[Lip position and arch width changes in class I patients after orthodontic treatment with four premolars extracted]

Tooth extraction is one of the most controversial subjects in orthodontics due to its inevitable effects on facial esthetics, and smile characteristics. The aim of this study was to evaluate lip position in relation to S-line and Snpog', Merrifield Z angle, as evaluating well as upper and lower arch widths in canine, premolar, and molar regions following four premolar extraction in class I malocclusion patients. Pre and post lateral cephalograms and dental casts of 47 class one malocclusion patients including 43 girls and four boys with the mean age of 12.7 +/- 1.86, treated by the same practitioner were used in this study. All patients had four first premolar extraction, and orthodontic treatment was performed with 0.22 slot standard edgewise appliance. Convenient improbable sampling was used in this cross sectional study. The distance of the most prominent points of lips from S-line and Sn-Pog', and Z-angle values were measured on lateral cephalograms. Upper and lower arch widths in canine, premolar and molar regions were also measured by a digital caliper on dental casts before and after treatment. To compare the changes, paired t-test with 0.05 significance level was used. Following orthodontic treatment with four premolar extraction, dental arch widths in upper and lower arch increased in canine region [p<0.001], but it was decreased in premolar and molar regions significantly [p<0.001]. It was also observed that, the lips were retracted significantly with reference to S-line and Sn-Pog' [p<0.001], and Z-angle was also increased [p<0.05]. Orthodontic treatment with four first premolar extractions in class one malocclusion patients resulted in: 1. Increase in upper and lower arch width in anterior region, and decrease in posterior region. This means that, first premolars extraction in Class one malocclusions does not increase buccal corridor width, and consequently have no adverse effects on smile esthetics. 2. More posterior position of the lips related to S-line and Sn-Pog' as well as increase in Zangle leading to more straight profiles in patients

[Neonatal survival rate and its related causes in NICU of private and governmental hospitals in Sari by survival analysis technique during 2005-2007]

Many children younger than 1 year old [about 4/000/000] are dying annually around the world, that three quarters of this mortality is related to neonatal period [4 weeks after birth]. Several factors such as environmental conditions, social and genetic factors are causes of decreasing neonatal mortality. The aim of this study was to determine the neonatal survival rate and its related causes in NICU of private and governmental hospitals in Sari. This survival analysis was a descriptive study of 500 neonates who were admitted into NICU of private and governmental hospitals [Booali Sina, Nimeyeh Shaban, Amir-Mazandarani, and Shafa Hospitals] in Sari during 2005 to 2007. Data was gathered by using Self-making Informational Form [validity and availability was confirmed by content validity and alpha- kronbach]. Information were obtained by interview with mothers, study of patient's chart, observation of the neonates, or phone interviews, after being discharged from the hospital. Statistical analysis of data was done by using Kaplan-Mayer survival analysis technique, and survival tables. Furthermore, risk factors were determined by logistic regression. Three-hundred twenty six neonates [65.2%] were the first rank of birth. Sixty-three mothers [12.6%] experienced previous neonatal mortality. 217 of mothers [43.4%] were illiterate and 85 [17%] had diplomas or higher education. 119 neonates [23.85] died within 28 days of life. There was a relationship between higher education level of mothers, polyhydraminous [over production of amniotic fluid according to sonography report], and delivery method, neonatal weight at birth, congenital anomalies, and neonatal survival rate. Eighty-seven expired neonates [73.1%] had birth weight lower than 2500gr, and 21 [16.8%] had gestational age lower than 36 weeks. The survival rate was higher among neonates within 21 and 22 days of life. The mortality rate among neonates with 2 to 3 days of life was higher than the other age group. We have not achieved adequate success in comparison with other developed countries in the improvement of neonatal survival rate during low gestational age. On the other hand, the physical and cognitive abilities of neonates were not evaluated in this study. We recommend further studies with more samples for assessment regarding survival rate of the neonates without disability