ISSN : 0376-4672
Introduction: The aim of the current study was to describe the prevalence and treatment of mandibular first molar eruption disturbances. Methods: A total of 38 mandibular first molars(M1mn) from 36 patients(17 males and 19 females; aged 9 years 2 months?35 years 10 months) were identified from the 13,391 patients that received orthodontic treatment from 1983?2012. The subjects were classified into 3 categories based on panoramic radiographic examination: impaction due to ectopic position of the tooth germ relative to the contra-side same tooth(Group 1), impaction due to obstruction of the eruption path with cyst or calcium mass (Group 2), and primary and secondary retention due to defects in the follicle or periodontal ligament(PDL; Group 3). The treatment outcomes were evaluated into four categories: no treatment(A), orthodontic traction(B), autotransplantation(C), and extraction due to orthodontic traction failure(D). Results: The prevalence rate of M1mn eruption disturbances in this sample was 0.27%. In Groups 1 and 2, most of the impacted M1mn were erupted successfully by orthodontic traction. In Group 3, most of the retained M1mn were failed to erupt and recommended for extraction. Conclusions: Treatment prognosis was favorable on Group 1 & 2 than Group 3. After removing an element of the cause in case of Group 1 & 2, orthodontic traction or periodic observation will be recommended.
The aim of the study was to analyze the distribution of dental filling materials for carious permanent teeth of school children in a city. The study was designed as time-serial study, using the data of the dental survey for children aged 8-, 10- and 12-year children living in Gimhae city. The samples were selected by stratified clusters sampling. The number of surveyed samples in depth-analysis for types of dental filling materials were 567 in 2009 and 331 in 2013, respectively. They had dental restorations on one or more teeth. The changing pattern of used dental filling materials was analyzed between 2009 and 2013. Statistical analysis was conducted according to variables related to dental filling material type; DMFT and DMFS index, number of fissure sealed teeth and surface and surveyed year. Amalgam filling rate decreased from 27.9% in 2009 to 18.8% in 2013, while filling rate of tooth-colored materials increased from 56.1% in 2009 and 68.9% in 2013. Amalgam filling rate was a negative correlation with filling rate of tooth-colored materials or gold and number of fissure sealed teeth and a positive correlation with DMFT index. Filling rate of tooth-colored materials was a negative correlation with filling rate of amalgam or gold and DMFT index and a positive correlation with number of fissure sealed teeth. The light-curing composite resin should be included in the reimbursement range of National Health Insurance to solve an inequity of dental health care services.
Teeth are made up of three hard tissues, enamel, dentin, and cementum. The dental pulp is the only non-mineralized connective tooth tissue that is surrounded by dentin. The dentin-pulp complex is able to respond to injury by producing hard tissue deposition. However, dentin is considered one of the most difficult tissues to regenerate because of its unique anatomic and physiologic nature. Recently, advances in understanding the applicability of bio-active dentin regenerating proteins are emerging with the development of biological-based therapies using bio-active materials. Dentin defects were regenerated by the deposition of tubular physiologic dentin after application of the bio-active protein in a beagle dog model. Therefore, the bio-active protein may be able to serve as a novel dentin regenerating material and improve symptoms of dentin hypersensitivity.
Nowadays, there has been an increasing interest in the preservation of natural dentition and the proper occlusion related to tooth wear for quality of life. Tooth wear means the loss of tooth enamel structure. This is happened by many causes which is the combined effects of many mechanisms. For keeping proper occlusion, dentists should check tooth wear status with acceptable methods and tools for the proper diagnosis. Until now, there have been many traditional qualitative ways to measure tooth wear which are intuitive, rapid, and simple. On the contrast, they are not objective nor reproducible. With the development of related technique, new quantitative methods using CAD and 3d scanners. This article aimed to introduce qualitative and quantitative methods for tooth wear measurements.
In clinical dentistry, botulinum toxin is generally used to treat the square jaw, bruxism, and temporomandibular joint diseases. Recently, this procedure has been expanded and applied for cosmetic purposes, and it is becoming a key task to be aware of the precise anatomical structure of the target muscles to be cautious during treatment and how to prevent side effects. Therefore, the purpose of this study is to observe the anatomical structure of the superficial layer of masseter muscle and to provide a most effective botulinum toxin injection method through clinical anatomical consideration. It was observed that the muscle belly of superficial part of the superficial layer was originated from the deep to the aponeurosis of masseter muscle and descend, then changed gradually into the tendon structure attaching to the inferior border of the mandible. In this study, we named this structure deep inferior tendon. This structure was observed in all specimens. We conclude that the use of superficial layer and deep layer injection should be considered to prevent paradoxical masseteric bulging in consideration of the deep inferior tendon of superficial part of superficial layer of masseter muscle.
