Analysis of the Factors Affecting Surgical Success of Implants Placed in Iranian Warfare Victims.

OBJECTIVE: The aim was to evaluate the survival time and success rates of dental implants in warfare victims and factors that affect implant success. SUBJECTS AND METHODS: This retrospective study involved 250 Iranian warfare victims who received dental implants from 2003 to 2013. Patients' demographic characteristics, as well as the brand, diameter, length, location and failure rate of the implants were retrieved from patients' dental records and radiographs. The associations between these data and the survival rate were analyzed. Statistical analysis was carried out with χ2 and log-rank tests. RESULTS: Overall, out of the 1,533 dental implants, 61 (4%) failed. The maxillary canine area had the highest failure rate [9 of 132 implants (6.8%)], while the mandibular incisor region had the least number of failures [3 of 147 implants (2.0%)] and the longest survival time (approximately 3,182 days). Maxillary canine areas had the shortest survival (about 2,996 days). The longest survival time was observed in implants with 11 mm length (3,179.72 ± 30.139 days) and 3.75-4 mm diameter (3,131.161 ± 35.96 days), and the shortest survival was found in implants with 11.5 mm length (2,317.79 ± 18.71 days) and 6.5 mm diameter (2,241.45 ± 182.21 days). Moreover, implants with 10 mm length (10.7%) and 5.5-6 mm diameter (22.2%) had the highest failure rate; however, the least failure rate occurred when the implants were 11.5 mm in length (1.9%) and 3-3.5 mm in diameter (3.1%). CONCLUSIONS: The brand, length and diameter of implants affected the survival time, failure rate and time to failure. The location of the implant was not statistically significant regarding the mentioned factors, although it has clinical significance.

Simultaneous chin onlay bone graft using elongated coronoid in the treatment of temporomandibular joint ankylosis.

Temporomandibular joint (TMJ) ankylosis is a disabling condition that causes problems in mastication, digestion, speech, appearance, and hygiene. Treatment goals are to restore the joint function, to improve facial appearance, and to reestablish harmony among them. To achieve these goals, various strategies have been reported as 1-stage or multistage protocols. We describe a novel method to augment the chin structure with elongated coronoid process of the mandible, which is a sequence of TMJ ankylosis. By this 1-stage treatment that includes gap arthroplasty with interpositional temporalis fascia graft and chin augmentation with autogenous bone graft (elongated coronoid), functional disability and facial deformity of the patient with TMJ ankylosis were improved simultaneously.

Comprehensive treatment and rehabilitation of a patient with maxillary arteriovenous malformation.

Arteriovenous malformations (AVMs) of the maxilla are rare and potentially life-threatening conditions that can pose a therapeutic dilemma. We reported the first case of maxillary AVM in a 15-year-old girl who was treated by marginal hemimaxillectomy including overlying palatal mucosa and immediate replantation of the segment after removing the AVM tissues and teeth and covering by a full-thickness pedicled temporal muscle flap rotated into the mouth. Then, this preserved bone underwent distraction osteogenesis and dental implant rehabilitation successfully. This method was previously used for the definitive treatment of mandibular AVMs, and in this case, we applied this method for the first time in maxillary AVMs. In conclusion, this surgical method may be considered as a safe, convenient, and effective treatment and reconstructive modality for such vascular malformations in the maxilla and restores function and symmetry of the jaws while obviating the need for bone harvesting and future major reconstructive operations.

Metastatic Adenocarcinoma of Mandible with Unknown Primary Origin (CUP Syndrome): a Rare Case Report.

Metastatic lesions of the jaws are a diagnostic challenge because of their scarcity and uncharacteristic clinical-radiographic features. Carcinoma of unknown primary origin (CUP) is characterized by the existence of metastatic disease with no recognized primary neoplasm after a comprehensive work-up. CUP shows a poor prognosis with limited treatment choices. This paper presents a 64-year-old male with a chief complaint of paresthesia of the chin and lower lip. Panoramic radiography showed an ill-defined radiolucency in the left mandibular molar area and the residue of the first molar root. Microscopic examination demonstrated features of mucin-producing adenocarcinoma and was not similar to common neoplasms of the jaw. The whole-body scan revealed multiple osseous uptakes. CDX2 was diffusely positive. However, in the end, the origin of the primary tumor was not determined. Considering the aforementioned data, the diagnosis of metastatic adenocarcinoma with unknown primary origin was made. CUP of the oral cavity is an extremely rare event. The possibility of metastasis should be raised in a patient who complains of paresthesia. Awareness of the clinical and histopathologic features of these malignancies is crucial for clinicians and pathologists to have a proper diagnosis.

Leiomyosarcoma of the Maxilla: A Case Report and Literature Review.

Leiomyosarcoma is a malignant tumor arising from smooth muscle cells accounting for 10-20% of soft tissue sarcomas and less than 2% are located in head and neck region. We report a case of leiomyosarcoma of maxilla in a 26-year-old female patient referred to Shahid-Beheshti University of Medical Sciences, Faculty of Dentistry. Patient complained of swelling of left side of the face from 5 months ago without a history of significant illness. Clinical examination showed asymmetric swelling of left side of the face with tenderness. The lesion in the left buccal vestibule was tender to the touch and contained erythematous mucosa with a firm tissue. Results of the neck computed tomography (CT) scan indicated mucosal thickening in the left maxillary sinus. In the preoperative magnetic resonance imaging (MRI), a mass with an estimated size of 4.7×3.1×3.0cm was found, extending from the posterior wall to the posterolateral wall of the left maxillary sinus, causing impression and remodeling of the sinus wall. Incisional biopsy was preformed and immunohistochemistry suggested leiomyosarcoma. Partial maxillectomy of the posterior maxillary walls was performed, using an intraoral incision and dissection from the maxillary vestibule up to the mandibular vestibule. The tumor was excised using frozen section. Pathological examination reported the lesion compatible with leiomyosarcoma, with all surgical margins free of tumor. Post-operative MRI showed no definite mass in the region. In conclusion, according to the present results, the clinical features of leiomyosarcoma of the maxilla are clear, and diagnosis is feasible.

Does Caffeine Affect Dental Implant Stability? A Prospective Cohort Study.

Statement of the Problem: Caffeine intake affects bone metabolism through inhibition of osteoblast proliferation. Purpose: This study aims to assess the effect of caffeine consumption on implant stability in the healing period of patients. Materials and Method: A prospective cohort study is designed to assess implant stability in the posterior of the maxilla. Patients were divided into two groups based on daily caffeine intake as group 1 with consumption of 400 mg/daily caffeine or more, and group 2 with consumption of 100 mg/daily caffeine or less. The implant stability was measured by resonance frequency analysis (RFA). The mean implant stability quotients (ISQs) were calculated. RFA measurements were made at 4, 6 and 8 weeks after implant placement. Results: A total of 102 patients were studied (51 in each group). The mean of ISQ was 43.49± 2.32 in the group 1 and 42.78±2.34 in the group 2 at four weeks after insertion. The mean of ISQ was 50.86±3.06 in group 1 and 51.37±2.44 in the group at six weeks after implant placement. At eight weeks after implant surgery, the mean of ISQ was 56.78±3.77 in the group 1 and 57.84±1.82 in the group 2. The mean of ISQ between the two groups at 4, 6 and 8 weeks after implant placement was not statistically different. (p= 0.13, p= 0.36 and p= 0.08 respectively) The repeated measure test indicated a similar increase in ISQ in various study times in the two studied groups (p=0.47, df=1, F=0.52). Conclusion: Acquired data suggest that caffeine intake may not have a negative effect on implant stability in the healing period at the posterior of the maxilla.

Does Biphasic Calcium Phosphate-Coated Surface Increase the Secondary Stability in Dental Implants? A Split-Mouth Study.

Purpose: This study aimed to evaluate biphasic calcium phosphate coating (BCPC) on the secondary stability of dental implants compared to sand-blasted and acid-etched (SLA) implants. Materials and Methods: This is a split-mouth study. Thirty subjects (20 males and ten females) underwent a dental implant procedure to replace mandibular first or second molars bilaterally. The subjects were randomly assigned to BCPC or SLA groups. The resonance frequency analysis measurements were performed two, four, six, and eight weeks after the implant placement. Results: Sixty implants were placed in the two groups (30 implants per group). The mean ISQ was 52.26 ± 3.73 in group 1 and 50.21 ± 2.59 in group 2 on day 14 after the implant insertion, 63.20 ± 2.76 in group 1 and 58.80 ± 2.14 in group 2 on day 28, 72.30 ± 3.15 in group 1 and 64.53 ± 3.19 in group 2 on day 42, and 78.70 ± 1.56 in group 1 and 71.63 ± 3.22 in group 2 on day 56. The data analysis demonstrated significant differences between the two groups in terms of the mean ISQ at various evaluation times. Conclusion: Regarding ISQ measurements, the secondary stability in BCPC implants may be higher compared to SLA implants in two months after implant insertion.

Finite element analysis of stress distribution around a dental implant with different amounts of bone loss: An in vitro study.

BACKGROUND: The choice between reducing the bone height and inserting a shorter implant with a greater diameter or a longer and narrower implant without altering the bone height is a challenge in clinical practice. OBJECTIVES: The purpose of this finite element analysis (FEA) was to compare the pattern and level of stress around implants with different lengths and diameters and with different amounts of bone loss, which changes the implant-crown ratio over time, depending on the available bone and the treatment modality. MATERIAL AND METHODS: The FEA was carried out to evaluate the stress distribution in bone around 3.25 × 13 mm and 4 × 11 mm 3i implants, and 3.3 × 12 mm and 4.1 × 10 mm Straumann® implants. A 3D segment of the mandible was reconstructed from a computed tomography image of the posterior mandible. Occlusal force was simulated by applying 200 N vertical and 40 N horizontal loads to the occlusal node at the center of the abutment. The pattern of stress distribution in bone was evaluated in 10 models for each implant, representing 0-9 mm of bone resorption. RESULTS: The results showed that along with decreasing the implant insertion depth, and consequently the implant-crown ratio, the amount of stress in bone increased. The amount of stress increased with an increase in depth of bone loss in all models, but there was no significant change in the amount of stress in the first several millimeters of bone loss. CONCLUSIONS: The results suggest that in terms of stress distribution, it is better to reduce the bone height and insert shorter implants with a greater diameter than longer implants with a smaller diameter.

Decompression or Marsupialization; Which Conservative Treatment is Associated with Low Recurrence Rate in Keratocystic Odontogenic Tumors? A Systematic Review.

Various treatment modalities have been reported for keratocystic odontogenic tumors (KOT), with different recurrence rates. Marsupialization and decompression are two different conservative surgical techniques for the treatment of KOTs. This study aimed at comparing the recurrence rate between marsupialization and decompression in the treatment of KOTs with or without adjunctive treatments. This is a systematic review study. The research sources utilized were PubMed (MEDLINE), Google scholar, Ovid MEDLINE and Cochrane Library. The keywords which were selected based on Medical Subject Heading (MeSH) terms and PICOS criteria were odontogenic keratocyst, keratocyst odontogenic tumor AND marsupialization OR decompression OR cystectomy OR enucleation OR curettage. Statistical analyses were performed to compare the recurrence rate between marsupialization and decompression with or without adjunctive treatments, regarding various follow-up times. The number of subjects that underwent marsupialization was 182. There was a significant difference for the recurrence rate between the marsupialization and decompression groups without considering adjunctive treatments (p= 0.001). However, considering adjunctive treatments, there was no difference between marsupialization and the decompression groups (p= 0.18). It appears that decompression without any adjuvant treatment may have a lower recurrence rate than marsupialization. The recurrence rate was not different when enucleation or cystectomy was performed after decompression and marsupialization.

Knowledge and attitude of Iranian dental school educators towards prevention.

PURPOSE: To investigate knowledge of and attitudes towards prevention of dental caries among Iranian dental educators in relation to their personal and academic background. MATERIALS AND METHODS: Of the 15 Iranian state dental schools, 7 were selected by stratified random sampling to serve as clusters. All the present educators (n = 363) were individually asked to voluntarily complete a pre-tested anonymous questionnaire. A total of 291 educators completed the questionnaire (response rate of 80%). The questionnaire requested information on educators' knowledge of caries prevention and attitudes towards preventive dentistry. The educator's age, gender, highest academic degree, department of teaching, and familiarity with the discipline of dental public health (DPH) served as background factors. Chi-square test and a logistic regression model served in statistical analyses. RESULTS: Educators working in paedodontics, operative dentistry or periodontology departments had more extensive knowledge of caries prevention than did the others (p < 0.05). Women, as well as those familiar with DPH, reported more positive attitudes towards prevention than did the others (p = 0.05). In the regression model, having a more positive attitude towards prevention was associated with female gender (OR = 2.2, 95% CI: 1.2-4.1), more extensive knowledge of caries prevention (OR = 2.4, 95% CI: 1.1-5.6), and greater familiarity with DPH (OR = 2.0, 95% CI: 1.1-4.1). CONCLUSIONS: Dental educators seem to have different knowledge of and attitudes towards prevention based on their disciplines. This may reflect negatively in preventive practice among both the educators and students. Continuing education activities and placing emphasis and support on prevention-related research are recommended.

Bone engineering in dog mandible: Coculturing mesenchymal stem cells with endothelial progenitor cells in a composite scaffold containing vascular endothelial growth factor.

We sought to assess the effects of coculturing mesenchymal stem cells (MSCs) and endothelial progenitor cells (EPCs) in the repair of dog mandible bone defects. The cells were delivered in ß-tricalcium phosphate scaffolds coated with poly lactic co-glycolic acid microspheres that gradually release vascular endothelial growth factor (VEGF). The complete scaffold and five partial scaffolds were implanted in bilateral mandibular body defects in eight beagles. The scaffolds were examined histologically and morphometrically 8 weeks after implantation. Histologic staining of the decalcified scaffolds demonstrated that bone formation was greatest in the VEGF/MSC scaffold (63.42 ± 1.67), followed by the VEGF/MSC/EPC (47.8 ± 1.87) and MSC/EPC (45.21 ± 1.6) scaffolds, the MSC scaffold (34.59 ± 1.49), the VEGF scaffold (20.03 ± 1.29), and the untreated scaffold (7.24 ± 0.08). Hence, the rate of new bone regeneration was highest in scaffolds containing MSC, either mixed with EPC or incorporating VEGF. Adding both EPC and VEGF with the MSC was not necessary. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 105B: 1767-1777, 2017.

Oral health behaviour of Iranian dental school educators.

PURPOSE: To investigate oral health behaviour and smoking habits among academic staff members in Iran's dental schools in relation to their personal and academic background characteristics. MATERIALS AND METHODS: Out of 15 state dental schools, seven were selected randomly as clusters. All of the educators who were present (total n = 363) were asked to voluntarily fill in a self-administered pre-tested questionnaire. In addition to background and academic characteristics, the questionnaire requested information on smoking habits, oral self-care, and dental check-ups. Recommended oral self-care was defined as brushing at least twice a day and frequent use of fluoridated toothpaste. Chi-square test and binary logistic regression model served for statistical analyses. RESULTS: A total of 291 educators filled in the questionnaire (response rate = 80%). Women reported higher frequencies of brushing (p = 0.001), use of fluoridated toothpaste (p = 0.002), flossing (p < 0.01) and eating sugary snacks (p = 0.01) compared with men. Habitual cigarette and pipe smoking was reported by 22% and 3% of male educators respectively. Familiarity with the field of oral public health correlated to higher frequencies of brushing (p = 0.05) and flossing (p = 0.03). Smoker educators reported less favourable oral self-care habits than non-smokers. Female gender (p = 0.002, OR = 2.7) and familiarity with the oral public health field (p < 0.01, OR = 2.5) were associated with recommended oral self-care criteria. CONCLUSION: Dental educators should have positive attitudes towards and beliefs in effectiveness of preventive dentistry in order to increase public awareness of its importance.

Development of PLGA-coated ß-TCP scaffolds containing VEGF for bone tissue engineering.

Bone tissue engineering is sought to apply strategies for bone defects healing without limitations and short-comings of using either bone autografts or allografts and xenografts. The aim of this study was to fabricate a thin layer poly(lactic-co-glycolic) acid (PLGA) coated beta-tricalcium phosphate (ß-TCP) scaffold with sustained release of vascular endothelial growth factor (VEGF). PLGA coating increased compressive strength of the ß-TCP scaffolds significantly. For in vitro evaluations, canine mesenchymal stem cells (cMSCs) and canine endothelial progenitor cells (cEPCs) were isolated and characterized. Cell proliferation and attachment were demonstrated and the rate of cells proliferation on the VEGF released scaffold was significantly more than compared to the scaffolds with no VEGF loading. A significant increase in expression of COL1 and RUNX2 was indicated in the scaffolds loaded with VEGF and MSCs compared to the other groups. Consequently, PLGA coated ß-TCP scaffold with sustained and localized release of VEGF showed favourable results for bone regeneration in vitro, and this scaffold has the potential to use as a drug delivery device in the future.

Sequential supernumerary teeth development in a non-syndromic patient; report of a rare case.

Isolated impacted supernumerary teeth are quite rare, but they can be seen associated with several syndromes such as cleidocranial dysostosis or Gardner's syndrome. This article aims to discuss a case of sequential formation of supernumerary teeth with no other associated disease or syndrome. A 17-year-old Iranian male with 8 impacted supernumerary teeth was referred to the department of pediatric dental clinic at Shahid Beheshti Medical University in Tehran with a history of several impacted unerupted teeth. Repeated and periodical clinical and radiographic examinations revealed newly formed teeth buds in unusual dental ages. All extra teeth were associated with generalized enamel hypoplasia to some degree on their relative permanent adjacent teeth. The patient did not have any record of a systemic disease or any syndromic condition to relate his dental problem to. This rare condition involved repeated and continued formation of extra teeth out of the normal numbers and dental age evident in serial radiographs.

Evaluation of PKM2 and MAPK8IP2 Polymorphism in Ameloblastic Carcinoma: A Retrospective Quantitative Study.

Ameloblastic carcinoma (AC) is a rare malignant epithelial odontogenic tumor that histologically retains the features of ameloblastic differentiation and exhibits cytological features of malignancy in the primary or recurrent tumor. It may develop within a preexisting ameloblastoma or arise de novo or from an odontogenic cyst. Epidemiological evidence shows that human cancer is generally caused by genotoxic factors, genes involved in the susceptibility of cancer, including those involved in metabolism or detoxification of genotoxic environment and those controlling DNA replication. Nowadays, gene polymorphism has an important role in development of malignant tumor. We report a case series study of ameloblastic carcinoma and ameloblastoma to show the role of PKM2 and MAPK8IP2 polymorphisms in these tumors. The DNA was extracted separately from specimens in paraffin sections of the tumor. Polymorphism of these genes was determined by PCR-RFLP (Polymerase Chain Reaction-Restriction fragment length polymorphism) method. The allele distributions of all samples were in Hardy-Weinberg equilibrium. The genotype and allele distribution in these genes were not statistically different between patients and controls.

Marrow-derived mesenchymal stem cells-directed bone regeneration in the dog mandible: a comparison between biphasic calcium phosphate and natural bone mineral.

OBJECTIVE: This study was designed to compare mesenchymal stem cell (MSC)-based alveolar bone regeneration in biphasic bone substitutes and natural bone mineral in a canine full-thickness alveolar defect model. MATERIALS AND METHODS: MSCs were isolated from bone marrow aspirates and culture expanded through 3 successive subcultures. The bone differentiation potential of third passage cells was evaluated and confirmed in vitro before cells were used in the transplantation experiment. Undifferentiated cells were then incubated with 3 x 3 x 3 mm(3) hydroxyapatite/beta-tricalcium phosphate (HA/TCP) matrices (Kasios, Lanauguet, France) and 1- to 2-mm Bio-Oss spongiosa (Geistlich Biomaterials, Osteohealth, Switzerland), which is a natural bovine bone mineral (NBM). Kasios/cell, Kasios alone, Bio-Oss/cell, and Bio-Oss alone were implanted in masseter muscle and 4 cylindrical (10-mm diameter) through-and-through bilateral mandibular body defects in 4 mongrel dogs. Histomorphometric analysis was performed 6 weeks after insertion of the scaffold loaded with MSCs. RESULTS: H&E staining of the decalcified scaffold and scanning electron microscopy demonstrated large MSC coverage of the HA/TCP and Bio-Oss. Cell-loaded Kasios matrices showed the greatest amount of the bone regeneration among the groups in both the muscle (29.11%) and the bone specimens (65.78%). Cell-free biphasic scaffold revealed 44.9% bone fill in bone defects and 23.55% in muscle specimen, and Bio-Oss alone matrices had the least amount of new bone formation: 36.84% and 24.16% in bone and muscle specimens respectively. Kasios loaded with MSCs demonstrated more bone regeneration than Bio-Oss/cell but there was no significant statistical difference (P > .05). CONCLUSIONS: New biphasic synthetic bone substitutes may offer better conditions for bone regeneration than traditional bone substitute in combination with MSCs. They remained in the defect and contributed to bone regeneration.

Oral health behaviour and its determinants amongst Iranian dental students.

OBJECTIVES: To study the oral health behaviour (OHB) of Iranian senior dental students in relation to their gender, background characteristics, knowledge of preventive care, and attitudes towards preventive dentistry. MATERIALS AND METHODS: Using a cluster random sampling approach, a questionnaire survey was conducted with 327 senior dental students in seven dental schools. The questionnaire covered age, gender, parents' employment in dentistry, previous academic education in dental hygiene, oral self-care, most recent dental check-up, knowledge of preventive dentistry and attitudes towards it. Attending a dental check-up by a dentist or a classmate within the last year was defined as preventive care use. Chi-square test and logistic regression models were used for statistical analyses. RESULTS: Women reported significantly higher frequencies of tooth brushing (P < 0.001), fluoridated toothpaste use (P = 0.001) and flossing (P < 0.001) compared with men. Respondents who had been previously educated as dental hygienists had lower frequencies of eating sugary snacks (P < 0.001) and paid more attention to preventive care (P = 0.03) than others. Those with more extensive knowledge of preventive care reported higher frequencies of using fluoridated toothpaste (P = 0.05). Reported frequencies of brushing were higher amongst those with more positive attitudes (P = 0.03). In logistic regression models, having at least one parent employed as a dentist was significantly associated with higher frequencies of eating sugary snacks (P = 0.047, OR = 0.3) and more frequent preventive care use (P = 0.048, OR = 2.9). CONCLUSION: Education and training in preventive measures should be effective enough to overcome background characteristics. There is room for improving the OHB of Iranian dental students.

Prevention-oriented practice of Iranian senior dental students.

OBJECTIVES: To investigate self-reported preventive practice of Iranian senior dental students in dental caries management. SUBJECTS AND METHODS: To obtain an estimated sample size of 250 subjects, seven state dental schools were selected based on a stratified random sampling approach. All the senior dental students (n = 327) were asked to voluntarily fill in a self-administered pre-tested questionnaire during the spring term in 2005. In the questionnaire two hypothetical patient cases (a high-risk and a low-risk patient) were presented and the students were asked to express their conceptions on a five-point Likert scale about including each of nine given alternatives in the patients' treatment plans. The respondents' self-reported oral self-care (OSC), preventive knowledge, attitude towards prevention and self-perceived competency in giving preventive care were also assessed. Chi-squared test and logistic regression model served for statistical analyses. RESULTS: A total of 270 students filled in the questionnaire (response rate = 82%). Acquiring high scores of preventive practice as assessed by patient cases was found to be more frequent among those reporting recommended OSC (P = 0.007) and those with higher attitude scores (P < 0.001). Also, those reporting being competent in giving preventive care had higher scores of preventive practice compared with the others (P = 0.02). In the regression model, recommended OSC (P = 0.05, OR = 1.9) and positive attitudes towards preventive dentistry (P = 0.001, OR = 3.3) showed significant association with acquiring highest scores of preventive practice. CONCLUSION: To improve their preventive practice in the future, more emphasis should be placed on the dental students' own oral health behaviour and attitudes related to it.