Journal of Dental School
Year:2003 | Volume:21 | Issue:Specail Issue|Papers Count:21

Background & Aim: The objective of this investigation was to determine the causes and incidence of maxillofacial fractures at an emergency hospital in Hamedan, Iran.Materials & Methods: A total of 2,268 patients with 3,107 facial fractures treated between 1987-2001, were retrospectively analyzed. The average number of fractures for each patient was 1.37. Data on the patients, age, gender, cause, site, treatment modalities and trauma associated complications were recorded and assessed.Results: Men 21 to 30 years of age sustained the most facial fractures. The ratio of male to female was 3.84:1. The age range was 4 months to 90 years (mean 24.6 years). Most fractures were caused by motor vehicle accidents, (59.96%) followed by falls, (18.91%) and assaults, (10%). Isolated mandibular fractures, (52.64%) were most common, followed by isolated mid-facial fractures, (29.49%) and alveolar process fractures, (15.07%). 70.85% of patients were treated with closed reduction, 17.76% with open procedures and 11.37% by double approaches. Complications occurred in 5.55% of the patients were directly resulted from trauma.Conclusion: The incidence and causes of facial fractures reflect trauma patterns within the community and vary from one country to another.

Background & Aim: Chronic dental periapical lesions are induced as a result of chronic inflammatory reactions at the periphery of the root apices. The main causes of inflammation are microorganisms and their producets, which can finally destroy tissues by activating immunologic reactions. The presence of IgE containing cells and numerous mast cells, suggest that type I hypersensitivity reactions may participate in the disease process. but it is not well established that what kind of factors could act as allergens. One kind of the possible allergens are root canal filling materials. The aim of this study was to determine the correlation between IgE and failures of endodontic treatment in chronic periapical lesions. Material & Method: In this descriptive study, eighty periaplical lesions from eighty patients (female 55%, male 45%) were removed during surgical procedures. The lesions were divided into two groups on the basis of with or without history of endodontic treatment. All of the lesions which have history of endodnotic treatment, have proper endodontic treatment in radiographic features. The number of cases in each group was forty. Then, they maintained in explant cultures for 24 hours. With ELISA procedure, the presence and concentration of IgE in supernatant fluids were detected. Statistical analysis was made by Chi-square and T-test. Results: There were no significant correlations between the presence and concentration of IgE with the history of endodontic treatment.Conclusion: It is concluded that if type I hypersensitivity reactions have some role in the  pathogenesis of periapical lesions, the root canal filling materials probably do not have important roles in triggering allergic reactions and the role of bacterial antigens are more important than these materials.

Background & Aim: Until the last decades the chance of survival for patients suffered from different types of malignancies was less. In fact prior to 1950, patients with acute lymphoblastic leukemia had a hope to live less than 20 weeks, but with introducing the new methods of chemotherapy, radiotherapy and surgery, a vast improvement obtained in their prognosis with increase of children's life length suffering from cancer, different specialists concentrated on affects may result from the late treatment. Immediate effects of chemotherapy and radiotherapy on soft tissues had been identified well, but there is a less information from their long term effects on dental tissues during their developments.Material & Method: The purpose of this study which was performed in 1999 was to evaluate the relationship between chemotherapy and enamel defects in children suffered from malignant diseases who seek medical advise from Mofid children's hospital in Tehran.Results: In this study 42 patients containing, 15 girls and 27 boys -whom were under chemotherapy, were chosen and the same number of healthy control group were chosen assording to the following rules: For omitting the fluorosis factor, all cases were selected from the citizens of Tehran.- In all children with malignancies, chemotherapy should have been finished (In off therapy stage).- Non of children should have been under radiotherapy on dental and jaw area. - From 1471 teeth in 84 patients, 729 teeth (49.6%) were in case group and 742 teeth (50.4%) in control group. - From this number in first group 29 teeth (4%) and 13 teeth (2%) in control group had enamel involvement.- There was a significant relationship between involved teeth in control group (P<0.025).- The result of this study showed, although enamel defects were more in case group related to control, but this value was not considerable according to total number of children and the observed teeth need more investigation in the future for understanding the probable effects of chemotherapy on enamel genesis.

Background & Aim: Squamous cell carcinoma is the most common cancer in oral cavity with aggressive behavior. Many researches are done about pathogenesis and detection methods for this cancer. The purpose this research is the evaluation of the length of telomere in oral squamous cell carcinoma (OSCC) and its probably diagnostic value.Materials & Methods: We used the sensitive PCR technique based on primer extension method to determine the telomere length. The procedure steps were 1) DNA isolation 2) PCR assay 3) Electrophoresis for assessment of the PCR products 4) AgN03 staining. At last length of the telomere was determined in comparison with 1Kb marker.Results: In 5 cases of OSCC the telomere length was less than 5Kb and in the other 5 samples it was between 5-5.5Kb, but in all normal tissue samples length of the telomere was more than 5.5Kb (9.4-10.6Kb). The findings showed a significant statistical difference between two groups (P<0.01). Also with the more severe dysplastic changes, higher telomere shortening was seen.Conclusion: Telomere length is shortened is shortened in OSCC compare with normal tissue and can be a useful marker for diagnostic aims.

Background & Aim: Many studies have compared Ultrasonic and hand scaling in different aspects, but the aim of this study is to compare the effects of ultrasonic instrumentation and hand scaling in "post-treatment" dentinal hypersensitivity especially to cold stimuli. Material and Method: 30 patients, were selected sequentially. The mouth of each patient was divided into two sides: The Right and the left., and the examinated teeth of each side which were canines and premolars of upper and lower jaws and incisors of the lower jaw, was treated by one of the above methods of scaling. Dentinal hypersensitivity to cold stimuli was evaluated by means of thermal (ice stimuli, immediately and one week after instrumentation and responses were assessed on a severity scale and results were compared with each other.Results: From examinated teeth which were scaled with hand instruments immediately after instrumentation %10.6 showed no sensitivity to cold stimulus, while from the teeth which were scaled with ultrasonic device % 27.7 showed any sensitivity to cold stimulus. The results showed that the hand instrumentation caused more "post-treatment" dentinal hypersensitivity to cold stimulus immediately after instrumentation, and the same results can be seen one week after instrumentation. The type of statistical analysis used for this study is Man- Whitney U test.Conclusion: Results showed that the hand instrumentation produces more sensitivity after treatment.

Background & Aim: The purpose of this study was to evaluate the effects of pulsed Nd: YAG laser on decrease of dentinal microleakage beneath the restoration.Method & Material: 32 sound extracted premolar teeth were subjected to two standardized, V shaped, class V cavity preparations on both surfaces of buccal & lingual. Cavities were located at 1-2mm below the CEJ line. Teeth were divided into two groups of experimental and cotrol in a random manner. 20 and 15mJ/pulse laser energies were tested. Etching, bonding and filling were performed using tetric cream composite material. All samples were thermocycled for 1000 cycles followed by an immersing period of 1 week in 2% basic fuchsine, solution. Specimens were then sliced longitudinally and evaluated under a digital scanner for the extent of dye penetration. Result: Results indicated that the level of microleakage of laser treated cavities was significantly less than that of untreated cavities for 20mJ/pulse laser energy (P<0.05).No significant decrease in microleakage level was observed for the 15mJ/pulse laser energy.Conclusion: The pulsed Nd: YAG laser with the energy of 20 mJ/pulse and aforementioned features is appeared to be able to reduce microleakage toward pulp.

Oncogenic Rickets is a rare type of Rickets, classified into a category of hypophosphatemic Rickets. In this disease presumably several factors are released by the tumor which is capable of inhibiting renal 25-OHD 1-Hydroxylase system and this way could decrease level of serum phosphorus and manifestations of Rickets associated clinical signs.The case described below is a patient that been under follow-up for 11 years and the prominent notion seen is recurrence of both Rickets and mandibular giant cell lesions' clinical signs concurrently. In this patient by surgical removal of lesion, it was observed that after a short time, clinical and laboratory signs were improved significantly.

Aneurysmal bone cyst (A.B.C.) is a rare lesion of the jaws which is classified as a pseudo cyst. The etiology and pathogenesis have yet to be elucidated. Treatment of this benign lesion requires surgical curettage with regular post-operative follow up. In this article, a case of neurysmal bone cyst is reported in the maxillary anterior region of a seven-year-old boy who was refferred to the dept. of peadodontics, Shahid Beheshti Dental School, Tehran for a history of a large swelling on his face. Clinical, surgical and histological findings are presented associated with its treatment proceduces.

Background & Aim: application of various root conditioning agents to root surfaces during surgical therapy is in controversy to increase amount of root coverage. The purpose of this controlled study was to determine the clinical effects of topical application of doxycycline solution in root conditioning as an adjunct to the semilunar coronally repositioned flap for root coverage.Materials & Methods: 24 Miller C1 I gingival recessions in 7 patients, were treated with a semilunar coronally repositioned flap procedure. 12 recession in test group received doxycycline solution for 5 minutes; the remaining did not receive any root conditioning agent. Measurements assessed at baseline, 1 and 3 months follow up.Results: The mean percentage of root coverage was 71% corresponding to a mean percentage of 79% and 63% for the test group and control group, respectively. A significant difference n the clinical measurements (root coverage, clinical attachment level, width of keratinized gingiva) was found within groups (P<0.05), while these differences were not found to be significant between two groups. The mean of probing depth did not change significantly. The sensitivity to a stream of air decreased in both groups but this change was not statically significant. The mean width of recession reduced which was statically significant (P<0.05).Conclusion: The results confirmed that application of doxycycline as an adjunct to this technique in root coverage was not effective.

Background & Aim: The main objective of this study was to compare the efficacy of selective 10 types of Iranian and foreign-made toothbrushes in removing the microbial plaque.Materials & Methods: In the experimental study, Iranian-made toothbrushes including Mina, Mojan, Laleh, Jordan, Jarda and foreign-made ones including Oral-B, GUM, Crest, Dr.Best and Al-Falij were assessed. 240 students in 3 groups used these toothbrushes in different period (one, two or three months). At the end of each month each person was examined and the plaque index was measured.Results: Results showed that the efficacy of all types of toothbrushes in the same month and the efficacy of one type of toothbrush in different month's, has no significant difference.Conclusion: So, it is concluded not only we can prescribe Iranian made toothbrushes to remove the microbial plaque but also we can be sure of efficacy of toothbrushes during 3 months of usage.

Background & Aim: There has been an increasing propensity in recent years for the use of iodoform base materials for root canal treatment of necrotic primary teeth according to the various shortcomings that have been reported over the years about ZOE.Materials & Methods: In this study, we compared ZOE and Vitapex (a premixed Calcium hydroxide and iodoform paste) for root canal treatment of 40 necrotic primary teeth in two groups of children with mean age of 6 years and 6 months. All patients were followed clinically and radio graphically at 3 and 10 months postoperatively.Results: The overall success rate for vitapex wax 100% versus 80.9% for ZOE. Using Fisher Exact Test, the difference was not statistically significant (P>0.05). Vitapex group showed rapid elimination of extruding agentsl from periodical tissues.Conclusion: Both ZOE and vitapex gave encouraging results. However, vitapex can be used more safely if patient's return for follow up. Is in doubt.

Background & Aim: We conducted an investigation to determine whether Argyrophilic Organizer Region (AgNOR) count might be valuable in differentiation of melanotic lesions.Materials & Methods: Fifty cases of five melanotic lesions (10 of each) including Intradermal nevus, Junctional nevus, Dysplastic nevus, Melanoma in the horizontal growth phase, and Melanoma in vertical growth phase were evaluated. Each sample was stained with silver nitrate solution and then AgNORs were counted under the light microscope with a magnification of x1000.Results: Using one-way-Anova statistical test showed that the number of AgNORs in the five groups was significantly different (P<0.0001).Conclusion: AgNOR count can be used to distinguish various melanotic lesions from each other.

Background & Aim: The differences between males and females were also to be looked at especially achieved to template for upper and lower arch making arch wire in Iranian patients at fixed appliance therapy. To achieve confirm results pattern of a normal and ideal arch form should be obtained. Since 1904 many investigators have worked on different size and shapes, and presented variety of methods. The aim of this study was to investigate the Iranian aborigine population arch form, in normal occlusion compared to that commercial arch form.Materials & Methods: A total of 100 cases (50 girls and 50 boys) were evaluated in the age range of 14-18 years with normal occlusion. After preparing study models and occlusograms form evaluation was performed.Results: Results revealed that, the main difference between arch form boys and girls in to be the arch size, not it's their shape. Significant differences were observed between the shape and the size of the arch form of upper and lower jaw. Mean while a 4 degree polynominal curve present the dental arch shape with more than 97% correlation by S.D less than one mm.Conclusion: The dental arch form of individuals are different, there is no variation inform between male and female, significant differences in the upper and lower arch shape and size.

Background & Aim: It is well established that the main cause of inflammatory diseases of dental pulps is dental caries, which in turn is induced by microorganisms. The presence of immunoglobulin within the inflamed pulp has been nidely investigated. It is suggested that immune responses could also participate in pathogenesis of pulpitis. The aim of this study was to determine the correlation between presence and concentration of pulpal IgG, IgA and IgM and various states of carious lesions.Material & method: For this purpose, a total of forty pulpal samples were evaluated. They were divided into four groups by clinical and radiographic examinations. Each group consisted of 10 samples of either healthy erupted teeth or carious lesions in enamel or carious lesions in outer half of dentin, or carious lesions in inner half of dentin. Samples were stored in explants cultures for 72 hours. SRID method was used to detect and quantitate IgG, IgA and IgM in supernatant fluids. Statistical analysis was made by Kruskal Wallis, Mann- Whitney U, Chi square and Fisher exact tests.Results: There was no IgA or IgM in all the samples. IgG was present only in 10% of the samples of caries in the inner half of the dentin eases with mean level of 96±287.9 mg/100 ml. There was no significant difference between different states of dental caries and the presence and/or concentration of IgG. Although the mean level and presence of IgG was higher in the samples with lesions in the inner half of the dentin.Conclusion: It could be suggested that probably humoral immune response has no important role in early inflammatory changes of dental pulps in reversible pulpitis.

Background & Aim: There are many side effects after mesial tilting of the posterior teeth are observed. Different methods with fixed and removable appliances are recommented to upright the tilted molar but each of them has it's own disadvantages. This pilot study was performed to test the ability of combination of fixed and removable appliance to upright the tilted lower and molars for prosthodontic treatment.Methods & Materials: In this pilot study two patients were selected from of the Prosthodontic Department School of Dentistry Shaheed Beheshti Medical Science University to upright their mesially tilted second molars with a new method include a removable appliance as the anchorage unit with band and rectangular wire acting as uprighting force system. In both causes the tilted molar was uprighted for further investigation, applying this method on more cases is recommended.Results: The average improvement of molars axial inclination was 10.5°.Conclusion: The removable appliance could be used as anchorage to deliver an uprighting force to the lower tilted second molars.

Background & Aim: In order to systematically evaluate dentists' attitudes towards Antibiotic and Analgesic administration during pregnancy, this descriptive study was carried out among general dental practitioners and specialists participating at the 40thannual Iranian Dental Congress of 2000.Material & Method: A group of 385 dentists were selected non-randomly for the study. The distributed questionnaires were collected and the obtained data were analyzed resulting in the following findings. Results: 54 percent of the dentists were aware of the FDA classification relating to drug usage safety. Antibiotics and Analgesics were administrated by 92 percent and 91 percent of them respectively while 33 percent of them had been changing the antibiotic dosage and 58 percent analgesic dosage after indication. 47 percent of them were satisfied of the pharmacological courses during their university education according to data they reported. They were informed of the contraindication of doxycyclin, Gentamycin, Clindamycin, Chloramphenicol and Vancomycin use in pregnant women. But, they were not familiar with newly produced drugs such as naproxeri, Erythromycin Estolate, Coamoxiclav along with safety of drugs like Erythromycin Base, Cephalexin, Coamoxiclav and Penicillin G in the studied cases.Conclusion: Comparing the results of the study indicated that Iranian dentists had not enough knowledge relating to the use of the mentioned drugs. Their enough and better information and knowledge about NSAIDs in comparison to the foreign dentists reported in the researches was observed.

Background & Aim: The use of panoramic radiograph is increasing, due to its numerous advantages. Radiographic films used in these techniques are of double emulsion kind which is used with intensifying screens. Single Emulsion or Video films can also be used for this purpose. The aim of this investigation was to determine the exposure parameters to achieve an appropriate optical density in these two types of film, and also to evaluate the radiation doses under such parameters.Material & Method: This study was performed through a tissue equivalent phantom (RANDO phantom). First, with various tube voltages (KVp) and tube currents (mA). A total of 128 radiographs were taken from the phantom with these two types of film. The exposure parameters were determined under which both films showed the same density after examining the optical densities. Then, phantom was again exposed to the radiation and the absorbed doses were measured, using TLDs.Result: It was demonstrated That:1. SE films, require two times radiation in comparison to the double emulsion film in order to provide appropriate optical density,.2. Using SE films increases absorbing dose, of MBM up to 2-2.5 times, thyroid gland to 1.7-2 times and parotid gland dose up to 1.3 times, in comparison to the DE films.3. In DE films, under lower exposure parameters and desirable processing, absorbing dose of the MBM will increase to 3.5 times, thyroid gland to 1.5 times and parotid gland to 2.5 times normal dose.Conclusion: Considering the increased risk of radiation induced cancers following the repeated radiations, the use of SE film should strongly be avoided.

Background and Aim: It is important to understand craniofacial complex responses to orthopedic forces of headgear. This study was designed to investigate the pattern of stress distribution within craniofacial complex following the orthopedic headgear therapy by means of finite element method.Material & Method: A 3D computerized model of craniofacial skeleton was developed using C.T images of a young human dry skull in CAD-CAM-CAE center-Tehran. The elemented model of craniofacial-skeleton and headgear were prepared after the boundary conditions were defined. Loads of 1 kg (500 gr.per side) were applied on the model aligned with appliance in two ways: 1rst with pull angle of 30° superior and 2nd with pull angle parallel to occlusal plane.Results: Results showed maximum tensile stresses were presented in the maxillary first permanent molar area (which it's primary effect was observed) and in inferior parts of midpalatal suture the stress was in compressive form. While creating tensile stresses in superior parts of this suture and in sutures connecting the maxilla to other bones.Conclusion: The most stress concentration was observed in incisive area of midpalatal suture and in medial segment of lacrimomaxillary stuture. (floor of the orbit)