Journal of Dental Medicine

The effect of film and paper on quality of Cone beam CT image and their diagnostic accuracy in detection of inferior alveolar canal

Bentolhoda Kamali

Background and Aims: According to the research background and need to print CBCT images in case of emergency, this study has been done to compare the quality and accuracy of the two methods of film and paper printing for CBCT images.

Materials and Methods: The study of CBCT images taken from 5 patients was done and the cross-sectional slices on Fotolusio DNP papers and film AGFA were printed. Afterward, the images was exmined by a maxillofacial radiologist. The images’ quality were identified and recorded with anatomical, from 1 to 4 on forms. The accuracy was determined by the diagnosis of alveolar canal area and the comparison with the gold standard. Data were analyzed using independent chi-square and Fisher exact tests’.

Results: The images quality in anatomical landmarks consisting PDL (P=0.02), lamina dura (P=0.006), the inferior alveolar canal (P=0.01) and the filling (P=0.006) had a significant difference. There was no significant difference. For the lower border of the mandible landmark, there was no difference between the two methods of printing. In comparing the diagnostic accuracy between the two methods (P=1).

Conclusion: The results showed that the diagnostic quality in film printing is better than paper printing and the diagnostic accuracy is the same in both methods.

Principles of treatment planning for compromised first permanent molars in mixed dentition period: A review article

Behrad Tanbakuchi

Background and Aims: The first permanent molar is susceptible to caries, endodontic complications and developmental anomalies. Compromised teeth with poor prognosis could cause the clinician to face dilemmas. The aim of this review article was to assess recent guidelines on the treatment planning of compromised first permanent molars in mixed dentition period.

Materials and Methods: The design of the study was based on review of literature by searching the MEDLINE, Web of science and Google scholar. Key words (permanent first molar, extraction, treatment plan) were used. This search was limited to the English articles published after the year 2000.

Conclusion: A number of factors influenced decision-making process regarding compromised first permanent molars including the restorative status of the tooth, dental age of the patient, degree of crowding and occlusal relationships were assessed. The ideal time for removal of these teeth was 8-9 years of age. However, the current evidence for managing compromised first permanent molars demands clinical trials.

Evaluation of severity of dental caries in primary teeth among children 5-7 years-old in Tehran in 2016

Mona Hamedani Golshan

Background and Aims: This study aimed to assess the severity of tooth decay and related factors in children 5-7 years old, in 2016, in Tehran.

Materials and Methods: A descriptive and cross-sectional study was performed on 572 children aged 5-7 years old (300 girls and 272 boys) in public schools in Tehran, Iran. Severity of dental caries (number of decayed, missing, filled surfaces) recorded for C, D and E teeth according to WHO criteria. Data analysis was performed by Backward Linear Regression Analyses using SPSS 20 (P≤0.05).

Results: Assessment of dental caries severity according to the number of decayed surfaces showed generally higher figures in upper jaw. The order of average severity of carious teeth was C, E and D from low to high in both jaws. According to the results of Linear Regression Analysis, severity of dental caries was more than other children in boys (OR=1.83, 95%CI: 0.81-2.8), those visited dentist due to dental problems associated with pain (OR=1.17, 95%CI: 0.73-1.6), and those without fluoride therapy (OR=1.64, 95%CI: 0.58-2.6) in C, D and E teeth.

Conclusion: Flow the results, it was concluded that gender, level of mother's education, type of snack consumption, start age of tooth brushing, reason for dental visit and fluoride therapy affected severity of tooth decay.

The ability of panoramic radiographs to correlate transverse with sagittal dimensions in class III patients

Behzad Salari

Background and Aims: In the field of orthodontics, gaining comprehensive information around dento-skeletal complex is necessary to choose the best treatment plan for each patient. The aim of this study was to investigate the linear and angular parameters in panoramic radiographs to find a path to correlate transvers to sagittal dimensions.

Materials and Methods: Total number of sixty two, 8-14 years old children who sought for orthodontic therapy were selected (32 skeletal Class III and 30 skeletal Class I). They were exposed to x-ray to obtain the panoramic and lateral views in a controlled condition. Various linear and angular parameters were measured after tracing the landmarks on the panoramic radiograph. Data were obtained and analyzed using T-test. The level of significance was set at 0.05 (P<0.05).

Results: Linear parameters of Co-Co, Go-Go and PTM-PTM were significantly lower in class III patients than class I ones (P=0.04, 0.04, 0.02, respectively). The ramus width value was also lower in class III patients. Angular parameters of Me^˄and N^˄also showed the same results (P<0.001). Go^˄angle was significantly lower in the class I than class III patients (P=0.002, 0.007).

Conclusion: Some traceable linear and angular parameters were found in the panoramic radiographs which had the potential to correlate the transverse with sagittal dimension.

Assessment of sphenoid sinus volume in order to determine sexual identity, using multi-slice CT images

Shahab Etemadi

Background and Aims: Gender determination is an important step in identification. For gender determination, anthropometric evaluation is one of the main forensic evaluations. The aim of this study was the assessment of sphenoid sinus volume in order to determine sexual identity, using multi-slice CT images.

Materials and Methods: For volumetric analysis, axial paranasal sinus CT scan with 3-mm slice thickness was used. For this study, 80 images (40 women and 40 men older than 18 years) were selected. For the assessment of sphenoid sinus volume, Digimizer software was used. The volume of sphenoid sinus was calculated using the following equation: v=∑ (area of each slice × thickness of each slice). Statistical analysis was performed by independent T-test.

Results: The mean volume of sphenoid sinus was significantly greater in male gender (P=0.01).The assessed Cut off point was 9/35 cm³, showing that 63.4% of volume assessments greater than cut off point was supposed to be male and 64.1% of volumetry lesser than cut off point were female.

Conclusion: According to the area under Roc curve (1.65%), sphenoid sinus volume is not an appropriate factor for differentiation of male and female from each other, which means the predictability of cut off point (9/35 cm³) is 65/1% close to reality.

Evaluation of two educational interventions regarding prevention of early childhood caries on self-reported practice of parents of 2-5-year-old children receiving dental treatment under general anesthesia

Sara Ghadimi

Background and Aims: One of the most effective methods in reducing the prevalence of caries is oral health education. The aim of this study was to evaluate of two educational interventions regarding prevention of early childhood caries on self-reported practice of parents of 2-5-year-old children receiving dental treatment under general anesthesia.

Materials and Methods: In this interventional study, the effects of two different educational interventions
(pamphlet and pamphlet along with reminder) on self-reported practice of parents of 2-5-years-old children receiving dental treatment under general anesthesia was assessed. Thirty seven couples of children and mothers in two groups were randomly selected. Before and three months after interventions, a standard questionnaire regarding self-reported practice of mothers on prevention of early childhood caries was completed by respondents. Moreover, oral examination including Simplified oral hygiene index (S-OHI), dmft, and white spot lesions were rerecorded at the beginning and three months after interventions. At this time in one of the groups reminder phone calls were made every month. Finally, the answers were scored and data were statistically analyzed to be compared in pre- and post-test.

Results: Comparing each of the groups before and after interventions showed that in both groups there were significant differences in mothers’ perception of perceived ability to make child brush his teeth twice a day (P=0.001), and child’s tooth brushing frequency more than once a day (P=0.03). S-OHI had no significant difference after the intervention between two groups. But each group had a significant decrease three months after intervention (P=0.003). Also the mean number of white spots showed a significant decrease before and after intervention in each groups. Regarding mothers’ self-reported practice no significant difference was observed between two groups (P>0.05).

Conclusion: Using pamphlets along with or without reminder as educational measures had similar enhancing effects on the mothers’ self-reported practice on oral health of children within three months.

Checklist development for assessing the dental students' clinical skills in oral and maxillofacial medicine course and comparison with global rating

Shiva Shirazian

Background and Aims: The objective of this study was the development of a checklist for assessment of students’ clinical skills in the clinical oral medicine. The second aim was the assessment of stake holders’ satisfaction of this checklist in comparison to the routine global rating method.

Materials and Methods: The checklist was developed in an expert panel sessions and the validity and reliability of checklist were assessed by CVI and test-retest method, respectively. All students (n=66) were assessed in 2 groups, one with developed checklist and another with global rating. At the end of the session, the satisfaction’s level of staff and students were analysized using Wilcoxon and Mann-Whitney test and the mean scores of students were analysized using Paired T test.

Results: Content validity index (CV I) of checklist was 0.88. Reliability of checklist confirmed with high correlation coefficient (0.9). Staffs’ satisfaction had no significant difference between the two methods
(Wilcoxon P=0.06). The mean score of students who assessed by checklist was higher than global rating with no significant differences (P=0.06).

Conclusion: Regarding the higher students’ satisfaction from checklist and more attention to component of assessment and more objectivity of this method and also higher score in checklist, it seems that the use of a checklist is more proper method for assessing the students’ clinical skills.

Biomechanical comparison between pure Ti and Zr -2.5%Nb dental implants after implantation by finite element analysis (FEA)

Mohsen Sarafbidabad

Background and Aims: Improving dental implantation conditions in order to reduce the failure is always desirable for researchers. The aim of this study was to compare two different materials of dental implants from the viewpoint of biomechanical effect after placement and loading in the mandible.

Materials and Methods: A 3D model of mandible was designed in the MIMICS 10.01 software. Then, by using the obtained model, the end part of the mandible was designed in CATIA V5 software and a drilling operation was performed on the cortical bone of mandible by finite element analysis simulation method in DEFORM-3D V6.1 software. Thereafter, the 3D model of created hole was extract from the drilled site and an ITI dental implant model designed in the CATIA V5 software, was placed in the hole. The space remained between the implant and cavity was considered as a newly-formed cortical bone in drilled site after 6 weeks of dental implant placement and the mechanical properties of newly-formed bone were entered to DEFORM-3D V6.1 software. Then, a load was applied on the top surfaces of two dental implant models with the materials titanium and zirconium-2.5% niobium.

Results: The emerged volume changes in newly formed cortical bone around Ti and Zr-2.5 Nb dental implants were measured 0.238 and 0.242 percent, respectively. Furthermore, micro-motion of Ti and Zr-2.5 Nb dental implants were measured 0.00514 and 0.00538 mm, respectively.

Conclusion: The results of this study showed that Ti dental implant created better conditions than Zr-2.5 Nb dental implant in the mandible.