title: Requirement of alveolar bone formation for eruption of rat molars.
abstract: Tooth eruption is a localized event that requires a dental follicle (DF) to regulate the resorption of alveolar bone to form an eruption pathway. During the intra-osseous phase of eruption, the tooth moves through this pathway. The mechanism or motive force that propels the tooth through this pathway is controversial but many studies have shown that alveolar bone growth at the base of the crypt occurs during eruption. To determine if this bone growth (osteogenesis) was causal, experiments were designed in which the expression of an osteogenic gene in the DF, bone morphogenetic protein-6 (Bmp6), was inhibited by injection of the first mandibular molar of the rat with a small interfering RNA (siRNA) targeted against Bmp6. The injection was followed by electroporation to promote uptake of the siRNA. In 45 first molars injected, eruption was either delayed or completely inhibited (seven molars). In the impacted molars, an eruption pathway formed but bone growth at the base of the crypt was greatly reduced compared with the erupted first-molar controls. These studies show that alveolar bone growth at the base of the crypt is required for tooth eruption and that Bmp6 may be essential for promoting this growth.
authors: Department of Comparative Biomedical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, USA. gwise@vetmed.lsu.edu
authors: Gary E
authors: GE
authors: Wise
authors: Hongzhi
authors: H
authors: He
authors: Dina L
authors: DL
authors: Gutierrez
authors: Sherry
authors: S
authors: Ring
authors: Shaomian
authors: S
authors: Yao
mesh_terms: D000539:Alveolar Process / Q000033:anatomy & histology / Q000254:growth & development*; D000818:Animals; D000831:Animals, Newborn; D001846:Bone Development / Q000235:genetics; D055418:Bone Morphogenetic Protein 6 / Q000235:genetics; D003795:Dental Sac / Q000033:anatomy & histology / Q000502:physiology; D018274:Electroporation; D055785:Gene Knockdown Techniques; D020868:Gene Silencing; D008963:Molar / Q000502:physiology*; D010012:Osteogenesis / Q000235:genetics; D034741:RNA, Small Interfering / Q000235:genetics; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013997:Time Factors; D014078:Tooth Eruption / Q000235:genetics / Q000502:physiology*; D014095:Tooth, Impacted / Q000235:genetics / Q000473:pathology / Q000503:physiopathology; D014162:Transfection
chemical_list: C525818:Bmp6 protein, rat; D055418:Bone Morphogenetic Protein 6; D034741:RNA, Small Interfering