Risk assessment of mandibular incisive canal perforation during dental implant surgery in the anterior edentulous mandible: a virtual implant placement study using cone beam computed tomography.

OBJECTIVE: The aim of this study was to evaluate the risk of mandibular incisive canal (MIC) perforation caused by implants placed on cone beam computed tomography (CBCT) images in the edentulous mandibular anterior region. STUDY DESIGN: A total of 1200 dental implants were virtually inserted on 150 eligible CBCT scans. The relationship of different implant sizes with the incidence of MIC perforation and the relationship between crest height and perforation were evaluated. RESULTS: A total of 1200 virtual implant applications were performed on 150 patients. In 87% of cases, MIC was identified. Perforation in 12 and 14 mm implants was significantly higher than in 8- and 10-mm implants (P < .05). Perforation was found to be statistically significantly higher in crest heights that were ≤20 mm than in crest heights >20 mm (P < .05). CONCLUSIONS: Our results showed high perforation rates in the 12- and 14-mm implants and crests heights that were ≤20 mm during implant surgery in the mandibular anterior edentulous region. Perforation of the MIC should be considered a complication of implant surgery in the mandibular anterior region; therefore, CBCT images should be evaluated before implant placement.

Retrospective Assessment of the Anatomy and Dimensions of Nasopalatine Canal with Cone-Beam Computed Tomography.

Objectives: The objective of this retrospective study was to evaluate the anatomy and morphology of the nasopalatine canal in axial, sagittal, and coronal sections with cone-beam computed tomography and to appraise the effect of gender, age, and dental status on the nasopalatine canal. Material and Methods: Overall 1000 patients with cone-beam computed tomography (CBCT) images were analysed retrospectively. The morphology of the nasopalatine canal (NPC) was classified according to sections. Its sizes were measured, and variations were evaluated. The variables obtained were statistically analysed. Results: It was observed that the most common NPC shape was the cylindrical type (47.1%) in sagittal sections, and the C-shaped canal (51.1%) in coronal sections. In the axial section, two Stenson foramen (45.2%) were observed most frequently, and the most common form was found as oval (60.7%). In sagittal sections, statistically significant differences were obtained between all morphometric measurements and shapes of the NPC except the angle of the canal. It was found that all morphometric measurements in sagittal and coronal sections were higher in men. Also, it was found that the NPC angle and NPC length decreased with tooth loss. Conclusions: The nasopalatine canal shows many variations, and its dimensions differ according to gender, age, and dental status. For this reason, before the surgical procedures are applied to the maxilla, it should be evaluated radiologically to prevent complications.

Risk Assessment of Lingual Plate Perforation in Anterior Edentulous Mandibular Region: A Virtual Implant Placement Study Using Cone-Beam Computed Tomography.

BACKGROUND: The aim of this study was to evaluate the prevalence of lingual cortical bone perforation caused by virtually placed implants on cone-beam computed tomography images in the edentulous mandibular canine region and determine the relationship between the morphological structure of the crest and the risk of perforation. METHODS: Eight hundred dental implants were virtually inserted on 100 qualified cone-beam computed tomography scans. Crests were divided into 4 groups according to the crest morphology as Type U, Type L, Type P, and Type C. The distance between the implant tip and lingual plate was measured using a digital caliper. Incidence of lingual plate perforation and proximity of the implant tip to the lingual plate were measured for 4 types of the alveolar crest. RESULTS: A total of 800 virtual implant applications were performed in 100 patients who met the inclusion criteria. The incidence of lingual plate perforation was found to be significantly higher in Type U crests than in the other types. It was also found to be statistically significantly higher in Type L crests than in Type P and Type C crests. When the relationship between implant length and perforation was evaluated, perforation in 14 mm implants was significantly higher than 8, 10, and 12 mm implants. CONCLUSIONS: According to the results of this study, it was determined that high rates of perforation occurred in the U and L type crests and 14 mm implants during implant surgery in the mandibular anterior edentulous region.

Radiological Evaluation of Olfactory Fossa with Cone-Beam Computed Tomography.

OBJECTIVES: The aim of this retrospective study was to evaluate the morphology of the olfactory fossa in the Turkish population using cone-beam computed tomography according to Keros classification and to investigate the effect of age, gender and nasal septum deviation on the olfactory fossa. MATERIAL AND METHODS: Olfactory fossa (OF) were analysed in coronal sections on cone-beam computed tomography images of 385 individuals. Nasal floor (NF), medial ethmoid roof point (MERP), cribriform plate (CP) heights, CP depth and width, OF width, lateral lamella-cribriform plate angle (LLCPA), and nasal septum deviation angle (NSDA) were measured. Keros and Gera classifications were made according to the measurements. RESULTS: According to the Keros classification, 137 of 770 OFs were type I (17.8%), 554 (71.9%) were type II, and 79 (10.3%) were type III. The most common combination was Keros type II and Gera type II (45.6%). There was a positive correlation between CP depth and LLCP angle, NF, MERP and CP heights (P ≤ 0.05). NF, MERP, and CP heights, CP depth and LLCP angle were statistically significant differences according to Keros classification (P ≤ 0.05). Only the right LLCP angle showed a statistically significant difference according to the NSD sides (P = 0.014). CONCLUSIONS: The study shows that the lateral lamella-cribriform plate angle increases as the cribriform plate depth increases. This result suggests that it may moderate the risk during endoscopic sinus surgery. Also, according to the nasal septum deviation sides, the dimensions of the olfactory fossa did not change significantly, except for the lateral lamella-cribriform plate angle.

Comparison of Genial Tubercule Anatomy Based on Age and Gender.

OBJECTIVE: In our study, it was aimed to determine whether there were differences in genial tubercle dimensions depending on age and gender. METHODS: In this study, 220 cone beam computed tomography (CBCT) images of patients (110 female and 110 male) between the ages of 20-80 years were obtained from the archive of Izmir Katip Çelebi University Faculty of Dentistry. All patients were divided into decade groups according to their age, and each decade group was divided into two subgroups according to gender. The genial tubercle was defined radiologically using axial, coronal and sagittal sections as well as 3D reconstruction image with NNT software program. Sagittal, vertical and horizontal dimensions of the genial tubercle were measured and statistically analyzed. RESULTS: There was a weak negative correlation between age groups and vertical values (r=-0.142; p=0.036) whereas the correlation coefficients between age groups and sagittal and horizontal values were not statistically significant (r=-0.043; p=0.530 and r=-0.039; p=0.563). There was a strong positive correlation between vertical and sagittal values in men (r=0.705, p<0.001) and women (r=0.714, p<0.001) in the whole group. There was a weak positive correlation between horizontal and sagittal, horizontal and vertical values in men (r=0.362, p<0.001; r=0.231, p<0.001) and women (r=0.304, p<0.001; r=0.257, p=0.007) in the whole group. CONCLUSION: The vertical and horizontal dimensions of genial tubercle of men were higher than that of women. As the age of the patients increased, a decrease in the vertical values of the genial tubercle was observed.

Radiographic Evaluation of Infraorbital Canal Protrusion into Maxillary Sinus Using Cone-Beam Computed Tomography.

OBJECTIVES: The aim of this retrospective study was to evaluate the relation of the infraorbital canal course with the maxillary sinus using cone-beam computed tomography. MATERIAL AND METHODS: A total of 1000 infraorbital canals (IOC) were examined from 500 cone-beam computed tomography scans. IOCs were classified into three types based on the degree of protrusion into the sinus. The presence of Haller cells and mucosal thickening in the sinus were evaluated. The length of bony septum from the canal to the sinus wall (D1), the distance at which protrusion begins posterior to the inferior orbital rim (D2), the vertical distance from the canal to the sinus roof (D3), and the vertical distance from the canal to the sinus floor (D4) were measured. RESULTS: The prevalence of IOC protrusion into the sinus was 8.8%. There was a significant difference in the prevalence of Haller cells between IOC types (P < 0.01). However, no significant correlation was found between IOC types and the presence of mucosal thickening (P > 0.05). There was no significant difference in the mean D1, D2, and D3 between the genders (P > 0.05). The mean D4 was significantly higher in males than in females (P < 0.05). CONCLUSIONS: The protrusion of infraorbital canals into the sinus is a common variation that must be considered to prevent accidental injury. Our findings suggest that the risk of injury to the descending canals is very low during routine dentoalveolar procedures because the protruded canal is not close to the sinus floor.

Localization of the Mandibular Canal in a Turkish Population: a Retrospective Cone-Beam Computed Tomography Study.

OBJECTIVES: The aim of this study was to determine the location of the mandibular canal at the mental foramen region that is essential in order to prevent injuries to the inferior alveolar neurovascular bundle during mandibular surgical procedures. MATERIAL AND METHODS: The position of the mandibular canal was analysed using cone-beam computed tomography images from 300 Turkish patients, who were referred to Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Izmir Katip Celebi University for various complaints. The distances of the mandibular canal to the outer superior (D1), inferior (D2), buccal (D3), and lingual (D4) cortical margins were measured at 2 mm distal to the mental foramen. RESULTS: There were 148 (49.3%) males and 152 (50.7%) females with ages ranging from 15 to 74 years (39.15 [SD 17.8]). D1 was significantly greater than D2 and D3 was significantly greater than D4 on both left and right sides. While the mean D1, D2, and D4 in males were significantly greater than in females on both left and right sides. There was no significant difference between D3 in males and females on both left and right sides. CONCLUSIONS: The results showed that the mandibular canal was vertically located nearer to the inferior cortical border and horizontally nearer to the lingual cortical border of the mandible at the mental foramen region. Knowledge of the distances of mandibular canal to the outer cortical margins at this region of the mandible will be helpful for surgical procedures.

Cone-beam computed tomographic evaluation of accessory mental foramen in a Turkish population.

PURPOSE: The aim of this study was to evaluate the frequency and location of accessory mental foramen (AMF) in a Turkish population using cone beam computerized tomography (CBCT). METHOD: CBCT images of 1005 patients were retrospectively reviewed from the archive of the Department of Oral and Maxillofacial Radiology, Faculty of Dentistry, Izmir Katip Celebi University. The prevalence, size, and localization of AMFs were assessed according to gender and age. In addition, the vertical and horizontal dimension of the mental foramen (MF) with and without AMF was measured to investigate the relationship between MF dimensions and the presence and absence of AMF. The average distance between the MF and AMF was also calculated. All measurements were then analyzed statistically. RESULTS: A total of 149 AMFs in 123 (12.23%) patients were identified on the CBCT images of the 1005 patients reviewed. There was no significant correlation between presence of AMF and gender (p = 0.152). The most common localization of an AMF with respect to the MF was posterio-inferior (n = 52; 34.89%). A statistically significant difference was also found between the vertical and horizontal dimensions of the MF with and without AMF (p < 0.05). CONCLUSION: The results of this study demonstrate the high prevalence of AMF in the studied Turkish population. Considering the high prevalence and the structures passing through it, recognition of AMF and its detection using CBCT is important to prevent complications that may occur during and after surgical procedures.

A comparison of panoramic radiography and cone beam computed tomography in the detection of osteosynthesis complications in sheep mandibular angle fractures.

OBJECTIVE: The aim of this study was to compare the diagnostic efficacy of panoramic radiography (PANO) and cone beam computed tomography (CBCT) in detecting simulated complications of plate osteosynthesis applied to mandibular angle fractures (MAFs). STUDY DESIGN: Unfavorable MAFs were created in 100 fresh sheep hemimandibles. Fractures were fixed with 4-hole titanium miniplates and screws. Bone necrosis around the screws, penetration of the screw into the inferior alveolar canal, screw loosening, and plate breakage were simulated. The diagnostic efficacy of the imaging techniques was compared by using intra- and interobserver agreement scores and area under the receiver operating characteristic curve (AUC) values. Examination time (ET), confidence scores (CS), and planar preference (PP) in CBCT evaluation were assessed. RESULTS: Intra- and interobserver agreement scores varied between 0.61 and 0.91. AUCs for screw penetration into the inferior alveolar canal and screw loosening were significantly higher in CBCT than in PANO (P < .05). CBCT presented significantly higher ET and CS values compared with PANO (P < .05). PP showed significant differences among types of complications (P < .05). CONCLUSIONS: PANO provided acceptable outcomes in the detection of bone necrosis and broken plates around the screw, but CBCT was more likely to enable detection of all simulated types of complications with higher confidence.

Histological Effects of Er:YAG Laser Irradiation with Snoring Handpiece in the Rat Soft Palate.

OBJECTIVE: The aim of this study was to assess the effects of laser irradiation with a novel snoring handpiece on the histological structures of the soft palate in a rat model. BACKGROUND: Snoring is a common problem and studies have shown that 20-50% of the population is affected. An apnea-hypopnea index of <5/h without daytime somnolence is documented as simple snoring. No snoring treatment should ever be attempted until a sleep study has been completed to rule out sleep apnea. METHODS: Twenty adult Wistar rats, weighing 200-250 g, were used in this study. Rats were randomized into two groups: experimental group (n = 10) and control group (n = 10). Laser energy was delivered in a horizontal direction to the surface of the soft palate of each rat in the experimental group for 2 min with an Er:YAG laser (LightWalker AT; Fotona) with snoring handpiece (PS04) in a noncontact mode (1.15 W, 2 Hz, 1.5 J/cm(2)). The animals were sacrificed after 24 h, 1 week, 3 weeks, or 5 weeks. The soft palate of each rat was removed by excisional biopsy. The specimens underwent histological examination. Contractions and fibrosis were reported as grading from 1+ to 3+, while edema and hyperemia were evaluated according to the absence (0) or presence (1) of any changes. Statistical analysis was done with the Mann-Whitney U and Spearman's rho tests. RESULT: A noticeable contraction of the soft palate occurred immediately after laser application. Inflammatory changes were observed histologically at 3 weeks postoperatively. Keratinization appeared after the procedure in both groups and decreased gradually. Statistically, there was a strong correlation among inflammation and time and also keratinization and time (p < 0.05). CONCLUSIONS: The present study indicates that Er:YAG laser irradiation with snoring handpiece (PS04) causes acute shrinkage of the mucosa. This contraction decreases gradually but is still present at the end of fifth week.

Occurrence of Pneumatic Cavities Surrounding the Temporomandibular Joint.

OBJECTIVES: The aim of this study was to investigate the occurrence, the location, and the characteristics of the pneumatic cavities (PCAs) surrounding the temporomandibular joint (TMJ) by using cone-beam computed tomography. METHODS: A retrospective study was performed by using the three-dimensional data archives from Faculty of Dentistry, Bezmialem University, Istanbul, Turkey. The age and sex had been previously recorded for all of the patients. The location and the morphologic characteristics of the PCAs were documented. RESULTS: Pneumatic cavities were found in 18 patients (15%): 11 women (61%) and 7 men (39%). Eleven (57.9%) of the patients showed unilocular pneumatic air cells and 8 (42.1%) of them showed multilocular ones. The unilateral-to-bilateral ratio was 2.3:1. The age range was 8 to 76 years (mean 29.5 ±â€Š21.86 years), and the female-to-male ratio was 1.57:1. CONCLUSION: Cone-beam computed tomography provides images without superimposition that allows accurate and easy evaluation of the PCAs surrounding the TMJ. Our results suggest that the occurrence of PCAs is higher than has been previously reported; therefore, it is recommended for clinicians who are planning to perform TMJ surgery to think about the PCAs to understand the exact morphology for avoiding intraoperative complications.

Regenerative endodontic treatment of an infected immature dens invaginatus with the aid of cone-beam computed tomography.

Dens invaginatus is a developmental anomaly that results in an enamel-lined cavity intruding into the crown or root before the mineralization phase. This report presents regenerative endodontic treatment of a necrotic immature tooth with Oehler's type III dens invaginatus of a nine-year-old female patient. A diagnosis of dens invaginatus (Oehler's type III) and a large periapical lesion was established with the aid of cone-beam computed tomography (CBCT). In the presented case contrary to the classic revascularization protocol, mechanical instrumentation was performed which apparently did not interfere with the regeneration process. After mechanical instrumentation of the invaginated canal by manual K-files, the invaginated canal space was disinfected by triple antibiotic paste followed by blood clot induction from the periapical tissues and the placement of mineral trioxide aggregate. At one-year follow-up, the tooth remained clinically asymptomatic. Radiographic examination revealed complete healing of the periapical lesion. At the 20-month follow-up, the radiographic examination also showed that the open apex was closed and the walls of the root canal were thickened.

HLA-A, B (Class I) and HLA-DR, DQ (Class II) antigens in Turkish patients with recurrent aphthous ulceration and Behçet's disease.

OBJECTIVE: The aims of the present study were to typify the human leukocyte antigen system (HLA)-A, B (class I) and HLA-DR, DQ (class II) antigens and to assess the frequency of the presence of these antigens in the Turkish population with recurrent aphthous ulceration (RAU) and Behçet's disease (BD) compared to healthy subjects. SUBJECTS AND METHODS: Thirty patients with RAU, 30 with BD, and 15 healthy subjects were included in the study. HLA typing was performed by serology with commercial kits for HLA class I and II (One Lambda, Canoga Park, Calif., USA). RESULTS: The HLA-A23 frequency was 26.7% in the RAU patients, which was significantly higher than the 3.3% frequency in the patients with BD (p < 0.05). The HLA-A24 frequency was 33.3% in the RAU patient group, which was significantly higher (p < 0.05) than the frequency in the healthy subjects (6.7%). Significantly higher frequencies (46.7%) of HLA-A30 were found in the healthy subjects compared to the BD (13.3%) and RAU (3.3%) patients (p < 0.05 and p < 0.01, respectively). A higher frequency of HLA-B13 was observed in the RAU (23.3%) patients compared to the BD (0%) patients (p < 0.01). A decrease was observed in HLA-DR10 and HLA-DR17 in the RAU patients (p < 0.05), while a higher frequency of HLA-DR10 was observed in the BD patients compared to the RAU patients (p < 0.01). CONCLUSIONS: These results showed that RAU and BD were not in the same spectrum and the involvement of other genetic and/or environmental factors might be responsible for the development of these diseases and/or disease progression.

Interleukin-2, interleukin-6 and T regulatory cells in peripheral blood of patients with Behçet's disease and recurrent aphthous ulcerations.

BACKGROUND: One of the factors involved in the pathogenesis of Behçet disease (BD) and recurrent aphthous ulcerations (RAU) is a cell-mediated immune response in which several cytokines (interleukin-2, interleukin-6) and T regulatory cell (T reg cell) population seem to play a major role. The aim of this study was to measured the interleukin-2 (IL-2), interleukin-6 (IL-6) levels and analysis of CD4(+) CD25(+) Foxp-3(+) Treg cells in peripheral blood from patients with BD and RAU. In addition; we also analysed peripheral blood from healthy subjects for comparison. METHODS: Thirty patients (15 men and 15 women) with BD, 30 patients (12 men and 18 women) with RAU and 15 healthy control subjects (nine men and six women) participated in the study. Analysis of CD4(+) CD25(+) Foxp-3(+) Treg cells, IL-2 and IL-6 levels have been measured in flow cytometry. RESULTS: No statistical differences were observed in the serum levels of IL-2 and IL-6 between BD and RAU patients, and healthy subjects. Although there were no statistical differences in the number of CD4(+) CD25(+) Foxp-3(+) cells between groups, there were statistically significant differences in the number of CD4(+) CD25(bright) Treg cells. CD4(+) CD25(bright) Treg cells were significantly increased in BD and RAU patients compared to healthy subjects. Statistical analysis revealed no difference according to the number of CD4(+) CD25(bright) cells between BD and RAU patients. CONCLUSIONS: These results indicate that CD4(+) CD25(bright) T regulatory cells may be contributing factor in the pathogenesis of BD and RAU.

Evaluation of demands and needs for dental care in a sample of the Turkish population.

OBJECTIVES: To evaluate the demands and needs for dental care and to identify the level of dental and periodontal status in patients of different age groups visiting the Faculty of Dentistry, Marmara University, Istanbul, Turkey. METHODS: A total of 1000 first-visit patients (517 female and 483 male) were examined and questioned. The main complaint of each patient was recorded and considered to be a measure of demand for dental care. The World Health Organization's (WHO) basic methods were used to determine the tooth-based and orthodontic normative treatment needs. Periodontal status was determined by using the Community Periodontal Index of Treatment Needs (CPITN). In addition, prosthetic normative needs were assessed. RESULTS: This study showed that patients in different age groups required different treatments and had different main complaints. In total, 89.3, 74.1 and 57.7% of the patients named periodontal, restorative and prosthetic care as their main complaint, respectively. Approximately 21% of the total did not need restorations and extractions, and only 12% of the sample did not have a normative periodontal treatment need. About half of subjects needed fixed partial dentures. CONCLUSIONS: Normative treatment needs of patients were very high. Therefore, a new national strategy for oral health must be devised for Turkey. This study can assist in setting the baseline for that strategy.