A novel 3D scan method to quantify teeth wear / 대한치과보철학회지

STATEMENT OF PROBLEM: Tooth wear is physiological phenomenon. Ninety-seven percent of normal people have tooth wear and about 7% has pathologic teeth wear. If we know the amount of tooth surface loss caused by pathologic tooth wear, we may restore it ideally. PURPOSE: Recently, measurement of tooth wear by using 3D scan has been increasing. Therefore, we need to know how accurate 3D scan is. Past accuracy test on 3D scan was about linear change, but as we know that tooth wear is volume change. Thus, the purpose of this study is to know how accurate 3D scan is. MATERIAL AND METHODS: For accuracy test of 3D scanner, volume values measured by 3D scanner and micro-balance were compared. For test I, preliminary, 3 ball samples and 3 circular cones were made with pattern resin. For test II, 10 teeth shape rubber samples were used. RESULTS AND CONCLUSION: 1. The result of the accuracy test on 3D scan with 3 ball samples and 3 circular cones made of pattern resin has no significant difference(p<0.05). 2. The result of the accuracy test on 3D scan with 10 samples of tooth shape rubber has no significant difference(p<0.05). As a result, we may concluded the analysis of quantifying tooth wear used by 3D scan is useful in the clinic.

Relation Among Parameters Determining the Severity of Bronchial Asthma / 결핵

BACKGROUND: International consensus guidelines have recently been developed to improve the assessment and management of asthma. One of the major recommendations of these guidelines is that asthma severity should be assessed through the recognition of key symptoms, such as nocturnal waking, medication requirements, and objective measurements of lung function. Differential classification of asthma severity would lead to major differences in both long term pharmacological management and the treatment of severe exacerbation. METHODS: This study examined the relationship between the symptom score and measurements of FEV1 and PEF when expressed as a percentage of predicted values in asthmatics(n=107). RESULTS: The correlation of FEV1% with PEFR% was highly significant(r=0.83, p<0.01). However, there was agreement in terms of the classification of asthma severity in 76.6% of the paired measurements of FEV1% and PEFR%. Agreement in the classification of asthma severity was also found in 57.1% of the paired analysis of FEV1% and symptom score. 39% of the patients classified as having moderate asthma on the basis of FEV1% recording would be considered to have severe asthma if symptom score alone were used. Low baseline FEV1 and high bronchial responsiveness were associated with a low degree of perception of airway obstruction. CONCLUSION: The relationships between the symptom score, PEFR and FEV1 were generally poor. When assessing asthma severity, age, duration, PC20, and baseline FEV should be considered.