Dentin matrix protein 1 (DMP1) is a key regulator for osteoblast differentiation and mineralization of the bone extracellular matrix (ECM). Osteocalcin (OCN) is one of the most abundantly expressed non-collagenous protein by osteoblasts in bone. In the present study, we generated a mouse model (OCN-DMP1) that overexpresses full-length DMP1 utilizing the OCN promoter. Expression of genes encoding osteogenic transcription factors and ECM proteins during early post-natal development in male OC-DMP1 and wild type (WT) mice was evaluated in femurs and calvaria. Bones were dissected from n=4 animals at 15, 30, 60 and 90-days of age. Total RNA was isolated, reverse transcribed, and real-time PCR analysis was performed. Results confirmed a difference (p<0.05) in osteogenic gene expression between OC-DMP1 and WT mice at the specified time points. Additionally, a unique osteogenic gene expression profile for calvaria and femur, representing intramembranous and endochondral bone formation was identified. These data suggest that bone-specific DMP1 overexpression has a profound influence on bone development by impacting osteogenic gene expression. This animal model presented here provides new opportunities for analysis of in vivo roles of DMP1 in bone.
Orthognathic surgery performed in conjunction with orthodontic treatment is commonly performed to correct skeletal irregularities and realign the maxillomandibular relationship to improve occlusal function and facial esthetics. A thorough understanding of soft tissue esthetics, skeletal and occlusal relationships, and surgical techniques is required to obtain successful results. Surgical techniques have evolved greatly throughout history, as technological advances such as virtual surgical planning have become available and widely used to obtain predictable movements with minimized complications. The aim of this article is to review the orthognathic surgical procedures of the mandible, with particular attention to the indications, contraindications, preoperative assessment, surgical technique, and possible complications encountered.
Apatitic mineral of dentin forms within the collagenous matrix (intertubular dentin, ITD) secreted from the odontoblastic processes (OP). Highly calcified mineral (peritubular dentin, PTD) is deposited at the interface between the ITD and each process membrane, creating a tubular system penetrating the dentin that extends from the dentino-enamel junction to the predentin-dentin junction. We focus on determining the composition of the PTD both with regard to its organic matrix and the inorganic phase. A laser capture technique has been adapted for isolation of the mineralized PTD free of the ITD, and for the analysis of the PTD by SEM, TEM, and energy dispersive spectrometry (EDS), and comparison with similar analyses of intact dentin slices containing ITD bounded-PTD annuli. Elemental line scans clearly marked the boundaries between ITD, PTD, and OP components, and revealed differences in composition, and topographical surface roughness. The organic matrix of the PTD was shown to be sulfur rich, and further antibody labeling showed the sulfated organic component to be chondroitin sulfate B. In this organic matrix the Ca/P ratio was distinctly higher than in the ITD and intact PTD, indicating that polysaccharide bound S supplies the anionic counterion facilitating the formation of the apatitic PTD mineral.
Orthognathic surgery is a complex type of facial surgery that can have a profound impact on a patient's occlusal function and facial aesthetics. Close collaboration between the maxillofacial surgeon and an orthodontist is required, and the surgical team must have a strong foundation in facial analysis and firm understanding of the maxillofacial skeleton to achieve surgical success. Herein, we review the maxillary LeFort I osteotomy as it pertains to orthognathic surgery, with particular attention to the indications, contraindications, preoperative assessment, surgical technique, and possible complications encountered.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.