Virtual surgical planning in orthognathic surgery: a dental hospital's 10-year experience.

PURPOSE: The primary objective of this study was to evaluate how the utilization of virtual surgical planning (VSP) and the epidemiological profile of patients undergoing orthognathic surgery (OGS) have changed in the past decade. METHODS: The records of patients who had undergone orthognathic surgery at a national dental hospital were reviewed. Trends in VSP, epidemiological data, presentation of dentofacial deformity, and management details were recorded. RESULTS: A total of 1184 patients were included in this study. The majority of the patients seeking treatment in this dental hospital were young Chinese adults with dentofacial deformities requiring bimaxillary surgeries. Most patients presented with a skeletal Class III pattern (79.0%), and asymmetry was diagnosed in 80.8% of all cases. CONCLUSION: There was an initial slow pick-up rate for VSP, but this rapidly increased to a high adoption rate of 98.7-100% between 2019 and 2021. Together with an increasing body of evidence suggesting greater accuracy in VSP, utilization in this technology can be enhanced with greater familiarity with the technology and improvements in the VSP services.

Science and practice: challenges and perspectives of contemporary orthodontics.

Whether medicine is a science remains a philosophical question. Yet undeniably advances in science have revolutionarily influenced almost every aspect of medicine including dentistry. It is now exactly one hundred years from Edward H. Angle introduced fixed orthodontic appliances in the early 1900s and established orthodontics as the first dental specialty. Orthodontics has come a long way during its first century. Looking forward to all the challenges and opportunities, it is now time to reflect what science has given to our profession, what for gap still exists between the science and practice in orthodontics, and how we can make science more available to our practice in future.

The effect of a single nucleotide polymorphism in the matrix metalloproteinase-1 (MMP-1) promoter on force-induced MMP-1 expression in human periodontal ligament cells.

Matrix metalloproteinase-1 (MMP-1) 1G/2G (-1,607) polymorphisms have been identified and shown to influence the transcription of the MMP-1 gene. In order to compare the expression of MMP-1 with different MMP-1 gene promoter alleles after force loading, human periodontal ligament (PDL) cells were cultured and genotyped into three alleles by polymerase chain reaction and restriction endonuclease cleavage. The three genotypes of PDL cells were centrifuged and the expression of MMP-1 mRNA and protein were determined by reverse transcription-polymerase chain reaction and enzyme-linked immunosorbent assay. The results showed that centrifugal force upregulated the expression of both MMP-1 mRNA and protein in all three genotypes of PDL cells. The induction of MMP-1 by force was significantly greater in cells with a 2G/2G genotype or a 1G/2G genotype than in cells homozygous for the 1G allele. The MMP-1 mRNA and protein levels were significantly higher for cells with the 2G allele than for cells with the 1G/2G allele or the 1G allele. These results suggest that a single nucleotide polymorphism in the -1,607 bp MMP-1 promoter region might be associated with the difference observed in the endogenous expression of MMP-1 in PDL cells under mechanical force.

Molecular biology and its applications in orthodontics and oral and maxillofacial surgery.

Molecular biology is an exciting, rapidly expanding field, which has enabled enormously greater understanding of the biology of diseases and malfunctions in many fields. It chiefly concerns itself with understanding the interactions between the various systems of a cell, including the interrelationship of DNA, RNA and protein synthesis and how these interactions are regulated. Since the introduction of molecular biology into modern science, numerous other fields have been enabled to go "molecular". Advanced molecular biological techniques showed us new avenue towards finding answers to the questions asked for decades. The first part of this article described the history of molecular biology. It started as a joined discipline of other areas of biology, i.e. genetics and biochemistry in the 1930s and 1940s, and enjoyed its classical period and became institutionalized in the 1950s and 1960s. Major molecular techniques manipulating proteins, DNA and RNA were introduced and their mechanisms were concisely illustrated. The current knowledge of molecular biology and their applications in orthodontic and oral and maxillofacial surgery, i.e. osteoclast differentiation and function, regulation of tooth movement, mechanotransduction/cell-signalling, bone fracture healing, oral cancer as well as craniofacial/dental anomalies and distraction osteogenesis were discussed. Although the problems of introducing molecular technologies are still substantial, it is anticipated that the future of medicine/dentistry will be "molecular": molecular prevention, molecular diagnosis and molecular therapy.

Cell biology in orthodontic tooth movement: the known and the unknown.

This review is aimed at providing, at the cellular level, a concise and complete overview of the important knowledge on the mechanism of orthodontic tooth movement to orthodontists and postgraduates who are involved or interested in basic research. The construction of this article was oriented to the following key questions: Where an osteoclast starts to its first resorption site? When the cascade of a resorption cycle starts? What are the factors involved in bone remodeling and how they orchestrate? What happens before and after the formation of a resorption pit? Major findings in these aspects were summarized and discussed. In addition, related biological phenomenon such as orthodontically induced root resorption was intensively reviewed. By means of an updated and systematic review, the author intended to introduce more biological evidence to orthodontic intervention and to encourage evidence-based treatment in daily orthodontic practice.

[Dentistry and health system in Netherlands].

This study was aimed to introduce the dental education, practice and the health care system in Netherlands. The quality of dental education in Netherlands is quite high. There are three dental schools and recruit about 300 new students per year. Currently there are about 7623 dentists, 283 orthodontists, 203 oral surgeons, 8500 dental assistants and 2000 dental hygienists. In order to be a dentist, one needs to be registered in Individual Health Care Professions Act (BIG). Netherlands is also one of the leading countries in research on professional stress and burn-out in dentistry. This study summarized the main findings of research in this field. The refinement of the health care system in recent years in Netherlands has provided some insight and reference for the ongoing reformation and revolution of the public health system in China.