مجله دانشکده دندان پزشکی اصفهان
سال هشتم شماره 6 (پیاپی 34، بهمن1391)

The nasal projection should be considered in Cl II patients treatment planning. This study aimed to investigate the morphometric characteristics of the nasal profile in skeletal Cl II patients in a sample of Iranian population. In this random analytical/cross-sectional study cephalometric radiographs of 123 Cl II patient were evaluated using morphometric analysis. The radiographs were superimposed by Procrust superimposition technique and principal component analysis was carried out on 8 nasal soft tissue landmarks and 15 hard tissue landmarks to describe the existing natural tendencies. Multiple linear regression analysis was used to determine the relationship between morphometric characteristics of hard tissue and soft tissue nasal profile. Principal component analysis was carried out using Viewbox 4 orthodontic software and regression analysis was carried out by SPSS 15 software (α = 0.05). Variations of the soft tissue profile of the nose were described by 22 principal components (PCs). The first 7 PCs accounted for approximately 88.5% of the total shape variance. Correlation coefficient of the skeletal and soft tissue components was 35.5%. All Cl II patients have varied nasal forms and there is no significant relationship between skeletal pattern of Cl II patients and their nasal form.Key words:

This study was undertaken to compare the effect of two loss-oriented and gain-oriented messages on improving attitude، intention and oral health-related behaviors among students in Qazvin، Iran. In this randomized controlled trial the subjects were selected by stratified cluster sampling. The participants were asked to complete a questionnaire containing questions on attitude towards toothbrushing and flossing، intention to brush and floss and self-reported frequencies of toothbrushing and flossing behaviors during a week. The subjects were then assigned randomly to gain-oriented (n = 60) or loss-oriented (n = 60) groups and accordingly received pamphlets on the benefits of toothbrushing and flossing and and consequences of not brushing and flossing. The participants were asked to complete the questionnaire again one week after the intervention. Simultaneously، a checklist was completed on oral health behavior. Data were analyzed with ANCOVA and repeated measures ANOVA using SPSS. ANCOVA revealed that participants who were exposed to loss-oriented messages exhibited more favorable attitudes and intentions than those who were exposed to gain-oriented messages (p value < 0. 001). Furthermore، the repeated measures ANOVA indicated that students in the loss-oriented group reported higher frequencies of toothbrushing and flossing behaviors (p value < 0. 001). The study showed that loss-oriented messages should not be ignored. It appears that the loss-oriented messages are more compatible with the collective culture and they result in the promotion of oral health among students and adolescents.

Sometimes repair of indirect composite restorations is preferable to replacement. The aim of this study was to investigate the effect of different surface preparations of indirect composite resin restoration on the shear bond strength of direct composite resin to it. In this in vitro study eighty blocks of indirect composite resin were manufactured and randomly assigned to different surface treatment groups (n = 20): control group (CG)، no surface preparation; group 2، sandblasting with alumina particles (SBG); group 3، acid etching with 9. 5% hydrofluoric acid (HA); and group 4، acid etching with 37% phosphoric acid (PAG). The blocks were restored with direct composite resin and stored in an incubator for 24 hours after thermocycling (500 cycles at 5/55 ± 2°C). The specimens (n = 80) underwent fracture tests in an Instron instrument. Data were analyzed using one-way ANOVA and Tukey test (α = 0. 05). The highest shear bond strength values with a mean of 25. 93 MPa were recorded in group 3 (p value < 0. 001). The lowest shear bond strength values were recorded in groups 1 and 2 with 11. 00 ± 1. 83 and 12. 54 ± 2. 47 MPa، respectively (p value = 0. 097). There were significant differences between all the groups except for groups 1 and 2 (p value ≤ 0. 001). Based on the results، surface treatment technique influences the shear bond strength of indirect composite resin to direct composite resin and the best technique is etching with hydrofluoric acid.

Diet is one of the factors affecting oral health. Recent nutrition transition in Iran has led to increased consumption of high-calorie sources (bread، sugar and fats)، especially in younger people in different levels of education. This study aimed to assess oral health-related dietary knowledge and habits among the students of Isfahan University and Isfahan University of Medical Sciences. This cross-sectional study investigated oral health-related dietary knowledge and habits among 320 students of Isfahan University (in four schools) and 215 students of Isfahan University of Medical Sciences (in five schools) with at least four semesters of study at the university. The study was carried out in the second half of the academic year 2011-2012. After assessing the validity and reliability (ICC > 0. 7) of the self-administered questionnaire، data were collected through distribution in classroom. Descriptive analyses and chi-squared test were applied (α = 0. 05). The results showed that the mean scores for knowledge of students about cariogenicity of different foods and the role of diet in oral health was 31. 2 ± 7 (out of 48) and 4. 7 ± 1. 5 (out of 8)، respectively. Students of Isfahan University of Medical Sciences were significantly more knoeledgeable than the students of Isfahan University (p value < 0. 001). The mean score of their oral health-related dietary habits was 15. 44 ± 4. 3 (out of 32)، with no significant difference between the students of the two universities (p value > 0. 05). Oral health-related dietary knowledge of the students of Isfahan University and Isfahan University of Medical Sciences was generally moderate and their oral health-related dietary habits were poor. Appropriate strategies should be planned to improve oral health-related dietary knowledge and habits among university students.

Dentistry، in particular root canal therapy، is associated with a high level of occupational stress. This research was carried out with the aim of studying the level of occupational stress among endodontists and post-graduate and under-graduate dental students. In this descriptive survey the subjects consisted of endodontists (n = 36) and post-graduate (n = 41) and under-graduate (n = 47) dental students، selected using accessible sampling technique. The research tool was a researcher-made questionnaire on occupational stress during root canal treatment in ten domains. Data were analyzed using one-sample t-test. The results showed that endodontists had stress levels lower than the average (t = -4. 83 tot = -15. 48، p value < 0. 001) in nine domains of endodontic therapy، with average levels of stress in miscellaneous treatment modalities (t = -0. 47، p value = 0. 64). Post-graduate students exhibited stress levels lower than the average in ten domains of endodontic therapy (t = -2. 18 to t = 18. 69،p value < 0. 001) and under-graduate dental students exhibited stress levels lower than the average in nine domains of endodontic therapy (t = -15. 83 to t = 3. 93، p value < 0. 001) except for stress of working on maxillary and mandibular molars and access cavity preparation in special cases (t = 0. 16، p value = 0. 87). Job stress of endodontists and post-graduate and under-graduate dental students in the majority of domains are lower than the average; however، the stress of endodontists in some domains such as miscellaneous treatment modalities، and post-graduate and under-graduate dental students in injection and miscellaneous treatment modalities should be considered.

Temporomandibular joint (TMJ) dysfunction is one of the most common jaw disorders. Corticosteroids are indicated for severe pain in the TMJ، related to inflammatory conditions. The aim of this study was to compare histological effects of intraperitoneal injection of dexamethasone and hydrocortisone on TMJ inflammation in rats.

In this experimental study twenty-seven rats weighing 200-250 g were used. Inflammation was induced by opening the rats’ mouth 20 mm manually once a day for 10 consecutive days. The rats were randomly divided into three groups. Group I rats (n = 3) were left without any treatment; the rats in group II (n = 12) were injected with a single intraperitoneal dose of 1. 2 mg/kg of dexamethasone; the rats in group III (n = 12) were injected 32 mg/kg of hydrocortisone after 11 days. The control rats were sacrificed at 6 weeks، while the rats in groups II and III were sacrificed at weeks 1 and 6 after injection. The groups received scores of 1-11 according to four factors of synovial hyperpelasia، vascularity، fibrin deposits and synovial adhesion. Data were analyzed with Mann-Whitney and Kruskal-Wallis tests (α = 0. 05).

The results of this study indicated statistically significant differences in inflammation severity between the experimental groups of II and III and the control group (p value = 0. 006). There was a significant difference in inflammation severity in group II between week 2 and week 6 (p value = 0. 026).

Intraperitoneal injection of dexamethasone and hydrocortisone was seen to reduce rat TMJ inflammation in the histological evaluation. The greatest inflammatory response was seen in group II six weeks after injection of medicine.

Prevalence of malignancies is different in different communities and different at different times and locations in a community. Epidemiological studies can help recognize high-risk groups. The aim of this study was to evaluate the frequency of oral and paraoral malignancies based on patient age and gender and the area involved and the type of malignancy in one cancer referral center in Isfahan in a 5-year period from 2005 to 2010. In this retrospective descriptive/analytical study، data of 236 oral and paraoral malignancies was collected in a 5-year period from 2005 to 2010، along with data on age، gender and the area involved. The malignancies were divided into epithelial، salivary، hematologic، soft tissue and hard tissue groups based on their origin. Data was analyzed descriptively using SPSS. Oral cavity malignancies comprised 1. 8% of all the malignancies of the period in question. Mean age of patients with oral cavity malignancies was 54 years (56. 5 years in men and 52 in women). Male-to-female affliction ratio was 2. 2. The majority of the lesions were epithelial in origin (72%)، followed by salivary (15%)، hematologic (5. 5%)، soft tissue (2. 9%) and osseous lesions (2. 9%). A total of 20% of lesions had occurred in the larynx، with 17% in the tongue. The most common malignancy was squamous cell carcinoma (SCC) with a prevalence rate of 90% of epithelial lesions. SCC was the most common malignancy، with the highest prevalence rate in 56. 6-year-old males in the larynx and tongue.

Two-dimensional (2D) imaging has limitations in the evaluation of three-dimensional (3D) structures. In recent years، it has become possible to acquire 3D data of patients. This study sought to evaluate the accuracy of linear measurements of the skull made by cone-beam computed tomography (CBCT) technique and digital lateral cephalometry by two newly introduced Galileos and Planmeca machines. In this random descriptive/cross-sectional study، seven anatomical landmarks were determined on seven dry human skulls. Direct measurements on the skulls were made with a digital caliper. Then digital cephalometric radiographs and CBCT radiographs were taken. SPSS Ver. 11. 5 software was used for the data analysis. ICC (Intraclass Correlations Coefficients) test and mean percentage differences was calculated. The mean percentage differences between CBCT technique measurements and those made on dry skulls were less than 1 mm، less than 2 mm and 3 mm in 42%، 42% and 12% of variables. These mean differences between measurements lateral cephalometric images and those on dry skulls were less than 5 mm in 42% of cases and 10‒16 mm in the remaining 42%. The mean ICC values were more valuable in the CBCT technique than those in the digital lateral cephalometry technique. The accuracy of CBCT was much higher than digital lateral cephalometry. No directional magnification or minifying was observed I the CBCT technique.

Elimination of pathogens from root canal system is the goal of endodontic treatment. Cleaning and shaping the root canal system is one of the most important steps in root canal therapy. Irrigation during root canal preparation leads to the elimination of microorganisms that cannot be eliminated by physical methods. In addition، the smear layer created during root canal preparation with hand and rotary instruments should be eliminated by irrigants. This review article summarizes the chemistry، biology and procedures for efficient and safe irrigation and presents information on recent developments in root canal irrigants. In addition، it evaluates irrigants from the viewpoint of their effect on microorganisms and the smear layer. Review report: In this review article، studies were obtained and reviewed by running a search in various databases، including reference books، PubMed، ISI Web of Science، Scopus and Google search engine until 2011 using the terms root canal therapy، irrigant، antibacterial، chlorhexidine، smear layer and sodium hypochlorite.

Several materials have been introduced as root canal irrigants. Although sodium hypochlorite is the most routine irrigant during root canal preparation، it has its limitations and disadvantages like other irrigants and is unable to eliminate the smear layer completely. Therefore، no irrigant can provide ideal properties of a suitable irrigant.

Use of two or more irrigants with an appropriate sequence has been recommended to eliminate microorganisms and the smear layer from the root canal system. Use of chlorhexidine as the final irrigant has substantivity properties.

Microstomia signifies any significant decrease in the size of the oral aperture. The etiology might include disease، trauma، burns and surgical complications in the peri-oral areas. This article describes a practical method for the treatment of a maxillary-edentulous patient with severe microstomia. The patient was a 40-year-old woman who was completely edentulous in the maxilla، with severe microstomia. Due to reduced mouth opening، all the clinical procedures، from selection of a prefabricated tray for initial impression to designing the final prosthesis، are difficult and it is impossible to use a conventional impression tray and denture in such patients. Implant treatment was not possible for the patient because of financial problems; therefore، complete denture was the best choice. A sectional denture that can be worn and removed easily can be a treatment of choice for such patients. The primary impression in this patient was taken by a sectional tray and putty and wash. The special 2-sectional tray was fabricated for the patient. Then a 2-sectional denture was fabricated by ball attachment and finally was assembled in her mouth by palatal strap frame. In the first fallow-up of the patient after 1 year، she was satisfied with the esthetic and function of the denture، in addition to proper fit and stability of denture، without any traumatic injuries. Sectional dentures that are easily worn and removed can be successfully used for the treatment of patients with microstomia. Complete denture، Impression technique، Microstomia.