Although common cold is a major cause of morbidity among university students, studies on the risk factors in relation to physical, social, emotional life styles among university students are limited. We sought to evaluate the effects of life style, depressive symptoms, and social support in common cold among medical school students.

120 medical students were surveyed through a self-reported questionnaire. They were asked to rate the severity of eight respiratory symptoms of the Jackson Criterion during the previous month. The ratings were summed to calculate the total symptom score. Social support was assessed by using Interpersonal Support Evaluation List(ISEL). Depressive symptoms were assessed by using The Center for Epidemiologic studies Depression Scale(CES-D). A score of 16 or higher was used as the cut-off point for high depressive symptoms. Life style factors were also evaluated. that Wilcoxon rank sum test, Kruskal-Wallis test, Chi-square test, and logistic regression test were used.

The symptom score ranged from 0 to 18 and the median was 10 among those who had experienced symptoms. 33(34.4%) had experienced cold during the last month. The social support score ranged from 91 to 156 and the median was 113. The prevalence of high depressive symptoms was 36.7%. Students with lower social support and higher depressive symptoms had higher cold symptom scores, although it was not statistically significant. Students who had evaluated their sleep quality and health status as bad had higher cold symptoms scores. In multiple logistics regression analysis, depression, sleep quality, and self-perceived health status were either significant or border-line significant risk factors of cold.

Our study suggests that life style factors such as sleep quality and self-perceived health status is associated with an increased susceptibility to common cold.

This study was performed to evaluate the effect of autogenous iliac particulated marrow cancellous bone graft on osseointegration of implants in the dog tibia which has a loose bone marrow.

Three mongrel dogs, weighing about15kg or more, and RBM(resorbable blasted media) AVANA® implants(Osstem Inc., Korea) were used in this study. In the control groups, 2 implants sites were prepared conventionally with drills in the left metaphysic of tibia and 2 implants were placed in each dog under general anesthesia. In the experimental groups, 2 implant sites were prepared with drills. and the particulated marrow cancellous bone, which was obtained from the right ilium,was packed into both prepared sites with osteotomes in the right metaphysic of tib-ia in each dog. Two implants were placed. A total of 12 implants were placed in 3 dogs. The animals were sacrificed at 8 weeks after implant placement. The specimens were taken and embedded into the resin. H & E stain was done. The undecalcified specimens were prepared for histological examination and histomorphometric analysis of bone-implant contact ratios. The Mann-Whitney test was used to compare both groups.Values of p<0.01were considered statistically significant.

In the cross-sectional radiographs of the control group no trabecular bone was observed in the marrow space and the implant was surrounded with radiolucent marrow space. In the experimental group Some radioaque trabecular bone was observed in the marrow space of tibia and some of the trabecula was contacted with implant surface. Histologically,in the control group few trabecular bone was observed in marrow space and there was poor osseointegration in the marrow. In the experimental group most marrow space was filled with the trabecular boneand the implant surface was contacted with trabecular bone. In histomorphomeric analysis the bone-implant contact ratio of the experimental group(75.6%) was significantly higher than that of the control group(27.1%, p<0.01).

The autogeneous bone graft into the loose bone marrow can be an option to improve the bone density and to get better osseointegration of dental implants.