فهرست مطالب yasaman kheirandish

Statins affect the bone metabolism. Considering the role of nitric oxide (NO) in many physiological processes, this study assessed the effects of atorvastatin (ATOR) and NO on the mandible and skull bone density (BD) in ovariectomized rats. This study evaluated 48 female Sprague-Dawley rats in 6 groups (n=8). Groups 1 and 2 underwent sham surgery. Group 1 (sham) did not receive any medication, but group 2 (sham/ATOR) received atorvastatin. Groups 3 to 6 underwent ovariectomy. Group 3 (OVX) did not receive any medication, group 4 (OVX/ATOR) received atorvastatin, group 5 (OVX/L-NAME) received L-NG-nitro arginine methyl ester (L-NAME), and group 6 (OVX/ATOR/L-NAME) received both atorvastatin and L-NAME. Atorvastatin (40 mg/kg) was gavaged and L-NAME (3 mg/kg) was administered intraperitoneally for 4 weeks. All rats underwent lateral cephalometry before and after the interventions, and BD was measured at 2 points in the mandible and skull before and after the intervention by a digital densitometer. Data were analyzed by t-test, ANOVA, and Sidak test (alpha=0.05). The change in BD was 26.5±10.17 in the mandible and 22.17±9.45 in the skull in OVX group. These values were 25.63±5.55 and 28±8.59 in OVX/ATR, 1.5±7.78 and -1.88±4.39 in OVX/L-NAME, and 6.63±7.37 and 4.33±6.35 in OVX/ATOR/L-NAME, respectively. OVX/ATOR showed no significant difference (P=1), but OVX/L-NAME (P<0.001) and OVX/ATOR/L-NAME (P<0.001) groups showed significant differences with OVX group. The present findings indicated that atorvastatin had no significant effect on BD, but administration of L-NAME prevented osteoporosis in ovariectomized rats.

 This study aimed to evaluate the cone-beam computed tomography (CBCT) technique considering its reliability to diagnose resorption due to maxillary impacted canine.

 In this cross-sectional study, 68 CBCT images were observed by two oral and maxillofacial radiologists. The position of the impacted maxillary canine was assessed, and the severity of root resorption in adjacent teeth was determined in two rounds by viewing. Finally, statistical analyses were performed according to the percentage of agreement, intra-class correlation coefficient, and kappa. The data sheets were filled out by two radiologists who observed the CBCT images in two separate weeks and recorded their opinions about the position of the crown and root of the impacted maxillary canine. Further, four adjacent teeth were examined for root resorption.

 In most cases, no root resorption was observed in the lateral, central, and first premolars; however, the reported percentage of root resorption in the lateral premolar was higher than that of the others, and no root resorption was reported in the second premolars. Agreement on crown and root position was reported to be above 90% in all observations. In addition, the percentage of agreement was 98.5%, 95.6%, 98.5%, and 100% for root resorption, central incisor, lateral incisor, the first premolar, and the second premolar, respectively. Maxillary impacted canines were examined considering root resorption in adjacent teeth using CBCT, and its interpretation was reliable.

 Utilization of CBCT provides a worthy data about the impacted maxillary canine localization and effects on adjacent teeth, for more explanation and treatment of these cases.

Congenital diffuse infiltrating lipomatosis of the face (CDIL-F) is a rare clinicopathological entity with an unknown etiology, in which mature adipose tissue infiltrates the soft tissue structures in one side, and causes considerable asymmetry. Herein, we report a case of CDIL-F who underwent many surgical procedures without definite diagnosis during 12 years. CDIL-F presents symptoms with various severity levels due to infiltration of adipose tissue that makes removal difficult. Thus, it is recommended to inform patients about the high rate of recurrence.

 Although using panoramic images of the third impacted molars and assessing their proximity to mandibular canal, this technique has limitations such as two-dimensional nature and magnifications occurred which calls to use a three-dimensional radiographic modalities such as CBCT. This study compared the location of the mandibular third molar’s roots regarding the inferior alveolar canal using panoramic radiography and CBCT techniques.

 In a descriptive-analytical trial, 103 radiographic images of the patients’ impacted mandibular third molars were selected from the archives of Radiology Department of Tehran Dental School and assessed by means of panoramic and CBCT techniques. Three oral & maxillofacial radiologists assessed the positions of the mandibular third molars’ roots regarding the inferior alveolar canal in the panoramic and CBCT images at 2 time intervals. The assessments were repeated for next 2 weeks again. And then they were done on CBCT images. Frequency and percent of panoramic signs indicating the proximity of the mandibular third molars regarding buccal, lingual and medial positions of the teeth were obtained among the observers and 2 time intervals and the results were statistically analyzed by chi-square test. Significance level was considered to be 0.05 (p value = 0.05).

 Of total 103 impacted mandibular third molars, 56 (54.4%) had lingual location, 25 (24.3%) had medial location and 22 (21.3%) shoed buccal locations of the roots towards mandibular canal. (p value < 0.002) The frequency of the root deflections (p value < 0.003), diversion of canals (p value < 0.03), narrowings of the roots (p value < 0.005), interruption of the borders (p value < 0.006) and narrowing of the canals (p value < 0.04) were higher in the buccal positions of the third molar roots towards the mandibular canal compared to other positions. The differences were statisticaly significant in some cases. However, the frequency of darkening of the roots (p value < 0.04) was higher in the lingual positions of the third molars than other positions. The agreements of the obervers was acceptable when assessing the images regarding indices of the proximity of third molars’ roots and mandibular canal.

 Then, CBCT technique is a valuable tool to assess the location of the mandibular impacted third molars regarding the inferior alveolar canal. Using CBCT images of impacted third molars, the risk of damage to the alveolar nerve can be reduced.

This study aimed to assess the relation between dimensional changes and object location in the field of view (FOV) using cone beam computed tomography (CBCT).
A custom-made phantom was fabricated from base plate wax. To analyze the accuracy of measurements in horizontal and longitudinal dimensions, aluminum squares (0.5 mm thickness, 10×10 mm dimensions) were constructed and placed in three levels (upper, middle, and lower) and five positions (central, right, left, anterior and posterior). This phantom was scanned using Asahi, Planmeca and NewTom CBCT systems. CBCT scans were measured three times by use of their corresponding software. Statistical analysis was performed using one-way ANOVA, post-hoc test and two-way ANOVA (P The differences between the mean horizontal dimensions of different systems were not significant (P=0.296). However, the differences between the mean longitudinal dimensions of different systems were significant (P=0.039). The differences between the different positions and the mean horizontal and longitudinal dimensions were significant (P We found statistically significant differences in most of our comparisons; however, these differences were not clinically significant. Therefore, CBCT could be an accurate device for measurement of dimensions of objects placed in different positions in the FOV.

Statement of the Problem: Considering the high diagnostic accuracy and wide dynamic range of photostimulable phosphor plates (PSPs), they can be a good alternative for radiographic films.
This study was aimed to assess the effects of delay in scanning PSPs on the diagnostic accuracy of detection of approximal caries.
Radiographs from fifty-two extracted molar and premolar teeth were radiographed using DIGORA PSP (Soredex Corporation, Helsinki, Finland). The teeth were either intact or with non-cavitated approximal caries. The plates were scanned immediately (time zero) and at 10 min, 30 min, 60 min and 120 min after exposure. Sixty-five images were obtained and evaluated for presence or absence of approximal caries by two oral and maxillofacial radiologists and 2 restorative specialists. The diagnostic accuracy of approximal caries detection was measured using a 5-point rating scale. Definite presence of caries was confirmed using a stereomicroscope. Analysis of caries detection data was performed by calculating sensitivity and specificity using repeated measures with ANOVA.
Significant differences were found in complete negative predictive value, absolute negative predictive value and complete dentine sensitivity value between different scan times (p 0.05). The accuracy of approximal caries detection at 120 min was less than at 60 min and at 60 min was less than at 30 min.
In order to detect approximal caries more accurately, DIGORA PSPs should be scanned within 30 min after exposure.

Captopril is an oral angiotensin-converting-enzyme (ACE) inhibitor extensively used in the treatment of hypertension and heart failure. ACE has been suggested to function in bone cells and might therefore impact orthodontic tooth movement (OTM). Considering the controversy surrounding the effects of ACE and its inhibitors on osseous tissues, we aimed to evaluate the effect of captopril on OTM for the first time in a rat model.
Orthodontic appliances were fixed between the left first molars and incisors of 30 rats divided into three groups (n=10) receiving captopril, saline or no treatment. Following sacrifice on day 21, the amount of tooth movement was measured as the distance created between the first and second molars. Bone density was assessed by lateral cephalograms on days 1 and 21 and osteoclast number, root resorption and periodontal ligament (PDL) width were analyzed histologically. One-way ANOVA followed by post-hoc test were used for statistical analysis (P OTM significantly increased in the captopril group compared to the saline and no-treatment groups (P The present study showed that captopril administration could lead to increased OTM and decreased bone density in rats. Further studies are suggested to clarify its exact role at the cellular and molecular levels.

Nowadays, using implants as a choice in patient's treatment plans has become popular. The aim of this study was to determine the prevalence of mandibular lingual and maxillary buccal concavity, mean concavity depth and angle and its relation to age and gender.
In 200 CBCT, concavity depth and angle were measured in 2 mm superior to the inferior alveolar canal in the mandibular first molar area and in 1 mm distance from nasal floor in the midpoint region of maxillary lateral incisor and canine. Concavity depth and angle relationships with age and gender have been evaluated using Spearman Correlation and a t-test.
Mean and standard deviation of lingual concavity, concavity angle and ridge angle in mandible were 1.3±1.54 mm, 15.45±16.19 and 10.13±6.1. Mean and standard deviation of buccal concavity and concavity angle in maxilla were 5.35±1.03 mm and 30.6±5.75. Mandibular concavity depth was zero in 44% of subjects and more than zero in 56%. Results were more than 3 mm in maxillary samples. There was a linear relationship between mandibular concavity depth and age equaled to -0.27, p=0.007 and for mandibular concavity angle and age equaled to -0.25, p=0.01. There was no significant relationship between mandibular ridge angle and age. In maxilla, there was no linear relationship between age and gender with any other variables
It is necessary to provide more information on these region's anatomy using CBCT cross sections before implant placement.

Considering the effect of alcohol on bones, consuming alcohol may have some consequences on orthodontic tooth movement. The present study was aimed to evaluate the effect of alcohol consumption on bone density and orthodontic tooth movement in rats.
In this experimental study, thirty rats were divided into three groups and underwent 3 weeks of different injection regimen. Group A received no injection while rats in group B and C were infused with saline and a mixture of alcohol and saline respectively. Tooth movement at day 21 was measured by leaf gauge. Optical density was measured using a digital densitometer at the beginning and the end of the experiment around four lateral cephalometric landmarks. One-way analysis of variance (ANOVA) was used to determine the differences in tooth movement. Changes in bone density were analyzed using paired T-test after evaluation of interactions.
Mean tooth movement in group C was (0.4± 0.06 mm) was significantly higher than no injection (0.26 ± 0.04 mm) and saline infusion (0.29 ± 0.04 mm) groups (P=0.001). Significant decrease in bone density were observed in alcohol injected group in skull (P=0.005) and mandible(P=0.004) after three weeks of experiment.
Alcohol infusion could induce decreased bone density which might be a reason for faster tooth movement in alcohol-treated rats.

Precise radiographic assessment of the nasopalatine canal is required to prevent implant failure. The purpose of the current study was to determine the three dimensional (3D) morphology, as well as the dimensions of the nasopalatine canal using cone beam computed tomography (CBCT).
In this descriptive cross-sectional study, maxillary CBCT images from 300 patients (150 men, 150 women) were retrospectively evaluated. Sagittal and coronal views were reviewed to determine the nasopalatine canal morphology and dimensions. The difference in canal dimensions between men and women was evaluated using the Student’s t-test while the difference in canal morphology between the two sexes was assessed using Chi-square test.
A total of 199 (66.3%) patients had type A canal (cylindrical without a branch), 69 (23%) had type B canal (a canal with a branch in the upper part), and 32 (10.7 %) had type C canal (a canal with a branch in the middle part). Incisive foramen diameter was 4.7±1.11mm on the sagittal section. Alveolar bone width in the anterior part of the canal was 12.3±1.7mm in the upper one third, 10.7±1.7mm in the middle one third, and 9.8±1.4mm in the lower one third. The angle of canal with palate was 109.5±5.7°. On the coronal sections, canal length was 14.1±3.0mm, incisive foramen diameter was 4.6±1.0mm, and canal diameter in the nasal floor was 5.1±1.0mm.
Significant differences in canal morphology were observed among the patients and CBCT was useful in determining nasopalatine canal morphology and its dimensions before implant placement.

The aim of this study was to assess the effect of tube current, kilovoltage peak (kVp), metal type, and the position of metal objects on metal artifacts in cone-beam computed tomography (CBCT) images.
Titanium and cobalt-chromium rods were fabricated and placed in a dry human mandible. Samples were scanned using a Promax 3D CBCT unit with different milli-amperages and kVp. The artifacts induced by metal objects were evaluated using the Image J software in four regions of interest (ROIs) on each image.
A higher kVp decreased artifacts of the buccal surface of the rods in 97% of the cases (P=0.046) but did not affect the severity of artifacts between the two metal objects (P>0.05). Increasing the tube current had no effect on metal artifacts in 93% of the cases (P>0.05). Artifacts induced by a cobalt-chromium alloy were more severe than those with titanium (P Tube voltage, metal type and the position of metal objects affected the severity of metal artifacts on CBCT images. The metal type had the greatest effect on metal artifact intensity in this study.

This study aimed to evaluate the location and characteristics of mental foramen, anterior loop and mandibular incisive canal using cone beam computed tomography (CBCT).
This retrospective cross-sectional study evaluated 200 mandibular CBCT scans for the location of mental foramen, anterior loop prevalence and mandibular incisive canal visibility, its mean length and distance to buccal and lingual plates and inferior border of the mandible. The effect of age and gender on these variables was also analyzed (P Anterior loop and mandibular incisive canal were seen in 59.5% and 97.5% of the cases, respectively. The mean length of the mandibular incisive canal was 10.48±4.53mm in the right and 10.40±4.52mm in the left side. The mean distance from the endpoints of the canal to buccal plate was 3.63±1.73mm in the right and 3.66±1.45mm in the left side. These distances were 3.89±1.53mm in the right and 4.13±1.48mm in the left side to lingual plate and 9.98±2.07mm in the right and 8.62±1.97mm in the left side to the inferior border of the mandible. The distance from the endpoints of the canal to lingual plate was significantly different in the right and left sides. The distance from the endpoint of the canal to the buccal plate and inferior border of the mandible was significantly shorter in females (P=0.016), and had a weak, significant correlation with age (rsp=0.215, P=0.003).
Due to variability in mandibular incisive canal length and high prevalence of anterior loop, CBCT is recommended before surgical manipulation of interforaminal region.

Fluoxetine is a selective serotonin re-uptake inhibitor (SSRI) widely used for depression, bipolar disorder, anxiety and obsessive-compulsive disorder. The aim of this study was to assess the effect of fluoxetine on orthodontic tooth movement (OTM) in rats.
Forty-five male Wistar rats were randomly divided into three groups namely the control group (no medication), saline and fluoxetine dissolved in saline. In all groups, nickel titanium closed-coil spring was used between the left maxillary central incisor and first molar to exert 60g force at 2mm activation. Radiographs were taken at one and 21 days. After 21 days, the rats were sacrificed. The distance between the first and second molar teeth, optical density of bone, periodontal ligament (PDL) width, lacuna length and depth and number of osteoclasts were measured and compared among the groups.
Tooth movement significantly increased in the fluoxetine group (P=0.005). No significant differences were found in osteoclast count (P=0.069). The PDL width in the mesioapical region of root was significantly different among the groups (P=0.015). Statistical analysis did not show significant differences in depth or length of lacunae in any examined part of the root (P>0.05). Bone densitometry results showed that in fluoxetine group, density of bone in all four areas (alveolar bone, hard palate, skull and mandibular bone) significantly decreased from day one to day 21 (P This study indicated that fluoxetine decreased bone density, which resulted in subsequently greater tooth movement in rats; however, further studies are needed on humans.

Pantoprazole, is a proton pump inhibitor (PPI) prescribed for the treatment of upper gastrointestinal disorders, which in high doses has been suggested to decrease calcium absorption leading to hypocalcaemia and therefore osteoporosis. The aim of this study was to assess whether pantoprazol, could alter the rate of orthodontic tooth movement (OTM) in rats. A time course study was established using 72 rats which were divided into six groups of 12 samples each (four: vehicle; eight: pantoprazole + vehicle). Pantoprazole at a dose of 200 mg/kg suspended in carboxymethyl cellulose (0.25 percent) was administered by a gastric tube. The upper incisors and first molars were ligated by a 5 mm nickel-titanium closed-coil spring to deliver an initial force of 60 g. Animals were euthanized two weeks after orthodontic treatment followed by assessment of tooth movement and histomorphometric evaluation of the detached maxillae. Lateral skull radiographs were obtained once a week, starting from the first day to the 6th week of the study. OTM and bone density data were analyzed using independent sample t-test and repeated measures ANOVA. No significant changes in OTM measurements and optical density were observed in vehicle-receiving animals during the study (P=0.994). OTM was significantly increased after six weeks pantoprazole therapy which continued until the 7th week of the experiment (P=0.007). Optical density significantly increased in the pantoprazole-treated rats after six weeks. Long term PPI therapy at high doses could lead to osteoporosis and enhanced OTM.