Effect of Laser Pre-Drilling on Insertion Torque of Orthodontic Miniscrews: A Preliminary Study

PURPOSE: To evaluate the effect of different-sized drill tips and laser irradiation times on the initial stability of orthodontic miniscrews placed in Er,Cr:YSGG-laser pre-drilled holes in an animal model. MATERIALS AND METHODS: Laser pre-drilled holes were made in dog mandibular bone with an Er,Cr:YSGG laser using irradiation times of 5, 7, 9, 11, and 13 seconds, and tip diameters of 0.4 and 0.6 mm. The maximum diameter and depth of the pre-drilled holes was measured with micro computed tomography. The maximum insertion torque was measured during placement the miniscrew. RESULT: Laser pre-drilled holes were conical shaped. The maximum diameter of pre-drilled holes increased with longer laser irradiation times (P>0.05) and larger tip diameters (P < 0.05). The depth of pre-drilled holes increased with longer laser irradiation times and larger tip diameters (P < 0.05). When the 0.4 mm tip, but not the 0.6 mm tip, was used, the insertion torque decreased significantly with longer laser irradiation times (P < 0.05). CONCLUSION: Tip diameter impacted insertion torque more than irradiation time. It takes at least 9 seconds using a 0.6 mm tip to create a 0.8 mm diameter and 1.0 mm depth hole in thick cortical bone.

No Association of TGF-beta Gene Polymorphism with the Progression of Autosomal Dominant Polycystic Kidney Disease(ADPKD) in Korean Patients / 대한신장학회잡지

BACKGROUND: Two genetic loci, PKD1 and PKD2, have been identified as being responsible for ADPKD, and PKD1 is known to be associated with poor prognosis. However, the presence of intrafamilial clinical diversity suggests the presence of disease-modifying loci. Because the mechanism of renal failure in ADPKD includes cystic growth and tubulointerstitial atrophy and fibrosis, we studied the associations between two cytokine gene polymorphisms in the TGF-beta gene, which are known to be related with chronic tubulointerstitial inflammation, and ADPKD progression in Korean patients. METHODS: 47 normal controls and 114 individuals with ADPKD were genotyped by PCR-RFLP, and the TGF-beta gene leader sequence of T869C(Leu10Pro) variant was compared with MspA1I and G915C (Arg25Pro) with BglI. Statistic significances were determined using the Chi-square test. RESULTS: The distribution of alleles for the TGF-beta Leu10Pro polymorphism in ADPKD was : T 52%, C 48%, which was similar to the Korean(56 : 44, p= 0.670) and Western controls(65 : 35), and in addition, no differences were found between the CRF and the non-CRF groups(p=0.571) or the early hypertension and the normotension groups(p=0.252). The distribution of alleles for the TGF-beta Arg25Pro polymorphism was all GG type, which was different from Western controls(90 : 10, p=0.000). CONCLUSION: Our results suggest that the polymorphism at Arg25Pro of TGF-beta in Korean population has different allele distribution from Western, and the polymorphism at Leu10Pro of TGF-beta has no association with the renal progression of Korean ADPKD patients.

Two cases of Pulmonary Alveolar Proteinosis Improved by Whole Lung Lavage / 결핵

Pulmonary alveolar proteinosis(PAP) is a disorder in which an insoluble, proteinaceous material, rich in phospholipid, is deposited on alveoli and bronchioles. Several cases were reported since 1986, and the numbers of patients is increasing in Korea. Although the pathogenesis and causative treatment of PAP is not well known, whole lung lavage is the only consistently successful treatment. We report 2 cases of PAP which were confirmed by open lung biopsy with electron microscopy and clinically improved by whole lung lavage with a review of literature.