagen I, integrin beta5, and SPARC gene expression as revealed by comparison between the unopposed molar group and the control group. Immunohistochemical verification revealed increased levels of integrin beta5 and SPARC labeling in the periodontal ligament of the unopposed molar. Together our findings suggest that posteruptive axial movement of teeth was accomplished by significant formation of new root cementum and alveolar bone at the root apex in tandem with upregulation of collagen I, integrin beta5, and SPARC gene expression.
Luan
Xianghong
X
Department of Oral Biology, University of Illinois at Chicago College of Dentistry, Chicago, IL 60612, USA.
Ito
Yoshihiro
Y
Holliday
Sean
S
Walker
Cameron
C
Daniel
Jon
J
Galang
Therese M
TM
Fukui
Tadayoshi
T
Yamane
Akira
A
Begole
Ellen
E
Evans
Carla
C
Diekwisch
Thomas G H
TG
D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D015415:Biomarkers / Q000378:metabolism; D016723:Bone Remodeling; D001862:Bone Resorption; D024042:Collagen Type I / Q000096:biosynthesis; D003739:Dental Cementum / Q000502:physiology; D005109:Extracellular Matrix / Q000378:metabolism / Q000502:physiology*; D039641:Integrin beta Chains / Q000096:biosynthesis; D007527:Isoenzymes / Q000378:metabolism; D051379:Mice; D008963:Molar / Q000033:anatomy & histology / Q000378:metabolism / Q000502:physiology; D020411:Oligonucleotide Array Sequence Analysis; D015676:Osteonectin / Q000096:biosynthesis; D010519:Periodontium / Q000033:anatomy & histology / Q000378:metabolism / Q000502:physiology*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D000071681:Tartrate-Resistant Acid Phosphatase; D014070:Tooth / Q000033:anatomy & histology / Q000378:metabolism / Q000502:physiology*; D014078:Tooth Eruption; D020390:Tooth Socket / Q000502:physiology
D015415:Biomarkers; D024042:Collagen Type I; D039641:Integrin beta Chains; D007527:Isoenzymes; D015676:Osteonectin; C084344:integrin beta5; D000135:Acid Phosphatase; D000071681:Tartrate-Resistant Acid Phosphatase