ABSTRACT
@#Traditional titanium implants are bioinert, and some biological properties, such as osteogenic and antibacterial properties, can be obtained by adding different trace elements to their surfaces. These trace elements can help enhance implant-bone binding and effectively prevent peri-implantitis. Different trace elements have different advantages, and different modification methods can also affect the biological properties. In this paper, the biological properties of titanium implant surfaces modified by trace elements were reviewed. The results of a literature review show that implant surfaces modified by fluoride, silver, zinc, manganese, etc. can inhibit the growth of bacteria and reduce the negative impact on normal cells from bacteria. Other elements, such as strontium, tantalum and cobalt, can promote the differentiation of osteoblasts on the surface of titanium implants, improve the activity of alkaline phosphatase, and improve the expression of osteogenic genes, thus increasing the amount of bone formation and enhancing the strength of implant-bone integration. Most elements have multiple properties, and the combined application of two or more elements can yield more biological properties than a single element. Since there are many trace elements in the human body, there is still a wide research space available in the field of the surface modification of dental implants by trace elements.
ABSTRACT
@#Primary cilia are organelles present on most mammalian cells that sense environmental changes and transduce signaling, and they are the key coordinators of various signaling pathways during tissue development. This article reviews the progress of research on the distribution of primary cilia in tooth development and the related signaling pathways. A literature review shows that in odontogenesis, primary cilia play an important role in the mutual induction of the epithelium and mesenchyme; during the continuous proliferation and differentiation of cells, the distribution of primary cilia is temporally and spatially dependent. Although the reason for this distribution is still unclear, some experimental evidence indicates that this phenomenon is compatible with the function of cells and tissues in which primary cilia are distributed. Primary cilia are involved in the regulation of two important signaling pathways, Hedgehog and Wnt, in odontogenesis. Genes encoding cilia (such as Kif3a, Evc/Evc2 and Ift) can affect the development of teeth by regulating these two signaling pathways, and there is an interaction between the two signaling pathways. Deletion of related genes (such as Ofd1 and Bbs) can damage the transmission of upstream and downstream signals by damaging the structure or function of cilia, thereby causing various types of dental dysplasia, including small teeth, enamel hypoplasia, missing teeth, or craniofacial deformities.
ABSTRACT
@#For patients with dento-maxillofacial deformities who receive orthodontic-orthognathic combined treatment, the conventional treatment approach is preoperative orthodontic-orthognathic surgery-postoperative orthodontics. However, with the development of techniques used in orthodontic and orthognathic treatment, the surgery-first approach (SFA), namely, orthodontic surgery-postoperative orthodontics, has been widely used currently and displays several advantages, such as improving the treatment efficiency and providing patients with more satisfaction. This review provides a brief discussion and review of SFA concerning its development, indications, advantages and disadvantages, outcomes and stability, and the application and research progress of SFA in orthodontic-orthognathic combined treatment for patients with maxillofacial deformity. The literature review results showed that compared with the conventional treatment approach, SFA has relatively strict indications, which usually include patients with skeletal class Ⅱ/Ⅲ malocclusion, skeletal open bite, and bimaxillary protrusion or patients with facial asymmetry but who require little preoperative orthodontic treatment or removal of the compensation of the dental arch, specifically as follows: ①well-aligned to mildly crowded anterior teeth, ②flat to mild curve of Spee, ③normal to mildly proclined/retroclined incisor inclination, ④acceptable arch coordination, ⑤extensive occlusal contact between the upper and lower dentition requiring at least 3 occlusal contacts. Any occlusion that may affect the outcome of surgery or final result of the overall treatment, as well as any disease that may jeopardize the healing process after surgery, is regarded as a contraindication. Furthermore, SFA has potential disadvantages, such as a possible higher incidence of complications, including unstable occlusion and malunion of bones, which still require further research to be confirmed. Most researchers believe that no significant difference occurs between the outcome and stability of the two approaches. However, currently, we still need a sufficient sample size of prospective studies to provide accurate evidence.