Evaluation of mandibular condyle position in Class III patients after bimaxillary orthognathic surgery: A cone-beam computed tomography study.

Objective: This retrospective study evaluated the mandibular condyle position before and after bimaxillary orthognathic surgery performed with the mandibular condyle positioned manually in patients with mandibular prognathism using cone-beam computed tomography. Methods: Overall, 88 mandibular condyles from 44 adult patients (20 female and 24 male) diagnosed with mandibular prognathism due to skeletal Class III malocclusion who underwent bilateral sagittal split ramus osteotomy (BSSRO) and Le Fort I performed using the manual condyle positioning method were included. Cone-beam computed tomography images obtained 1-2 weeks before (T0) and approximately 6 months after (T1) surgery were analyzed in three planes using 3D Slicer software. Statistical significance was set at P < 0.05 level. Results: Significant inward rotation of the left mandibular condyle and significant outward rotation of the right mandibular condyle were observed in the axial and coronal planes (P < 0.05). The positions of the right and left condyles in the sagittal plane and the distance between the most medial points of the condyles in the coronal plane did not differ significantly (P > 0.05). Conclusions: While the change in the sagittal plane can be maintained as before surgery with manual positioning during the BSSRO procedure, significant inward and outward rotation was observed in the axial and coronal planes, respectively, even in the absence of concomitant temporomandibular joint disorder before or after the operation. Further long-term studies are needed to correlate these findings with possible clinical consequences.

Evaluation of mandibular cortical and trabecular radiomorphometry in familial Mediterranean fever patients.

OBJECTIVE: The objective of this retrospective study was to evaluate the mandibular cortical and trabecular morphology and microarchitecture of patients with familial Mediterranean fever (FMF) and compare them to those of healthy individuals by examining radiomorphometric indices on panoramic radiographs. STUDY DESIGN: We examined a group of 56 FMF patients aged 5 to 71 years and an age- and sex-matched control group of individuals with no systemic diseases. We classified the FMF and control groups according to age and sex and the FMF group according to colchicine use. We evaluated the quantitative radiomorphometic indices of gonial index, antegonial index, molar cortical thickness, mental index, panoramic mandibular index, and lacunarity, and the qualitative mandibular cortical index on all panoramic radiographs and performed between and within group analysis. RESULTS: Mean gonial index, antegonial index, and molar cortical thickness values of the FMF group were significantly smaller than those of the control group. Significantly fewer patients in the FMF group were classified as mandibular cortical index type 1 compared to the control group. There were no significant differences in quantitative index values according to colchicine use in the FMF group or regarding the categorical parameters of age, sex, and mandibular cortical index classification. CONCLUSIONS: Radiomorphometric values of the mandibular basal cortex posterior to the mental foramen differ significantly in FMF patients compared to healthy counterparts. Dentists should note mandibular morphologic changes indicative of low bone density when examining panoramic images of patients with this disease.

Fractal dimension analysis of different mandibular regions in familial Mediterranean fever patients: A cross-sectional retrospective study.

Familial Mediterranean fever (FMF) is a genetic condition that may cause loss of bone mineral density (BMD) due to chronic inflammation. Previously, fractal dimension (FD) analysis values of mandibular cortical bone were shown to be lower in osteoporosis. Therefore, FD might be considered as an auxiliary tool to refer patients for dual-energy x-ray absorptiometry (DXA), which is the gold standard for BMD measurement. The purpose of this cross-sectional retrospective study was to evaluate trabecular and cortical microarchitecture of the mandible with FD analysis on panoramic radiographs in a subpopulation of FMF. Also, the effect of colchicine use was investigated. Forty-three FMF patients, aged between 10.8 and 71.2 years, and age- and gender-matched control group consisting of patients, who had no systemic diseases, were included. Demographic information such as age and gender, and colchicine use were recorded. In terms of age, the patients were classified as <30 and 30< years. On each panoramic radiographs five regions of interest were selected on the mandible as: 1- premolar, 2- molar, 3- angular, 4- condylar, and 5- basal cortical bone regions on right (R) and left (L) sides. Statistical significance was accepted at p<0.05 level. Intra- and inter-observer agreements demonstrated good to excellent consistency. In FMF patients, L3 and L4 values were higher, whereas L5 values were lower (p<0.05) than the control group. In terms of age, the difference between groups was insignificant in FMF patients (p>0.05), whereas in control group R3 and L4 values were higher in the 30< age group (p<0.05). Regarding gender and colchicine use, the difference between groups was insignificant (p>0.05). FMF disease might be a candidate for referral to DXA examination based on decreased bone density in the mandibular cortex detected by FD measurements on routine panoramic radiographs. Further studies are warranted to ascertain this relationship.

Proximity of healthy posterior teeth to the maxillary sinus floor in relation to mucosal thickening: a CBCT study.

OBJECTIVES: To evaluate the relationship between proximity of the root apices of healthy maxillary posterior teeth to the maxillary sinus floor (MSF) and mucosal thickening (MT) of the MSF using cone beam computed tomography (CBCT). METHODS: Eighty-four CBCT images obtained from the patients, aged between 20 and 70 years with healthy and fully dentate maxillary posterior sextants, were included. The anatomical relationship between root apices of maxillary posterior teeth and MSF, was evaluated: (Type 1: no contact, Type 2: at least one root apex in contact, Type 3: at least one root apex protruding into MSF). Besides, MT of the MSF was measured from the thickest region. The patients were categorized into two groups based on the absence (≤ 2 mm) or the presence (2 < mm) of MT. Statistical significance was accepted at p < 0.05. RESULTS: Intraexaminer consistency demonstrated an excellent agreement (p < 0.05). The prevalence of Type 1, 2, and 3 proximity were found as 26 (15.5%), 61 (36.3%), and 81 (48.2%); respectively. Overall, 62 (36.9%) maxillary sinuses demonstrated MT (2 < mm, mean: 8.6 ± 7.5 mm). The prevalence and mean values of MT (2 < mm) were not found to be statistically significantly different in terms of sex and proximity types (p > 0.05). Logistic regression analysis results were not found to be statistically significant (p > 0.05). CONCLUSION: The proximity of healthy maxillary posterior teeth to the MSF was not found to be a contributing factor for the MT of the MSF. Further studies with larger samples, taking the other factors causing MT into consideration, are needed.

Perceived sources and levels of stress, general self-efficacy and coping strategies in preclinical dental students.

Dental education programs are known to be highly stressful and stress can affect general health. The aims were to identify sources of stress among preclinical students and to evaluate their perceived levels of stress, self-efficacy and effective coping strategies in a private dental school. One hundred preclinical students in a Turkish private dental school were surveyed using dental environment stress (DES), perceived stress (PSS), general self-efficacy (G-SES) and brief coping scales (Brief-COPE). Age, gender, history of psychiatric treatment, factors that affected the choice of dentistry, choice rank of dental school, scholarship and income was recorded. 'Exams and grades' followed by 'Fear of failing course or year' were found to be the most stressprovoking factors. The most and the least stressprovoking DES domains were 'Workload' and 'Social stressors', respectively. 'Social stressors' affected male more than female (p < .05). The most and the least common coping strategies were found to be 'Planning', and 'Drug', respectively. Female used 'Instrumental support' more than male (p < .05). Demographic factors had impact on the perceived stress factors and levels, as well as coping strategies. Unlike previous studies establishing high stress levels in dental students, preclinical students displayed moderate level of stress. Clinical dental education might be more responsible for creating stress.

Perceived sources and levels of stress, general self-efficacy and coping strategies in clinical dental students.

The aims of this study were to identify sources of stress among clinical students and to evaluate the students' perceived levels of stress, general self-efficacy and effective coping strategies in a private dental school environment. The study group consisted of 130 undergraduate clinical dental students in a Turkish private dental school, during the academic year 2014-2015. The students were surveyed using modified version of the dental environment stress (DES) survey, the perceived stress scale, the general self-efficacy scale (G-SES) and the brief coping scale. Age, sex, year of study, history of psychiatric treatment and factors that affected the choice of dentistry were also recorded. Final year and female clinical dental students, who were found to be the most stressful students, had moderate to high perceived stress scores. Total and 'Faculty and administration' related DES scores increased with the year of study. Stressors related to 'Workload' and 'Clinical training' affected females more than males. G-SES scores were higher in male students and students, who had no history of psychiatric treatment. The most and the least common coping strategies were 'Planning' and 'Substance abuse', respectively. 'Religion' was found to be one of the main coping strategies. Stress factors affecting Turkish clinical dental students studying at private dental school differed from the previously reported stress factors affecting students studying at a governmental dental school. Advanced year and female students experienced more stress than the other students.

Evaluation of pneumatization in the articular eminence and roof of the glenoid fossa with cone-beam computed tomography.

BACKGROUND: Detection of air cavities, so called pneumatizations, nearby to the temporomandibular joint (TMJ) area is important, as they represent sites of minimal resistance and facilitate the spread of various pathologies into the joint as inflammation, tumor or fractures and serve as a possible complicating factor in TMJ surgery. AIMS: To determine the prevalence of pneumatization of the articular eminence (PAT) and roof of the glenoid fossa (PRGF) using cone-beam computed tomography (CBCT). STUDY DESIGN: Cross-sectional study. METHODS: Acquired images of 111 patients (222 TMJs) were evaluated. The presence of pneumatization was recorded at the articular eminence and roof of the glenoid fossa. Age and gender were recorded for all patients and type (unilocular or multilocular) and laterality were noted for the cases of pneumatization. RESULTS: The mean age of the study group was 48.86±18.31 years. Among all the patients, 73 (65.8%) had PAT, while 13 (11.7%) had PRGF. Forty-two (37.8%) of the patients had PAT bilaterally; whereas 3 of them (2.7%) presented PRGF bilaterally. The percentage of PAT was higher for females (73.6%) than males (51.3%) (p<0.05). CONCLUSION: CBCT images are an accurate and reliable means of detection of the exact size and type of pneumatization and the relationship of pneumatization to the adjacent tissues. This is especially significant before a surgical intervention is planned in this region, in order to make a sound diagnosis.

Articular eminence inclination, height, and condyle morphology on cone beam computed tomography.

AIM: The aim of the present study was to examine the relationship between articular eminence inclination, height, and thickness of the roof of the glenoid fossa (RGF) according to age and gender and to assess condyle morphology including incidental findings of osseous characteristics associated with osteoarthritis (OA) of the temporomandibular joint (TMJ) using cone beam computed tomography (CBCT). MATERIALS AND METHODS: CBCT images of 105 patients were evaluated retrospectively. For articular eminence inclination and height, axial views on which the condylar processes were seen with their widest mediolateral extent being used as a reference view for secondary reconstruction. Condyle morphology was categorized both in the sagittal and coronal plane. RESULTS: The mean values of eminence inclination and height of males were higher than those of females (P < 0.05). There were significant differences in the RGF thickness in relation to sagittal condyle morphology. Among the group of OA, the mean value of the RGF thickness for "OA-osteophyte" group was the highest (1.59 mm), whereas the lowest RGF values were seen in the "OA-flattening." CONCLUSION: The sagittal osteoarthritic changes may have an effect on RGF thickness by mechanical stimulation and changed stress distribution. Gender has a significant effect on eminence height (Eh) and inclination.

In Vitro Detection of Dental Root Fractures with Cone Beam Computed Tomography (CBCT).

BACKGROUND: Since the diagnosis of non-displaced longitudinal fractures present difficulties for the dentist, three-dimensional evaluation is necessary. OBJECTIVES: The aim of this study is to demonstrate the accuracy of cone beam computed tomography (CBCT) in detecting dental root fractures in vitro. MATERIALS AND METHODS: An in vitro model consisting of 210 recently extracted human mandibular teeth was used. Root fractures were created by mechanical force. The teeth were placed randomly in the empty dental alveoli of a dry human mandible and 15 different dental arcs were created. Images were taken with a unit Iluma ultra cone-beam CT scanner (Imtec Corporation, Germany). Three dental radiologists separately evaluated the images. RESULTS: According to the fracture types and fracture presence, there was an overall statistically significant agreement between the key and readings. Kappa values for intra observer agreement ranged between 0.705 and 0.804 indicating that each observer gave acceptable ratings for the type and presence of fractures. CONCLUSIONS: Detailed information about root fractures may be obtained using CBCT.

Measurements of the foramen magnum and mandible in relation to sex using CBCT.

The purpose of this study was to evaluate pre-existing CBCT images of a large sample of adult females and males to provide data on foramen magnum and mandibular measures of sexual dimorphism for use as a reference sample in cases of establishing identity in unknown fragmentary skulls. The study group consisted of 161 adult patients. 3D images of the patients were assessed retrospectively. FM measurements were obtained from reformatted axial sections. Six mandibular measurements were taken. According to the results, the study identified four mandibular measurements as final predictors of sex which are as follows: the gonial angle (G-angle) and ramus length (Ramus-L), gonion-gnathion length (G-G-L) and bigonial breadth (BG-Br). It was found that the cross-validated grouped overall predictive accuracy was 83.2% for FM and mandible measurements. It could correctly identify males in 77.3% and females in 87.4% of the cases. To assess sexual dimorphism, the gonial angle and ramus, gonion-gnathion lengths, and bigonial breadth of the mandible and sagittal diameter of the FM may be used on CBCT images.

Assessment of root canal treatment outcomes performed by Turkish dental students: results after two years.

The aim of this study was to evaluate radiographically the periapical status and technical standard of root canal therapies performed by a group of undergraduate dental students in Turkey two years following completion of the treatments. A random sample of 264 patients who received root canal treatment from undergraduate students at the Yeditepe University Faculty of Dentistry in 2009 were recalled after two years. The study sample consisted of 319 root-filled teeth in 158 dental patients (females=97, males=61) who presented to the student clinics during that time frame. For each root-filled tooth, two periapical radiographs were examined to identify the periapical status, one showing pre-treatment and the other showing post-treatment status. The quality of endodontic treatment was examined according to the distance between the end of root filling and radiographic apex and the density of the obturation according to presence of voids within the root filling material. This examination found that 54.2 percent of roots had fillings of acceptable length, while 37.3 percent were short, 7.8 percent were overfilled, and 0.6 percent was unfilled; 2.5 percent of the teeth were observed with broken root canal instruments. After two years, PAI scores of teeth with acceptable length of root canal filling (0-2 mm from the radiographic apex) were found to be lower than those of the overfilling and short filling cases (>2mm) (p<0.01). Moreover, voids were detected in the root canal fillings of 52.7 percent of endodontically treated teeth. The PAI scores of root fillings with inadequate density were significantly higher than adequate ones (p<0.01). Although endodontic treatments performed by undergraduate students do not appear to be unqualified compared to those performed by general practitioners, more emphasis must be placed on the technical quality of endodontic treatment to obtain better results.