Evaluation of the Prevalence of Atherosclerosis Within the Course of Internal Carotid Artery in Cone Beam Computed Tomography Images

The aim of the present study was to retrospectively evaluate the gender-related and age-related prevalence and severity of calcifications within the segments of the internal carotid artery in cone beam computed tomography (CBCT). By using a documented visual scale, out of 400 CBCT examinations a total of 304 CBCT scans of adult patients over 40 years old were evaluated as to the prevalence and severity of intracranial calcifications within the segments of the internal carotid artery. Calcifications were found in 117 CBCT scans. These calcifications were detected along the extracranial (C1: 53%), petrous (C2: 22.2%), Lacerum (C3:27%), cavernous (C4: 94%), and ophthalmic-clinoid (C5/C6: 65%) segments. The Friedman test showed significant differences in the severity of calcifications among the internal carotid artery segments. The McNemar test showed no significant differences between calcifications on the right or left side segments. The Chi square test showed no significant differences in the prevalence of calcifications between men and women; it also showed that the prevalence of calcifications increased with increase in age (P < 0.05). In this study, the frequency and severity of calcifications decreased throughout the C4, C5/C6, and C1 segments in a descending order; moreover, an increased incidence of calcifications by increase in age was documented irrespective of gender.

Feasibility of CBCT in Diagnosing Otosclerosis by Measuring CBCT Bone Density: A Preliminary Study

The aim of this study was to measure cone beam computed tomography (CBCT) derived bone density of 6 anatomic points around the otic capsule in preoperative assessment of patients with clinically suspected otosclerosis, and to compare these densities with control group. CBCT images of 21 patients (34 ears, the otosclerosis group) with surgically confirmed otosclerosis and 26 patients (52 normal ears, the control group) were evaluated in this prospective study. Six regions of interest (ROI) were set manually around the otic capsule with the slice thickness of 0.3 mm. The mean CBCT bone density these regions were measured and compared in the case and control groups. In the case group, the mean CBCT bone density at the fissula ante fenestram (FAF) was significantly lower than the control group. Moreover, at the 4 points of the other ROIs (3-6) CBCT bone densities were significantly lower in the case group compared to the control group (p < 0.01). In this group, among 13 bilateral otosclerosis, 22 ears had conductive hearing loss (CHL), 4 ears had mixed hearing loss (MHL) and among 8 unilateral otosclerosis, 5 ears had CHL, 3 ears had MHL. Our study showed the mean CBCT bone density of ROIs 1 and 6 were correlated with the average air-bone gap in the bilateral and unilateral otosclerosis group, respectively. Quantitative evaluation of CBCT with a slice thickness of 0.3 mm can be used as a suitable tool for diagnosis and follow-up of otosclerosis in temporal bone.

A Radio-Odontometric Analysis of Sexual Dimorphism in First Molars Using Cone-Beam Computed Tomography

OBJECTIVE

Different techniques for sex prediction are developed and used in the forensic medicine field. One of these methods is based on the teeth morphometry. The aim of the present study was to evaluate the degree of sex determination of the maxillary and mandibular first molar teeth in cone beam computed tomography images.

METHOD AND MATERIALS

This study was carried out on cone beam computed tomography images of 100 men and 100 women with a mean age of 21.28 ± 2.47 years. The roof, floor and height of pulp chamber, as well as marginal enamel thickness and dentin thickness at the height of contour, tooth width, and crown length were measured. Student t test and discriminant analysis were applied to assess the differences in the measured parameters between men and women.

RESULTS

According to the present study, the maxillary first molar was more dimorphic than the mandibular teeth. The accuracy of sex identification of mandibular and maxillary first molar tooth was 84% and 77%, respectively. The mesiodistal measured variables were more accurate in sexual differentiation than the buccolingual ones. For sex differentiation, the most dominant variables for maxillary and mandibular first molar teeth were crown height and dentin thickness, respectively.

CONCLUSIONS

The first molar tooth showed an acceptable level of sex determination accuracy based on the odontometric measurements.

Designing and Fabricating Nano-structured and Micro-structured Radiation Shields for Protection against CBCT Exposure

Researchers have always been interested in finding new and effective materials for protection against radiation. This experimental study aimed to design and fabricate new types of nano-material and micro-material based shields against the ionizing effect of cone beam computed tomography (CBCT) X-rays. To fabricate a flexible prototype, we added dioctyl phthalate (DOP) oil to emulsion polyvinyl chloride (PVC) powder. The paste was mixed and dispersed. Then, nano- and micro-powders of WO₃ and Bi₂O₃ were added to the paste, with the weight ratio of 20% PVC, 20% DOP, and 60% nano- and micro-metals. Using an ultrasonic mixer, the polymer matrix and metals were mixed and a paste with a thick texture was developed. The resultant paste was poured into glass molds and the molds were then heated in an oven. After cooling, the resultant sheets were selected for further experiments. A CBCT unit and dosimeter were used to evaluate the characterization and X-ray shielding properties of the fabricated prototypes. The half-value layers (HVL) for nano-WO₃, micro-WO₃, nano-Bi₂O_3, and micro-Bi₂O₃ were 0.0390, 0.0524, 0.0351, and 0.0374 cm, respectively. In addition, the linear attenuation coefficient (µ) for these materials were 17.77, 13.20, 19.71, and 18.5 cm⁻¹, respectively. The findings indicate that nano-structured samples are more effective in the attenuation of X-ray energy. The nano-structured WO₃ prototype was nearly 34% more efficient in attenuating radiation compared to the micro-structured WO₃ prototype. This difference in nano- and micro-structured Bi₂O₃ prototypes was 6.5%.

Difficulty of palatal impacted canine treatment in different sagittal and vertical skeletal malocclusions: A retrospective 3D evaluation

OBJECTIVE

To evaluate the difficulty of impacted canine treatment in different kinds of sagittal and vertical malocclusion using the KPG index, a novel 3D classification system for canine impaction.

MATERIALS AND METHODS

In this cross-sectional study, 74 cone-beam computed tomography (CBCT) images of subjects with palatally impacted canines were collected from one dental radiographic clinic. Impacted canines were assessed and KPG index of difficulty of treatment was calculated for each tooth. Lateral cephalograms corresponding with each CBCT were also traced and analysed. To assess the relationship between the level of treatment difficulty and type of malocclusion, the Chi² test was used. The Kruskal-Wallis H test was used to assess the difficulty score between the three classes of malocclusion.

RESULTS

There was no correlation between different sagittal skeletal measurements and treatment difficulty of impacted teeth (P>0.05). A positive correlation was shown between KPG index and linear measurements of A to Pn and facial angle (FH-N Pog) (P<0.05). Difficulty of treatment did not differ among various patterns of vertical growth.

CONCLUSION

Treatment of impacted canines is more difficult in patients with maxillary prognathism and it is recommended that these patients be more meticulously evaluated prior to treatment.

Critical care usage after major gastrointestinal and liver surgery: a prospective, multicentre observational study

BACKGROUND

Patient selection for critical care admission must balance patient safety with optimal resource allocation. This study aimed to determine the relationship between critical care admission, and postoperative mortality after abdominal surgery.

METHODS

This prespecified secondary analysis of a multicentre, prospective, observational study included consecutive patients enrolled in the DISCOVER study from UK and Republic of Ireland undergoing major gastrointestinal and liver surgery between October and December 2014. The primary outcome was 30-day mortality. Multivariate logistic regression was used to explore associations between critical care admission (planned and unplanned) and mortality, and inter-centre variation in critical care admission after emergency laparotomy.

RESULTS

Of 4529 patients included, 37.8% (n=1713) underwent planned critical care admissions from theatre. Some 3.1% (n=86/2816) admitted to ward-level care subsequently underwent unplanned critical care admission. Overall 30-day mortality was 2.9% (n=133/4519), and the risk-adjusted association between 30-day mortality and critical care admission was higher in unplanned [odds ratio (OR): 8.65, 95% confidence interval (CI): 3.51-19.97) than planned admissions (OR: 2.32, 95% CI: 1.43-3.85). Some 26.7% of patients (n=1210/4529) underwent emergency laparotomies. After adjustment, 49.3% (95% CI: 46.8-51.9%, P<0.001) were predicted to have planned critical care admissions, with 7% (n=10/145) of centres outside the 95% CI.

CONCLUSIONS

After risk adjustment, no 30-day survival benefit was identified for either planned or unplanned postoperative admissions to critical care within this cohort. This likely represents appropriate admission of the highest-risk patients. Planned admissions in selected, intermediate-risk patients may present a strategy to mitigate the risk of unplanned admission. Substantial inter-centre variation exists in planned critical care admissions after emergency laparotomies.

Comparison of Dental Panoramic Radiography and CBCT for Measuring Vertical Bone Height in Different Horizontal Locations of Posterior Mandibular Alveolar Process

STATEMENT OF THE PROBLEM

Accurate measurement of the available bone height is an essential step in the pre-surgical phase of dental implantation. Panoramic radiography is a unique technique in the pre-surgical phase of dental implantations because of its low cost, relatively low-dose, and availability.

PURPOSE

This article aimed to assess the reliability of dental panoramic radiographs in the accurate measurement of the vertical bone height with respect to the horizontal location of the alveolar crest.

MATERIALS AND METHOD

132 cone-beam computed tomography (CBCT) of the edentulous mandibular molar area and dental panoramic radiograph of 508 patients were selected. Exclusion criteria were bone abnormalities and detectable ideal information on each modality. The alveolar ridge morphology was categorized into 7 types according to the relative horizontal location of the alveolar crest to the mandibular canal based on CBCT findings. The available bone height (ABH) was defined as the distance between the upper border of the mandibular canal and alveolar crest. One oral radiologist and one oral surgeon measured the available bone height twice on each modality with a 7-dayinterval.

RESULTS

We found a significant correlation between dental panoramic radiographs and cone-beam computed tomography values (ICC=0.992, p< 0.001). A positive correlation between the horizontal distance of the alveolar crest to the mandibular canal and measured differences between two radiographic modalities had been found (r=0.755, p< 0.001). For each single unit of increase in the horizontal distance of the alveolar crest to the mandibular canal, dental panoramic radiographs showed 0.87 unit of overestimation (p< 0.001).

CONCLUSION

Dental panoramic radiographs can be employed safely in the pre-surgical phase of dental implantation in posterior alveolus of mandible, especially in routine and simple cases.

Comparison of the Bony Changes of TMJ in Patients With and Without TMD Complaints Using CBCT

STATEMENT OF THE PROBLEM

Temporomandibular joint disorders (TMD) may show a poor correlation between their clinical findings and radiological characteristics.

PURPOSE

The aim of this study was to assess the osseous alterations of temporomandibular joint (TMJ) in symptomatic and asymptomatic subjects by employing cone beam computed tomography (CBCT) images.

MATERIALS AND METHOD

In this study, CBCT images of 120 temporomandibular joints in 30 patients with TMJ disorder and 30 age- and sex-matched individuals without TMJ complaints were evaluated. Osteoarticular derangements of the joint were assessed by two experienced examiners. Data was statistically analyzed with SPSS software using chi-square test (p <0.05).

RESULTS

Out of 120 CBCT images (60 in each group), at least one osseous change was observed in 90% and 86.7% joints in symptomatic and asymptomatic subjects, respectively. There were no significant differences between symptomatic and asymptomatic subjects regarding frequency of osteoarticular changes including flattening (73.3% vs. 75%), irregularity (36.7% vs. 48.3%), sclerosis (20% vs. 8.3%), cyst (3.3% vs. 3.3%), erosion (13.3% vs. 21.7%), hypoplasia (3.3% vs. 5%), ankylosis (1.7% vs. Zero), osteophyte (43.3% vs. 40%), decrease joint space (3.3% vs. 3.3%), and increase joint space (5% vs. 5%). (p> 0.05).

CONCLUSION

By employing CBCT as a modern diagnostic imaging tool, findings of this study revealed that the frequency of various temporomandibular joint alterations on CBCT images is comparable in patients with and without TMD complaints, suggesting that some people with TMJ structural damage may not display clinical manifestations. Moreover, CBCT imaging might not be necessary for TMD patients and more attention should be given to clinical examination.

Cone Beam CT Study of Temporal Crest Canal

STATEMENT OF THE PROBLEM

It is crucial for clinicians to be certain about the location of mandibular canal and determine any anatomical variants relevant to it. The temporal crest canal (TCC) is a rare anatomical variant of mandibular canal that lack of awareness about its presence can complicate surgical procedures.

PURPOSE

This study investigated the anatomical characteristics and prevalence of the TCC using CBCT.

MATERIALS AND METHOD

This descriptive cross-section study evaluated 327 CBCTs (654 sides) from all the patients with various problems. TCC on sagittal and axial plans were identified and then classified into two types based on their configuration. The prevalence of TCC was calculated amongst men and women.

RESULTS

Six TCC (0.91%) were observed in 654 sides. We observed all 6 TCCs in females. One case (0.30%) was bilateral TCC, and the remaining four (1.22%) cases were unilateral TCC (two on the left and two on the right side). Considering the classification of TCC, five sides had presentation of type I and one case was type II based on Kawai et al. study.

CONCLUSION

Three-dimensional images of CBCT data are useful in confirming the presence of TCC. TCC is considered as a clinically significant structure; therefore, this variation should be carefully investigated using reconstructed CBCT images.

Cone Beam Computed Tomographic Evaluation of Mandibular Asymmetry in Patients with Cleft Lip and Palate

Objective:

The purpose of the present study was to compare mandibular vertical asymmetry in patients with unilateral and bilateral cleft lip and palate and subjects with normal occlusion.

Materials and Methods:

Cone beam computed tomography scans of three groups consisting of 20 patients with unilateral cleft lip and palate, 20 patients affected by bilateral cleft lip and palate, and a control group of 20 subjects with normal occlusion were analyzed for this study. Condylar, ramal, and condylar plus ramal asymmetry indices were measured for all subjects using the method of Habets et al. Kruskal-Wallis and Mann-Whitney tests were used to determine any significant differences between the groups for all indices at the 95% level of confidence.

Results:

There were no significant differences regarding sex for all mandibular asymmetry indices in all three groups. All Asymmetry indices (condylar, ramal, and condylar plus ramal asymmetry) were significantly higher in the unilateral cleft group compared with the other two groups.

Conclusion:

Cone beam computed tomography images showed that patients with cleft lip and palate suffered from mandibular asymmetry. Subjects with unilateral cleft lip and palate had a more asymmetric mandible compared with the bilateral cleft lip and palate and control groups. Therefore, the mandible appears to be the leading factor in facial asymmetry in subjects with unilateral cleft lip and palate.

Comparison of the Effects of Transcutaneous Electrical Nerve Stimulation and Low-Level Laser Therapy on Drug-Resistant Temporomandibular Disorders

STATEMENT OF THE PROBLEM

Temporomandibular disorder (TMD) is a clinical term used for clinical signs and symptoms that affect the temporomandibular joints, masticatory muscles, and associated structures. Surgical and non-surgical treatments can be used for management of TMD. Non-surgical route is the main part of the treatment, since clinicians prefer non-aggressive treatment for TMD such as pharmacological and physical therapy. Low-level laser therapy (LLLT) and transcutaneous electrical nerve stimulation (TENS) are the main procedures in physical therapy.

PURPOSE

The aim of this study was to evaluate the effectiveness of TENS and LLLT in treatment of TMD patients who did not respond to pharmacological therapy.

MATERIALS AND METHOD

This clinical trial was performed on 45 patients who randomly received either TENS or LLLT for 8 sessions. LLLT was applied with diode laser (Ga-Al-As, 980nm, dose 5j/cm²) and TENS by using two carbon electrodes with 75 Hz frequency (0.75 msec pulse width). Helkimo index and visual analogue scale (VAS) were measured during the treatment period and throughout the follow-up sessions.

RESULTS

Significant reduction in the VAS and Helkimo index was observed in both TENS and LLLT group. There was no significant difference between the two methods during the treatment; however, TENS was more effective in pain reduction in follow-ups.

CONCLUSION

This study justified the use of TENS therapy as well as LLLT in drug-resistant TMD. Both were useful in relieving the pain and muscles tenderness, although, TENS was more effective than LLLT.

Influence of Head Position on the CBCT Accuracy in Assessment of the Proximity of the Root Apices to the Inferior Alveolar Canal

STATEMENT OF THE PROBLEM

The most important risk factor for inferior alveolar nerve (IAN) damage is the proximity of the mandibular root apices to the alveolar canal. Failure to position the patient's head at standardized orientation during cone beam computed tomography (CBCT) scans might adversely affect the relative position of the alveolar canal and mandibular root apices with subsequent treatment failure.

PURPOSE

The purpose of the present study was to investigate the influence of the orientations of the skull during the scanning procedure on the accuracy of CBCT images in determining the positional relationship of the mandibular tooth apices to the alveolar canal.

MATERIALS AND METHOD

CBCT scans of 7 human dry skulls were obtained by using NewTom VGi CBCT in standard, tilt, flexion, extension and rotation positions of the head. The shortest radiographic distance between the mandibular tooth apices and the IAN canal of 20 points were measured on cross sectional images of CBCT in all position scans. A sample t-test was used to compare the measurements at different head position with the standard position values.

RESULTS

Significant differences were found in the measurements of normal and tilt orientations. However, there was no statistically significant difference between the measurements in standard position and other deviated positions. The mean errors in all head positions were less than 0.5mm.

CONCLUSION

Alteration of patient head positioning during CBCT scanning does not affect the relative position of the IAN and the apices of posterior teeth.

Low vs. high haemoglobin trigger for transfusion in vascular surgery: protocol for a randomised trial

BACKGROUND

In patients with cardiovascular disease, guidelines for administration of red blood cells (RBC) are mainly based on studies outside the vascular surgical setting with the recommendation to use a haemoglobin (hb) trigger-level lower than by guidelines from The European Society for Vascular Surgery. Restricting RBC transfusion may affect blood O₂ transport with a risk for development of tissue ischaemia and postoperative complications.

METHODS

In a single-centre, open-label, assessor blinded trial, 58 vascular surgical patients (> 40 years of age) awaiting open surgery of the infrarenal aorta or infrainguinal arterial bypass surgery undergo a web-based randomisation to one of two groups: perioperative RBC transfusion triggered by hb < 8 g/dl or hb < 9.7 g/dl. Administration of fluid follows an individualised strategy by optimising cardiac stroke volume and near-infrared spectroscopy determines tissue oxygenation. Serious adverse event rates are: myocardial injury (troponin-I ≥ 45 ng/l or ischaemic electrocardiographic findings at day 30), acute kidney injury, death, stroke and severe transfusion reactions. A follow-up visit takes place 30 days after surgery and a follow-up of serious adverse events in the Danish National Patient Register within 90 days is pending.

DISCUSSION

This trial is expected to determine whether a RBC transfusion triggered by hb < 9.7 g/dl compared with hb < 8 g/dl results in adequate separation of postoperative hb levels, transfusion of more RBC units and maintains a higher tissue oxygenation. The results will inform the design of a multicentre trial for evaluation of important postoperative outcomes.

A cone beam computed tomographic evaluation of the size of the sella turcica in patients with cleft lip and palate

OBJECTIVE

Changes in the size of the sella turcica are frequently related to pathologies and syndromes. The aim of this was to compare the sella turcica dimensions in patients with unilateral and bilateral cleft lip and palate and non-cleft subjects.

METHODS

Cone beam computed tomography (CBCT) images of three groups consisted of 20 patients with unilateral cleft lip and palate; 20 patients with bilateral cleft lip and palate and a control group consisting of 20 non-cleft subjects were the research population in this pilot study. The sella turcica linear dimensions in terms of length, depth and diameter were measured for all subjects. One-way ANOVA test was used to determine any significant differences among the three groups for the measured parameters.

RESULTS

The length, depth and diameter of sella turcica were found to be significantly smaller in the unilateral and bilateral groups compared with the normal age and gender matched group. No significant differences were found in the measured variables between the unilateral and bilateral cleft patients.

CONCLUSION

CBCT images showed a greater likelihood of abnormal sella turcica dimensions in patients with unilateral and bilateral cleft lip and palate. Therefore, the sella turcica dimensions may have an intrinsic relationship to the cleft condition.

Evaluation of Condylar Position after Orthognathic Surgery for Treatment of Class II Vertical Maxillary Excess and Mandibular Deficiency by Using Cone-Beam Computed Tomography

STATEMENT OF THE PROBLEM

In orthognathic surgeries, proper condylar position is one of the most important factors in postoperative stability. Knowing the condylar movement after orthognathic surgery can help preventing postoperative instabilities.

PURPOSE

The aim of this study was to evaluate the condylar positional changes after Le Fort I maxillary superior repositioning along with mandibular advancement by using cone beam computed tomography (CBCT).

MATERIALS AND METHOD

This cross-sectional study was conducted on 22 subjects who had class II skeletal malocclusion along with vertical maxillary excess. Subjects underwent maxillary superior repositioning (Le Fort I osteotomy) along with mandibular advancement. The CBCT images were taken a couple of days before the surgery (T0), and one month (T1) and 9 months (T2) after the surgery. The condyles positions were determined from the most superior point of the condyle to three distances including the deepest point of the glenoid fossa, the most anterior-inferior point of the articular eminence, and the most superior point of the external auditory meatus in the sagittal plane.

RESULTS

The mean mandibular advancement was 4.33±2.1 mm and the mean maxillary superior repositioning was 4.66±0.3 mm. The condyles displaced inferiorly, anteriorly, and laterally between T0 and T1. They were repositioned approximately in the initial position in T2. No correlation was observed between the mandibular and maxillary movement and the condylar positions.

CONCLUSION

The condyles displaced in the inferior-anterior-lateral position one month after the bilateral sagittal split osteotomy for mandibular advancement in combination with the maxillary Le Fort I superior repositioning. It seems that the condyles adapted approximately in their initial position nine months after the surgeries.

Clinical surface modification process using the nitrogen plasma and its anti-bacterial efficiency

In this research, the cotton fabrics were treated with nitrogen plasma for the clinical and anti-bacterial purposes. Turmeric was used a as a natural dye. Some part of both untreated and plasma treated samples was immersed in silver nitrate as a mordant before dyeing. Effect of plasma and silver nitrate on dye ability of cotton samples was compared and studied. Samples were analyzed with different experimental methods, such as scanning electron microscopy (SEM), Reflection spectro-photometry and antibacterial test. Results showed that, turmeric dye have anti-bacterial efficiency and good antibacterial activity achieved by plasma treatment of fabrics. In case of AgNO3 treatment, samples showed 100% antibacterial activity. It also concluded that, nitrogen plasma has synergic effect on antibacterial activity of turmeric as natural dye on cotton fabrics.

Sexual Dimorphism of Maxillary Sinus Dimensions Using Cone-Beam Computed Tomography

Sex determination of unknown persons plays an important role in forensic medicine. Cone-beam computed tomography (CBCT) is an excellent imaging modality for accurate measurement of maxillary sinus dimensions. This study aimed to evaluate whether maxillary sinus measurements on CBCT scans can be applied for sex determination. The width, length, and height of maxillary sinuses in CBCT images of 100 patients (50 males and 50 females) were measured. Student's t-test and discriminant function analysis were used to compare differences in the measured parameters between males and females. The correct predictive accuracy rate of sex determination was 78% in females and 74% in males with overall accuracy of 76%. Based on discriminant analysis, the most pronounced variable in differentiation of sex groups was maxillary sinus height. This study suggests that maxillary sinus measurements can be valuable for sex determination in forensic investigation, especially for cases in which other traditional methods are not applicable.

Risk of early recurrent stroke in symptomatic carotid stenosis after best medical therapy and before endarterectomy

BACKGROUND

The early recurrence of neurological symptoms (NR) after urgent aggressive best medical therapy (BMT) in symptomatic carotid stenosis is not well documented.

AIMS

To investigate the risk of ipsilateral NR after urgent aggressive BMT in patients with symptomatic (50-99%) carotid stenosis up to carotid endarterectomy (CEA), with emphasis on the first 14 days after index-event.

METHODS

Prospective population based study, covering a period of 4½ years. NR rate was determined after initiation of urgent aggressive BMT and until CEA and compared to NR up to 90 days prior to index-event. Urgent BMT consisted of loading dose aspirin and clopidogrel thereafter therapy with aspirin and clopidogrel together with a statin.

RESULTS

Of 8200 symptomatic patients (ischemic stroke, transient ischemic attack and ocular events), 250 (3%) patients underwent CEA, 47% within 14 days of the index-event and 99% within 14 days of surgical referral. The overall NR from index-event to CEA in symptomatic patients was significantly lower 1.6% (95% CI 0.5-4%) after BMT when compared with NR in the 90 days prior to referral to a stroke clinic 25% (95% CI 20-30%, p < 0.00001). Peri-operative bleeding 5% (95% CI 3-8%) was comparable with other studies.

CONCLUSION

Urgent aggressive BMT after index-event is associated with a significant reduction in the risk of early NR in CEA candidates. The early risk of recurrent stroke in patients with symptomatic significant carotid stenosis is dramatically reduced after urgent aggressive BMT in specialised stroke clinics.

Cone Beam Computed Tomographic Analysis of the Course and Position of Mandibular Canal

PURPOSE

Estimation of the relative position of infra alveolar nerve (IAN) canal and its relation to the mandibular anatomical landmarks can be clinically useful in minimizing the risk of surgery complications such as neurosensory disturbances that may occur after invasive mandibular surgical procedures. The purpose of the present study was to investigate the anatomic location and radiographic course of the mandibular canal compared to anatomic landmarks on CBCT and to discuss its clinical significance and also to determine the possible correlations between the mandibular position and the age of the patients.

METHODS

This cross sectional study was conducted on 242 CBCT of patients (99 males and 143 females). The location of canal was evaluated in 4 different regions. The first section in trans-axial view after mental foramen, in which the loop of mandibular canal is formed, was selected as point 1 for measurement and intervals of 10 mm, respectively, points 2, 3, 4 were selected for measurement. On these sections, the shortest linear distances (mm) from the most buccal and lingual aspects of the canal to the corresponding cortical plates of the mandible and also the minimum linear distance between the inferior aspect of canal and inferior border of mandible in these regions were calculated.

RESULTS

There was statistically significant correlation between the anatomic course of the canal and the patients' gender. The mean vertical position of the canal, as measured from the lower border of the IAN canal to the inferior border of the mandible, was 8.50 mm, ranging from 4.80 to 14.50 mm. On average, the mandibular canal was situated more lingually at all sites to the point it reached the mental foramen. However, at the mental foramen region (Point 1), it was located closer to the buccal cortical plate.

CONCLUSION

Assessment of the exact course of the IAN preoperatively along the body of the mandible by using CBCT might contribute to efficient and accurate surgical planning and therefore positively influence the surgical results. The results of this study confirm the necessity of using CBCT before invasive surgical procedures to determine the variations in the relative position and course of IAN canal.

Comparison of the Pharyngeal Airway Volume between Non-Syndromic Unilateral Cleft Palate and Normal Individuals Using Cone Beam Computed Tomography

STATEMENT OF THE PROBLEM

Individuals with cleft lip and cleft palate mostly have airway problems. Introduction of cone beam computed tomography (CBCT) and imaging software has provided the opportunity for a more precisely evaluating 3D volume of the airway.

PURPOSE

The purpose of this study was to analyze and compare 3D the pharyngeal airway volumes of cleft palate patients with normal individuals using CBCT.

MATERIALS AND METHOD

30 complete cleft palate patients were selected from the Department of Orthodontics; Dental University (Shiraz, Iran) who had CBCT scans of the head. The control group included 30 individuals with Class I angle occlusion who were matched for age and gender with the experimental group. ITK-SNAP 2.4.0 PC software was used to build 3D models of the airways for the subjects and measuring airway volumes. The statistical analyses were performed using SPSS software (version 19). Mann-Whitney test was adopted with p< 0.05 as statistical significance.

RESULTS

The average volume of the pharyngeal airway of cleft group was 18.6 cm3, with mean volumes of 6.8 cm3 for the superior component and 11.3 cm3 for the inferior component. The total and superior airway volume of cleft group were significantly lower than non-cleft groups (p= 0.008, p= 0.00, respectively) but the inferior airway volumes were not significantly different between the cleft and non-cleft groups. There was a significant and positive correlation between superior airway volume and inferior airway volume in cleft palate patients (r=+0.786, p< 0.001) and control group (r=+0.575, p= 0.001).

CONCLUSION

3D analysis showed that the nasal and total airway was restricted in individuals with cleft palate but the inferior airway was not compromised in these individuals. This would be a crucial data to be considered for surgeons during surgical planning.

Effect of radiofrequency radiation from Wi-Fi devices on mercury release from amalgam restorations

BACKGROUND

Dental amalgam is composed of approximately 50% elemental mercury. Despite concerns over the toxicity of mercury, amalgam is still the most widely used restorative material. Wi-Fi is a rapidly using local area wireless computer networking technology. To the best of our knowledge, this is the first study that evaluates the effect of exposure to Wi-Fi signals on mercury release from amalgam restorations.

METHODS

Standard class V cavities were prepared on the buccal surfaces of 20 non-carious extracted human premolars. The teeth were randomly divided into 2 groups (n = 10). The control group was stored in non-environment. The specimens in the experimental groups were exposed to a radiofrequency radiation emitted from standard Wi Fi devices at 2.4 GHz for 20 min. The distance between the Wi-Fi router and samples was 30 cm and the router was exchanging data with a laptop computer that was placed 20 m away from the router. The concentration of mercury in the artificial saliva in the groups was evaluated by using a cold-vapor atomic absorption Mercury Analyzer System. The independent t test was used to evaluate any significant differences in mercury release between the two groups.

RESULTS

The mean (±SD) concentration of mercury in the artificial saliva of the Wi-Fi exposed teeth samples was 0.056 ± .025 mg/L, while it was only 0.026 ± .008 mg/L in the non-exposed control samples. This difference was statistically significant (P =0.009).

CONCLUSION

Exposure of patients with amalgam restorations to radiofrequency radiation emitted from conventional Wi-Fi devices can increase mercury release from amalgam restorations.

Correlation between condylar position and different sagittal skeletal facial types

OBJECTIVE

Condylar position may play a key role in the stability of orthodontic treatment of patients presenting with different skeletal patterns. The aim of the present study was to assess via cone beam computed tomography (CBCT) correlations between condylar position and sagittal skeletal relationship.

PATIENTS AND METHODS

Condylar positions in CBCT images of 20 patients presenting with a Class I skeletal pattern, 20 with a Class II skeletal pattern, and 20 with a Class III skeletal pattern were evaluated retrospectively. The χ (2) test was used to assess the correlation between condylar position and sagittal skeletal relationships.

RESULTS

The condyles were anteriorly positioned in patients with Class II skeletal pattern in comparison with those with Class I and III skeletal patterns. No significant differences in condylar position between Class I and Class III subjects were detected.

CONCLUSION

A significant correlation between condylar position and sagittal skeletal patterns was observed in the present study. This relationship should be considered when planning and carrying out the appropriate orthodontic treatment for temporomandibular anomalies.

Is Mandibular Fossa Morphology and Articular Eminence Inclination Associated with Temporomandibular Dysfunction?

STATEMENT OF THE PROBLEM

Finding a significant relationship between temporomandibular joint (TMJ) morphology and the incidence of temporomandibular dysfunction (TMD) may help early prediction and prevention of these problems.

PURPOSE

The purpose of the present study was to determine the morphology of mandibular fossa and the articular eminence inclination in patients with TMD and in control group using cone beam computed tomography (CBCT).

MATERIALS AND METHOD

The CBCT data of bilateral TMJs of 40 patients with TMD and 23 symptom-free cases were evaluated. The articular eminence inclination, as well as the glenoid fossa depth and width of the mandibular fossa were measured. The paired t-test was used to compare these values between two groups.

RESULTS

The articular eminence inclination and glenoid fossa width and depth were significantly higher in patients with TMD than in the control group (p < 0.05).

CONCLUSION

The articular eminence inclination was steeper in patients with TMD than in the control group. Glenoid fossa width and depth were higher in patients with TMD than that in the control group. This information may shed light on the relationship between TMJ morphology and the incidence of TMD.

Evaluation of Anatomic Variations in Maxillary Sinus with the Aid of Cone Beam Computed Tomography (CBCT) in a Population in South of Iran

STATEMENT OF THE PROBLEM

Anatomic variations of the maxillary sinus can be detected in cone-beam computed tomography (CBCT) and may assist to locate the posterior superior alveolar artery (PSAA) and define the maxillary sinus morphology more accurately for a more strict surgical treatment plan.

PURPOSE

The study aimed to determine normal variations of the maxillary sinus with the aid of CBCT in a sample population in south of Iran.

MATERIALS AND METHOD

This cross-sectional prevalence study was based on evaluation of 198 projection data of CBCT scans of some Iranian patients aged 18-45 who referred to a private oral and maxillofacial radiology center in Shiraz from 2011 to 2013. CBCT scans were taken and analyzed with NewTom VGi device and software. The anatomic variations which were evaluated in the axial images included the presence of alveolar pneumatization, anterior pneumatization, exostosis, and hypoplasia. Moreover the location and height of sinus septa, and the location of PSAA were assessed. SPSS software (version 17.0) was used to analyze the data.

RESULTS

In a total of 396 examined sinuses, maxillary sinus alveolar pneumatization was the most common anatomic variation detected. Anterior pneumatization was detected in 96 sinuses (24.2%). Antral septa were found in 180 sinuses (45.4%) and were mostly located in the anterior region. Meanwhile, PSAA was mostly detected intra-osseous in 242 sinuses (65.7%).

CONCLUSION

Anatomic variations of the maxillary sinus were common findings in CBCT of the maxilla. Preoperative imaging with CBCT seems to be very helpful for assessing the location of PSAA and the maxillary sinus morphology, which may be used to adjust the surgical treatment plan to yield more successful treatments.

The Feasibility of Ultrasonography in Defining the Size of Jaw Osseous Lesions

STATEMENT OF THE PROBLEM

Jaw bone lesions are common pathologic conditions. The role of ultrasonography in evaluation of the extra-osseous lesions is confirmed, however, this imaging modality is not the diagnostic routine for the intra-osseous jaw lesions.

PURPOSE

The purpose of this study was to evaluate the efficiency of ultrasonography in diagnosis of intra-osseous jaw lesions concerning their size and content and also to study its correlation with the histopathological findings.

MATERIALS AND METHOD

For this study, 15 patients with intra-osseous jaw lesions in the maxilla and mandible were selected from those referred to the Department of Oral Surgery. Panoramic imaging, computed tomography (CT) or cone beam computed tomography (CBCT) and ultrasonography (USG) were performed for all the lesions. The size of the lesions was measured by USG and then compared with CT or CBCT. Moreover, the correlation amongst the echographic patterns and histopathologic results was evaluated.

RESULTS

In 12 cases, size values were in complete agreement with CT or CBCT. The size of 3 lesions could not be measured by the radiologist due to the thickness of buccal cortical plate.

CONCLUSION

Findings of this study suggested that USG might be feasible in estimating the size of intra-osseous jaw lesions with little underestimation. This study also confirmed that ultrasound imaging was a very useful imaging technique which could provide significant diagnostic information regarding the content of jaw bone lesions where the buccal bone thickness was thin enough.

Treatment of Intrabony Defects by DFDBA Alone or in Combination with PRP: A Split-Mouth Randomized Clinical and Three-Dimensional Radiographic Trial

OBJECTIVES

The efficacy of adding platelet-rich plasma (PRP) to demineralized freeze-dried bone allograft (DFDBA) in order to improve the clinical and radiographic results obtained in treatment of deep periodontal intrabony defects has yet to be fully elucidated.

MATERIALS AND METHODS

This double blind, split-mouth randomized controlled clinical trial was conducted on 12 patients with two comparable bilateral intrabony defects. Each pair of defects was randomly treated with DFDBA+PRP (test) or DFDBA alone (control). Clinical attachment level (CAL), intrabony defect depth (IDD), distance from the stent to the alveolar crest and pocket depth (PD) as well as radiographic parameters including the radiographic defect depth, width and angulation were measured at baseline and six months post-operatively. The paired t-test was used to compare the pre and post-treatment values and the unpaired t-test compared the test and control groups.

RESULTS

The mean reductions in PD and CAL were 4.5 ±1.3 mm and 3.6±1.6 mm in sites treated with DFDBA+ PRP, respectively (P<0.01); these reductions were 4.1±1.4 mm and 3.5±1.3 mm, respectively in DFDBA group (P<0.01). Radiographic evaluation revealed 2.5±1.1 mm reduction in the radiographic defect depth in the test and 2.1±1.2 mm in the control sites. The defect angulation increased at both sites. Statistically, there were no significant differences between the two treatment modalities (P<0.01).

CONCLUSION

This study showed that both treatments resulted in significant PD reduction, CAL gain and IDD reduction. Also, PRP failed to enhance the results obtained by DFDBA.

Does platelet-rich plasma enhance healing in the idiopathic bone cavity? A single-blind randomized clinical trial

The presence of an idiopathic bone cavity (IBC) is usually identified during routine dental radiographic examinations. The purpose of this study was to investigate the effect of platelet-rich plasma (PRP) on bone healing in the idiopathic bone cavity. This was a single-blind randomized clinical trial. Twenty-four subjects were assigned randomly to two groups. Subjects in group 1 received PRP through a buccal window approach, and those in group 2 underwent conventional management via the creation of a window on the buccal wall and curettage of the walls of the defect. Subjects were followed up at 3, 6, and 9 months after the intervention. The amount of bone formation as determined on panoramic radiographs was divided into four categories: stage 1: ≤25% of the defect showed opacity; stage 2: 25-50% of the defect showed opacity; stage 3: 50-75% of the defect showed opacity; and stage 4: >75% of the defect showed opacity. There was a significant difference between the two groups with regard to the various healing stages at the three time points (P<0.05). When compared with conventional management of the idiopathic bone cavity, the use of PRP may enhance bone formation.

Relationship of elongated styloid process in digital panoramic radiography with carotid intima thickness and carotid atheroma in Doppler ultrasonography in osteoporotic females

STATEMENT OF THE PROBLEM

Cardiovascular disease and osteoporosis are major health dilemmas. Osteoporotic patients frequently display vascular calcification that consequently increases the cardiovascular morbidity and mortality.

PURPOSE

This study aimed to investigate the relation of osteoporosis, vascular calcification (atheroma, intima-media thickness (IMT)) and elongated styloid process (ESP) in a sample of osteoporotic and normal female individuals.

MATERIALS AND METHOD

This study recruited 78 women who were assessed for bone mass density (BMD). Sample included individuals with normal BMD (n=13, 17 %), osteopenia (n=36, 46 %), and osteoporosis (n=29, 37%). The presence of atheroma and IMT was examined using color Doppler ultrasonography (CD-US). In addition, digital panoramic radiographs (PRs) were obtained to assess ESP.

RESULTS

In this study, 55 subjects (70%) with low BMD exhibited at least one side ESP. Femoral BMD decreased significantly in subjects with ESP (p= 0.03). Bilateral ESP was correlated with the presence of atheroma (p= 0.029). The CIMT was greater in patients with ESP, although the relation was not significant.

CONCLUSION

The obtained data suggest referring the aged individuals with ESP for BMD assessment and individuals with low bone mass and ESP for more cardiovascular risk assessment.

Association between mandibular condylar position and clinical dysfunction index

OBJECTIVES

Condylar position in the glenoid fossa has been associated with temporomandibular disorders. The purpose of the present study was to investigate the correlation between clinical dysfunction index (Di) and mandibular condylar position in patients with temporomandibular joint dysfunction (TMD) using cone beam computed tomography (CBCT).

METHODS

In this cross-sectional study, participants were recruited from the Department of Maxillofacial Radiology at Shiraz Dental University in Iran. The condylar position was assessed on the CBCT images of 120 temporomandibular joints in 60 patients with TMD. Patients were divided into 3 groups based on Helkimo's clinical Di. The chi-square test was used to correlate degree of the Helkimo's Di with the mandibular condylar position. The p value was set at 0.05.

RESULTS

A total of 60 patients (42 women and 18 men; mean age, 33.4 years) participated in this study. Significant differences in condylar position were found among the 3 groups (Di I, II, and III) (p < 0.05). Patients with mild to moderate TMD were found to have anteriorly and concentric seated condyles. Posteriorly seated condyles were found in patients with severe TMD.

CONCLUSION

Condylar position is associated with different severity of TMD.

An in vitro comparison of diagnostic accuracy of cone beam computed tomography and phosphor storage plate to detect simulated occlusal secondary caries under amalgam restoration

BACKGROUND

This study was aimed to compare the diagnostic accuracy and feasibility of cone beam computed tomography (CBCT) with phosphor storage plate (PSP) in detection of simulated occlusal secondary caries.

MATERIALS AND METHODS

In this in vitro descriptive-comparative study, a total of 80 slots of class I cavities were prepared on 80 extracted human premolars. Then, 40 teeth were randomly selected out of this sample and artificial carious lesions were created on these teeth by a round diamond bur no. 1/2. All 80 teeth were restored with amalgam fillings and radiographs were taken, both with PSP system and CBCT. All images were evaluated by three calibrated observers. The area under the receiver operating characteristic curve was used to compare the diagnostic accuracy of two systems. SPSS (SPSS Inc., Chicago, IL, USA) was adopted for statistical analysis. The difference between Az value of bitewing and CBCT methods were compared by pairwise comparison method. The inter- and intra-operator agreement was assessed by kappa analysis (P < 0.05).

RESULTS

The mean Az value for bitewings and CBCT was 0.903 and 0.994, respectively. Significant differences were found between PSP and CBCT (P = 0.010). The kappa value for inter-observer agreement was 0.68 and 0.76 for PSP and CBCT, respectively. The kappa value for intra-observer agreement was 0.698 (observer 1, P = 0.000), 0.766 (observer 2, P = 0.000) and 0.716 (observer 3, P = 0.000) in PSP method, and 0.816 (observer 1, P = 0.000), 0.653 (observer 2, P = 0.000) and 0.744 (observer 3, P = 0.000) in CBCT method.

CONCLUSION

This in vitro study, with a limited number of samples, showed that the New Tom VGI Flex CBCT system was more accurate than the PSP in detecting the simulated small secondary occlusal caries under amalgam restoration.

The accuracy of a designed software for automated localization of craniofacial landmarks on CBCT images

BACKGROUND

Two-dimensional projection radiographs have been traditionally considered the modality of choice for cephalometric analysis. To overcome the shortcomings of two-dimensional images, three-dimensional computed tomography (CT) has been used to evaluate craniofacial structures. However, manual landmark detection depends on medical expertise, and the process is time-consuming. The present study was designed to produce software capable of automated localization of craniofacial landmarks on cone beam (CB) CT images based on image registration and to evaluate its accuracy.

METHODS

The software was designed using MATLAB programming language. The technique was a combination of feature-based (principal axes registration) and voxel similarity-based methods for image registration. A total of 8 CBCT images were selected as our reference images for creating a head atlas. Then, 20 CBCT images were randomly selected as the test images for evaluating the method. Three experts twice located 14 landmarks in all 28 CBCT images during two examinations set 6 weeks apart. The differences in the distances of coordinates of each landmark on each image between manual and automated detection methods were calculated and reported as mean errors.

RESULTS

The combined intraclass correlation coefficient for intraobserver reliability was 0.89 and for interobserver reliability 0.87 (95% confidence interval, 0.82 to 0.93). The mean errors of all 14 landmarks were <4 mm. Additionally, 63.57% of landmarks had a mean error of <3 mm compared with manual detection (gold standard method).

CONCLUSION

The accuracy of our approach for automated localization of craniofacial landmarks, which was based on combining feature-based and voxel similarity-based methods for image registration, was acceptable. Nevertheless we recommend repetition of this study using other techniques, such as intensity-based methods.

Measuring agreement between cervical vertebrae and hand-wrist maturation in determining skeletal age: reassessing the theory in patients with short stature

INTRODUCTION

The objective of this study was to determine the degree of agreement between hand-wrist radiography and cervical vertebral maturation analysis in patients diagnosed with short stature.

METHODS

A cross-sectional study was designed; 178 patients (90 girls, 88 boys) diagnosed with short stature and seeking treatment were selected. The patients were divided into 2 groups (76 with familial short stature, 102 with nonfamilial short stature). Hand-wrist and lateral cephalometric radiographs were obtained from the patients. The hand-wrist radiographs were analyzed using the Fishman method, and the lateral cephalometric views were categorized according to the method of Hassel and Farman. The degree of agreement between the 2 methods of predicting skeletal maturation was measured by calculating the contingency coefficient and the weighted kappa statistic.

RESULTS

A high degree of agreement was observed between the 2 methods of analyzing skeletal maturation. It was also observed that agreement was higher in girls in the familial short-stature group, whereas boys had higher agreement in the nonfamilial short-stature group.

CONCLUSIONS

Cervical vertebral maturation can be a valuable substitute for hand-wrist radiography in patients with short stature.

Clinical and radiographic comparison of the effects of two types of fixed retainers on periodontium - a randomized clinical trial

Background

Most orthodontists believe that fixed retainers are necessary to maintain ideal dental relationships. However, untoward side effects might result from their long-term placement. The aim of this study was to evaluate the clinical and radiographic effect of two commonly used fixed retainers on the health of the periodontium.

Methods

Thirty patients were randomly divided into two groups to receive either a fiber-reinforced composite retainer or a spiral wire retainer extended on the lingual surfaces of both maxillary and mandibular arches from canine to canine. Periapical radiographs were obtained from the patients at the time of placement of the retainers and after the 6-month period to assess the radiographic conditions of the periodontium. Clinical examination was carried out at the same two time intervals.

Results

Even though there were no significant differences between the two groups of study at the beginning of the trial, there were statistically significant differences after the 6-month follow-up regarding the main outcomes of the study. Nearly all indices showed to deteriorate after 6 months in the fiber-reinforced group, while in the spiral wire group, this was not the case. As for the secondary outcomes, radiographic examination did not reveal any statistically significant differences after 6 months or between the two groups.

Conclusions

It can be concluded that spiral wire retainers elicit less detrimental periodontal response in the short-term follow-up compared to fiber-reinforced composite retainers as revealed by the primary outcomes of the study.

Trial registration

ClinicalTrials.gov: NCT01314729

Electronic supplementary material

The online version of this article (doi:10.1186/s40510-014-0047-8) contains supplementary material, which is available to authorized users.

The effect of vertical bracket positioning on torque and the resultant stress in the periodontal ligament--a finite element study

Background

The ideal built-in tip and torque values of the straight wire appliance reduce the need for wire bending and hence reduce chair time. The vertical position of the bracket on the tooth surface can alter the torque exerted on the tooth. This is a result of the altered surface curvature observed at each vertical position. To further clarify the role of vertical bracket positioning on the applied torque and the resultant stresses in the periodontal ligament (PDL), we designed a mandibular first premolar using finite element modeling.

Methods

Cone beam computed tomography of 52 patients (83 lower first premolars) was selected to be included in the study. Curvature was measured for points along the labial surface with increasing distances (0.5 mm increments) from the cusp tip by calculating the angle between tangents drawn from these points and the axis joining the cusp tip and the root apex. The mean values for each distance were calculated, and a finite element model was designed incorporating these mean values. The resultant stress and hydrostatic pressure in the PDL were calculated using finite element analysis.

Results

The labial surface of the mandibular first premolar demonstrated a 26.39° change from 2.5 to 6 mm from the cusp tip. The maximum Von-Mises stress and hydrostatic pressure in the PDL were observed at the root apex for all of the bracket positions, and these values demonstrated, respectively, a change of up to 0.059 and 0.186 MPa between two successive points.

Conclusions

It can be concluded that the variation in the vertical position of the bracket can have an important effect on the torque and subsequently on the stresses and pressures in the PDL.