Journal of Dental Medicine

Background and Aim: Preserving canal curvature during different phases of canal preparation is an important point. In Endodontic therapy all efforts are made to prepare canal in a way that final canal follows the primary canal curvature. The purpose of this study was to evaluate the efficacy of root canal preparation performed by students at Endodontic Department of Dental School, Tehran University of Medical Sciences.

Materials and Methods: In this retrospective study, classic method of step- back technique was investigated for preserving canal curvature in mesial roots of first mandibular molars and mesiobuccal roots of first maxillary molars between years 2000 and 2004. A randomly selected sample of 400 dental patient records was investigated by 4 observers (Endodontic department professors), searching for procedural errors. A clear explanation sheet of curvature preservation and procedural errors such as ledge formation, apical foramen transportation, zipping and stripping and a questionnaire were prepared for observers. The observers went through reliability test and kappa value for agreement between every two observers. The results were above 0.8. Data were analyzed by EPI6 statistical computer program, using Chi-Square and Fisher exact test with P<0.05 as the limit of significance.

Results: This study consisted of 152 first maxillary molars and 248 first mandibular molars. The prevalence of curvature preservation in mesial root of first mandibular molars and mesiobuccal root of first maxillary molars were 38.5% and 47.6% respectively. Procedural errors detected consisted of 33% ledge formation, 26.1% apical foramen transportation, 1.8% zipping and 4.1% stripping for mesial root of the first mandibular molars. The results for the first maxillary molars were 27%, 19%, 3.2% and 3.2% respectively.

Conclusion: The study results revealed the efficacy of endodontic education and the proficiency of junior and senior students in preparing curved posterior root canals. The results obtained in this retrospective study are comparable to prospective studies.

Background and Aim: Qigong is a type of Chinese psychosomatic exercise that integrates meditation, slow physical movements, and breathing. Numerous physical and mental benefits have been classically ascribed to qigong. On the other hand, unstimulated saliva is thought to play an important role in oral immunity, enamel stability and moisturizing the oral mucous membrane. Impaired salivary secretion leads to dental caries, mucosal deterioration and mouth dryness. The aim of the present study was to analyze the effect of a qigong program on various parameters of saliva such as quantity of unstimulated saliva, pH and SIgA.

Materials and Methods: Twenty three subjects participated in this clinical trial study. The experimental subjects underwent a qigong training program, conducted by a qualified instructor. The program consisted of half an hour daily practice for 6 months (spring and winter). Saliva was collected in two periods: once during the spring before the experiment commencement and the second, in the following spring. During each period saliva collection was done on tuesday of each week. pH and quantity of salvia measurements were taken simultaneously. SIgA measurements were also taken based on the values obtained in the last phase of the experiment at the end of each spring. The results were analyzed using paired sample T test, one way repeated measure and Bon Ferroni multiple comparison. P<0.05 was the level of significance. Results: Based on our findings, the change in the amount of unstimulated salvia as well as SIgA was statistically significant (P<0.001) however, there was no significant difference in pH values before and after experiment.

Conclusion: These findings demonstrate that after 6 months of practicing qigong, significant changes in amount of unstimulated saliva and SIgA occurred in participants. The authors suggest that qigong may be a beneficial adjunctive treatment that enhances amount of unstimulated saliva and SIgA.

Background and Aim: Chin cup is an orthopedic appliance for treating growing skeletally Cl III patients. The amount of chin forward movement in addition to morphologic changes in bony structure, determines the final profile of treated patients. The aim of this study was to evaluate the amount of morphologic changes of symphysis after chin cup therapy in skeletally Cl III patients.

Materials and Methods: In this clinical trial, twenty eight cephalometries before and after chin cup therapy of 14 skeletally Cl III patients were analyzed. Landmarks introduced by Ricketts were determined to evaluate the symphysis and describe its relation to mandible. َAlso four additional measurements regarding the symphysis individually were evaluated and analyzed. Data were analyzed by paired t and pearson tests with P<0.05 as the level of significance.

Results: The results showed that the height of symphysis increased after treatment (P=0.02), but its depth decreased (P=0.04). The sysmphysis turned down and back.

Conclusion: These findings suggest that in Cl III malocclusions with a prognathic mandible, chin cup therapy creates changes in the horizontal dimension of symphysis morphology, which improves the Cl III profile. If the patient isn't a vertical grower, vertical changes of symphysis would be desirable. In addition, changes in the vertical dimension of the mandible (body and ramus) could be observed as a backward and downward rotation.

Background and Aim: One of the most common causes of facial pain, is muscular pain. MPDS is one of the most important disorders of facial area that many of patients suffer from pain, tenderness of one or more masticatory muscles and limitation of movement. Psychological factors play an important role in MPDS. Anxiety and depression by increasing muscle tension, can cause myofacial pain syndrome They can also accompany the syndrome as comorbidities or develop as sequelae of chronic pain and disability. Many approaches can be used to treat myofacial pain syndrome. The least invasive and least traumatic approach should be se.lected. Often, treatment for myofacial pain syndrome fails, because underlying problems go untreated. Progressive Muscle Relaxation (PMR) is mainly used for treating anxiety and depression. The aim of this study was to evaluate the effect of PMR in improving signs and symptoms of patients with MPDS.

Materials and Methods: In this before and after clinical trial study, 33 patients with MPDS that had anxiety and or mild depression(were assessed by Beck Inventory)were treated by PMR in a period of a month (3 visits)and were followed up until 2 months. Analysis was done using paired t-test/ wilcoxon-sign-rank test.

Results: The results of this study showed that variants like intensity of pain, tenderness of masticatory muscles, maximum opening of mouth with and without pain, anxiety (p<0.001) and depression (p=0.001) improved significant 16 after treatment in comparison with before treatment.

Conclusion: In conclusion, PMR is effective in improving signs and symptoms in patients with MPDS. Therefore psychological status should be considered in treatment plan of these patients.

Background and Aim: A major aspect of the adaptive host response in periodontitis is the antibodies. Several risk and susceptibility factors for periodontitis, including smoking, age and composition of the subgingival microflora, have also been suggested to influence antibody production. The present study was conducted to investigate plasma levels of immunoglobulin (Ig) G antibodies in periodontitis patients of Caucasian Iranian heritage referred to dental faculty, Tehran University of Medical Sciences in relation to disease severity and smoking.

Materials and Methods: In this study, 36 patients with severe periodontitis, 39 with moderate periodontitis and 40 controls without periodontal destruction were enrolled. From the total of 80 patients, 21 were diagnosed with aggressive periodontitis and 54 with chronic periodontitis. IgG isotypes were analyzed in plasma samples.

Results: Patients group in comparison with control group had shown higher level of Immuno globolins. There was no significant difference about the IgG1 level in moderate and seven group and also in chronic and aggressive groups (p<0/001). But the level of IgG2 was shown the significant difference in the all study groups. Smoking was significantly reduced the level of IgG1 and IgG2.

Conclusion: The current study shows that non-smoker periodontitis patients have higher levels of IgG2 than smoker periodontitis patients.

Background and Aims: There is not sufficient knowledge about the relationship between smoking and vertical bone loss in periodontal diseases. There are also important evidences which propose harmful effects of smoking on periodontal tissues including alveolar bone. The purpose of this study was to assess the relationship between smoking and prevalence and severity of vertical bone defects.
Materials and Methods: This case-control study consisted of 71 individuals with angular bone defects (case) and 69 individuals without angular bone defects (control) between 18 to 70 years old. People were selected by radiography, examining and filling up the questionnaire. Vertical bone defect was defined as interproximal bone resorption to the extent of ≥2mm with a clear angel towards the Mesial or Distal of root. Data were analyzed using SPSS software.
Result: The mean age of studied individuals was 37.14 years (±12.72). Among people with angular bone defects, 21.1% were light smokers and 25.4% were moderate-heavy smokers. There was a significant difference between smokers and nonsmokers in terms of smoking status and the chance of having angular bone defects (P=0.001). Simultaneous study of the effect of sex, age, brushing and smoking status showed that except sex, other variables have a significant effect on angular bone defects. The chance of having angular bone defects in light and heavy-moderate smokers was more than that in nonsmokers (adjusted OR=4.17 and adjusted OR=3.87, respectively).
Conclusion: These observations propose that smoking is related to increase in prevalence and severity of vertical bone defects. Smoking is considered as a potential risk factor for vertical periodontal bone loss.

Background and Aims: Fissure sealant therapy is a national program in elementary schools in Iran. Therefore, evaluation of the parents' knowledge and attitude is necessary to improve the program.
Materials and Methods: In this cross-sectional and descriptive-analytic study, Iranian students were chosen in a randomized cluster manner. The questionnaires were filled-out by students' parents to evaluate their general information, knowledge, and attitude. Moreover, students were examined for having any fissure-sealed teeth. Data were collected and analyzed by multiple logistic regression tests.
Results: 414 boy students and their parents were participated in this study. 57.6% of parents knew that fissure sealant prevents the caries and 44.5% believed that fissure sealant is important to prevent caries. However, only 8.9% of children had fissure sealant. Parents' knowledge was significantly related to the source of oral health information and oral health education. Regular dental visits and high level education was effective in increasing the knowledge about sealant therapy. There was a significant relation between parents' attitude toward fissure sealant and level of education, oral health education and numbers and times of dental visit (P<0.001). There were a significant relation between tooth sealing and parents' oral health information.
Conclusion: Regular dental visits and oral health education have positive role in parent's knowledge and attitude and practice. So parents must be encouraged to have regular dental visit and dentists must be emphasized to give them necessary education. School is the best place for giving proper information to parents.