Prevalence of Middle Mesial Canals and Isthmi in the Mesial Root of Mandibular Molars: An In Vivo Cone-beam Computed Tomographic Study.

INTRODUCTION: Many studies have investigated the morphology of the mandibular molar, but the prevalence of the middle mesial (MM) canal in the mesial root of the mandibular molar is still the subject of controversy. In addition, in previous literature, a true MM canal has not been clearly distinguished from an isthmus between the mesiobuccal and mesiolingual canals. Therefore, the objectives of this study were 2-fold: METHODS: Ninety limited field of view cone-beam computed tomographic scans were observed. One hundred twenty-two mature mandibular first and second molars with no previous root canal treatment, no root resorption, and intact crowns were retrospectively evaluated. Data regarding the sex, age, presence of MM canals, and number of root canals in the mesial root were recorded. RESULT: Of the 122 teeth, 20 (16.4%) had true MM canals. The prevalence of MM canals was 26% in first molars and 8% in second molars (P < .05). The frequency of isthmi in the mesial roots was 64.7%. The frequency of isthmi was higher in second molars, but the difference was not statistically significant (P > .05). CONCLUSIONS: This study showed a high prevalence of mandibular molars with MM canals or isthmi. The detection and biomechanical cleaning of these areas during nonsurgical or surgical root canal treatment are critical.

Configuration of the inferior alveolar canal as detected by cone beam computed tomography.

AIMS: The aim of this study is to evaluate the course of the inferior alveolar canal (IAC) including its frequently seen variations in relation to root apices and the cortices of the mandible at fixed pre-determined anatomic reference points using cone beam volumetric computed tomography (CBVCT). MATERIAL AND METHODS: This retrospective study utilized CBVCT images from 44 patients to obtain quantifiable data to localize the IAC. Measurements to the IAC were made from the buccal and lingual cortical plates (BCP/LCP), inferior border of the mandible and the root apices of the mandibular posterior teeth and canine. Descriptive analysis was used to map out the course of the IAC. RESULTS: IACs were noted to course superiorly toward the root apices from the second molar to the first premolar and closer to the buccal cortical plate anteriorly. The canal was closest to the LCP at the level of the second molar. In 32.95% of the cases, the canal was seen at the level of the canine. CONCLUSIONS: This study indicates that caution needs to be exercised during endodontic surgical procedures in the mandible even at the level of the canine. CBVCT seems to provide an optimal, low-dose, 3D imaging modality to help address the complexities in canal configuration.

Endodontic clinical management of a dens invaginatus case by using a unique treatment approach: a case report.

INTRODUCTION: Dens invaginatus is a developmental anomaly that poses treatment challenges when nonsurgical root canal therapy is deemed necessary. Teeth with complex root canal morphology often require a comprehensive treatment approach to effectively clean, shape, and disinfect the pulp canal space before obturation. Endodontic clinical management of a tooth with dens invaginatus might include using cone-beam computed tomography (CBCT) to aid in the diagnosis and treatment-planning phase and use of the surgical operating microscope in performing the clinical phase of treatment. A novel approach could include using the revascularization technique as the final treatment step in the management of a dens invaginatus case in which the root apex has not completed formation. METHODS: This case report will provide both an overview of the feasibility of using CBCT scans in diagnosis and treatment planning and a step-by-step clinical technique, by using surgical operating microscope and the revascularization technique, in the successful endodontic management of a complex dens invaginatus case. CONCLUSIONS: Five-month and 12-month follow-up clinical and radiographic findings will provide a candid view of inherent advantages and challenges of this technique.

Detection of vertical root fractures by using cone-beam computed tomography: a clinical study.

INTRODUCTION: Vertical root fractures of teeth (VRFs) often pose a diagnostic dilemma because of the difficulty in detection of these in intraoral radiographs except in certain cases with very distinct clinical findings. This often leads to unwarranted extraction of the tooth. Cone-beam computed tomography (CBCT) produces three-dimensional images and allows precise visualization and evaluation of VRFs or cracks in extracted teeth, as reported previously. This clinical pilot study was designed to determine the diagnostic accuracy of noninvasive CBCT for detection of suspected VRFs in endodontically treated teeth by using exploratory surgery to confirm the presence or absence of a fracture. METHODS: Thirty-two teeth in 29 patients with clinical signs and symptoms suggestive of VRF were included in the study after informed consent was obtained. They underwent a limited area CBCT evaluation. All CBCT studies were blinded, and 2 board-certified oral and maxillofacial radiologists assessed the presence or absence of VRF through sequential evaluation of the three-dimensional volume. Subjects underwent surgical exploration as part of treatment, which helped establish the presence or absence of VRF. RESULTS: Pearson correlation coefficient by using surgical finding to confirm presence/absence of fracture was 0.602, positive predictive value was 91%, and negative predictive value was 67%. The sensitivity was 88%, and specificity was 75%. CONCLUSIONS: This study revealed the superior diagnostic accuracy of CBCT for detection of VRF.

Maxillary sinusitis of odontogenic origin: cone-beam volumetric computerized tomography-aided diagnosis.

OBJECTIVE: Study of radiographic features of maxillary sinusitis of odontogenic origin as visualized on 3-dimensional advanced imaging is essential for prompt diagnosis and appropriate management. This study attempted to describe and delineate radiographic characteristics of this condition. STUDY DESIGN: Three cases of failed endodontic therapy presenting with confounding clinical signs and symptoms were subjected to 3-dimensional imaging with cone-beam volumetric computerized tomography (CBVCT) to evaluate changes in the maxillary sinuses. RESULTS: CBVCT showed varying involvement of the ipsilateral maxillary sinus in all 3 cases. The presentation varied from presence of intrasinus fluid to reactionary osseous response within the sinus. CONCLUSIONS: CBVCT as a diagnostic aid to evaluate the involvement of the maxillary sinuses in cases of endodontic treatment failure seems to assist with formulation of a definitive diagnosis. Appropriate interventions may be instituted, including an otolaryngology consultation.

Correlation of tuned aperture computed tomography with conventional computed tomography for evaluation of osseous healing in calvarial defects.

OBJECTIVE: To compare the diagnostic efficacy of iteratively restored tuned aperture computed tomography (TACT) with conventional computed tomography (CT) for evaluation of osseous healing in induced calvarial defects. STUDY DESIGN: Fifty-six calvarial defects in 14 rabbits received 1 of 4 possible treatments: copolymer membranes with and without bone marrow stromal cells (BMSCs), BMSCs alone, or no treatment (control). Healing was measured after 2, 4, and 8 wks as remaining defect areas measured on TACT and CT images. Histomorphometric analyses were done on the specimens. RESULTS: Bone formation was minimal to none in control defects and those treated with BMSCs or polymer matrices alone. Healthy bone formation was noted in defects treated with polymers impregnated with BMSCs. Unresolved defect area measurements using TACT and CT of osseous healing showed a high positive correlation. CONCLUSIONS: Potential for TACT to accurately detect osseous healing in surgical defects was demonstrated. High resolution of TACT combined with generation of information in 3D yields comparable performance to CT.

Digital and advanced imaging in endodontics: a review.

This review provides an overview of digital radiography as it exists, including advanced imaging such as computed tomography (CT), cone beam volumetric imaging, and micro-CT as relevant to the practice of endodontics. An evidence-based approach to adoption of different imaging technologies is included to assist the practitioner with the selection process of imaging modalities. Commonly used imaging terminology is introduced, as well as the advantages and disadvantages of image processing. New image reconstruction techniques have been introduced that provide information three-dimensionally to the clinician for routine endodontic and surgical treatment planning. The age of three-dimensional imaging and image processing is here. Limitations and advantages of newly introduced imaging modalities are discussed briefly.

Effect of iterative restoration on the detection of artificially induced vertical radicular fractures by Tuned Aperture Computed Tomography.

OBJECTIVE: The purpose of this study was to evaluate the effect of the number of iterative restorations (IR) on the diagnostic accuracy of Tuned Aperture Computed Tomography images (TACT) for detection of induced vertical/oblique root fractures in mandibular teeth. STUDY DESIGN: Fractures were induced in 28 single-rooted, endodontically treated cadaver mandibular teeth while another 26 such teeth served as controls. TACT slices reconstructed by using 9 arbitrary projections (angular disparity of 9 degrees -20 degrees) were iteratively restored 1, 2, and 3 times. Eight observers scored their diagnoses by using a confidence rating scale. Ground truth was available from direct examination with transillumination, following extraction. RESULTS: Mean areas under the representative ROC curves for the 3 operations were 0.96 (3 IRs), 0.87 (2 IRs), and 0.86 (1 IRs). Analysis of variance demonstrated significant differences between 3 and 1 to 2 IRs (P <.01), as well as between observers (P <.01). CONCLUSION: Diagnostic accuracy of TACT for vertical/oblique root fracture detection improved after 3 IRs.