جستجوی مقالات مرتبط با کلیدواژه « مندیبل » در نشریات گروه « پزشکی »

The mandibular bone, similar to other bones in the human body, has a number of effective anatomical features that the use of radiographic images of these features can be effective in various findings, such as forensic dentistry. The present study aimed to estimate age, gender, and height by measuring the anthropometric radiographic indices of the mandible in 20-50-year-olds of Iranian race.

This cross-sectional study was performed on 100 people (50 female and 50 male) who were referred to the Orthodontics Department of Ilham Dental School in 2018. The required information was extracted and recorded from patients' panoramic radiographs. Statistical analysis was performed using descriptive statistics, t-test, and SPSS (version 22) software.

The results of this study showed no significant difference between any of the studied variables with age (P>0.05). However, a significant difference was observed between mandibular width, mandibular height, gonial angle, mandibular canal, and the superior-inferior position of the mandibular foramen with gender and height (P<0.05). Moreover, no significant difference was found between the location of the mental foramen and the posterior and anterior position of the mandibular foramen with height (P>0.05). In addition, although no significant difference was seen between the antegonial angle and gender, the antegonial angle had a significant relationship with height (P<0.04).

There is a significant relationship between skeletal variables and gender and height, and it may be possible to determine the gender and height of individuals by evaluating radiomorphometric indices.

One of the most common odontogenic cysts is odontogenic keratocyst (OKC), which originates from the cell rests of the dental lamina. The peak incidence of this cyst is in the second and third decades of life. It tends to occur more in males and is often seen in the mandible, especially the posterior area. One of the important features of this lesion is its high expansion without clinical swelling. In cases where the lesion is small, it is usually asymptomatic; however, in larger cases, it may be accompanied by pain, swelling, or drainage.

A 42-year-old woman referred with a complaint of mandibular swelling. The patient described pain in some cases with low to moderate intensity without any specific pattern. An external oral examination showed face asymmetry with right mandibular swelling in the chin area. Intraoral examination revealed buccal expansion in the right mandible from dental mesial 32 to 46 mesial. All teeth involved in the lesion (32-46) responded positively to the cold test and pulp electrical test. In panoramic radiography, a unilocular radiolucent lesion with well-demarcated and corticated borders was observed in the mandible anterior from 32 to 46 mesial, and in the cone beam computed tomography radiographic view, the perforation of the buccal and lingual cortex was observed. The patient underwent incisional biopsy and marsupialization, and the sample was referred to the pathologist for histopathological examination. In the microscopic examination, histopathological characteristics of OKC were observed.

Although the usual feature of OKC is a lesion without bone swelling, according to this case report, in the differential diagnosis of this lesion, lesions with expansion and perforation of the cortex should also be considered.

Odontogenic cysts and tumors are lesions found in the upper and lower jaw and oral soft tissue. The understanding and correct diagnosis of odontogenic tumors is essential because they can be invasive or recurrent in nature and even rarely show malignant changes. The aim of this study was to evaluate the frequency of odontogenic tumors in Isfahan, Shiraz and Yazd cites.

 TThis is a cross-sectional descriptive- analytical study that was performed in the mentioned centers. The records of registered samples from the first year of establishment to 2018 have been reviewed which is approximately 18,000 cases. Samples data were extracted and recorded based on sex, age, jaw and location of involvement in affected jaw. Data were analyzed using descriptive statistics and
Chi-square test (p value < 0.05).

 In this study, a total of 498 odontogenic tumors were evaluated. The number of odontogenic tumors in Isfahan, Shiraz and Yazd cities was 313, 130 and 55, respectively. The mean age of the patients was 30.1 ± 15.9 and most of the patients were in the age group of 20 to 40 years and 53.4% were female. The most common sites of involvement were the right mandibular (29.1%) and then the left mandibular (28.3%) and the most common tumor was ameloblastoma (50.2%) and then complex odontoma (16.7%).

Due to the frequency observed for odontogenic tumors, understanding the clinical and pathologic features of these lesions is essential for rapid and appropriate diagnosis and treatment.

 Due to the increased prevalence of third molar impaction and the complications and existence of disagreements regarding the predicting factors for the impaction of this tooth, the aim of this study was to evaluate the relationship between the position of the mandibular third molar with different vertical skeletal dimensions on the panoramic images.

This cross sectional study was carried out on lateral cephalogram and orthopantomogram records of 130 orthodontic patients visiting to Isfahan (Khorasgan) University Dental School. Age range of the sample was 20-35 years. Various facial forms were determined with mandibular plane angle (SN-GoGn), jarabak index and Y-axis; S-GN– Frankfort plane. Beta angle; which is the angle between intersecting long axis of mandibular second molar and mandibular third molar was measured to determine the angle of eruption of mandibular third molar. Eruption pattern was classified as per Pell & Gregory and winter’s system. The data were analyzed by Chi-square test (p value < 0.05).

There was a significant difference in the frequency distribution of growth pattern on the left side of the jaw (p value = 0.048). There was no significant difference in the frequency distribution of the eruption pattern in the right side of the jaw (p value = 0.11). There was no significant difference in the frequency distribution of eruption surface in the right face between different facial forms (p value = 0.49) But on the left side of the jaw there was a significant difference between the three facial forms (p value = 0.049). Frequency distribution of mandibular third molar impaction was significantly different between the three facial forms (p value = 0.03). There was no significant difference between the three facial forms in terms of frequency of eruption angle in the right side of the jaw (p value = 0.25) and also in the left side of the jaw (p value = 0.15).

The incidence of impaction was significantly more in patients with long face than in other two groups. The prevalence of surface and pattern of third molar eruption in only one side of jaw was significantly different between the three facial forms. There was no significant difference between the frequency of angle of eruption and facial skeletal types in both jaws.

The nutrient canals in the anterior region of the mandible are derived from the incisive branch of the inferior neurovascular bundle in which any surgery damages could lead to more hemorrhage and postoperative paresthesia. Evaluating the incidence and anatomical location of these canals using dental CBCT is the purpose of this study.

In this study, the CBCT scans of 196 patients- consist of 89 women and 107 men, average age of 49.1 from archive of the radiology department of the Isfahan Islamic Azad University were scrutinized. sex, location, number, size (mesial-distal and buccal-lingual diameter), shape (round or ovoid) of nutrient canals were recorded. Results were analyzed Mann-Whitney, independent t-test, and Kruskal-Wallis test. (p value < 0.05).

There are nutrient canals in 83.6% of the cases, in most of the cases (73.4 %), two nutrient canals in the anterior region of the mandible were detected. The independent t test showed that the average mesial-distal (p value = 0.48) and buccal-lingual (p value = 0.40) nutrient foramen diameter in between dentate and edentulous ones had no meaningful relation. The number of nutrient canals in the anterior region of the mandible in dentate was meaningfully higher than the edentulous ones (p value < 0.001).

there are nutrient canals in most of the cases. There was no significant correlation between age and the number of nutrient canals in the anterior region of the mandible. There was no significant correlation between sex and the number of nutrient canals in the anterior region of the mandible. There was significant correlation between dentate and edentulous ones and the number of nutrient canals in the anterior region of the mandible. Preoperative knowledge of these findings via CBCT scans would be useful to prevent the complication of mandibular surgery.

Intraosseous mucoepidermoid carcinoma is a rare lesion that is mostly seen in the mandible and in the premolar and molar region. In some cases, clear cells can be seen, which makes it difficult to diagnose. The purpose of this case report is the clinical and histopathological evaluation of the clear cell variant of hntraosseous mucoepidermoid carcinoma in the anterior region of the lower jaw that was referred to the dentistry faculty of Ardabil University of Medical Sciences.

The inferior alveolar canal is an important anatomical structure in the field of dentistry implants and cone beam computed tomography (CBCT) is an important diagnostic technique. The aim of this study was to evaluate the prevalence of anatomical variations of the mandibular canal observed in CBCT images.

This descriptive-analytic study 384 inferior alveolar canals were evaluated in 192 patients who were referred to the radiology department of Isfahan Azad University in 1396 for a cone- beam computed tomography. Radiographs were performed to assess the frequency of different left and right mandibular canal segregations by sex in terms of upper and lower position, baccolingual position, shape of the general canal. The frequency and different types of existing mandibular plug canals were also evaluated. Data were analyzed by Chi Square, independent T-test, Paired t- test (p value < 0.05).

The mandibular canal was 2.1% of the lower position, 11.9% of the upper position and 86% of the middle position. Statistically significant differences were observed between the frequency distributions of canal positions and gender(p value = 0.004). The prevalence of Bifid mandibular canals was 14.8%. There was no significant relationship between the shape of the general channel path and gender. There was no significant difference between the mean distance between the mandibular canal and the buccal cortex in both Molar and Ramus with the sex of the subjects and the side of the canal (p value < 0.05).

The highest frequency of mandibular canal in most subjects was on the right in the intermediate position. The mean distance between mandibular canal and buccal cortex in Ramos and Molars area on both right and left sides was not significantly different between men and women.

Odontomas are the most common odontogenic tumors. These lesions are usually considered a hamartoma than a neoplasm. Unlike normal tooth morphology, tissue arrangement is irregular in these lesions. Odontoma has self-limiting and slow growth, and if left untreated, its size will not increase over time. Most of these lesions are clinically asymptomatic and are detected on routine radiographs prepared for other purposes. Odontomas usually are located pericoronally and cause tooth eruption disorders such as the lack of permanent teeth or retention of deciduous teeth. In some cases, an odontoma can cause swelling and expansion of the jaw. The purpose of the current report is presenting an unusual complex odontoma in a 10-year-old boy, which was closely related to the roots of tooth #30. Odontomas are usually located pericoronally and near the roots of adjacent teeth, separated by a septum of bone. There are a few reported cases such as the current case, with fusion to the tooth structure. There was slight intraoral swelling and tenderness in the affected region. Unlike most reported cases, tooth eruption disturbance was not observed. Extreme proximity of odontoma and the roots of tooth were detected in Cone-beam Computed Tomography examination. Separative bone septum and the sharp outline of the tooth roots did not detected. The lesion and the related tooth were removed by surgical treatment, and the patient was followed for 2 years.

Bifid condyle is a rare anomaly in mandible with unknown etiology. Patients with this anomaly may have symptoms but they are usually asymptomatic and it is accidently found in routine radiographic examinations. In recent years with development of three-dimensional (3D) imaging modalities, the reported cases of bifid condyle have extremely increased. This article presents the report of two different cases of this anomaly which were diagnosed using panoramic radiography and cone-beam computed tomography (CBCT) techniques.

The first case was a 35-year-old man without any clinical symptoms referred to obtain panoramic radiography for routine dental checkups. Unilateral bifid condyle was accidentally found in panoramic view. The second case was a 40-year-old woman with chief complaint of pain in temporomandibular joints (TMJs) on both sides. There were no signs of abnormality of condyle in clinical examinations and panoramic radiography. Thus, for further assessment, CBCT images were obtained and the presence of bilateral bifid condyle was confirmed.

Since two-dimensional radiographs such as panoramic images have less accuracy in diagnosing the anomalies of TMJ, the 3D imaging modalities such as CBCT can be the gold standard for better assessment and definite diagnosis, especially in symptomatic patients.

Teeth may need root canal treatment for various reasons. The anatomy of the root canal varies not only between different types of teeth but also between similar teeth. Although there must be at least one canal in the root, some roots have multiple canal of different length. The goal of this study was investigation of the number of root canals in mandibular molars and premolars teeth in Ilam in 2020.

This study was descriptive-analytic study that performed on 60 mandibular premolars and molars (first premolars 15, second premolars 15, first molars 15, second molars 15) randomly with considering of the sex of patients. Data were analyzed by SPSS22.
(Ethic code: IR.MEDILAM.REC.1399.064)

In the first and second premolars, the highest frequency of single canal as 86.7% and 93.3%, respectively. In the first and second molars, the highest frequencies related to the three channels were 53.3% and 86.7%, respectively. The prevalence of 4-channel molars was higher in women and 3-channel in men. This difference was not statistically significant. Between two radiologists and endodontists to determine the number of root canals in the first and second premolars and the first and second molars, a good agreement was reported with kappa agreement coefficient of 0.92 and (P = 0.000).

According to the results of the present study, the first and second mandibular premolars had mostly single root and one canal, and the first and second mandibular molars had often   two roots and three channels.

Tooth occlusion is a common anomaly that is caused by several factors including local and systemic factors. The most common teeth that may be occluded are tertiary permanent teeth, maxillary canines, maxillary and mandibular premolars, and maxillary central incisors. The aim of the present study was to investigate the prevalence of occlusion of different teeth in patients referred to the Oral and Maxillofacial Radiology Clinic in Yasuj during 2017-2018

In this retrospective study, 2536 digital panoramic radiographs were studied among patients who were over 14 years old and referred to the Oral and Maxillofacial Radiology Clinic in Yasuj during the years 2016 to 2017. Patients with a history of trauma, developmental abnormalities, syndromic, pathological problems, and edentulousness were excluded. Radiographs were taken with the VATECH digital panoramic device (pax-i3D). The graphs were examined and a tooth was considered to be occluded, which was prevented from growing normally by a bone or a lateral tooth, as well as a tooth whose occlusal surface was visibly lower than the occlusal surface of adjacent teeth. Chi-square test was used to examine the relationship between age and type of impacted teeth and the difference between men and women in terms of impacted teeth.

Out of 2536 patients, the maxillary molar teeth (number=57) were 2.2%, mandibular molar teeth (number = 46) 1.8%, maxillary canine (number=39), 1.5%, maxillary premolars, respectively. Number=8) 30%, canine (number=7) 3% and incisor (number=4) was 4.2%, which had the most impacted teeth related to the maxillary molars and there were no mandibular premolars and mandibular incisors in this study. There was no significant difference between age and sex in terms of latency.

Dental occlusion in Yasuj city is not considered high, and the highest prevalence of occlusion is after maxillary molars, mandibular molars and maxillary canines. Therefore, if the canine teeth do not grow in time, radiography is recommended to examine their occlusion and use appropriate treatment.

Fractures of the facial bones and jawbones could cause functional problems along with social and cosmetic problems. Various factors (including road accidents, assault, falling from height, sport injuries, and getting hit by a hard object) could cause these fractures. Collecting and reporting accurate epidemiologic data regarding the facial fractures are major steps toward planning preventive measures. The aim of this study was to collect the epidemiologic data regarding maxillofacial fractures in two referral centers (Shariati and Sina hospitals) in the city of Tehran.

The study was a cross-sectional retrospective investigation. All the necessary data were collected from the patients’ files and analyzed using SPSS 25.

The present study pursued data of 454 trauma admitted patients in oral and maxillofacial surgery wards of Shariati and Sina hospitals in 1397 and 1398. These data showed that a number of 374 patients of all patients were men and the other 80 were women. The ratio of male patients to female patients was 4.5:1. In 290 of cases (64%), the fractures occurred as combined fractures and in 164 cases (36%), the fractures occurred as single fracture. These fractures happened mostly in the mandibular bone and in mandibular body, and the least of these fractures happened in Orbit. This study showed that there was a significant relation (with 95% confidence level) between the mandibular body fractures and mandibular angle fractures. This study also showed that there was another significant relation (with 95% confidence level) between the mandibular angle fractures and LeFort 2 fractures. In addition, this study also showed (by using k2 exam) a relation between the etiology of trauma and the number of fractures.

This present study showed that the maxillofacial fractures happened mostly in men much more than women. If we put motorcycle accidents and car accidents in a group together called road accidents, the most common etiology of maxillofacial fractures is road accidents. The results showed that the most fractures happened in the age range of 15-25 year old.

Mandibular second premolars are the third most frequent impacted. By evaluating the three-dimensional position of the impacted tooth and timely treatment, possible problems and damage to adjacent structures can be prevented. This study was designed to assess the position of Impacted Mandibular Second Premolar (MnP2) as well as the effect on adjacent structures using CBCT imaging due to the lack of adequate studies in this field.

This cross-sectional study was performed on 25 impacted mandibular second premolars. Two radiologists assessed and compared CBCT images to determine the following variables: unilateral/bilateral, position of the crown, root resorption of the adjacent permanent teeth, root dilaceration, depth of impaction, type of impaction, pathology incidence, residual primary tooth, position and distance to inferior alveolar nerve canal and the mental foramen.

In most cases, unilateral impaction was seen (19(76%), p=0.063). Crown position of most of MnP2 was displaced lingually (17(68%), p=0.324). Vertical and distoangular position of tooth were more common (12(48%) and 5(20%), p=0.922). Root resorption of the adjacent permanent teeth and dental pathologies did not occur in any of cases. Most of Mnp2 were categorized under the classification as mild (14(56%), p=0.270).

According to the results of the present study, it is unlikely that the MnP2 of young patients analyzed in this study would adversely affect adjacent structures.

 Bone remodeling is a continuous and complex process and it seems that the morphologic changes in mandible is under the influence of age and dental status of the patient. The Gonial angle is a region of mandible that affects from these changes. The aim of this study is the evaluation of Gonial angle size and its correlation with cortical thickness and height of mandibular residual body in various dental status by means of panoramic radiography.

 In this cross sectional study 252 panoramic radiographs of patients who went to Sari Dental School Clinic were examined. Dental status of patients was recorded in the form of relevant information and the patients were categorized in three different groups: Dentate, Partially Dentate and Edentulous group. Panoramic measurement was performed by using software DFW v2.8. All the data were analyzed by software SPSS v16 and descriptive statistics and methods of inferential statistics (p value < 0.001).

 The mean size of gonial angle in dentate, partially dentate and edentulous was 119.92 ± 3.79, 123.48 ± 3.43 and 127.14 ± 5.20 degrees. The mean height of cortical thickness in dentate, partially dentate and edentulous was 3.52 ± 0.73, 3.12 ± 0.54 and 2.86 ± 0.71 mm. The mean height of mandibular residual body in dentate, partially dentate and edentulous was 25.62 ± 2.50, 19.95 ± 3.07 and 14.75 ± 4.67 mm.

 Gonial angle size has an inverse ratio with cortical thickness and height of residual mandibular body

One of the important parameters for implant placement is the presence of sufficient bone in terms of height and transverse thickness. Dental surgeons using the lateralization technique for inferior alveolar nerve transposition face challenges due to the neurological disorders caused by this technique. This study was conducted to evaluate the prevalence of neurological disorders associated with nerve transposition following implant placement.

In this descriptive study, 26 patients over 18 years of age were selected. These subjects were toothless in the posterior mandibular region for a long time. Moreover, in these patients, the distance between the posterior ridges to the roof of the inferior alveolar canal was less than 10 mm. The prevalence of neural complications were assessed after 1 week 1,3,6 and 12 months following nerve transposition by using a questionnaire. The collected data were analyzed in SPSS software (version 19) using the Chi-square test to measure mean and standard deviation through and a significance level of 0.5.

The study sample (n=26) consisted of 16 (61.5%) males and 10 (38.5%) females with the mean age of 56±6.7 years. The most common complication related to the inferior alveolar nerve was experiencing anesthesia which was reported to be 96.2%, 96.2%, 96.2%, 57.7%, and 19% during the 1st week, 1st month, 3rd month, 6th month, and 12th month post-surgery, respectively. Furthermore, it was reported that the tingling sensation decreased from 30.8% in 1 week to 11.5% in 3 months, 6 months, and 1 year after the surgery.

Considering the results, all patients reported experiencing neurological disorders the day after the surgery; however, they recovered to normal state after a few weeks.

The presence of bifid mandibular canals are among the anatomical variations in the inferior mandibular canals. Lack of attention to these canals can lead to complications, such as anesthesia and bleeding during dental treatments. This study aimed to investigate the prevalence of bifid canals and its relationship with the position and width of the main canal in the population-based panoramic radiographs in Qom, Iran.

This analytical-descriptive, cross-sectional, and retrospective study investigated 2415 panoramic radiographs of 1320 females and 1095 males (age range: 18-86 years) who refereed to Dentistry School and Salamat Clinic in Qom, Iran, during 2019. The radiographs were evaluated regarding the presence of bifid mandibular canals on the right and left as well as canal width and distance using Scanora software. The data were analyzed in SPSS software through descriptive statistics (i.e., frequency, mean±SD) and analytical statistics (i.e., Chi-square, independent t-test, and Mann-Whitney test). A p-value less than 0.05 was considered statistically significant.

According to the results, the prevalence of the bifid mandibular canal was observed in 64 (2.6%) cases. Moreover, three (0.1%) individuals had bilateral bifid mandibular canals; therefore, the total number of the bifid mandibular canals was estimated at 67 cases. Furthermore, type 2 bifid mandibular canals were the most common type. In addition, the presence of bifid mandibular canals had no significant relationship with age, gender, width, and distance to the inferior border of the mandible.

The presence of bifid mandibular canal in panoramic images had no significant relationship with age, gender, width, and distance to the inferior border.

The surgical extraction of third molars is the most frequent surgical procedure in oral surgery. Subcutaneous emphysema is an uncommon clinical condition caused by forceful injection of air into the loose connective tissue below the dermal layer, and mostly is the result of using a high-speed air-driven hand piece during surgical tooth extraction. Subcutaneous emphysema is seen mostly in the third and fifth decade of life and in the right mandibular wisdom tooth extraction surgery site. Emphysema can spread to deep spaces such as infratemporal, pterygomandibular, masseteric, lateral or retropharyngeal or mediastinum. This study presents a case report of subcutaneous emphysema occurred during the third molar extraction by using an air-driven hand piece in a 28-year-old female patient. This study has no specific ethical considerations. Informed consent was obtained from the patient to use her information and images. Case management and the issues relative to the diagnosis and prevention of this surgical complication are discussed. Trismus was present with maximum opening of about 30 mm, and no signs of dysphagia and dyspnea were reported. Patient was administered 4 million units of penicillin Intravenous (IV) every 4 hours, metronidazole 500 mg IV every 8 hours solved in 100-cc normal saline infused slowly, and rinsing mouth with 0.2% chlorhexidine every 8 hours. The patient was hospitalized for 36 hours and treated with antibiotic regimen, and then followed up for day 5 until complete resolution of swelling, maximum opening up to 50 mm, and lack of crepitation. No other local, systemic and infectious complications occurred.

Alterations in mandibular condyle morphology is one of the common problems in different age groups. These variations of the condylar are mostly progressive due to the initial changes in remodeling. Therefore, alterations in the size and shape of the condylar bone are of particular importance in the diagnosis of temporomandibular joint-related diseases. This study aimed to determine the radiographic changes in mandibular condyles and its related factors.

This historical cohort research was carried out on 99 patients in the Faculty of Dentistry, Islamic Azad University, Tehran, in 2016. In this study, the temporomandibular disorders (TMDs), age and Eichner's model were evaluated. Mandibular condyle changes were evaluated using panoramic radiography. Data were analyzed with chi-squared test and Pearson’s correlation coefficient, using SPSS 22 (α = 0.05).

In this study, of 99 cases of radiographic examination in three different age groups, 71 cases (71.7%) of condyle deformity were detected. Ely's cyst was the most commonly seen condylar radiographic change, and 50.5% of the subjects had at least one affected condyle, followed by flat condyle (49.5%), erosion (16.2%) and osteophyte (10.1%) in descending order. Sclerosis (1%), condylar convexity (3%) and condylar concavity (2%) were relatively rare.

Based on the results, condylar changes did not increase with age. Statistically, TMD was not responsible for condylar deformity. The Eichner's pattern C (without occlusal contacts on the remaining teeth) was found to be the most frequent in subjects aged 60-70 years. This indicates that the occlusal forces in the elderly was very low and weak, and the occlusion and edentulism did not have a direct relationship with the condyle deformity.