• Journal of the korean academy of Pediatric Dentistry
• /
• v.41 no.3
• /
• pp.199-206
• /
• 2014

The number of reported traumatic injuries has been increasing in recent years, particularly that of dental trauma in children and adolescents. While the risks associated with dental trauma in this population have been increasingly realized, domestic reports on this issue seem to be insufficient. The purpose of this study was to investigate the prevalence of dental trauma and to evaluate the relevant risk factors and the level of self-recognition. 1,371 adolescents attending middle schools at Yangsan were surveyed via clinical examination and questionnaire; the results were as follows: According to the clinical examination, the overall prevalence of dental trauma was 16.8% with preponderance of males (19.2%) compared to females (13.7%) (p < 0.05). The average number of injured teeth per adolescent with a history of trauma was 1.34. Comparing the prevalence, maxillary central incisors and enamel fracture occupied the highest ranks by tooth type and mode of trauma, respectively. Class II division 1 malocclusion and overjet exceeding 8.0 mm were identified as significant risk factors (p < 0.05). The degree of self-recognition of dental trauma showed a low coincidence rate compared with results of the clinical examination. Males expressed a higher level of satisfaction toward the results of treatment for dental trauma than females (p < 0.05).

• The Journal of Korean Academy of Prosthodontics
• /
• v.44 no.1
• /
• pp.103-111
• /
• 2006

Statement of problem: The previous unilateral bite force recorder has several limitations for taking long time for measuring and causing discomfort to subjects. Because of these reasons, it could not use widely for epidemiological researches. However, 'Dental Prescale System' which is new equipment for measuring bite force, is more convenient for measuring bite force than previous unilateral recorder. Purpose: The purpose of this study was to compare a new technique(Dental Prescale System) using pressure sensitive foils for recording of maximal jaw closing force with conventional measurement using unilateral bite force recorder Material and method: This studies included 22 healthy dental students in college of dentistry Yonsei university in Rep of Korea. Mean age was 23.9 years. All subjects had continuous dental arches and no significant malocclusion or signs from the teeth and craniomandibular system. The Dental Prescale System (Fuji Film, Tokyo, Japan) consists of a horseshoe-shaped pressure sensitive sheet (50H, R type) and a computerized scanning system.(FPD705) We also used unilateral bite force recorder(Denbotics Co. Seoul, Rep.Korea) for comparing with Dental Prescale. Results and conclusion: The total bite force recorded with Dental Prescale System (1423 N) was systematically higher than that recorded by unilateral bite force recorder. (256 N) However, the maximum bite force values measured in the two ways were significantly correlated (r=0.46, p<0.05). The Dental Prescale bite force calculated for first molar (208 N) was lower than that recorded by unilateral bite force recorder. (256 N) The two values were also very significantly correlated. (r=0.66. p<0.001) There were significantly different in bite force between two measurement methods. The reasons were first, unilateral bite force recorder measured only the bite force of a part of teeth, and Dental Prescale measured the total teeth force. Second, in measurement, a difference in muscle contraction appeared by an extent of mouth-opening. Third, unilateral bite force recorder has the reducing effect of the bite force by protective tape. Fourth, Dental Prescale has limitations during the computer scanning procedure. Therefore, Dental Prescale System is considered to be a very promising alternative to be conventional bite force recording methods.

• The korean journal of orthodontics
• /
• v.33 no.1 s.96
• /
• pp.1-9
• /
• 2003

The purpose of this study was to find out and evaluate discrepancies between preorthodontic prediction values and actual postorthodontic values and factors contributing to it in 45 patients(17 male, 28 female) who were diagnosed as skeletal Class III ma)occlusion and received presurgical orthodontic treatment and orthognathic surgery at Yonsei university dental hospital. Lateral cephalograms were analysed at pretreatment(T1), orthodontic Prediction(T2), immediately before surgery(T3) and designated the landmark as coordinates or X and Y axes. The samples were divided according to ALD, upper and lower incisor inclination(Ul to SN, IMPA), COS, extraction, the position of extracted teeth and the statistical significance was tested to find out the factors contributing to the prediction. The results were as follows: 1. Differences between preorthodontic prediction values and actual postorthodontic values(T2-T3) were statistically significant(p<0.05) in the x coordinates of U6mbc, L1x and in y coordinates of U1i, U1x, U6me, U6mbc, L6mbc 2. The accuracy of prediction is relatively higher in horizontal changes compared to vortical changes. 3. The statistical significance(p<0.05) between prediction and actual values is observed more in the landmarks of the maxilla than the mandible. 4. Differences between prediction and actual values of incisor and first molar were statistically significant(p<0.05) according to extraction vs non-extraction, extraction type, ALD in the maxilla and according to ALD, IMPA in the mandible. Discrepancies between preorthodontic prediction values and actual postorthodontic values and factors contributing to the prediction must be considered in treatment planning of Cl III surgical patients to increase the accuracy of prediction. Furthermore future investigations are needed on the prediction of vortical changes.