[Radiographic assessment of upper airway size in skeletal sagittal and vertical jaw discrepancies]

An important factor in the process of diagnosis and orthodontic treatment planning is patient's respiratory function that has a direct correlation with the upper airway size. The aim of this study was to measure and compare nasopharyngeal, oropharyngeal and hypopharyngeal airway volumes in Iranian subjects with sagittal [Class I, II and III] and vertical [normodivergent, hyperdivergent and hypodivergent] jaw discrepancies using standard cephalometric radiographs. In this descriptive cross-sectional study, 100 pre-treatment lateral cephalograms of orthodontic patients were evaluated to assess the size of upper airway space including the nasopharynx, oropharynx and hypopharynx. In order to assess airway dimensions in patients with sagittal and vertical discrepancies, subjects were divided into two large groups of normal sagittal and normal vertical patterns. Airway size was measured in sagittal plane in 50 subjects with normal vertical patterns and in vertical plane in 50 subjects with normal sagittal patterns. Linear variables i.e. the size of nasopharyngeal space [PNS-UPW], oropharyngeal space [U-MPW] and hypopharyngeal space [V-LPW] were measured by cephalometric tracing. Data were analyzed using SPSS version 15 software and chi-square, ANOVA and Tukey's HSD tests. Understudy subjects had normal age and gender distribution pattern. In patients with normal sagittal pattern, by an increase in vertical dimension, size of nasopharynx [PNS-UPW], oropharynx [U-MPW] and hypopharynx [V-LPW] decreased and the mentioned volumes were significantly smaller in subjects with hyperdivergent facial patterns compared to hypodivergents. In subjects with normal vertical pattern, by an increase in ANB angle, size of oropharynx [U-MPW] and hypopharynx [V-LPW] decreased and the mentioned volumes in CL II patients were significantly smaller than in CL III subjects; whereas, the largest nasopharynx [PNS-UPW] was observed in CL I subjects. Sagittal and vertical discrepancies affect upper and lower airway dimensions and by an increase in facial height, the mentioned volumes decrease. Smaller ANB angle results in larger airway dimensions

Orthodontic tooth movement and root resorption after different doses of celecoxib drug treatment in rats

Non- Steroidal Anti Inflammatory [NSAIDs] medications used for treatment of pain related to orthodontic treatment could slow down tooth movements. Selective cyclooxigenase- 2 inhibitors are alternatives to conventional non steroidal drugs. The aim of this study was to compare three different doses of Celecoxib on orthodontic tooth movement and root resorption in Rats. Forty male Rats randomly divided into the following groups; D [the application of orthodontic appliance with taking medications]; E [without any intervention] and experimental groups included A [received 25 mg/kg], B [received 50 mg/kg] and C [received 100 mg/kg] dose of Celecoxib. NiTi coil spring was ligated between the right side maxillary incisor and 1[st] molar. The animals were sacrificed after two weeks and distance between 2 teeth was measured with Caliper. After preparation of histological sections, amount of root resorption, numbers and maximum depth of resorption lacunae in mesial root surfaces of molar was measured. Data were analyzed with ANOVA, LSD and Tukey HSD. The maximum tooth movement was found in group A [0.8537 mm], D, C, B and E respectively. Statistical analysis did not show any significant difference between the different doses of Celecoxib drug in tooth movement. The usage of Celecoxib [particularly in higher doses; 100 mg/kg] decreased the number of resorption lacaunae in mesial root of first maxillary molar [P< 0.05]. 100 mg/kg dose of celecoxib was found to be optimum for the lowest effect on tooth movement and the most protection against root resorption

In vitro study on the solubility of zinc phosphate and polycarboxylate as orthodontic band cements

Different cements are used to attach orthodontic bands which require special considerations in terms of technique sensitivity during setting reaction, water solubility and decomposition over time each of which may result in attachment failure, decalcification and caries in long term. This study was designed to assess the weight changes of different zinc phosphate and polycarboxylate cements used in orthodontics. An experimental study was designed to compare two available conventional cements [zinc phosphate and polycarboxilate] in the department of dental materials, SBMU School of Dentistry, Tehran, Iran. The cements were categorized according to ADA 8 index and the data were analyzed with electronic balance. Weight variations were recorded after 6 weeks floating the samples in water and data were subjected to analysis using Repeated Measured ANOVA test. There was the maximum mean value of weight loss for Aria Dent zinc phosphate cement and the least with Adhezor zinc phosphate within the period of study. Regarding plycarboxylate cement, Aria Dent polycarboxylate displayed the greater weight variation over the time compared to other conventional cement and the minimum value of weight loss was for Durelon cement. It is concluded that Aria Dent zinc phosphate and polycarboxylate cement display greater weight variations over time compared to other conventional cements

Study motives and career plans of postgraduate students in dental School, Shahid Beheshti University of Medical Sciences

Nowadays, there is great emphasis on the commitment of dentists as health care workforce, thus, awareness of their motivations and expectations is important in order to promote general and oral health. The aim of the present study was to evaluate dental post graduate student s motivations and career choice plans in relation to sex, marital status and parent s education in Shahid Beheshti University of Medical Sciences, Tehran, Iran in 2009-2010. A total of 1 16 dental post graduate students have been participated in this survey and a valid and reliable questionnaire was designed in three sections based on previous studies consisting of motivations and career choice plans and was distributed among them. Data were entered in to SPSS [16] and were analyzed with Mann Whitney test. Social/occupational prestige was the most important motivation [%92]. On the other hand, there was significant association between motivations and career choice plans with marital status and parent s job as dentist/physician. Influence of family had significantly more impact among residents who had dentist/physician parents compared to those with parents in other occupations [p=0.01 1] [%65]. The most important career choice plan was to work in private sector [94/84%]. The married people were inclined to constitute a professional dental clinic with colleagues [p<0.0037] [%86]. Single students had more interest in research in the field of dentistry [p=0.047]. The most important motivations were social/ occupational prestige, income, independence and personal interest in dentistry respectively. The most important career choice plans were working in private sector, recruitment in university as dental faculty and constitution a professional dental clinic with colleagues