To determine the accuracy of Pederson and Parant Scale for predicting the difficulty level of mandibular third molar extraction. Prospective cross-sectional, 6 months from January 2012 to June 2012. All consecutive patients who presented for the extraction of impacted third molars were included in the study. Orthopantomograms (OPGs) were advised and on these OPGs third molars were classified as easy, moderate or difficult according to standard Pederson scale. Similarly modified Parant scale was utilized to predict the difficulty of removal of third molars. Root pattern was also noted on the OPG. These parameters were then compared with peri-operative parameters like time taken for extraction and need for crown or root sectioning using Chi Square test. A p value of <0.05 was taken as significant. A total 50 patients were included in the study. Out of these 24 were males and 26 females with a male to female ratio of 1:1.08. The age ranged from 18-38 years with a mean of 26.32±5.43 years. The pre operative predictions for Pederson’s and Modified Parant’s Score were compared with per operative findings using Chi-Square test. The results were insignificant in terms of Pederson Scale (p value>0.05) while significant results were obtained in case of Parant Scale (p value<0.05). Statistically significant results were seen for root pattern and level of difficulty (p value<0.05). These scales failed to predict difficulty level of tooth removal accurately especially in cases of distoangular impactions. When combined with root pattern, the accuracy of prediction gets significantly better.

BACKGROUND:Angiotensin-converting enzyme as a key enzyme of the renin-angiotensin system, through the degradation effects of substance P mechanism, is involved in the occurrence and development of Alzheimer’s disease.
OBJECTIVE:To research the relationship between angiotensin-converting enzyme gene polymorphism and Alzheimer’s disease in Jiamusi region, as wel as the effect of gender and hypertension on the relationship.
METHODS:This case-control study included 96 Alzheimer’s disease patients. Another 102 subjects served as controls coming from the same area and in the same environmental condition. DNA segments were amplified using PCR in 20 g/L agarose gel electrophoresis and observed under ultraviolet lamp. II, ID, DD genotypes and genotype frequencies were calculated for statistical analysis. On this basis, according to clinical data col ected, we investigated association of Alzheimer’s disease with hypertension and gender.
RESULTS AND CONCLUSION:There was significant difference between Alzheimer’s disease patients and controls in angiotensin-converting enzyme genotypes and al ele frequency. There was statistical y significant difference between Alzheimer’s patients with hypertension and controls in angiotensin-converting enzyme genotypes and al ele frequency. There was no statistical difference between Alzheimer’s disease patients with different genders and controls in angiotensin-converting enzyme genotypes and al ele frequency. These findings indicate that there are some relationships between angiotensin-converting enzyme polymorphism and Alzheimer’s disease. II genotype is a risk factor for Alzheimer’s disease, angiotensin-converting enzyme II genotype is a risk factor for Alzheimer’s disease with hypertension.