Journal of Dental School

Objectives Periodontal clinical parameters are highly sensitive for the assessment of bone resorption, while radiographic images are highly specific. Two-dimensional parallel periapical (PA) and bitewing (BW) intraoral radiographs are used as adjuvant methods to assess bone resorption in periodontal diseases. The present study aimed to compare the efficacy of PA and BW radiographs in assessing marginal bone level.

Methods This cross-sectional study was conducted on 77 (52 females and 25 males) subjects with a mean age of 40.12±14.9 years with chronic periodontitis. Parallel PA and BW radiographs of patients, who required periodontal flap surgery or crown lengthening, were acquired, and evaluated. The distance between the alveolar bone crest (ABC) and the cemento-enamel junction (CEJ) was determined during surgery using the Williams probe. The same distance was measured in proximal areas on intraoral radiographs using Romexis Version 11.4. To evaluate intra-observer agreement, three observers re-evaluated the radiographs after a minimum of 1 week. Intra-class correlation coefficient (ICC) was applied to evaluate the inter- and intra-observer agreement. Data were analyzed using the Shapiro-Wilk test and paired t-test.

Results According to the results, the mean distance between the CEJ and ABC was 4.61±1.22 mm, and the mean distance on the PA and BW radiographs was 4.20±1.23 (P<0.001) and 4.02±1.06 mm (P<0.001), respectively. PA radiography was more accurate than BW radiography, although the difference was insignificant (P=0.182). The mean ICC value of the inter-observer agreement was 0.88 for BW and 0.87 for PA radiographs. The mean intra-observer agreement was 0.97 and 0.95 for BW and PA radiographs, respectively.

Conclusion The accuracy of PA radiography was higher than BW radiography. However, there was no significant difference regarding the accuracy of these two techniques in determining the level of ABC in the posterior area of the jaws.

Objectives Children’s dental fear is a major issue in avoidance of dental visits, which exacerbates dental health problems and is associated with multiple factors. The dentist’s behavior is one of the influential factors in dental fear. This study aimed to evaluate the relationship between dentistry students’ personality type and children’s dental fear.

Methods This descriptive, analytical, cross-sectional study was performed on 30 dentistry students and 34 children in the pediatric ward of Shahid Beheshti Dental School, Tehran, Iran. The children’s age was in the range of 7-9 years. To evaluate the students’ personality type, Bortner questionnaire was used, and to investigate children’s dental fear, the Dental Subscale of the Children's Fear Survey Schedule (CFSS-DS) was employed. The children completed the questionnaire twice, once before and once after treatment with the assistance of their parents. Fisher’s exact test (P<0.05), independent t-test (P<0.05), and ANCOVA (P<0.05) tests were performed for statistical analysis. This study was approved by the Ethics Committee of Shahid Beheshti School of Dentistry (ethical ID: IR.SBMU.DRC.REC.1398.176).

Results According to the students’ responses to the Bortner questionnaire, they were divided into two groups: 18 students with type A personality and 12 students with type B personality. The children were also divided into two groups. Twenty-two children were treated by dentists with type A personality (group A), and twelve children were treated by dentists with type B personality (group B). Changes in the mean CFSS-DS score following dental treatment were +2.09±7.7 and -2.17±4.95 in group A and group B, respectively. The mean change in the CFSS score of children in group A was higher than that of children in group B, although the difference was not significant (P=0.096).

Conclusion The personality type of dentistry students does not significantly affect children’s dental fear.

Objectives: This study aimed to investigate background and job characteristics of dental assistants in Iran and to assess their knowledge and practice about infection control.

Methods: This cross-sectional study conducted on a sample of dental assistants in Tehran. The participants answered an online questionnaire including demographic (age, gender, marital status, and the highest educational attainment) and job related (years in practice, income, working hours, job related educational course and certificate, knowledge and practice regarding infection control) questions.

Objectives This study aimed to investigate the background characteristics and job profile of dental assistants in Iran and to assess their knowledge and practice regarding infection control.  

Methods This cross-sectional study was conducted on a sample of dental assistants in Tehran, Iran. The participants completed an online questionnaire, including demographic (age, sex, marital status, and the highest level of educational attainment) and job-related (years of practice, income, working hours, job-related educational course and certificate, and knowledge and practice related to infection control) information.

Results A total of 386 dental assistants completed the questionnaires. The mean age of the assistants was 29.27±6.8 years, and 96% of them were female. Overall, 56-68% of the respondents reported <5 years of working experience, worked 30-80 hours per week with a monthly salary of nearly $80-100, and completed an educational course on dental assistance. Nearly one-third of the participants reported high satisfaction with their job, and less than 10% of them were satisfied with their salary. The assistants had adequate knowledge about most aspects of infection control. Nearly 40% of them reported no education on infection control, and 35-45% declared that they usually sterilized dental rotary instruments using disinfectants, but not autoclaving. Almost 60% of the assistants reported complete vaccination before entering their job.

Conclusion Dental assistants in Iran are rather young, highly educated women with a relatively high workload, but low job satisfaction. Their professional knowledge and performance were deficient in some aspects, reflecting inadequacies in their education. Delivery of efficient dental services with high standards requires qualified dental personnel with formal academic education based on an efficient credentialing system.

Objectives This study aimed to assess the anatomical variations of the greater palatine canal (GPC) and greater palatine foramen (GPF) in an Iranian subpopulation using cone-beam computed tomography (CBCT).

Methods This cross-sectional study was conducted on 193 CBCT scans of adults (94 males, 99 females) taken between 2017-2021 that were retrieved from a radiology clinic in Urmia, Iran. Axial sections were used to assess the position, diameter, and shape of GPF, and sagittal sections were used to assess the length and path of GPC. Data were analyzed by paired and independent t-test, Wilcoxon test, Mann-Whitney test, and Chi-square test (alpha=0.05).

Results In most cases (97.34% of males and 98.49% of females), GPF was located distal to the maxillary first molar. The mean distance between the GPF and midpalatal suture was significantly greater in males than females (15.2±1.8 vs. 14.3±1.5 mm; P=0.002). The mean diameter of GFP was significantly larger in males than females in both mesiodistal (2.34±0.64 vs. 1.96±0.63 mm, P<0.05) and anteroposterior (4.69±1.17 vs. 4.07±1.20 mm, P=0.001) dimensions. The mean length of GPC in males was significantly higher than that in females (28.55±2.62 vs. 26.90±3.31 mm, P<0.05). The most common form of GPF and GPC (on sagittal sections) was oval, and sigmoid, and curve, respectively. The most common GPC path was anterior-inferior (65.96% of males and 64.65% of females).

Conclusion The present results provided valuable information regarding the anatomical variations of GPF and GPC in Iranian population. CBCT was proven to be a valuable tool for assessment of maxillofacial anatomical landmarks

Objectives Considering the educational value of non-wax and virtual typodonts, in this study, the results of the evaluation were compared to quantify each of the indicators in the evaluation of knowledge, attitude, and performance.

Methods All tenth-semester dental students were divided into 2 equal groups of 25 and were trained by two typodontists. A standard questionnaire with a Cronbach α of .830 was used to evaluate their knowledge and attitude, which was prepared based on a 7-point Likert scale. To analyze the data, the paired t test, independent t test, and analysis of covariance (ANOVA) were used with SPSS version 21. The significance level was set as 0.05.

Results In each of the 2 educational methods, a significant increase in the overall score of the questionnaire completed by the students was observed after the educational intervention (P < 0.001).  Among the 17 questions related to students, only 1 question in the non-wax typodont group and 4 in the virtual typodont group did not show a significant effect of the intervention (P > 0.05).

Conclusion Both typodonts had remarkable educational advantages and accounted for a large share of the points in the questionnaires. In cases where physical sense was important in education, non-wax typodont and in cases where spatial understanding of biomechanics was necessary in tooth movement, virtual typodont was superior.

Objectives The aim of this study was to evaluate the prevalence and anatomical variations of retromolar canal (RMC). Since RMC contains neurovascular bundle that contribute to the innervation and nutrition of the pulp and periodontium of the mandibular teeth, it is necessary to pay attention to the clinical importance of this landmark, to prevent possible surgical complications and anesthetic failures.

Methods In this descriptive-analytical study, 450 CBCT scans were evaluated. The scans were evaluated for presence of the RMC and linear measurements (distance to second and third molar, height, width and diameter) were made with NNT software. Descriptive statistics were used to assess data. Data were analyzed using paired t-test adopting significance for p value ≤0.05.

Results The prevalence of RMC was 7.1%. Among of the existed RMC, 71.9% were unilateral and 28.1% were bilateral. The mean height of canal was 9.33 ± 3.65 mm, and the mean width of the canal was 0.87 ± 0.4 mm. The mean distance of RMC to the third and second molar were 10.44 ± 5.1 mm and 11.71 ± 3.73 mm respectively. No significant differences were detected between the two genders.

Conclusion The prevalence of the RMC was observed to be 7.1% and was well observed in CBCT images. Accurate assessment of this anatomic landmark helps prevent surgical complications especially prior to third molar anesthesia and extraction.

Objectives The release of secretions and aerosols during dental procedures is a common way of transmitting viral infections in the dental environment. Therefore, the use of effective antiviral materials such as Silver-containing solutions at non-cytotoxic doses can be of great importance. The present study aimed to review the antiviral effects of silver nanoparticles on infectious viruses for the purpose of disease prevention.

Methods In this review, databases, including Web of Science, PubMed, Medline, and Google Scholar, were electronically searched for relevant articles, using the following keywords: “nano-silver”, “antiviral”, “virus”, and “disinfection”. A total of 291 relevant articles published during 2010-2022 were found; according to the inclusion criteria, only 20 studies were directly included in this study. Full-text articles written in English, which openly examined the cellular effects of silver nanoparticles on infectious viruses, were carefully selected.

Results Using nanoparticles such as silver nanoparticles for dental practice disinfection purposes is documented and can be advantageous for their antiviral effects.

Conclusion Incorporating nanoparticles into dental materials is the most common application of nanoparticles in dentistry, which leads to an increase in antimicrobial properties of dental materials. Cancer diagnosis and treatment, regeneration of alveolar bone defects, and treatment of tooth hypersensitivity are the other emerging applications of nanoparticles in dentistry.

Objectives Hemifacial microsomia (HFM) is an asymmetric craniofacial malformation, which results from hypoplasia of the first and second branchial arch components and is characterized by a wide spectrum of phenotypic expressions, varying from the underdevelopment of the temporomandibular joint, mandible, facial and trigeminal nerves, masticatory muscles, ears, and hypoplastic maxillary, temporal, orbital, and zygomatic bones to conductive hearing loss due to external and middle ear deformities. Management of this developmental defect is multidisciplinary and associated with various phenotypic spectra and severities. A wide range of treatment protocols, such as surgical interventions, have been proposed, especially for mandibular hypoplasia, including rib or fibular bone grafting, distraction osteogenesis (DO), orthognathic surgery, and a combination of these procedures.

Case In this study, the treatment course and 17-year follow-up of a patient with HFM were described. The treatment included autogenous costochondral grafting, followed by full-time application of an asymmetric hybrid functional appliance, fixed orthodontic therapy, orthognathic surgery, and contour modification surgery to achieve optimal facial aesthetics.

Conclusion Patients can benefit from functional jaw orthopedics psychosocially and the consequent enhanced facial symmetry during childhood and adolescence is really advantageous