Journal of dentistry (Shiraz, Iran)最新文献

Plasmacytoma is an abnormal proliferation of monoclonal B-cells, and it can occur in several forms including multiple myeloma, solitary plasmacytoma of the bone, and extramedullary plasmacytoma primary. The solitary plasmacytoma of the bone accounts for about 3-10% of all plasma cell neoplasms, and occurs most often in the vertebrae, whereas the solitary plasmacytoma of the mandible is an extremely rare occurrence. This case report presents a 61-year-old woman with various underlying diseases diagnosed with solitary plasmacytoma of the mandible. This case is very well documented with radiographic imagery, clinical, and histopathological findings.

The central granular cell odontogenic tumor (CGCOT) is a rare, benign, slowly growing, odontogenic neoplasm. CGCOT was not considered as a distinct entity in the WHO classification reported on 2017. This study reports a rare case of CGCOT involving the right side of maxillary anterior region of a 39-year-old white woman. In addition, to better delineate the clinical, radiographic, histopathologic and immunohistochemical characteristics of CGCOT, a literature review of all published cases (in PubMed/ Google Scholar/ MEDLINE/Scopus) of CGCOT is provided. CGCOT is a very uncommon tumor, with only 51 reported cases in the literature. The present case is interesting regarding to its rarity for being in the maxillary anterior region, which has not been previously reported in Asia. The immunohistochemical findings of the current case and other cases in the literature review, verified the mesenchymal origin of granular cells and odontogenic nature of the epithelium islands, which can be a possible promise for placing this lesion in the future WHO odontogenic tumor classification.

Statement of the problem: In most cases, insertion of single implants with a standard diameter is used to replace a molar tooth but placing two implants with a narrow diameter seems to be a viable treatment modality to withstand functional and biomechanical forces.

Purpose: This study aimed to evaluate and compare stress distribution in the bone surrounding a single molar area rehabilitated by a single implant versus two implants with a narrow diameter.

Materials and method: The study was conducted by computer-aided in vitro modeling. The initial model used a single implant, 4.8 mm wide in diameter, inserted with a 3.9-mm distance from both sides and 12.6-mm mesiodistal space. The second model used two 3.3-mm narrow-sized implants with a 3-mm distance from one another, 1.5 mm from both sides, and a 12.6-mm mesiodistal space. Following the completion of these models, a 100-N force was exerted obliquely, once in three locations and once in the mesial aspect of the implant-supported crown. Stress distribution was then measured using finite element analysis (FEA) with ANSYS Workbench software package in both models.

Results: The maximum stress in the bone around the single implant was less than that around double implants. The maximum stress of cortical bone in three-point loading was lower than mesial loading either in one (146.7 vs. 126.72 MPa) or two implants model (186.8 vs. 139.24).

Conclusion: According to the results, because of more cortical bone contact area, the stress of surrounding bone in wide implant was decreased.

Statement of the problem: Xerostomia is a subjective sensation of dry mouth considered as a complex state affecting multiple oral functions. Pilocarpine may be a useful medication for the treatment of xerostomia, but its side effects limit its use under certain conditions. Recent studies have focused on the pilocarpine mouthwash as an alternative.

Purpose: We have undertaken this study to review the latest available scientific evidence systematically, concerning the effects of pilocarpine mouthwash on salivary flow rate in patients with xerostomia.

Materials and method: An electronic search for randomized controlled trials published in English until September 2021 related to pilocarpine mouthwash and salivary flow rate in patients with dry mouth was performed in PubMed/Medline, Web of Science, Google Scholar, Embase, and Scopus. A random-effects meta-analysis was conducted to evaluate the relationship between the groups.

Results: Two papers with 86 patients were selected for the final review based on strict eligibility criteria. According to the results of the meta-analysis, the mean visual analogue scale in the patient treated with pilocarpine mouthwash was 0.88 unit lower than that of the control group in the fourth week follow; however, it was not statistically significant (pooled mean difference=-0.88, 95% CI = (-2.72; 0.95), p= 0.34).

Conclusion: It seems that the use of pilocarpine mouthwash can increase the salivary flow rates; however, no optimal dose and application regimen can currently be suggested due to the high heterogeneity of the data. Regarding the relief of the symptoms using pilocarpine mouthwash, the existing evidence does not support its effectiveness.

Statement of the problem: Gubernacular canal (GC) is a canal that extends from the follicle of unerupted permanent teeth to the alveolar bone crest filled with remnants of the dental lamina. This canal is thought to guide tooth eruption and be related to some pathologic conditions.

Purposes: This study aimed to determine the presence of GC and its anatomical characteristics in teeth, which failed to erupt normally on cone beam computed tomography (CBCT) images.

Materials and method: This cross-sectional study evaluated CBCT images of 77 impacted permanent and supernumerary teeth obtained from 29 females and 21 males. The frequency of GC detection, its location in relation to the crown and root, the anatomical surface of the tooth from which the canal has originated, and the adjacent cortical table to which the canal opens, along with the length of the GC were studied.

Results: GC was observed in 53.2% of teeth. The anatomical tooth aspect of origin was occlusal/ incisal in 41.5% and crown in 82.9% of teeth. Moreover, 51.2% of GCs opened in palatal/lingual cortex and 63.4% of canals were not located along the tooth long axis. Finally, GC was detected in 85.7% of teeth undergoing the crown formation stage.

Conclusion: Although GC was introduced as an eruption pathway, this canal is also present in impacted teeth. This means that presence of this canal does not promise the normal eruption of tooth and the anatomical characteristics of GC may influence the eruption process.

Statement of the problem: Mobile usage has increased worldwide over the past two decades. There are conflicting reports about the carcinogenic effects of cell phone radiation on the oral mucosa. Micronucleus (MN) is considered a reliable marker for genotoxic damage.

Purpose: This study aimed to identify the impact of mobile phone radiation on the MN frequency in oral mucosal cells.

Materials and method: In this descriptive-analytical study, 50 mobile phone users between the age group of 20-38 years were included. Samples were obtained from the right and left cheek mucosa of each subject (a total 100 cell samples). Every participant filled out a questionnaire about his or her cell phone usage habits. Additionally, personal information such as age, gender, and body mass index (BMI) were assessed. The Feulgen and Papanicolaou staining methods were used for staining of the cell samples. A total of 1000 cells in each sample were evaluated for MNs.

Results: The mean number of MN in exposed and non-exposed mucosa by Feulgen method was 0.71±1.13 and 0.57±1.36, respectively. Also in Papanicolaou staining, the mean number of MN in the exposed mucosa and non-exposed mucosa was 6.94±6.61 and 6.54±6.88, respectively, but these differences were not significant (p> 0.05). The frequency of MN in non-specific DNA staining was significantly (5- to 6-fold) higher than DNA-specific staining. We observed no statically significant differences between MN frequency according to age, gender, BMI, and other cell phone usage habits (p> 0.05).

Conclusion: This study showed that cell phone use does not cause genotoxic effects in the buccal mucosa in the oral cavity. Moreover, using non-specific DNA staining methods can increase the frequency of MN by more than 5- to 6-fold.

Statement of the problem: New calcium silicate base cements are introduced as root repair materials in order to defeat the problems of early root repair materials. Their mechanical properties such as solubility and porosity should be concerned.

Purpose: This study was conducted to evaluate the solubility and porosity of the NanoFastCement (NFC) as a new calcium silicate base cement comparing to mineral trioxide aggregate (MTA).

Materials and method: In this in vitro study, scanning electron microscope (SEM) was used to evaluate the porosity at five different magnifications (200×, 1000×, 4000×, 6000× and 10000×) in secondary backscattered electron mode. All analyses were performed at 20kV. The obtained images were subjected to qualitative evaluation regarding the porosity. Solubility was determined following the international standards organization (ISO) 6876 method. Twelve specimens in specially fabricated stainless steel ring molds were weighed, initially and after 24 hour and 28 days of immersion in distilled water. Each weight was measured three times to record the average weight. Solubility was measured by calculating the difference of the initial and final weight.

Results: Solubility of the NFC in comparison with MTA showed no statistical difference (p Value > 0.05) after one day and 28 days. NFC acted like MTA and showed an acceptable solubility value at exposure time intervals. In both groups, solubility increased as time went on (p Value<0.05). The porosity of NFC was comparable to MTA, and NFC presented a less porous and a slightly smoother surface compared to MTA.

Conclusion: NFC has similar solubility and porosity to Proroot MTA. Therefore, it can be a good, more available and less expensive substitute for MTA.

Statement of the problem: For many years, practitioners have been encountered with dental rehabilitation of atrophic jaws. Among many of alternatives, free iliac graft can be a reasonable and also problematic choice to be accomplished.

Purpose: The aim of this study was to evaluate the implant survival rate and bone loss in implants inserted in reconstructed jaws with free iliac graft.

Materials and method: In this clinical trial study, twelve patients that underwent bone reconstruction with free iliac graft were included in this retrospective study. The patients underwent surgery over a 6-year period from September 2011 to July 2017. Panoramic images were taken immediately after implant insertion and at the follow-up session. The parameters that were assessed included implant survival rate, bone level changes, and surrounding tissue conditions.

Results: One hundred and nine implants were placed in eight female and four male patients, of which 65 (59.6%) were inserted in the reconstructed maxilla and 44 (40.3%) in the reconstructed mandible. The interval between the reconstruction surgery and follow-up session was 28.75 months and the mean interval between implant insertion and the follow-up session was 21.75 months, ranging from 6 to 72 months. The total average of crestal bone resorption was 2.44 mm (range: 0 to 5.43 mm).

Conclusion: This study found that rehabilitation of atrophic jaws with dental implants placed in free iliac graft was associated with acceptable marginal bone loss, survival rate, satisfaction, and esthetic results among the patients.

Statement of the problem: Medial depression of the mandibular ramus (MDMR) as a normal anatomical variation might complicate orthognatic surgeries that involve ramus. When planning an orthognatic surgery, it is clinically valuable to notice MDMR in osteotomy site to decrease the risk of failure.

Purpose: The aim of present study was to evaluate the prevalence as well as characteristics of MDMR in three skeletal sagittal classifications.

Materials and method: This cross sectional study evaluated 530 cone beam computed tomography (CBCT) scans, of which 220 were enrolled. The skeletal sagittal classification, the presence of MDMR, the shape, depth, and width of MDMR were recorded for each patient by two examiners. Chi-square test was performed to determine the differences between three skeletal sagittal groups and between two genders.

Results: The overall prevalence of MDMR was 60.45%. MDMR was mostly detected in class III (76.92%), followed by class II (76.66%), and class I (54.87%). In the analyzed CBCT scans, semi-lunar was the most common shape detected (42.85%), followed by triangular (30.82%), circular (18.04%), and tear-drop (8.27%). The depth of MDMR was not significantly different between three sagittal groups and between genders; however, the width of MDMR was higher in class III group and in male patients. In the present study, MDMR was found to be more common in patients with class II and class III skeletal classifications. Although, MDMR was more frequent in class III, the difference between class II and class III was not significant.

Conclusion: More caution is needed during orthognatic surgery in patients with dentoskeletal deformities during the splitting of the ramus. Moreover, higher width of MDMR in class III and male patients should be concerned when planning an orthognatic surgery for these patients.

Statement of the problem: One of the rare adverse effects in patients who take bisphosphonates is the osteonecrosis of the jaw in the oral cavity following any trauma such as tooth extraction.

Purpose: The aim of this study is the histopathological evaluation of the jaw following intra-ligament anesthesia injection in Zoledronate-treated rats.

Materials and method: In this descriptive-experimental study, rats weighing 200-250 g were divided into 2 groups. The first group received a 0.6 mg/kg dose of zoledronate and the second group received normal saline. Five injections with a 28-day interval were performed. At the end of the injection, the animals were sacrificed. Then, five-micrometer histological slides were prepared from the first maxillary molars and the surrounding tissues. Hematoxylin and eosin staining was performed to evaluate osteonecrosis, infiltration of inflammatory cells, fibrosis, and root and bone resorption.

Results: There was no difference between the macroscopic and clinical features in both groups and no evidence of osteonecrosis of the jaw was observed in the samples. From the histological point of view, all the samples had normal tissues and none of them showed any evidence of inflammation, tissue fibrosis, disorder, or pathological root resorption.

Conclusion: According to the histological findings, the periodontal ligament space, the bone adjacent to the roots, and the dental pulp conditions were similar in both groups. Osteonecrosis of the jaw did not develop in the rats that took bisphosphonates after intraligamental injection.