Avicenna Journal of Dental Research
Year:2017 | Volume:9 | Issue:2|Papers Count:7

Background: This study was performed to assess the diagnostic accuracy of panoramic radiography in determining the position of impacted permanent maxillary canines.Methods: This was a diagnostic study to define how accurate panoramic radiography is in determining the position of impacted permanent maxillary canines. In panoramic radiographs of 33 patients (with 44 total impacted maxillary canines), and angulation, magnification and superimposition were assessed. The long axis of the impacted canine to the occlusal line was named angle. The long axis of the impacted canine to the vertebral line was named angle. The real position of the teeth was determined by CBCT. Sensitivity, specificity, positive predictive value, negative predictive value and accuracy of panoramic radiography were calculated. Kappa test was used to assess the agreement between panoramic radiography and CBCT. Roc curves were used to define cut-off point values.Results: angulation showed 84.3% of palatal impacted maxillary canines and 41.6% of buccal teeth in their real position. angulation showed these positions in 81.8% and 87.5% of cases, magnification in 37.5% and 58.3% of cases and superimposition in 53.6% and 100% of cases. The degree of agreement between CBCT and angulation, angulation, magnification, and superimposition was 0.275, 0.526, 0.03 and 0.224, respectively. Cut-off point values for angulation, angulation and CII were 65 degrees, 63 degrees and 1.11, respectively.Conclusions: Among different methods, angulation showed the highest accuracy in the localization of impacted maxillary canines.a angulation and superimposition ranked second and third in terms of accuracy. Magnification had the least accuracy.

Background: The minimum standard treatment plan for the reconstruction of an edentulous mandible, according to York, is an overdenture supported by two implants.Objectives: The aims of this study were to evaluate and compare the clinical outcomes and peri-implant marginal bone loss around implants in patients treated with mandibular overdentures supported by 1, 2, 3, 4, and 5 implants.Materials and Methods: Atotal of 25 patients with ameanage of 62.7 years old, whowere treated with implant supported mandibular over dentures at Hamedan’s faculty of dentistry, were enrolled in this cross-sectional study. Amongthese patients, 6 had overdentures supported by one implant, 9 had overdentures supported by two implants, 2 had overdentures supported by three implants, 5 had over dentures supported by 4 implants, and 3 had over dentures supported by 5 implants. The clinical and radiographic parameters around the implants were assessed, including: probing depth, width of keratinized gingiva, bleeding on probing, peri-implant inflammation, calculus formation, implant mobility, adverse events, and radiographic signs of peri-implant bone loss (distance between the implant shoulder and the level of the mesial and distal proximal bone). The ANOVA and the Fisher’s Exact test were used to evaluate the significant differences among the groups.Results: None of the implants had loosened and no adverse events were seen around the implants. Additionally, the clinical variables did not show significant correlation with the number of implants. Overall, the bone resorption showed an inverse and significant relationship with the number of implants (P=0.001).Conclusions: With mandibular over dentures supported by 1, 2, 3, 4, and 5 implants, favorable clinical outcomes can be achieved. However, when increasing the number of implants, marginal bone loss decreases. For example, the patients with five implants showed less marginal bone loss than those with a lesser number of implants.

Introduction: Fibrous dysplasia is a developmental bone disease that is characterized by replacement of normal bone with fibrous tissue.Case Presentation: A 58-year-old man came to the Oral and Maxillofacial Radiology Department, Hamadan College of Dentistry, with swelling on the left side of the maxilla. The lesion was diagnosed to be fibrous dysplasia of the maxilla with involvement of the maxillary sinus, based on the radiographic and histopathologic features.Conclusions: Some radiographic features, such as a ground glass appearance and reduction in antrum size while keeping the original shape, are characterizations of fibrous dysplasia.

Background: The hyoid bone position may change in class III patients following different surgical procedures, including mandibular setback, maxillary advancement, and bimaxillary advancement.Objectives: The aim of this study was to conduct a detailed cephalometric evaluation of changes in the hyoid bone position following treatment of class III skeletal deformities via different surgical procedures (ie, mandibular setback, maxillary advancement, and bimaxillary advancement).Methods: A total of 120 consecutive patients, who were diagnosed with skeletal class III deformities, were recruited in this study. All the patients were adults with complete growth and cephalograms taken at 1monthbefore operation (T1) and 1 to 9 months postoperation (T2) in the natural head position. The patients were divided into 3 groups according to the type of surgery: group 1, bimaxillary advancement; group 2, mandibular setback; and group 3, maxillary advancement. The hyoid bone position was evaluated at both T1 and T2 in each group. The results were compared using paired t test and one-way ANOVA.Results: The hyoid bone position showed no significant changes in groups 1 and 3 (P<0.05), whereas a significant difference was found both horizontally and vertically in group 2 (P<0.05).Conclusions: The hyoid bone position changed only after mandibular setback surgery; the bone was displaced downward and backward following mandibular retraction. On the other hand, neither bimaxillary nor maxillary advancement could change the hyoid bone position.

Introduction: A dentigerous cyst is the most commonly developed cyst of the jaw. It is most frequently associated with impacted canines and mandibular third molars. Bilateral dentigerous cysts are rare and are generally associated with developmental syndromes or systemic diseases.Case Presentation: We report on an eight-year-old boy who presented with a complaint of bilateral malposed first mandibular molars. There was no complaint of pain and no swelling. An intraoral examination revealed buccal tipping of both the right and left first mandibular molars with slight swelling. The overlying mucosa was completely normal and there was no tenderness on palpation. This unusual case occurrence associated with the crowns of the bilateral impacted lower second molars. There are no cases reported with bilateral dentigerous cyst involving mandibular second molars. The clinical and radiographic findings, especially the cone beam computed tomography (CBCT) views, were suggestive of dentigerous cysts.Conclusions: After the surgical removal of the cysts, the specimens were sent for histopathological evaluation. A microscopic examination suggested infected dentigerous cysts.

Background: Numerous studies showed that the convergence angle (CA) of prepared teeth for fixed prosthodontics in the clinical practice is greater than the recommended values.Objectives: This cross-sectional study aimed to compare the total occlusal convergence (TOC) angles of metal ceramic fixed prosthodontics among dental students [final-year undergraduate (UG) and Master Prosthodontics (MS) students] and general practitioners (GP) in their private clinics with the recommended value (£12 degrees).Methods: The buccolingual (BL) and mesiodistal (MD) TOC of 114, 90, and 111 stone dies referred to UG, MS, and GP, respectively, were measured. These dies included incisors, premolars, and molars. One sample Wilcoxon signed rank test, Mann-Whitney U test, Kruskal-Wallis, and Fisher exact test were used for statistical analysis.Results: Mean values of TOC for UG were 27.8 degrees BL and 20.9 degrees MD, whereas they were 30.6 degrees BL and 18.2 degrees MD for MS. GP had TOC of 35.5 degrees BL and 24 degrees MD. GP had significantly higher TOC values than the other groups (0.001>P value £0.007). In each group, TOC did not differ when calculated for partial fixed prosthodontic and single crown abutments (0.117£ P value £0.797). Molars in general had the highest TOC values. Only 0.9%, 3.3%, and 0.9% of UG, MS, and GP, respectively, respected the TOC £12 degrees.Conclusions: In all the groups, tooth preparations were inconsistent with the recommended TOC values, even among specialists in fixed prosthodontics. These results support the existing literature that the recommended values were rarely achieved and may require reconsideration.Clinical Significance: Clinically, the CA values of prepared teeth for fixed prosthodontics exceed the recommended values in most cases, not only among general practitioners, but also among students in academic institutes. Thus, the effects of teeth preparations with CA greater than the recommended values on the longevity of the prosthodontics should be further investigated.

Background: Pattern of tooth eruption (TE) may vary in different communities and may be affected by many factors. It also may cause nutritional problems in infants and anxiety in parents. The current study aimed at investigating the relationship between birth weight and other factors contributing to the time of the first TE.Methods: The current study employed the multistage sampling method to select 126 infants admitted to the health centers of Hamadan, Iran. Health records of infants were listed and relevant information was collected using a questionnaire and interviewing the parents. The tooth emergence was considered as TE in the current study. Finally, the recruited infants were examined for the eruption of the first primary tooth. Descriptive, linear, and the curve regression tests were used with SPSS version 16.Results: Despite the significant differences in weight and height between male and female infants, no significant relationship was observed between time of the first primary TE and most of the studied variables. Height, feeding with formula, family income, and mother’s age had inverse effects on TE time. Infants who were fed with synthetic formula milk had earlier TE. Eruption sign and infant height had the most effects on delayed TE.Conclusions: No significant relationship was observed between the eruption time of the first primary tooth and the studied variables. Nevertheless, there was a significant association between the infant’s height and time of the first primary TE.