Incidence of hypercementosis in mandibular third molars determined using cone beam computed tomography.

Purpose: This study was conducted to investigate the incidence and predictors of hypercementosis in mandibular third molars using cone beam computed tomography.

Methods: Using a retrospective approach, 1,160 cone beam computed tomography image sets were analyzed. Two oral radiologists independently evaluated the image sets based on four severity grades: 0, no hypercementosis around the root; 1, hypercementosis surrounding less than half of the root surface; 2, hypercementosis surrounding more than half of the root surface; and 3, hypercementosis surrounding the entire root surface.

Usefulness of MR imaging for odontogenic tumors.

MRI has become an invaluable diagnostic tool in all areas of the body. However, it has not been widely used to image odontogenic tumors of the jaw. Major advantages of MRI include excellent soft tissue contrast in the absence of ionizing radiation.

3D evaluation of the morphological and volumetric changes of the tongue and oral cavity before and after orthognathic surgery for mandibular prognathism: a preliminary study.

Background: The volumetric ratio of the tongue to the oral cavity has been recognized to be one of the important factors for the maintenance of stable occlusion. Oral cavity capacity is changed after orthognathic surgery in patients with mandibular prognathism; however, the volumetric changes of the oral cavity including the tongue before and after surgery have not been analyzed. The purpose of this study was to evaluate the morphological and volumetric changes of the tongue and oral cavity following orthognathic surgery using a newly developed vinyl polysiloxane impression method.

Morphological comparison of artificial teeth position utilising denture space in glossectomy patients.

Objective: This study aimed to compare the denture space of edentulous glossectomy patients with that of a control group from the perspective of artificial teeth positioning by using three-dimensional techniques.

Background: It is known that the shape of the denture space may be affected by tongue resection or reconstruction. However, the details of artificial teeth positioning in these patients remain unclear.

The development of new image receptor-holding instruments with appropriate horizontal X-ray beam angulation for periapical radiographs.

Objectives: This study aimed to develop new image receptor-holding instruments with appropriate horizontal X-ray beam angulation, based on the anatomical data of posterior region interproximal surfaces derived from archived CT images.

Methods: CT images of 92 patients with sound upper and lower dental arches were collected from our CT database and analyzed to determine the angles between the tangential interproximal contact line and the central groove line of posterior teeth. The average angle for each site was calculated and used to modify instruments using a three-dimensional printer.

Evaluation of tongue volume and oral cavity capacity using cone-beam computed tomography.

The aims of this study were to reveal the usefulness of a newly developed method for measuring tongue volume (TV) and oral cavity capacity (OCC) and to assess the relationship between them. The tongue was coated with a contrast agent, and the TV and OCC were determined using cone-beam computed tomography (CBCT). We enrolled 20 adults who were scheduled to undergo CBCT to evaluate the relationship of the third molar roots to the alveolar nerve before molar extraction.

Ability of Cone-beam Computed Tomography to Detect Periapical Lesions That Were Not Detected by Periapical Radiography: A Retrospective Assessment According to Tooth Group.

Introduction: The detection of periapical lesions by periapical radiography (PR) can be hampered by structural noise, the impact of which differs among tooth groups. The aim of this study was to investigate the ability of cone-beam computed tomographic (CBCT) imaging to detect periapical lesions that could not be detected with PR according to tooth group.

Methods: This study retrospectively evaluated teeth that (1) had previously undergone root canal treatment (178 teeth from 86 patients), (2) had coincidentally been located within the field of view of CBCT scans performed for endodontic reasons, and (3) had also been examined with PR.

Non-Hodgkin lymphoma involving the mandible: imaging findings.

Objective: The aim of this study was to investigate the imaging findings of non-Hodgkin lymphoma (NHL) involving the mandible.

Study Design: The imaging studies of 4 patients with NHL involving the mandible were retrospectively reviewed. Panoramic and computerized tomographic (CT) images were available for all patients.

Trial of a CAD/CAM system for fabricating complete dentures.

The purpose of this study was to evaluate the fabrication of a complete denture using a CAD/CAM system. Cone beam CT was used to measure the complete denture and the artificial teeth. After a 3D complete denture image was structured using 3D CAD software, we factored out the artificial teeth and obtained a 3D denture base image.

Morphological observation of the medial pterygoid muscle by the superimposition of images obtained by lateral cephalogram and MRI.

Objective: To observe the morphological relationship between the maxillofacial skeleton and medial pterygoid muscle by superimposing images constructed by MRI on a cephalogram.

Design: Cross-sectional study.

Setting: The Departments of Maxillofacial Orthognathics and Orthodontics, Tokyo Medical and Dental University.

Standardization of thresholding for binary conversion of vocal tract modeling in computed tomography.

Postoperative head and neck cancer patients suffer from speech disorders, which are the result of changes in their vocal tracts. Making a solid vocal tract model and measuring its transmission characteristics will provide one of the most useful tools to resolve the problem. In binary conversion of X-ray computed tomographic (CT) images for vocal tract reconstruction, nonobjective methods have been used by many researchers.

Diagnostic accuracy of cone-beam CT in the assessment of mandibular invasion of lower gingival carcinoma: comparison with conventional panoramic radiography.

Purpose: To evaluate the diagnostic accuracy of cone-beam CT in assessing mandibular invasion by lower gingival carcinoma and compare it with that of panoramic radiography.

Patients And Methods: Fifty patients with squamous cell carcinoma of the lower gingiva who were examined by both panoramic radiography and cone-beam CT before surgery were included in this study. Five radiologists used a 6-point rating scale to independently evaluate cone-beam CT and panoramic images for the presence or absence of alveolar bone and mandibular canal involvement by tumor.

A comparative study of cone-beam computed tomography and conventional panoramic radiography in assessing the topographic relationship between the mandibular canal and impacted third molars.

Objective: To evaluate the diagnostic accuracy of cone-beam CT compared with panoramic images in predicting neurovascular bundle exposure during extraction of impacted mandibular third molars.

Study Design: Cone-beam CT and panoramic images of 142 impacted mandibular third molars were prospectively evaluated to assess tooth relationship to the mandibular canal. These interpretations were then correlated with intraoperative findings.