The Journal of the Dental Association of Thailand最新文献

The removable bite jumping appliance with lower lip bumper is a new orthodontic appliance designed to correct the abnormal habit of lower lip biting children with mentalis muscle hyperactivity. Upper anterior teeth protrusion, mandible retrusion, lower anterior teeth lingual collapse and anterior deep bite usually are found in association with this lower lip biting habit, especially in the mixed dentition period (7-12 yrs). The function of this appliance is similar to the partial functional appliance. It is made into two parts: upper removable plate with anterior inclined bite plane and lower lip bumper attached to the upper plate. Three cases are discussed and compared before and after treatment. Changes in both skeletal and dental pattern were recorded in the following aspects: increase in the posterior rotation of mandible (increased SN-MP), stimulation of forward growth of the mandible (the increase is SNB value overcomes the increase in SNA, through reduction ANB), retroclination of upper maxillary teeth (reduced 1-NA), proclination of lower anterior teeth (increased 1-NB), the reduction of overjet. Additionally, the normal position of the lower lip provided by this appliance effectively corrects the lip biting with mentalis muscle hyperactivity.

One method to prevent cross-contamination in dental clinic is to immerse the impressions in disinfectants before making master models. This study to evaluate the effect of disinfectants on dimensions of the elastomers namely polyether, condensation silicone, addition silicone and polysulfide, the disinfectant used in this study is 1% Sodium hypochlorite, 0.13% Sporicidin and 10% Gigasept. Being left under room temperature and immersed in distilled water are two types of controls. Dimensional changes can be measured on master model and compared with the brass standard model. The study reveals that the three disinfectants have no effect on vertical dimensions of all four elastomers but have statistically effect on horizontal dimensions of only polyether (p less than .05). It concludes that all the elastomeric impressions except polyether should be immersed in disinfectants before making master models.

Median diastema in twenty patients aged 17-30 years old were restored randomly with two light cured composite resins. The restoration were assessed and compared after one year for colour changing, gingival inflammation, surface chipping and lost of restorative materials. There have no difference in colour changing of the two materials on the tooth surface (p = 0.01), and there have no difference in the inflammation of the gingiva surrounding the two materials (p = 0.01). These two materials have no difference in adhering to the tooth surface (p = 0.01).

The project was designed to study the accumulation of calculus on the tooth surface in school children. One hundred and twenty two 10-15 years of age school children in both sexes were participated in the study. They were evaluated by a dentist for the presence and quantity of calculus deposits on the labial and lingual surfaces of the lower six anterior teeth using Volpe-Manhold calculus scoring method. The subjects were divided into three groups according to their calculus scores as "slight" (10-25 mm.) "moderate" (26-40 mm.) and "heavy" (greater than 40 mm.). Then all subjects received a complete oral prophylaxis, including the removal of all subgingival and supragingival deposits. At six months and twelve months after oral prophylaxis all subjects were evaluated for the calculus deposition by the same dentist. The results revealed that redeposit of calculus at six and twelve months of the three groups were statistically different (p less than 0.05). The "slight" calculus group had the calculus deposit, after oral prophylaxis, less than the "moderate" and the "heavy" group. The "heavy" group had the calculus deposit much more than the "moderate" group.

This study was based on the examination of 726 amalgam restorations of the permanent molar teeth, 331 teeth from boys and 395 teeth from girls. The age distribution of amalgam restorations was 6-30 months, and the age of children was 6-12 years when teeth to be filled. The purpose of the study was to assess the prevalence of recurrent caries of teeth restored and quality of amalgam restorations rendered by dentists. The results showed that the age of majority of children whose teeth restored was 9 years old, 28.7 percent of all. 91.1 percent of the restorations were one surface fillings, 68.30 and 22.8 percent were occlusal and other single surface respectively. The recurrent caries found in both fracture and sound fillings were 19.42 percent. The rate of fracture was 48.10 percent and increased with the increasing age of restorations. At 19-24 months the fracture rate was highest, 54.1 percent. The defect of surface was 51.52 percent, that did not increase with the increase of restoration age. A statistically significant correlation was found between the defect of surface texture and fracture of restoration.

Excessive occlusal force caused by deep bite is an etiology of alveolar bone resorption as well as premature loss of permanent teeth. Deep bite correction in adult patients should comprise of intrusion and/or proclination of anterior teeth in order to prevent skeletal alteration and relapse. The objective of the article was to present indication and mechanics of intrusion and proclination of anterior teeth with a case report of the patient who had a problem of masticatory system especially temporomandibular joint, cuspid protection system and deep bite.

Actinobacillus actinomycetemcomitans and Capnocytophaga are subgingival bacteria that have correlation with juvenile periodontitis. Studies were carried out in a group of 20 patients with juvenile periodontitis before, after treatment by scaling, root planing, oral hygiene instruction and 20 patients with healthy gingiva as a control group. Gingival index, plaque index, pocket depth were measured. Subgingival bacteria were counted on selective media and compared by phase contrast microscopy. Before treatment all measurements in the patients and the control group were significantly different (P less than 0.05). In the patients before and after treatment all clinical measurements were significantly different (P less than 0.05) but the amount of A.actinomycetemcomitans and Capnocytophaga were not significantly different (P greater than 0.05). These results indicate that treatment of juvenile periodontitis by scaling, root planing and oral hygiene instruction improve the clinical measurements but are not effective in reducing proportions of subgingival bacteria.

Scleroderma is a systemic disease that not only causes pathology in several organs but also has interesting oral manifestations. The patients could come to see dentist due to abnormalities in oral cavity or complications from the progression of the disease. The purpose of this article is to update information about scleroderma in order to assist dentist in diagnostic process and dental treatment.

Although systemic and topical fluoride together with sealant can be used to prevent dental caries efficiently. There are three more procedures of preventive dentistry in children which dentists should educate parents and children along with the first two routinely. The reasons, problems and techniques of dental health education in plaque control, diet and infant oral health counseling will be reviewed in this article.

The use of Ketalar as a general anesthetic in dental treatments particularly in extractions of unco-operative children of 2-5 years was studied. By monitoring the vital signs (blood pressure and heart rate) during the operations, it was found that reducing the Ketalar dose to 0.5-0.7 mg/Kg (usual dose is 1-2 mg/Kg) did not give rise to any unfavorable consequences. In more than 600 children during the past 12 years, there were no serious dangers with the Ketalar usage; however, some toxic or side effects of the anesthetic had to be cautioned.