Incidental findings of skull-base abnormalities in cone-beam computed tomography scans with consultation by maxillofacial radiologists.

INTRODUCTION: Cone-beam computed tomography (CBCT) gives orthodontists and other dental clinicians 3-dimensional information for planning treatment in the craniofacial region. Often overlooked are incidental findings outside the treatment region of interest. METHODS: Two patients with incidental findings of skull-base abnormalities are presented. The orthodontic patient was tentatively diagnosed with a notochordal remnant in the clivus; the implant patient exhibited an empty sella turcica. RESULTS: For the clivus lesion in the orthodontic patient, an artifact was ruled out after a second CBCT image and further distinguished from a fat-containing tumor after magnetic resonance imaging. The impression after magnetic resonance imaging was a notochordal remnant, although chordoma was also included in the differential, warranting a 6-month follow-up magnetic resonance image to confirm the diagnosis. The CBCT study for the implant patient demonstrated an enlarged sella turcica. The impression after the magnetic resonance imaging was an enlarged and partially empty sella with no evidence of a pituitary mass. CONCLUSIONS: Orthodontists and implant surgeons may come across incidental findings outside their area of expertise on CBCT scans, highlighting the importance of appropriate consultation with maxillofacial radiologists. Notochordal remnants may present as nonexpansile intraosseous low-density areas. The challenge in distinguishing these lesions radiographically with chordomas warrants follow-up to confirm a diagnosis. An empty sella is a noteworthy finding because of its potential for endocrine and neuro-ophthalmological disorders despite an asymptomatic presentation.

Efficacy of the CALM® Algorithm in Reducing Motion-Induced Artifacts in CBCT Imaging: A Fractal Dimension Analysis of Trabecular Bone.

OBJECTIVE: The primary goal of this investigation was to ascertain the efficacy of the CALM® motion artifact reduction algorithm in diminishing motion-induced blurriness in Cone Beam Computed Tomography [CBCT] images. The assessment was conducted through Fractal Dimension [FD] analysis of the trabecular bone. METHODS AND MATERIALS: A desiccated human mandible was subjected to Planmeca ProMax 3D® scanning under eight distinct protocols, marked by variations in motion presence [at 5, 10, and 15 degrees] and the deployment of CALM®. In every scan, five distinct regions of interest [ROIs] were designated for FD analysis, meticulously avoiding tooth roots or cortical bone. The FD was computed employing the box-counting method with Image-J 1.53 software. RESULTS: Our findings reveal that a 5-degree motion does not significantly disrupt FD analysis, while a 10-degree motion and beyond exhibit statistical differences and volatility among the sites and groups. A decreased FD value, signifying a less intricate or "rough" bone structure, correlated with amplified motion blurriness. The utilization of CALM® software seemed to counteract this effect in some instances, reconciling FD values to those akin to the control groups. Nonetheless, CALM®'s efficacy differed across sites and motion degrees. Interestingly, at one site, CALM® application in the absence of motion resulted in FD values considerably higher than all other groups. CONCLUSION: The study indicates that motion, particularly at 10 degrees or more, can considerably impact the FD analysis of trabecular bone in CBCT images. In some situations, the CALM® motion artifact reduction algorithm can alleviate this impact, though its effectiveness fluctuates depending on the site and degree of motion. This underscores the necessity of factoring in motion and the employment of artifact reduction algorithms during the interpretation of FD analysis outcomes in CBCT imaging. More research is necessary to refine the application of such algorithms and to comprehend their influence on different sites under varying motion degrees.

Assessment of alveolar bone changes in response to minimally invasive periodontal surgery: A cone-beam computed tomographic evaluation.

Purpose: The aim of this study was to evaluate 3-dimensional cone-beam computed tomography (CBCT) images of alveolar bone changes in patients who underwent minimally invasive periodontal surgery-namely, the pinhole surgical technique (PST). Materials and Methods: Alveolar bone height was measured and compared on CBCT images of 254 teeth from 23 consecutive patients with Miller class I, II, or III recession who had undergone PST. No patient with active periodontal disease was selected for surgery. Two different methods were used to assess the alveolar bone changes postoperatively. In both methods, the distance between the apex of the tooth and the mid-buccal alveolar crestal bone on pre- and post-surgical CBCT studies was measured. Results: An average alveolar bone gain >0.5 mm following PST was identified using CBCT (P=0.05). None of the demographic variables, including sex, age, and time since surgery, had any significant effect on bone gain during follow-up, which ranged from 8 months to 3 years. Conclusion: PST appears to be a promising treatment modality for recession that results in stable clinical outcomes and may lead to some level of resolution on the bone level. More long-term studies must be done to evaluate the impact of this novel technique on bone remodeling and to assess sustained bone levels within a larger study population.

Implementation of a modified quality assurance protocol for CBCT machines within UT health San Antonio School of Dentistry.

OBJECTIVES: To implement the quality control assurance protocol (including the re-establishment of baseline data from 2016) to monitor the stability of image quality of CBCT machines located within the UT Health San Antonio School of Dentistry. METHODS AND MATERIALS: Five CBCT machines ProMax 3D Mid® (Planmeca Oy, Helsinki, Finland), 3D Accuitomo XYZ Slice View Tomograph® (Model MCT-1, Type EX-1F8; Fushimi-ku, Kyoto: J. Morita Mfg. Corp), Veraviewepocs 3D (Model R100; Fushimi-ku, Kyoto: J. Morita Mfg. Corp), PreXion3D Excelsior® (PreXion, San Mateo, CA), and i-CAT FLX Series® (Imaging Sciences International, Hatfield, PA) were tested for Artifact, Contrast-to-Noise Ratio, Noise, Spatial Resolution, and Contrast Resolution using a custom insert configuration in the SEDENTEXCT IQ phantom. RESULTS: Four-scan benchmark mean values for Artifact, Contrast-to-Noise, Noise, Spatial Resolution, and Contrast Resolution were determined for the five machines tested with associated alert and action level thresholds calculated. CONCLUSION: This newly developed QA protocol established image quality baseline values. Recommended tests, frequency, and actions levels have been updated and control charts established for future trend analysis to enable proper implementation of a QA protocol monitoring CBCT machines at UT health San Antonio.

Comparison of photothermal radiometry and modulated luminescence, intraoral radiography, and cone beam computed tomography for detection of natural caries under restorations.

OBJECTIVES: The aim of this ex vivo study was to measure the sensitivity, specificity, and receiver operating characteristic (ROC) area under the curve (AUC) of a caries diagnostic system based on photothermal radiometry and modulated luminescence (PTR/LUM) and compare them with the values for digital intraoral radiography (IR) and cone beam computed tomography (CBCT) in detecting recurrent decay. STUDY DESIGN: Class 2 composite restorations were prepared on 70 proximal surfaces: 35 with caries and 35 without caries. The gingival floor of the restored surfaces was assessed for caries under the restorations using each of the 3 modalities. Statistical calculations and analysis were performed using the R statistical computing environment. RESULTS: The average scores for sensitivity among the 6 observers were 0.89 for PTR/LUM, 0.38 for IR, and 0.40 for CBCT. Sensitivity for PTR/LUM was significantly greater than sensitivity for IR and CBCT. Average scores for specificity were 0.83, 0.80, and 0.70 for PTR/LUM, IR, and CBCT, respectively. CBCT had significantly lower specificity. The AUC was 0.65 for IR and 0.59 for CBCT, which were significantly different. PTR/LUM had moderate intraobserver agreement. CONCLUSIONS: PTR/LUM, which involves non-ionizing radiation, can serve as a sensitive adjunct in early caries detection and monitoring.

Evaluation of artifacts generated by titanium, zirconium, and titanium-zirconium alloy dental implants on MRI, CT, and CBCT images: A phantom study.

OBJECTIVE: The aim of this study was to assess artifacts generated by zirconium, titanium, and titanium-zirconium alloy implants on magnetic resonance imaging(MRI), computed tomography(CT), and cone beam computed tomography(CBCT) and to correlate the findings to the dose-area product and exposure factors on CT and CBCT. STUDY DESIGN: Three phantoms were built by embedding zirconium, titanium, and titanium-zirconium implants in ultrasound gel. MRI, CT, and CBCT images were acquired by using multiple sequences and settings. For MRI, "artifact" was described as the length of signal void beyond the limits of the implant. For CT and CBCT, "artifact" was calculated by subtracting the gray level of the darkest pixel from the level of the lightest pixel. RESULTS: On MRI, zirconium implants had minor distortion artifacts, whereas titanium and titanium-zirconium implants created extensive artifacts (P < .05). On CT and CBCT, artifacts were less prominent with titanium and titanium-zirconium implants compared with zirconium (P < .05). Titanium grade 5 implants with 0.3 and 0.4 mm3 voxels produced the least severe artifacts. CONCLUSIONS: MRI images were less affected by artifacts from zirconium implants, whereas CT and CBCT images showed less severe artifacts from titanium and titanium-zirconium alloy implants. CT generated greater artifacts compared with CBCT. Larger CBCT voxel sizes reduced the dose-area product and the severity of artifacts.

3D Volume Rendering and 3D Printing (Additive Manufacturing).

Three-dimensional (3D) volume-rendered images allow 3D insight into the anatomy, facilitating surgical treatment planning and teaching. 3D printing, additive manufacturing, and rapid prototyping techniques are being used with satisfactory accuracy, mostly for diagnosis and surgical planning, followed by direct manufacture of implantable devices. The major limitation is the time and money spent generating 3D objects. Printer type, material, and build thickness are known to influence the accuracy of printed models. In implant dentistry, the use of 3D-printed surgical guides is strongly recommended to facilitate planning and reduce risk of operative complications.

Optical Coherence Tomography.

Optical coherence tomography (OCT) is a noninvasive diagnostic technique providing cross-sectional images of biologic structures based on the differences in tissue optical properties. OCT has been widely used in numerous clinical applications and is becoming popular as a promising technology in dentistry. Today, dental hard (tooth) and soft (hard palate mucosa and gingiva mucosa) tissues are visualized with OCT. With new developments in technology, the applications of OCT are being investigated in various fields in dentistry, such as to detect microleakage around restoration, tooth cracks/fractures, examination of periodontal tissues/pockets, early detection of oral cancerous tissues, and in endodontics for location of pulp canal.

Cone beam computed tomography image optimization to detect root fractures in endodontically treated teeth: an in vitro (phantom) study.

OBJECTIVES: The aim of this study was to evaluate the effect of an optimization filter (OF) and voxel size on the accuracy of root fracture detection. STUDY DESIGN: Half of 40 endodontically treated roots were fractured, and the other half were left intact. All teeth were randomly placed into 5 bovine ribs. Each rib was scanned with the Planmeca ProMax 3-D using 4 different settings: 75 µm and 100 µm voxel size with and without an OF. Five reviewers reported if a fracture was present by using a 5-point scale. Intra-/interobserver agreement, area under the receiver operative characteristic curve, accuracy, sensitivity, and false-positive rates were analyzed. RESULTS: High κ-values indicated strong intra-/interobserver agreement. There was no significant difference in fracture detection between any of the evaluated techniques. CONCLUSIONS: Because of the decreased cost, dose area product, and time required, compared with the other imaging modalities studied, the high-resolution mode (100 µm) without an OF is recommended for root fracture detection in endodontically treated teeth.

The effect of milliamperage, number of basis images, and export slice thickness on contrast-to-noise ratio and detection of mandibular canal on cone beam computed tomography scans: an in vitro study.

OBJECTIVES: The aim of this study was to evaluate the effect of milliamperage, number of basis images, and export slice thickness on contrast-to-noise ratio (CNR) and confidence in detecting mandibular canal. STUDY DESIGN: Two phantoms were used. Each phantom consisted of a dry mandible with an epoxy resin bone tissue substitute block and a water-equivalent block, submerged in water. Each mandible was scanned with a Morita 3D Accuitomo cone beam computed tomography (CBCT) machine (Morita, Kyoto, Japan). Scans were made with 180-degree and 360-degree rotations, at 4, 6, and 8 mA. Each scan was exported in Digital Imaging and Communications in Medicine (DICOM) format at slice thicknesses of 0.125 mm, 0.25 mm, 0.75 mm, and 1.0 mm, resulting in 24 image sets for each phantom. The CNR was calculated. Variables were analyzed using factorial analysis of variance. The scans were also evaluated by five observers who were asked to state their confidence in detecting the mandibular canal on a four-point confidence scale. RESULTS: Increasing the number of basis images, milliamperage, or export slice thickness significantly increased the CNR. Reducing the export slice thickness improved observers' confidence in detecting the mandibular canal. CONCLUSIONS: The CBCT acquisition settings should be carefully chosen, depending on specific diagnostic tasks. The lowest slice thickness equal to the voxel size should always be used for exporting CBCT data despite the higher noise.

Multiple myeloma in bisphosphonate-affected jaws--a diagnostic challenge: case report.

OBJECTIVE: To discuss the challenges in diagnosis and appropriate management of critical underlying pathoses if a patient presents with signs and symptoms indicative of different conditions that may coexist. SUMMARY: This case features clinical and radiographic challenges in reaching a diagnosis in a middle- aged man undergoing bisphosphonate therapy for multiple myeloma. The patient had history of bisphosphonaterelated osteonecrosis of the jaw (BRONJ) in the mandible. The patient presented with pain and swelling in the anterior maxilla, associated with paresthesia of upper lip. The radiographic features were suggestive of BRONJ and invasive fungal sinusitis. MRI appearance was suggestive of malignant involvement by plasmacytoma or lymphoma. Although biopsy is usually not advocated in bisphosphonate-affected jaws, it was advised in this case and was positive for multiple myeloma. Vigilance is required to correlate clinical and radiologic findings and further investigations must be considered if malignancy is suspected.

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.