Supernumerary teeth are commonly observed as an isolated developmental anomaly. While the familial tendency of supernumerary teeth has been documented, its genetic causality has not yet been determined. The purpose of this paper was to presents two cases with supernumerary teeth and the process leading to the diagnosis and determination of their underlying conditions. Cases were evaluated and family histories reviewed. Genetic counseling was recommended for the probands and followed by genetic testing of selected family members. The proband of family one, who has multiple supernumerary teeth, was determined to have a RUNX2 missense mutation (c.379C>T, p. Pro127Ser) and diagnosed with cleidocranial dysplasia. The proband of family two, who has a premolar region supernumerary tooth, was reported to have no bone defects also presented with a RUNX2 missense mutation (c.1381G>C, p. Gly461Arg). When patients present with multiple supernumerary teeth, a recommendation and guidance to genetic counseling and testing may facilitate accurate diagnosis and management.
There is currently no consensus in the literature whether the aetiology of a Class II subdivision is dental, skeletal or both. The aim of this study was to identify and quantify skeletal and dental asymmetries in Class II subdivision malocclusions.
This preliminary study was designed to test the clinical efficacy of a modified Ti-mesh combined with particulate allograft for vertical ridge augmentation (VRA). Five healthy patients with vertical ridge deficiency in the posterior mandible were recruited. Preoperative width of the keratinized mucosa (KM) and mucosal thickness (MT) were measured. Cone beam computed tomography (CBCT) scans were taken preoperatively, immediately, and 5 months after VRA. The amount of vertical bone gain was measured on CBCT scans. Bone core biopsies were taken for histomorphometric examinations. The mean ± standard deviation KM on the facial and lingual sides was 3.9 ± 1.7 mm and 3.3 ± 1.3 mm, respectively. The mean thickness of the flaps, measured at the facial, lingual, and crestal sites, was 2.9 ± 0.8 mm, 1.8 ± 0.8 mm, and 3.2 ± 1.2 mm, respectively. The mean vertical gain was 3.4 ± 1.9 mm when only the sites with the greatest vertical defect in each subject were studied. Histometric analysis of the bone cores revealed that percentages of the soft tissue, residual allograft, and new bone were 42.2% ± 10.0%, 25.2% ± 13.5%, and 32.6% ± 4.9%. The use of a Ti-mesh and particulate allograft may be a viable option for vertical augmentation of sites with slight to moderate ridge deficiency.
The American Academy of Oral and Maxillofacial Radiology established an ad hoc committee to draft evidence-based recommendations and clinical guidance for the application of patient contact shielding during dentomaxillofacial imaging.
Types of Studies Reviewed
The committee reviewed monographs and reports from radiation protection organizations and studies that reported radiation dose to gonads, breasts, and thyroid gland from dentomaxillofacial imaging.
Results
Considering the absence of radiation-induced heritable effects in humans and the negligible dose to the gonads and fetus from dentomaxillofacial imaging, the committee recommends discontinuing shielding of the gonads, pelvic structures, and fetuses during all dentomaxillofacial radiographic imaging procedures. On the basis of radiation doses from contemporaneous maxillofacial imaging, the committee considered that the risks from thyroid cancer are negligible and recommends that thyroid shielding not be used during intraoral, panoramic, cephalometric, and cone-beam computed tomographic imaging.
Practical Implications
This position statement informs and educates the reader on evolving radiation protection practices and provides simple, unequivocal guidance to dental personnel to implement these guidelines. State and local authorities should be contacted to update regulations to reflect these recommendations.
Temporomandibular joint osteoarthritis (TMJ OA) is a disease with a multifactorial etiology, involving many pathophysiological processes, and requiring comprehensive assessments to characterize progressive cartilage degradation, subchondral bone remodeling, and chronic pain. This study aimed to integrate quantitative biomarkers of bone texture and morphometry of the articular fossa and joint space to advance the role of imaging phenotypes for diagnosis of Temporomandibular Joint Osteoarthritis (TMJ OA) in early to moderate stages by improving the performance of machine-learning algorithms to detect TMJ OA status. Ninety-two patients were prospectively enrolled (184 h-CBCT scans of the right and left mandibular condyles), divided into two groups: 46 control and 46 TMJ OA subjects. No significant difference in the articular fossa radiomic biomarkers was found between TMJ OA and control patients. The superior condyle-to-fossa distance (p < 0.05) was significantly smaller in diseased patients. The interaction effects of the articular fossa radiomic biomarkers enhanced the performance of machine-learning algorithms to detect TMJ OA status. The LightGBM model achieved an AUC 0.842 to diagnose the TMJ OA status with Headaches and Range of Mouth Opening Without Pain ranked as top features, and top interactions of VE-cadherin in Serum and Angiogenin in Saliva, TGF-β1 in Saliva and Headaches, Gender and Muscle Soreness, PA1 in Saliva and Range of Mouth Opening Without Pain, Lateral Condyle Grey Level Non-Uniformity and Lateral Fossa Short Run Emphasis, TGF-β1 in Serum and Lateral Fossa Trabeculae number, MMP3 in Serum and VEGF in Serum, Headaches and Lateral Fossa Trabecular spacing, Headaches and PA1 in Saliva, and Headaches and BDNF in Saliva. Our preliminary results indicate that condyle imaging features may be more important in regards to main effects, but the fossa imaging features may have a larger contribution in terms of interaction effects. More studies are needed to optimize and further enhance machine-learning algorithms to detect early markers of disease, improve prediction of disease progression and severity to ultimately better serve clinical decision support systems in the treatment of patients with TMJ OA.
This article analyses dose measurement and effective dose estimation of dental CBCT examinations. Challenges to accurate calculation of dose are discussed and the use of dose-height product (DHP) as an alternative to dose-area product (DAP) is explored.The English literature on effective dose was reviewed. Data from these studies together with additional data for nine CBCT units were analysed. Descriptive statistics, ANOVA and paired analysis are used to characterize the data.PubMed and EMBASE searches yielded 519 and 743 publications, respectively, which were reduced to 20 following review. Reported adult effective doses for any protocol ranged from 46 to 1073 µSv for large fields of view (FOVs), 9-560 µSv for medium FOVs and 5-652 µSv for small FOVs. Child effective doses from any protocol ranged from 13 to 769 µSv for large or medium FOVs and 7-521 µSv for small FOVs. Effective doses from standard or default exposure protocols were available for 167 adult and 52 child exposures. Mean adult effective doses grouped by FOV size were 212 µSv (large), 177 µSv (medium) and 84 µSv (small). Mean child doses were 175 µSv (combined large and medium) and 103 µSv (small). Large differences were seen between different CBCT units. Additional low-dose and high-definition protocols available for many units extend the range of doses. DHP was found to reduce average absolute error for calculation of dose by 45% in comparison with DAP.Large exposure ranges make CBCT doses difficult to generalize. Use of DHP as a metric for estimating effective dose warrants further investigation.
