Evaluation of Optic Canal and Surrounding Structures Using Cone Beam Computed Tomography: Considerations for Maxillofacial Surgery.

The optic canal connects the anterior cranial fossa and the orbit and maintains the optic nerve and the ophthalmic artery. Within the extent of the surgical approach of the region, risk of iatrogenic injury of the neural and vascular structures increases. The aim of this retrospective morphometric study is to investigate the radiological anatomy of orbita, optic canal, and its surrounding using cone beam computed tomography (CBCT) scans in a group of Turkish population.Cone beam computed tomography images of a total of 182 patients were evaluated by 2 observers. Anatomical parameters regarding optic canal and orbita were measured for all patients from axial, sagittal, and three-dimensional reconstructed images. To assess intraobserver reliability, the Wilcoxon matched-pairs test was used. Pearson χ test and Student t test were performed for statistical analysis of differences, sex, localization, and measurements (P < 0.05).Repeated CBCT evaluation and measurements indicated no significant inter and intra-observer difference were found (P > 0.05). The orbita width and height were larger for the males than females (P < 0.05). No significant difference was observed for optic canal shape, dimensions of infraorbital foramen (IOF) and supraorbital foramen (SOF), SOF-midline distance, and SOF-IOF distance according to sex and location (P > 0.05). Examination CBCT scans revealed that the shape of the optic canal was 70% funnel and 28% Hourglass shape, 2% amorph type round.These results provide detailed knowledge of the anatomical characteristics in the orbital area which may be of assistance for surgeons preoperatively. Cone beam computed tomography scans can be an alternative modality for multislice computed tomography with submillimeter resolution and lower dose in preoperative imaging of the orbit.

Evaluation of root canal sealer filling quality using a single-cone technique in oval shaped canals: An In vitro Micro-CT study.

The aim of this study was to evaluate and compare the presence of voids in oval root canals filled with different root canal sealers (EndoSequence BC Sealer, Smartpaste bio, ActiV GP) and to compare those with root canals filled with AH Plus sealer using micro-CT. In total, 40 freshly extracted human single-root maxillary premolars were used. Specimens instrumented with the EndoSequence NiTi rotary instrument were assigned randomly into four groups. In each group, root canals were filled with single-cone gutta-percha and one of the tested sealers. Each specimen was then scanned using micro-CT at a voxel resolution of 13.47 µm. Proportions of sections with voids in cross-sectional images and void volumes for each sealer were calculated in the apical, middle, and coronal thirds. Differences according to root canal sealers were evaluated statistically using the Kruskal-Wallis test and the Mann-Whitney U-test at a significance level of 5%. The analysis showed a decrease in void formation in the apical third, with a significant difference between the apical and coronal thirds among bioceramic sealers, ActiV GP, and AH Plus (p < 0.05) but no significant difference between the apical and middle thirds or between the middle and coronal thirds was found for the sealers tested (p > 0.05). All root canal sealers tested resulted in voids. The bioceramic sealers (EndoSequence BC Sealer, Smartpaste bio) produced similar voids which had the fewest in the apical third of root canals among the sealers tested which can be related due to root canal anatomy variations.

Comparison of intraoral radiography and cone-beam computed tomography for the detection of periodontal defects: an in vitro study.

BACKGROUND: This study aimed to compare the diagnostic accuracy of cone-beam computed tomography (CBCT) unit with digital intraoral radiography technique for detecting periodontal defects. METHODS: The study material comprised 12 dry skulls with maxilla and mandible. Artificial defects (dehiscence, tunnel, and fenestration) were created on anterior, premolar and molar teeth separately using burs. In total 14 dehiscences, 13 fenestrations, eight tunnel and 16 without periodontal defect were used in the study. These were randomly created on dry skulls. Each teeth with and without defects were images at various vertical angles using each of the following modalities: a Planmeca Promax Cone Beam CT and a Digora photostimulable phosphor plates. Specificity and sensitivity for assessing periodontal defects by each radiographic technique were calculated. Chi-square statistics were used to evaluate differences between modalities. Kappa statistics assessed the agreement between observers. Results were considered significant at P < 0.05. RESULTS: The kappa values for inter-observer agreement between observers ranged between 0.78 and 0.96 for the CBCT, and 0.43 and 0.72 of intraoral images. The Kappa values for detecting defects on anterior teeth was the least, following premolar and molar teeth both CBCT and intraoral imaging. CONCLUSIONS: CBCT has the highest sensitivity and diagnostic accuracy for detecting various periodontal defects among the radiographic modalities examined.

Survival rate of short, locking taper implants with a plateau design: a 5-year retrospective study.

BACKGROUND: Short implants have become popular in the reconstruction of jaws, especially in cases with limited bone height. Shorter implants, those with locking tapers and plateau root shapes, tend to have longer survival times. We retrospectively investigated the cumulative survival rates of Bicon short implants (<8 mm) according to patient variables over a 5-year period. MATERIALS AND METHODS: This study included 111 consecutively treated patients with 371 implants supporting fixed or removable prosthetics. Data were evaluated to acquire cumulative survival rates according to gender, age, tobacco use, surgical procedure, bone quality, and restoration type. Statistics were performed using chi-square, Mann-Whitney, and Kruskal Wallis H tests. RESULTS: The survival rate was 97.3% with, on average, 22.8 months of follow-up. Patients older than 60 years had higher failure rate than the other age groups (P < 0.05). Placed region, age, and bone quality had adverse effects on survival rate in the <8 mm implant group with statistically significant difference (P < 0.05). CONCLUSIONS: Approximately 23-month follow-up data indicate that short implants with locking tapers and plateau-type roots have comparable survival rates as other types of dental implants. However, due to limitations of study, these issues remain to be further investigated in future randomized controlled clinical trials.

Comparative evaluation of shaping ability of two nickel-titanium rotary systems using cone beam computed tomography.

BACKGROUND: We evaluated and compared the effects of different NiTi rotary systems--ProTaper Next and New One Shape--on the volume of dentin removed, canal transportation, and canal curvature in extracted human teeth using CBCT scanning with different voxel sizes. METHODS: Fifty extracted human maxillary first molars with mesiobuccal canal curvature (25-35°) were used. Specimens were instrumented with the ProTaper Next or New One Shape. Pre- and post-instrumentation scans were performed to compare transportation at the levels of 2, 5, and 8 mm and volumes with two different voxel sizes (0.125-and 0.100-mm(3)) using 3D CBCT images. This study evaluated and compare the volume of dentin removed, canal transportation, and canal curvature. Differences according to instrumentation and voxel sizes were assessed using the Mann-Whitney U-test and the Wilcoxon signed-rank test. RESULTS: Significant differences were found between apical and coronal levels for both systems (p < 0.05) in canal transportation. In comparing the systems, similar values were found at each level, without significant difference (p > 0.05) in terms of canal curvature and volume. Voxel sizes did not affect the measurements on canal volume, curvature or transportation; no significant difference was found between the 0.100- and 0.125-mm(3) voxel sizes (p > 0.05). CONCLUSIONS: Both instrumentation systems produced similar canal transportation and volume changes. The two voxel resolutions also showed similar results, however a 0.125-mm(3) voxel size can be recommend for a flat panel CBCT scanner with lower exposure dose.

Accuracy of virtual models in the assessment of maxillary defects.

PURPOSE: This study aimed to assess the reliability of measurements performed on three-dimensional (3D) virtual models of maxillary defects obtained using cone-beam computed tomography (CBCT) and 3D optical scanning. MATERIALS AND METHODS: Mechanical cavities simulating maxillary defects were prepared on the hard palate of nine cadavers. Images were obtained using a CBCT unit at three different fields-of-views (FOVs) and voxel sizes: 1) 60×60 mm FOV, 0.125 mm(3) (FOV60); 2) 80×80 mm FOV, 0.160 mm(3) (FOV80); and 3) 100×100 mm FOV, 0.250 mm(3) (FOV100). Superimposition of the images was performed using software called VRMesh Design. Automated volume measurements were conducted, and differences between surfaces were demonstrated. Silicon impressions obtained from the defects were also scanned with a 3D optical scanner. Virtual models obtained using VRMesh Design were compared with impressions obtained by scanning silicon models. Gold standard volumes of the impression models were then compared with CBCT and 3D scanner measurements. Further, the general linear model was used, and the significance was set to p=0.05. RESULTS: A comparison of the results obtained by the observers and methods revealed the p values to be smaller than 0.05, suggesting that the measurement variations were caused by both methods and observers along with the different cadaver specimens used. Further, the 3D scanner measurements were closer to the gold standard measurements when compared to the CBCT measurements. CONCLUSION: In the assessment of artificially created maxillary defects, the 3D scanner measurements were more accurate than the CBCT measurements.

Metastasis of prostate carcinoma in the mandible manifesting as numb chin syndrome.

BACKGROUND: Numb chin syndrome is an uncommon but well-recognized symptom in medical oncology. This condition can be related to metastatic neurological manifestation of malignancy, often with no clinically visible pathology. About 1% of oral cancers, which are located in the soft tissues and jaws, are metastases of primary tumors located elsewhere in the body. The posterior mandible is the most common site of metastasis of the oral region because of its rich blood supply in active areas of hematopoiesis. This article describes prostate carcinoma metastasis located in the mandible and temporomandibular joint of a 78-year-old male. CASE PRESENTATION: A 78-year-old male patient presented to our outpatient clinic with a complaint of numbness and pain on the left site of the mandible. The patient stated that he had been suffering from this numbness for 1 to 2 months. In the medical anamnesis, it was discovered that patient had prostate carcinoma (CA) 5 years previous, and since then, he had visited his doctor periodically for an annual examination. In these examinations and on the basis of tests carried out at the hospital 1 year previous, it was stated that no CA relapse traces were detected. The patient had visited his dentist 2 months previous for pain and numbness of the left molar region. CONCLUSIONS: We report numb chin syndrome, which is an uncommon neurological manifestation of metastatic malignancy. The clinical course and rapid deterioration after the initial presentation of this syndrome is discussed. This clinical situation illustrates the importance of good medical history review prior to all procedures by the medical professions dealing with oncology patients. An awareness of this condition is crucial, especially in symptoms with unexplained facial pain and numbness.

Evaluation of the superior semicircular canal morphology using cone beam computed tomography: a possible correlation for temporomandibular joint symptoms.

OBJECTIVE: This study aimed to assess the superior semicircular canal (SSCC) morphology and to determine whether superior semicircular canal dehiscence (SSCD) correlates with temporomandibular joint (TMJ) symptoms. STUDY DESIGN: Clinical data and cone beam computed tomography (CBCT) scans of 175 patients were retrospectively examined by 2 observers. Distribution and thickness measurements of the different types of bone cover of the SSCC were performed. RESULTS: Five radiologic SSCC patterns were identified from CBCT data: 147 cases (42%) were defined as normal (0.6-1.7 mm thickness); 62 cases (17.71%) had a papyraceous pattern (<0.5 mm); 77 cases (22%) showed a thick pattern (>1.8 mm); and 42 cases (12%) had a pneumatized pattern. Observer 1 and 2 diagnosed SSCD in 22 of 350 (6.28%) temporal bones individually and had no discordances between the 2 reviews. All patients with SSCD were identified as having TMJ signs and symptoms (P < .05). CONCLUSIONS: Maxillofacial radiologists should be informed about these structures, which can be helpful for the interpretation of CBCT scans.

Evaluation of foramen tympanicum using cone-beam computed tomography in orthodontic malocclusions.

The foramen tympanicum is a persistent anatomic formation of the temporal bone due to a defect in ossification normal bone physiology in neonatal or postnatal period. This study determined the occurrence and location of the foramen tympanicum in a Turkish sample using cone-beam computed tomography. Scans of 370 sites in 185 patients were retrospectively analyzed to determine foramen tympanicum occurrence, sizes, and locations according to their orthodontic malocclusions. Measurements were done on axial and sagittal sections to identify the dimensions. Differences in foramen tympanicum incidence by measurements, sex, side, malocclusions, and location were statistically evaluated. Foramen tympanicum was determined in 42 (22.7%) of 185 patients. No statistical difference was found considering location and sex (P > 0.05), but it was found more bilaterally in female patients within significance level at P = 0.024. Mean sizes did not differ significantly by sex but were found to be greater in females. In axial diameter, the average measurement was found wider on the right side of all patients (P = 0.017). The findings showed a greater foramen tympanicum dimension among class II than among class I and III subjects (P < 0.05). Knowledge about these structures is helpful for the interpretation of imaging (especially cone-beam computed tomography) and provides valuable information especially before orthognathic surgery to avoid intraoperative reconstruction and complications.

Florid osseous dysplasia in a middle-aged Turkish woman: A case report.

Florid osseous dysplasia (FOD) is an uncommon, benign, cemento-osseous lesion of the jaws. The etiology of FOD is still unknown. It is often asymptomatic and may be identified on routine dental radiographs. The classic radiographic appearance of FOD is amorphous, lobulated, mixed radiolucent/radiopaque masses of cotton-wool appearance with a sclerotic border in the jaws. In our case the lesion was found incidentally on routine periapical radiographs taken for restored teeth and edentulous areas. For further and detailed examination, a panoramic radiograph and cone-beam computed tomograph (CBCT) were taken. The panoramic radiograph and CBCT revealed maxillary bilateral and symmetrical, non-expansile, well-defined, round, radiopaque masses in contact with the root of the maxillary right second molar and left first molar teeth. Our aim in presenting this case report was to highlight the importance of imaging in diagnosis of FOD.

The visibility of secondary caries under bonding agents with two different imaging modalities.

This study investigated the visibility of secondary caries lesions associated with two different adhesive systems of composite restorations (Optibond Solo Plus and Clearfil SE Bond) using a conventional dental x-ray film (Kodak D Speed) and a digital system (Digora) based on storage phosphor-plate technology for detection of secondary caries. For imaging techniques and adhesive systems, false positive scores were high. Intraobserver agreements ranged between 0.432 and 0.778, while interobserver agreements for the readings ranged 0.321-0.731 and 0.411-0.701, respectively. No statistical difference was found between the Az (area under curve) values obtained from PSP (photostimulable storage phosphor) and film images with the exception of the second observer's first reading for total etch adhesive system (Optibond Solo Plus) (p=0.0258). Furthermore, no statistical difference was found between both the bonding systems assessed (p>0.05). Adhesive materials should also have enough radiopacity to facilitate diagnosis of secondary caries.

Radiopacity evaluation of composite restorative resins and bonding agents using digital and film x-ray systems.

OBJECTIVE: The purpose of this in vitro study was to explore the radiopacity of composite resins and bonding materials using film and phosphor plates. METHODS: Nine composite dental resin specimens and human tooth slices were exposed together with an aluminium stepwedge using dental film and phosphor plates. Eight dentin bonding specimens were prepared and exposed in a similar manner. Their radiopacity on film was assessed using a transmission densitometer, and the radiopacity with phosphor plates was assessed digitally using the system's own software (Digora). Data were analysed using one-way analysis of variance (ANOVA) and post-hoc Tukey tests (P<.05). Film and phosphor plate radiopacity values were compared using simple regression analysis. RESULTS: Excellent linear correlation was found between film and phosphor plates for both composite resins and bonding agents. The composite materials Spectrum Tph and Natural Look exhibited the highest radiopacity with film and with phosphor plates, respectively. All the dentin bonding agents tested exhibited lower radiopacity than dentin. CONCLUSION: Synergy, Ice, Filtek Silorane, Filtek Z250, Clearfil Majesty Posterior, Herculite Classic, Spectrum Tph, and Natural Look composite materials exhibited greater radiopacity than dentin, and all the dentin bonding agents tested exhibited lower radiopacity than either enamel or dentin.

Delayed diagnosis of oral squamous cell carcinoma: a case series.

INTRODUCTION: In malign neoplasms, oral cancer is one of the important causes of mortality and morbidity. Squamous cell carcinoma is the most common form of oral cancers in adults and is related to risk factors such as smoking and alcohol consumption. CASE PRESENTATION: In this article, we present three case reports of oral squamous cell carcinomas with delayed diagnosis. The first patient was a 52-year-old Turkish man, the second patient was a 61-year-old Turkish man and the third patient was a 60-year-old Turkish woman. All were referred to the Ankara University Faculty of Dentistry with pain, swelling and various complaints in their jaws. CONCLUSION: Early diagnosis is of vital importance for the prognosis of the patients with oral squamous cell carcinomas. For this reason, dentists play a crucial role in the early detection and prevention of oral cancers.

Observer ability to detect ex vivo simulated internal or external cervical root resorption.

INTRODUCTION: The objective of this study was to assess observer ability to detect ex vivo simulated internal and external cervical root resorption. METHODS: A total of 90 single-rooted mandibular anterior teeth were split along the coronal plane. By using a 0.5-mm diameter round bur, 50 of the teeth were drilled to simulate resorptive cavities (25 internal and 25 external cervical resorption), and the remaining 40 teeth were left without surface defects. The sectioned teeth were rejoined and placed in the alveolar sockets of a dry human mandible in groups of 6 and imaged with intraoral film by using 3 different angulations and with a cone-beam computed tomography (CBCT) unit. Film and CBCT image sets were evaluated twice by 3 separate observers. Teeth were scored for the presence and location of resorption by using a 5-point scale. Intraobserver and interobserver kappa coefficients and Az values were calculated for each observer and image set. Differences between modalities were compared by using z statistics, with the significance level set at α = 0.05. RESULTS: Both intraobserver and interobserver agreements were statistically higher (p < .05) for the Iluma CBCT images than for the intraoral images. Az values for CBCT images were also statistically higher (p < .05) than for film images for all observers and readings. In addition, kappa and Az values of external cervical resorption cavities were statistically higher (p < .05) than those of internal cervical resorption cavities for all observers, image types, and readings. CONCLUSIONS: High-resolution Iluma CBCT images performed better than film in the ex vivo detection and localization of simulated internal and external cervical root resorption.

Submandibular displacement of a mandibular third molar root during extraction: a case report.

A 46-year-old female patient with complaints of pain and swelling on right submandibular region and limitation on mouth opening was reported. She had undergone an unsuccessful surgical procedure under local anesthesia performed by a general practitioner for removal of impacted mandibuler right third molar 1 week earlier. On clinical examination floor of the mouth was tender to palpation. Panoramic and the periapical radiographs showed presence of a radiopaque mass similar to that of a tooth root. Computed tomography scans were obtained for detailed radiographic examination, thereby the presence of a high density area in the submandibular region was detected. Under general anesthesia the displaced root was removed and the postoperative course was uneventful.