فهرست مطالب seyed hosein hoseini zarch

The analysis of complaints against health professionals assists in improving health care services. The objective of this study was to evaluate complaints against dentists working in Mashhad, Iran during 2012-2017.

In this study, all the available completed dental complaint cases from the archive of the Mashhad Medical Council addressed within a six-year time period (from 2012 through 2017) were reviewed. The required information was extracted based on a checklist including variables such as the gender of dentists and complainants, the age of dentists and complainants, dentists’ degree, the place of service provision, the type of services provided, the causes of complaints, and the sentences issued to dentists (conviction or non-conviction).

A total of 208 cases were evaluated, and in 67 (32.2%) cases, dentists had been found guilty. Most cases involving convicted dentists were associated with male dentists, female complainants, general dentists, and in-office services. In the cases of convicted dentists, the most common service provided was endodontic treatment and the most common cause of complaint was failed or incomplete treatment.

To reduce the growing number of complaints against dentists, their skills should be improved, especially in endodontic treatment services. It is advisable for general dentists to consider referring patients to specialists either for more skilled treatments or to allow their patients’ expectations to be better met.

Cone-beam computed tomography is used for specialized imaging of dental and maxillofacial structures. CBCTs capabilities and facilities for dental and maxillofacial imaging have resulted in their increasing clinical use. Although the dose of CBCT tests is low, its widespread use increases the cumulative dose. This study was conducted to evaluate head and neck effective dose and image quality in different organs for various exposure techniques in CBCT imaging.

This study was performed on various CBCT imaging examinations. Head and neck parts of anthropomorphic male Rando® Alderson Phantom and thermoluminescent dosimeters were used for organ dosimetry. Contrast to noise ratio and signal to noise ratio were evaluated for image quality assessments. For this purpose, the region of the tooth and soft tissue images were randomly used as the basis.

Mean effective dose for face and paranasal sinuses imaging in three modes (  standard, low-dose, ultra-low dose), temporomandibular imaging in two modes(standard & low dose), and dental imaging in implant and endo imaging modes was equal to 382.17, 193.97, 79.96, 262.6, 135.67, 53.93, 682.83, 335.75, 184.18, and 234.57 μSv, respectively.Signal -to -noise ratio (SNR) for the above-mentioned procedures was equal to 6.04, 5.73, 3.71, 6.3, 6.00, 4.08, 14.2, 12.3, 7.51, and 6.97, respectively.

The present study showed, when low dose and ultra-low-dose modes are chosen, the patient's dose will be severely reduced in most CBCT procedures. Contrast-to-noise ratio (CNR) and SNR will diminish too, but they are sufficient for some diagnostic purposes.

This study aimed to investigate the positional changes of the hyoid bone following orthognathic surgery in skeletal class III patients.

This double-blinded quasi-experimental study was carried out in Mashhad University of Medical Sciences, Iran, from Apr 2019 to Jun 2020. All skeletal Class III patients who were candidates for orthogenetic surgery were included. They underwent mandibular setback surgery using bilateral sagittal split osteotomy. Cephalometric assessments in relation to hyoid bone position and posterior airway space (PAS) were conducted one day preoperatively (T0), as well as one week (T1), six months (T2) and one year (T3) postoperatively, determining the parameters like the Long axis of the hyoid bone (LAH), Retrognation (RGn), Hyoidale (H), Palatal plane (PP), Mandibular plane (MP) and C3 Vertebrae (C3). All cephalograms were examined using AudaxCeph, Planmeca software. The data analysis was performed via SPSS-19
(P<0.05)

25 class III patients, including 18 females (72%) and 7 males (28%) with a mean age of 24.32±5.87, were studied. The cephalometric analysis demonstrated significant decreases in variable angles during the follow-up periods, except for LAH-MP angle (P<0.001). The hyoid bone moved downward and backward relative to its original position following the mandibular setback surgery. However, the bone gradually returned to the preoperative location between 6 to 12 months postoperatively.

The findings revealed the downward and backward movement of the hyoid bone following the mandibular setback surgery, returned near to its  preoperative position after 1 year, postoperatively.

Most dental traumas occur in the maxillary anterior region, and the related complications can be observed as root and crown fractures or luxation injuries. Root fracture indicates cementum, dentin, and pulp fractures that may be extended longitudinally or horizontally across the tooth root. This study aimed to investigate the accuracy of two different voxel sizes in cone beam computed tomography (CBCT) and the effect of filtration and artifact reductionalgorithm (AR) in the diagnosis of horizontal root fracture (HRF) in the presence and absence of intracanal metallic post (IMP).

Artificial HRF was created randomly in 15 endodontically treated teeth at mid-root and coronal areas. Moreover, 15 intact teeth served as the control group. The cast posts were made for 30 teeth before fracture. The teeth were inserted in artificial casts for imaging and the images were prepared by CBCT system in 0.075 mm and 0.15 mm voxel sizes and were subjected to filtration and AR systems. An experienced radiologist analyzed the radiographic images. The sensitivity, specificity, and accuracy of the HRF diagnosis condition were calculated.

Sensitivity values ranged from 46.7% in 0.15 mm voxel size in the presence of IMP to 100% in 0.075 mm voxel size in the absence of IMP. The specificity rate for all the studied techniques was 100%. The most negative effect of IMP was observed in the diagnosis of one-third of the coronal root and cervical area fractures.

The highest sensitivity and accuracy (100%) in the Promax 3DMax system was observed in 0.075mm voxel size in the absence of IMP. This result was in line with the results obtained with real samples. Filtration and AR systems were ineffective in the diagnose the HRF.

 The spheno‐occipital synchondrosis (SOS) is an important growth center which plays an important role in cranial base development and can define the final relation of SOS with the upper and lower jaws. The morphology and fusion degree of SOS varies in different ages among different populations.

 Thus, the aim of this study was to evaluate the age and sex dependence of ossification of the spheno-occipital synchondrosis in the Iranian population using CBCT.

 This cross-sectional retrospective study was performed on 517 CBCT images of 6- to 18-year-old patients in Mashhad, Iran. Patients with obvious pathology or fractures were excluded from the study. The SOS ossification was classified into four stages from 0 to 3. Two independent observers scored the images. The ossification stage of the SOS was classified according to the age and sex of the patients. Kruskal-Wallis and Kendall’s tau-b used for statistical analysis.

 In this study, 517 samples of 260 females (50.3%) and 257 males (49.7%) with a mean age of 12.03 ± 3.74 years were examined. A significant difference did not exist between males and females regarding their stage of SOS ossification, although males were younger at the SOS transitional stages of 0 to 1, and 1 to 2 compared to females. Also, the SOS starts the ossification process at the age of 11 in females and 10.8 in males.

 The present study showed in the mean age of 16.81 ± 1.12 years, most subjects were in developmental stage 3. Due to the fact that in developmental stage 3 SOS closes, there were no passive maxillary growth after this time. In none of the SOS stages, females and males differed significantly in mean age (P > 0.05). The age of the onset of SOS closure in females was 11 years and in males it was about 10.8 years.

Ankylosis of temporomandibular joint describes the pathological development of bony connections or fibrosis that occurs in the region between the condylar head of the mandible and the glenoid fossa of the temporal bone. This condition can severely affect the function of temporomandibular joint and its mobility. The aim of this study was to evaluate the practicality of CBCT imaging in different types of temporomandibular joint ankylosis.

This cross-sectional study involved 32 cases of ankylosed temporomandibular joint from 26 patients (12 males and 14 females) aged 8-65 years (mean age: 29.8±14.3) who had visited a private maxillofacial clinic between 2013 and 2016 for CBCT images of temporomandibular joint and had been diagnosed with ankylosis by a maxillofacial surgeon. The present study relied on both Dongmei’s and Sawhney’s classifications to assess the different types of joint ankylosis. A number of morphological parameters, including: D1 (the mediolateral diameter of the condyle), D2 (the width of the bony fusion area), D3 (the degree of calcification in the bony fusion area) and D4 (the D2/D1 ratio) were also defined and registered.

All of the four variables (D1, D2, D2/D1 and D4) showed a negative correlation with the extent of mouth opening, but the amounts were non-significant (P>0.05). The level of agreement between the two classification approaches was significantly low (P=0.003). The highest degree of coronoid hyperplasia was seen in types II and III according to both Sawhney’s and Dongmei’s classifications. The greatest measure of condylar head displacement was observed in types II and III of Sawhney’s, and type III of Dongmei’s classification. Connection in the lateral side of the joint in type III of both Sawhney’s and Dongmei’s classifications was the most frequent case. More severe cases of ankylosis were commonly associated with older ages, but the relationship was not significant (P>0.05).

CBCT seems to be the most advantageous modality of imaging as far as temporomandibular joint abnormalities are concerned, including ankylosis. Although the application of the two conventional classifications (Sawhney’s and Dongmei’s) produced little agreement in terms of radiological findings, it seems that the employment of such classifications in conjunction with CBCT imaging is a promising method for the diagnosis and evaluation of temporomandibular joint ankylosis.

The aim of this study was to evaluate the radiographic features of stafne bone defects in patients referred to a private radiology center from March 2013 to 2016 in Mashhad, Iran.
In this retrospective cross-sectional study 5000 CBCTs were evaluated with the definitive diagnosis of SBD. Radiolucencies between the molar region and angle of mandible were considered as SBD and if no increase in the size of the depressions was observed in the second panoramic view, the diagnosis of SBD was made. After selecting the radiographs with SBD, all their radiographic characteristics were recorded.
Among the 5000 CBCT radiographs, 10 (0.2%) SBD cases were diagnosed, 9 in males and only 1 case in a female. All SBDs were between the molar regions and the angle of mandible and were categorized as the posterior variant of SBD. In our studied cases SBD was near the inferior border of mandible and in 3 cases the depressions disrupted the continuity of the inferior mandibular border. The lesion’s shape was oval in 7 cases and round in the others. In total 5 cases were categorized as type I, 4 as type II and one case as type III of SBD.
According to our findings, SBD is an uncommon lesion in the mandible and CBCT can be used as a non-invasive method to detect this defect..

Due to increasing use of X-rays in diagnosis and treatment of diseases, this study aimed to measure and compares the absorbed dose in a number of sensitive organs of head and neck in different radiographic techniques.
Thermoluminescence dosimeter (TLD) and a male equivalent RANDO phantom were used to measure the absorbed dose in organs. The dosimeters were set in certain sites of phantom related to eye, parotid, thyroid gland, occipital area and temporomandibular joint (TMJ). Panoramic and Caldwell techniques with two different exposure conditions as well as Waters technique with three different exposure conditions were performed. Cone-beam computed tomography (CBCT) was applied in low and normal resolutions with different field of view (FOV), and the mean absorbed dose was calculated and compared by the dosimeters related to each of the organs.
The panoramic imaging technique revealed the lowest dose for the eyes, but interestingly higher doses for the parotid gland and the occipital area. In total, Waters and Caldwell imaging techniques indicated that the occipital area and the parotid gland absorbed a higher dose than other organs. In the majority of CBCT scans the parotid region received the highest dose. However, during sinus CBCT (both in low-dose and high-dose modes), the TMJ and eye areas absorbed the highest dose. Investigation of the use of thyroid shield on the absorbed dose in this organ in CBCT showed an average 22% reduction in dose.
In total, panoramic, Waters and Caldwell imaging techniques indicated that the occipital area and the parotid gland absorbed a higher dose than other organs. In the majority of CBCT scans, the parotid region received the highest dose.

Canine impaction is a common occurrence. In this study, we sought to investigate the root anatomy and length of impacted canines and lateral incisor adjacent to impacted maxillary canine.
In this retrospective study, three-dimensional tomographic imaging was performed on 26 patients with unilateral maxillary canine impaction. In this study, we evaluated root length and anatomy of impacted canines, in terms of resorption intensity and curvature, with Planmeca Romexis Viewer 4.0. Furthermore, crown shape as well as root length and anatomy of the lateral incisors adjacent to impacted canines were investigated and compared with the other side on the dental arch, where canine eruption was normal.
Root length of impacted canines was significantly lower than that of normal canines (P=0.011). There were no significant differences between root length of lateral incisors adjacent to impacted canines and root length of lateral incisors adjacent to normal canines (P=0.221). Moreover, the resorption intensity of the adjacent lateral incisors was higher than that of the impacted canines. No significant differences were noted in root resorption intensity between the lateral incisors adjacent to the imacted canines and the lateral incisors adjacent to normal canines (P=0.36). In addition, resorption intensity was significantly higher in impacted canines than in normal canines (P=0.024). Root anatomy of impacted canines was not significantly different from that of normal canines (P=0.055). The crown shape of the lateral incisors adjacent to impacted canines was not significantly different from that of the lateral incisors adjacent to normal canines (P=0.052).
Impaction can probably affect root length and canine resorption severity. However, root and crown shape of lateral incisors cannot always be associated with canine impaction.

Assessment of the lateral wall thickness of the maxillary sinus is very important in decision making for many surgical interventions. The association between the thickness of the lateral wall of the maxillary sinus and the dental status is not well identified.. To compare the thickness of the lateral wall of the maxillary sinus in individuals with and without teeth to determine if extraction of the teeth can lead to a significant reduction in the thickness of the maxillary sinus lateral wall or not..Patients and In a retrospective study on fifty patients with an edentulous space, the thickness of the lateral wall of the maxillary sinus,one centimeter above the sinus floor in the second premolar (P2), first molar (M1) and second molar (M2) areas was determined by cone beam computed tomography scans(CBCTs) and a digital ruler in Romexis F software (Planmeca Romexis 2.4.2.R) and it was compared with values measured in fifty dentated individuals. Three way analysis of variance was applied for comparison after confirmation of the normal distribution of data.. The mean of the wall thickness in each of these points was lower in patients with edentulous spaces; however it was not significant. There was no association between gender and the thickness of the lateral wall of the maxillary sinus, but location was associated with different thicknesses.. The differences in the thickness based on the location and dental status necessitates assessment of the wall thickness of the maxillary sinus in addition to the current evaluation of bone thickness between the sinus floor and the edentulous crest before maxillary sinus surgery..

Assessment of the lateral wall thickness of the maxillary sinus is very important in decision making for many surgical interventions. The association between the thickness of the lateral wall of the maxillary sinus and the dental status is not well identified.. To compare the thickness of the lateral wall of the maxillary sinus in individuals with and without teeth to determine if extraction of the teeth can lead to a significant reduction in the thickness of the maxillary sinus lateral wall or not..Patients and In a retrospective study on fifty patients with an edentulous space, the thickness of the lateral wall of the maxillary sinus,one centimeter above the sinus floor in the second premolar (P2), first molar (M1) and second molar (M2) areas was determined by cone beam computed tomography scans(CBCTs) and a digital ruler in Romexis F software (Planmeca Romexis 2.4.2.R) and it was compared with values measured in fifty dentated individuals. Three way analysis of variance was applied for comparison after confirmation of the normal distribution of data.. The mean of the wall thickness in each of these points was lower in patients with edentulous spaces; however it was not significant. There was no association between gender and the thickness of the lateral wall of the maxillary sinus, but location was associated with different thicknesses.. The differences in the thickness based on the location and dental status necessitates assessment of the wall thickness of the maxillary sinus in addition to the current evaluation of bone thickness between the sinus floor and the edentulous crest before maxillary sinus surgery..

Considerable number of medical claims is annually submitted to the disciplinary court of Mashhad Medical Council (MMC) which a part of them are dental malpractice claims. The objective of this study was to analyze these dental claims. This was a retrospective descriptive-analytical study on dental claims submitted to disciplinary court of MMC during 2006 to 2012. Data including gender of plaintiff, subject of claim, gender of defendant(s), defendants’ field of expertise, the judgment of board of experts and the final verdict were entered into a predesigned checklist. During 7 years, 243 claims were submitted. Plaintiffs were women in 51% of cases, men in 41% of cases and legal entities in 8% of cases. Defendants were men in 81% cases and women in 19% of cases. Eighty-three percent of defendants were general practitioners, 15% were specialists and 2% were denture makers. According to the subject of claims, most were related to endodontic therapy (28%), complications of dental extraction (17%), restorative treatments (13 %) and prosthodontics (11 %). In 10% of cases, claims were about non-clinical issues including advertisement violations and occupational misbehavior. According to the judgment of board of experts, 52% of defendants were acquitted, 22% were sentenced of malpractice and in 12% of cases the plaintiff(s) acquiesced while 11% of cases were archived due to forbearance of the plaintiff. Among the 203 claims against general dentists, 48 cases (24%) and among the 36 claims against specialist dentists, 7 cases (19%) were sentenced of malpractice which were not significantly different (P = 0.4). Among the confirmed dental malpractices, most were related to endodontic therapy (30%). Dentists should consider the possibility of occurring malpractices and to reduce its rate, they should update their professional knowledge and increase their information about legal and criminal issues of their job. Training about legal issues and ethics should be included in the curriculum of dentistry students.

Contemporary cephalometric analysis in orthodontics is based on comparison between craniofacial portions and reference planes. One of these planes is Frankfort Horizontal (FH) Plane that can be made by anatomic portion or machine portion. The aim of this study was to determine and compare the angle between Anatomic Frankfort Horizontal plane (AFH) and True Horizontal (TH) with the angle formed by Machine Frankfort Horizontal plane (MFH) and TH. In this Analytical-descriptive study، digital lateral cephalograms were taken in Natural Head Position from 50 orthodontic patients with the minimum age of 14 and class I malocclusion (Viazis analysis on Onyx Ceph software was employed to confirm the class I malocclusion). Then on each cephalogram، two FH planes were constructed using machine and anatomic portions. Then the angle between each FH plane and TH plane was measured and recorded. Finally، the data were analyzed by paired t-test (=0. 05). Machine Frankfort Horizontal plane (MFH) and Anatomic Frankfort Horizontal plane (AFH) showed significant differences of -5. 66 and -1. 58 degrees with True Horizontal plane (TH) respectively (P<0. 001). For cephalometric evaluation in orthodontic patients if the Frankfurt plane be used، it is better to use anatomical portion، because the difference between the Anatomic Frankfort Horizontal plane (AFH) and True Horizontal plane (TH) is significantly less than the difference between the Machine Frankfort Horizontal plane (MFH) and True Horizontal plane (TH).