Crevicular alkaline phosphatase activity during the application of two patterns of orthodontic forces.

OBJECTIVE: The objective of this study was to test the hypothesis that using a gradually increasing orthodontic force would induce an increased activity of osteoblasts compared to a relatively constant orthodontic force. PARTICIPANTS AND METHODS: Twelve orthodontic patients participated in this study. In a split mouth design, one maxillary canine undergoing distal movement received a relatively constant continuous retraction force, while the contralateral canine received a gradually increasing retraction force. Gingival crevicular fluid (GCF) samples were collected from both experimental sites at weekly intervals and analysed spectrophotometrically for the activity of alkaline phosphatase enzyme, which was used as a biological marker for osteoblastic activity. RESULTS: With the exception of the maxillary first molar receiving gradually increasing orthodontic force, the results revealed a consistent pattern of alkaline phosphatase activity. This pattern included an initial rise from baseline to the first week, then a peak in the second week. This peak was followed by a reduction in enzyme activity in the third week. The overall increases in enzyme activity at the maxillary canines and the maxillary first molars in the relatively constant force group were 179·76% and 332·90%, respectively. The overall increases in enzyme activity at the maxillary canines and the maxillary first molars in the gradually increasing force group were 304·81% and 493·08%, respectively. CONCLUSION: The use of gradually increasing orthodontic force induces increased activity of osteoblasts during the initial stage of orthodontic tooth movement compared to that induced by a relatively constant orthodontic force.

Optimal waist circumference cutoff points for the determination of abdominal obesity and detection of cardiovascular risk factors among adult Egyptian population.

OBJECTIVE: To determine the best anthropometric measurement of obesity, and its optimal cutoff, that best predicts the presence of cardiovascular risk factors among adult Egyptian population. METHODS: This is a cross-sectional study including a representative randomly chosen sample of the adult Egyptian population from all Alexandria Districts (the second largest governorate in Egypt) based on the multistage random technique. It included 3209 subjects (1567 men, 1642 women) aged 18-80 years from urban and rural areas. The response rate was 80.2%. History, blood pressure, and anthropometric measurements were taken. Laboratory investigations included fasting lipid profile, fasting plasma glucose, and serum uric acid. Different criteria of metabolic syndrome were used and compared. Receiver operator characteristic curve and Youden index were used to determine predictability and cutoffs. RESULTS: Waist circumference (WC) is the best to predict at least two other components of the metabolic syndrome as defined by the International Diabetes Federation (IDF). The optimal WC cutoffs were 100.5 and 96.25 cm for Egyptian men and women, respectively. The Joint Interim Statement definition (JIS) of metabolic syndrome was the best to predict cardiovascular disease in both genders and diabetes mellitus in women. The prevalence of metabolic syndrome and abdominal obesity was 42.5%, 61%, respectively (ATPIII definition); 43.8%, 61% (American Heart Association definition); 44.3%, 76.4% (IDF definition); 33.8%, 51.7% (IDF definition with Egyptian cutoffs); and 41.5%, 51.7% (JIS with Egyptian cutoffs). CONCLUSION: WC cutoffs in Egyptians differ from those currently recommended. Prevalence of metabolic syndrome and abdominal obesity is high in Egypt, despite being lower on using the Egyptian cutoffs.