dr. roshanak ghaffari

The ethmoid roof separates the ethmoid cells from the anterior cranial fossa. From the medial side, the roof of the ethmoid is connected to the lateral lamella of the ethmoid plate, which is the thinnest bone at the base of the skull and is most vulnerable to damage during endoscopic surgeries. The purpose of this study is to investigate the height of the lateral lamella in patients with hypoplasia/aplasia of the paranasal sinuses and deviation of the nasal septum using reconstructed multiplanar images by cone‑beam computed tomography (CBCT).

In this descriptive‑analytical (cross‑sectional) study, 192 CBCT images (89 males and 103 females) with an age range of 18 years and older were examined. These 192 participants included 58 cases of frontal sinus (FS) hypoplasia/aplasia, 42 cases of maxillary sinus (MS) hypoplasia/aplasia, 12 cases of sphenoid sinus (SS) hypoplasia/aplasia, 40 cases of nasal septum deviation, and 40 cases as a control group. As Keros classification indicates, the depth of the olfactory fossa was estimated in three categories: type 1 (1–3 mm), type 2 (4–7 mm), and type 3 (8–16 mm). The height of the lateral lamella was measured in the coronal section in all images. The septum deviation angle was also measured in the coronal section. For statistical analysis, Shapiro–Wilk, independent t, nonparametric Mann–Whitney, Pearson correlation, and Kruskal–Wallis tests were done using the SPSS 22 software.

The most common type of olfactory fossa in all disorders and the control group was type II of the Keros classification. The highest average lateral lamella height was in the SS hypoplasia group (6.226 mm) and the lowest in the FS aplasia group (4.411 mm). The lateral lamella height in FS aplasia/hypoplasia groups was significantly lower than the control group (P = 0.002 and P = 0.044). The average deviation angle of the nasal septum was 19.73° ±5.35° and no significant relationship was found between this angle and the height of lateral lamella (P = 0.938). The height of the lateral lamella in the FS hypoplasia group was significantly higher in men than in women (P = 0.019), but in other groups, there was no relationship between lateral lamella height and gender. Seventy‑five percent of the participants of the nasal septum deviation group were type II of Keros classification and the remaining 25% were type I.

The lateral lamella height in hypoplastic/aplastic FSs is lower than normal, and this information is useful in preventing complications during endoscopic sinus surgery.

 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.

Ponticulus posticus (PP) (arcuate foramen) is an abnormal bony bridge in the posterior arch of the atlas, which could possibly cause certain complications such as headache. Our goal was to assess the prevalence and size of PP on lateral cephalometric radiographs and its relationships with cervicogenic headache and migraine.

This cross?sectional study was a descriptive–analytical type and was performed in Isfahan Azad Dental University. Lateral cephalometric radiographs of 150 patients referred to the radiology department were selected to assess the prevalence and size of the anomaly. A checklist was prepared to evaluate cervicogenic headache and migraine among patients.

Our sample consisted of 97 females and 53 males with an age range between 5 and 56 years. The prevalence of PP was 21.3% (12% complete and 9.3% incomplete), and an insignificant difference was noted between the prevalence of complete and incomplete foramen (P > 0.05). The prevalence of foramen was higher in women (59.4%), but it was not significant. The mean width of complete foramen was 6.40 mm, and the mean heights in individuals with complete and incomplete foramen were 4.71 and 4.84 mm, respectively. Among patients with the anomaly, 43.8% had cervicogenic headache and 9.4% had migraine. There was a significant association between the presence of foramen and both types of headaches (P < 0.05). However, there was no significant correlation between the shape of anomaly and the presence of  ervicogenic headache and migraine (P > 0.05).

Our study showed a high prevalence of PP and its significant association with cervicogenic headache and migraine.

Radiography is a valuable adjunct to the diagnosis of periodontal disease. This study aimed to compare the accuracy of two periapical radiographic and digital biting techniques in assessing bone resorption in posterior teeth of patients with chronic periodontitis.

This descriptive-analytical study was performed on 36 samples of interproximal surfaces of posterior teeth in patients with chronic periodontitis, candidate of flap surgery referring to the department of periodontitis, faculty of dentistry, Islamic Azad University of Isfahan (Khorasgan) in 2015. First two methods of imaging include periapical and digital bitewing were performed and the necessary distances were measured by a radiologist. Then, during surgery, and before the bone contour correction, the distance from the reference point to the alveolar bone shaft (gold standard) was measured by a Williams probe. Data were analyzed using Paired t-test. (α = 0.05).

Out of 36 specimens, respectively in bitewing and periapical radiographs 2 and 1 cases were equal with clinical and in 16 (44.4%) and 20 (55.6%) distances were more. The average difference of amount of bone resorption in bitewing was 0.2 ± 0.12 mm and there was no significant difference between estimated mean value (p value = 0.01). Average difference of amount of bone resorption in periapical to clinical method was 0.87 ± 0.26 it was significant difference (p value = 0.001).

According to result, the use of bitewing radiography to determine the rate of bone resorption in posterior teeth is preferable to periapical radiography.

Hyoid bone is a solitary bone, which is composed of a main body and two pairs of horns (greater, and lesser). This bone has an important function in respiration, swallowing, and speech. This study aimed to define the morphology and the frequency of fusion of hyoid bone and its relationship with age and sex on CBCT images.

In this cross-sectional descriptive analytical study, the CBCT images of 163 patients (92 females and 71 males) were analyzed using Type I OnDemand 3D software. In the axial cross-sections, the thickness and length of the hyoid body was measured; in coronal cross-sections, hyoid bone height was measured; and on the thick axial crosssections, the angle between the hyoid bone greater horn and the hyoid bone body midline was measured. The body and greater horn were classified into four categories in terms of fusion (non-fusion with a distance > 2.5 mm, non-fusion with a distance < 2.5 mm, partial fusion and complete fusion). The data were analyzed with Kolmogorov-Smirnov, chi-squared, and Fisher’s exact tests, paired t-test, and Kruskal-Wallis nonparametric test using SPSS 25 (α = 0.05).

In 79.7% of the patients the fusion was similar on both sides (p value = 0.806). There was no significant difference in hyoid bone fusion morphology between male and female groups and between the two sides (p value = 0.977). The most and least frequent types of hyoid bone fusion were type II (non-fusion with a distance < 2.5 mm) and type III (partial fusion), respectively. With the exception of the 10-19 year age group, type II category was the most common type, while type I was the most common in the 1–19-year age group. Hyoid bone fusion morphology varied significantly between the different age groups (p value < 0.05). Hyoid bone size (thickness, length, and height) was greater in men compared to women (p value < 0.05); however, the angle exhibited no significant difference between the male and female subjects (p value = 0.591). Of all the hyoid bone dimensions, only the length of its body was significantly different between the different age groups (p value < 0.05).

With advancing age, the distance between the body and the greater horn of the hyoid bone decreased, and its fusion frequency increased. Only the hyoid body length was different between the different age groups, and the other hyoid bone dimensions were the same. All the hyoid bone dimensions were greater in men compared to women, with the exception of the angle. It is possible to differentiate males from females based on the above-mentioned parameters. CBCT can help reconstruct the hyoid bone using its multiplanar reconstruction with lower radiation.

IIt is important to have proper knowledge about the blood supply of the maxillary sinus to prevent unnecessary complications during surgeries. The aim of the present study was to evaluate the posterior superior alveolar artery (PSAA) in subjects > 20 years of age using the CBCT technique. In this descriptive ‒ analytical study, CBCT scans of 135 patients, with a mean age of 34.4 years, were analyzed. The diameter, the distance to the medial wall of the sinus and the position of the artery within the sinus wall were evaluated on coronal sections. Data extracted from the SIDEXIS 3D software program were analyzed with SPSS 20, using independent T-test, Chi-squared test and one-way ANOVA (p value < 0.05). In 243 (90%) patients, PSAA was detected within the maxillary sinus, with no significant difference in distribution of the artery between females and males (p value = 0.33). The most and least frequent locations of the artery were in the first molar and the first premolar areas, respectively. The most common type of artery was intraosseous (type I). The maximum and minimum mean distances between the artery and the medial wall of the artery were found in the third molar and the first premolar areas, respectively. In addition, the mean distance between the artery and the medial wall and the mean vertical diameter decreased with aging (p value 0.001). CBCT can provide useful information about the anatomic structures inherent to the maxillary sinus and PSAA to prevent unnecessary complications during surgery.

TAll parts of the temporal bone might be pneumatized by mastoid air cells. The aim of this study was to determine of the prevalence of pneumatized articular eminence of the temporal bone on CBCT scans.
In this descriptive analytical study, 150 CBCT scans were evaluated for the presence or absence of pneumatization of articular eminence and other data such as age, sex and the involved side for each case were recorded in special datasheets. Data were analyzed with SPSS 20, using chi-squared test.
Pneumatized articular eminence (PAT) was observed in 9 cases (6%). The prevalence of PAT in males was 33.3%, with 66.7% in females, with no statistically significant differences. Unilateral involvement was more prevalent than the bilateral form. In seven patients (77.8%) PAT was multilocular, and two patients (22.2%) with PAT exhibited unilocular form on the scans.
Prevalence of PAT is higher than what has been reported to date; it has been reported less frequently due to the absence of clinical symptoms and signs.

Jaws spiral tomography and panoramic radiography have wide applications in dentistry, and the parotid gland is one of the most sensitive organs of the head and neck..
The aim of this study was to evaluate and compare the parotid-absorbed dose in spiral tomography and panoramic radiographs using a thermoluminescent dosimeter..
A radiation analog dosimetry phantom was placed in a Cranex Tome radiograph device, and a parotid absorbed dose was measured in both techniques. Thermoluminescent dosimeters were placed bilaterally in the parotid region (on the tube side and the opposite side). Spiral tomography dosimetry was done for the upper and lower jaws in the anterior and posterior regions. Each region contained four slices of 2 mm and four slices of 4 mm in thickness. The results were analyzed by a Wilcoxon test..
For the tube side parotid, the average absorbed doses in spiral tomography of the anterior and posterior parts of the maxilla and mandible, with the 2 mm slice thickness, were 1.70/1.40 and 1.65/1.60 mGy, respectively. The average absorbed doses with the 4mm slices were 1.65/1.70 and 1.75/1.57 mGy, respectively. For the opposite parotid, the average absorbed dose in spiral tomography of the anterior and posterior parts of the maxilla and mandible, with the 2 mm slice thickness, were 1.40/1.30 and 1.40/1.67 mGy, respectively. The average absorbed doses with the 4mm slices were 1.50/1.66 and 1.40/1.50 mGy, respectively. The average absorbed dose of the panoramic radiograph was 1.40 mGy..
There was no statistically significant difference in the parotid absorbed dose between spiral tomography and a panoramic radiograph (P value = 0.18). The overall results of this study were similar to other studies..

Foramen tympanicum is a normal variation of tympanic plate of the temporal bone which exists in the tympanic plate at birth time and will rarely remain open through adulthood. The aim of this research study is to assess the prevalence of this foramen in people over 6 years of age.
In this descriptive-analytic planned cross-sectional study, cone beam computed tomography (CBCT) images of 159 patients (318 ears) over 6 in the Isfahan Province during 2015–2016 were evaluated. The foramen was detected in the axial plane and then was confirmed on the other planes. On each image, the location, size, and configuration of the foramen were studied. Patients were asked about the symptoms in case the foramen was detected. Finally, the data were analyzed using the Chi-square test, independent t-test, McNemar, Fisher, and Pearson correlation coefficient (P > 0.05).
Atotal of 159 images of the patients aged 6–78 years including 99 males and 60 females were studied, of which 11 patients (6.9%) had at least the foramen on one side. The foramen prevalence was symmetrical on both sides (5%), but the tympanic plate’s thinning was significantly higher on the right side (11.3%) than on the left side (5.7%) (P = 0.04). The general shape of the foramen seemed to be oval when axial and sagittal diameters were compared. Statistical analysis indicated a negative correlation between patients’ age and the foramen diameter (P = 0.03, r = −0.324).
Using high-resolution CBCT images, the prevalence of the foramen tympanicum in people over 6 in Isfahan was found to be 6.9% and symmetrical in the two sides and in both genders.

Orthodontic mini-implants are widely placed in the palate. Cortical bone and soft tissue thickness of the palate are important factors for determining the location of mini-implants. The present study investigated the palatal cortical bone thickness using cone-beam computed tomography (CBCT). In this descriptive-analytical trial, 150 eligible CBCTs were selected from males and females in two 19‒40 and 8‒18 age groups. Cortical bone thickness was measured on 8 coronal slices (with 3-mm distances from the incisive foramen) at 0 (midline), and 3- and 6-mm distances from the palatal midline using On Demand 3D software. Data were analyzed with Student’s t-test between two age groups and genders while repeated measures ANOVA was used to analyze data on anterior, middle and posterior areas of the palate (α=0.05). Cortical bone thickness means were 1.38±0.28, 1.1±0.33 and 1.16±0.43 mm in the anterior, middle and posterior regions, respectively (p value < 0.001). Cortical bone was thicker in males at 3-mm distance from the midline compared to females (p value < 0.001) and in the 19‒40 age group compared to the 8‒18 age group (p value < 0.03). There were no significant differences between the two age groups and genders in cortical bone thickness at midline and at 6-mm distance from the midline. Under the limitations of the present study, the anterior region of the palate exhibited the thickest cortical bone; however, mini-implants can be placed in the posterior areas due to the adequate bone thickness.

Frontal sinus and nasal septum have different forms in different people. Frontal sinuses are different in shape even in monozygotic twins. The aim of this study was to determine the prevalence of different combined patterns of frontal sinus and nasal septum in men and women referring to a treatment center in Isfahan. In this descriptive/analytical study Water’s views of 198 subjects aged 20‒40 were collected. The particulars of frontal sinuses in relation to the presence or absence of the sinus proper, symmetry or asymmetry, the form of the septum and the superior border outline of the sinus and the form of the nasal septum were evaluated and recorded. Data were analyzed with chi-squared test (α= 0.05). Bilateral presence of frontal sinus was observed in 100% of the subjects. There were no relations between sex and the presence of a septum within the frontal sinus (p value = 0.53), sinus symmetry (p value = 0.35), and form of the nasal septum (p value = 0.89). There was a significant relation between sex and the presence of a scalloped superior border outline of frontal sinuses (p value < 0.05), with more scalloped borders in men compared to women. Under the limitations of the present study, it was concluded that the combined patterns of frontal sinuses and nasal septa on radiographs cannot be used to distinguish males from females.

Digital radiography systems can be used to detect dental caries. These systems have the advantage of reducing patient dose. The purpose of this study was to compare digital photostimulable phosphor plate, charge coupled device and cone-beam computed tomography systems in detection of interproximal demineralization.

In this cross-sectional analytical laboratory study, sixty extracted human teeth with sound mesial and distal surfaces were selected. Using a ¼ round bur (0.5 mm in diameter) cavities were prepared to a depth of 0.25 mm just apical to the interproximal contact point on 15 surfaces of teeth. A ½ round bur (0.6 mm in diameter) was used to prepare cavities to a depth of 0.3 mm on 15 surfaces and a #1 round bur was used to prepare cavities 0.4 mm in depth on 15 surfaces. The teeth were mounted in groups of three in wax blocks. The images were captured by digital CBCT, PSP and CCD systems under a standard condition. One oral radiologist observed the images to detect interproximal defects twice three weeks apart. Then, sensitivity and specificity were calculated and Cochran test was used for statistical analysis with SPSS 20).α=0.05).

The sensitivity rates of CBCT, PSP and CCD systems for the detection of lesions measuring 0.25 mm in depth (incipient caries) were 100%, 93.3% and 86.7%, respectively (p value = 0.22); there was no differences between the systems in the detection of deeper lesions (100%). There was a high agreement rate between the radiographic systems evaluated and the gold standard in the detection of lesions with varying depths (CCD=94.4% and CBCT/PSP=100%). Specificity of all the systems was 100%.

Under the limitations of this study, there were no significant differences between CBCT, PSP and CCD digital radiographic systems in the detection of interproximal demineralization. The specificity of all the three systems was the same.

With increase of digital imaging, the need for storage space and transmission speed also increases. Compressed images need less storage space and decrease the transmission time. However, compression could compromise image quality. The aim of this study was to evaluate the infl uence of image compression on the identifi cation of cephalometric points on direct digital lateral cephalogram images, compared with the digital imaging and communications in medicine (DICOM) format. In this analytical-descriptive study, 19 direct digital lateral cephalograms saved in DICOM format were used. They were converted to joint photographic experts group (JPEG) 2000 format with quality factors 85, 75, and 60 adding up to 76 images (DICOM, JPEG 85, 75, and 60). The images were randomized and eight cephalometric points were identifi ed on each image by a professional, using the x-y coordinate system. Analysis of variance (ANOVA) was applied to investigate if there was a statistically signifi cant difference in the location of cephalometric points between each group of images. All tests were applied at a signifi cance level of 5%. The results did not demonstrate any statistically signifi cant difference in the identifi cation of the eight cephalometric points between the DICOM images and the JPEG2000 quality factors 85, 75, and 60. JPEG2000 images of lateral cephalograms with quality factors 85, 75, and 60 did not demonstrate any alterations in the identifi cation of cephalometric points compared with the DICOM format. JPEG2000 is a reliable fi le format for the compression of digital lateral cephalograms.

Raising the knowledge of skeletal and soft tissue changes with aging has been highly essential due to an increasing demand for aesthetic facial surgery following aging. The aim of this study is to evaluate the three dimensional computed tomographic images and process of changes in mandible with aging. In this descriptive study, the facial CT scans were obtained from 124 subjects (70 men and 54 women). The population of the study was categorized in three ages (21 to 30, 31 to 40, 41 to 50). Each CT image was reinforced under volume rendering three-dimensional reconstruction by using the three dimensional analysis software volume viewer. The specific parts of mandible consisting of bigonial width, mandibular body height, ramus breadth, ramus height, mandibular body length and mandibular angle were measured and the data were analyzed employing two-ways analysis of variance. In both genders, there was no significant changes in bigonial width with aging (P=0.88). Mandibular body height for both genders decreased with aging but the result was not statistically significant (P=0.19). Ramus breadth decreased with aging in both genders (P=0.02).Considering the obtained means, ramus height and mandibular body length did not show significant changes in different age categories (P=0.09) (P=0.54). In both genders mandibular angle increased with aging (P=0.17). Mandibular angle in women is greater than men and also for ramus breadth. There is no significant difference between men and women.

The soft palate is the posterior fibro-muscular portion of the palate, with a main role in velopharyngeal closure which assists in the normal functions of sucking, swallowing and pronunciation. The aim of this study was to investigate variations in the morphology of soft palate in normal subjects.

In this descriptive-analytical study 169 digital lateral cephalograms were selected from normal Iranian subjects (94 women and 75 men), with age ranges of 15-20 and 21-35, referring to a private oral radiology center in Isfahan. Morphology of the soft palate on lateral cephalograms was examined and classified into 6 types. In addition, the soft palate lengths in each type and differences in relation to age and gender were evaluated. Data were analyzed by t-test, chi-squared test and one-way ANOVA (p value > 0.05).

The morphology of the soft palate was classified into 6 types. Type 1 (leaf-shaped) was the most prevalent. There was a significant difference in the shape of the soft palate between males and females (p value = 0.02). The mean length of the soft palate in men was more than that in women (p value = 0.03). In addition, the soft palate length in type 3 (butt-like(was significantly shorter than that in other types (p value < 0.05).

The soft palate exhibits variable radiographic appearances on lateral cephalograms. Attention to these anatomic variations might assist velopharyngeal closure in patients with cleft palate, obstructive sleep apnea syndrome and speech disorders.

The majority of carious lesions are not well-defined radiolucencies. Approximately 40% demineralization is required for radiographic detection of a lesion. The actual depth of penetration of carious lesion is deeper than may be detected radiographically. However, digital subtraction images permit to detect 1-5 % decrease of mineral mass per unit volume. The goal of the present study was to evaluate the accuracy of digital subtraction radiography in the detection of dental demineralization in vitro. Methods & Materials: This study was based on observational-diagnostic method which was done on 30 extracted human teeth, categorized in two groups A and B, each having 15 members. In each of teeth, one approximal enamel demineralization lesion was induced using an acidified system (PH=4.8). Direct digital radiography were obtained under standardized condition of teeth before demineralization. After 7 days, the teeth of group B and after 42 days, group A removed from acid and new radiographs were taken. The images of the 7th and 42nd days were subtracted from the baseline radiograph (before creation of the lesion). Then teeth were histologically evaluated. Direct digital and subtraction images were interpreted by three observers to detect presence or absence of the lesion, then the diagnostic accuracy of both methods was determined. After 7 days, the sensitivity, specificity, accuracy, positive predictive value and negative predictive value for incipient lesions in direct digital radiography were 0%, 80%, 40%, 0% and 44% respectively and in digital subtraction radiography were 66.7%, 86.7%, 76.7%, 83.4% and 72.3% respectively. However after 42 days the sensitivity, specificity and accuracy of both methods were 100%. Digital subtraction radiography has a fairly acceptable accuracy in detection of the incipient proximal lesions in comparison with DDR. For moderate proximal lesions DSR has the same accuracy as DDR.