Teeth segmentation and carious lesions segmentation in panoramic X-ray images using CariSeg, a networks' ensemble.

Background: Dental cavities are common oral diseases that can lead to pain, discomfort, and eventually, tooth loss. Early detection and treatment of cavities can prevent these negative consequences. We propose CariSeg, an intelligent system composed of four neural networks that result in the detection of cavities in dental X-rays with 99.42% accuracy. Method: The first model of CariSeg, trained using the U-Net architecture, segments the area of interest, the teeth, and crops the radiograph around it. The next component segments the carious lesions and it is an ensemble composed of three architectures: U-Net, Feature Pyramid Network, and DeeplabV3. For tooth identification two merged datasets were used: The Tufts Dental Database consisting of 1000 panoramic radiography images and another dataset of 116 anonymized panoramic X-rays, taken at Noor Medical Imaging Center, Qom. For carious lesion segmentation, a dataset consisting of 150 panoramic X-ray images was acquired from the Department of Oral and Maxillofacial Surgery and Radiology, Iuliu Hatieganu University of Medicine and Pharmacy, Cluj-Napoca. Results: The experiments demonstrate that our approach results in 99.42% accuracy and a mean 68.2% Dice coefficient. Conclusions: AI helps in detecting carious lesions by analyzing dental X-rays and identifying cavities that might be missed by human observers, leading to earlier detection and treatment of cavities and resulting in better oral health outcomes.

Perineural spread in head and neck malignancies: imaging findings - an updated literature review.

Perineural spread (PNS) represents the tumor's ability to disseminate along nerves. The aim of this article is to review the relevant literature about the PNS in head and neck tumors (HN). The important information for imaging analysis is summarized in a diagnostic flow-chart. The pathogenesis, clinical signs, prognostic importance, and technical considerations for computer tomography and magnetic resonance imaging are briefly discussed. The anatomical pathways of the cranial nerves (CNs) and the main check-points are synthesized. Most commonly affected nerves are the trigeminal and facial, although any of the CNs may be involved. The described imaging features represent important clues for an optimal differential diagnosis. PNS worsens the prognosis and significantly changes the treatment, thus radiologists should be aware of this entity and be able to find it on imaging in the appropriate clinical context.

Salivary exosomal microRNAs as biomarkers for head and neck cancer detection-a literature review.

BACKGROUND: MicroRNAs (miRs) are small, non-coding mRNA molecules which regulate cellular processes in tumorigenesis. miRs were discovered in extracellular environment and biological fluids, carrying marks of head and neck squamous cell carcinoma (HNSCC). They were also identified in abundance in salivary exosomes, in which they are protected by exosome lipid barrier against enzymatic injuries and therefore, the accuracy of exosomal miR-based cancer detection increase. This systematic review aimed to reveal and inventorize the most reliable exosomal miRNAs in saliva samples which can be used as novel biomarkers for early detection of HNSCC. MATERIALS AND METHODS: A systematic literature search, according to PRISMA guideline, was performed on Pubmed and Google Academic libraries, based on specific keywords. Original articles published between 2010 and 2021 were selected. The quality of each paper was assessed using the Quality Evaluation Scoring Tool. RESULTS: At the end of selection process, five studies met the inclusion criteria. These studies analyzed twelve salivary exosomal miRs, presenting different methods of exosome and miR identification for HNSCC detection. A comprehensive explanation of the miR pathways of action was drawn and illustrated in this review. CONCLUSION: Exosomal miRs are promising biomarkers for oral cavity and oropharyngeal cancer detection. miR-10b-5p, miR-486-5p, miR-24-3p and miR-200a stand as the most useful ones in saliva sample examination.

Ultrasound dimensional changes of the anterior belly of the digastric muscle induced by orthognathic surgery and botulinum toxin A injection in Class II malocclusion.

OBJECTIVES: The aim of the study is to evaluate the ultrasonographic dimensional changes of the anterior belly of the digastric muscle (ABDM), occurring after intramuscular botulinum toxin A (BTX-A) injection during orthognathic surgery, in a series of five Class II malocclusion patients. METHODS: All the patients received 20 units of BTX-A, into both ABDM, intraoperatively. The length, width and cross-sectional area (CSA) of the ABDM were ultrasonographically measured at three different time points: T0 (preoperatively), T1 (postoperatively at 2 weeks after the surgical intervention), and T2 (postoperatively at 6-9 months). RESULTS: A statistically significant higher length of the ABDM was noted postoperatively, at T1 and T2 compared to T0. The patients showed an increased length by 12.2% at 2 weeks postoperatively and continued to increase, reaching 24.6% at 6 months. A decreased width of ABDM by 6.5% at T1 compared with T0 was also found. CONCLUSIONS: Postoperative ultrasound (US) follow-up measurements in patients with Class II malocclusion, orthognathic surgery and intraoperative BTX-A injection in the ABDM, showed dimensional changes of the muscle, with elongation and thinning. The muscular modifications were more pronounced at 6 months postoperatively, indicating consistency and potential benefit of using BTX-A in reducing the risk of surgical relapse. Further data on longer-term follow-up and larger number of cases are necessary.

The Changes in Upper Airway Volume after Orthognathic Surgery Evaluated by Individual Segmentation on CBCT Images.

Objectives:The aim of this CBCT study was to evaluate the postoperative volume changes of the rhinosinusal airway space, maxillary sinuses and nasal fossa, that occur after Le Fort I osteotomy, using individual segmentation of 3D virtual models. Material and methods:A number of 16 patients (with Class II and Class III malocclusions) who underwent a CBCT examination for orthognathic surgery at six month-interval between preoperative and postoperative evaluations were included. Patients with thickening of the sinus mucosa, craniofacial syndromes, maxillofacial trauma, rhinoplasty or other maxillofacial pathological conditions were excluded from the study. Individual segmentation of airway volumes was performed by the ITK-SNAP 2.0 software. Paired student t-test was used for the statistical examination of volume changes and Pearson's test for the assessment of intra-rate correlation. Outcomes:A statistically significant decrease in the rhinosinusal volume in Class II (9.36±3.43 cm3) and Class III malocclusions (3.65±2.96 cm3) was found after Le Fort I osteotomy. A decrease in volume was also found for maxillary sinuses (5.63±1.52 cm3 for Class II and 6.72±4.5 cm3 for Class III malocclusion). Nasal fossa decreased in volume (3.79±3.8 cm3) in Class II malocclusion patients and increased (3.07±2.39 cm3) in Class III malocclusion patients. The Pearson correlation revealed a high intra-rate agreement of measurements. Conclusion:Le Fort I osteotomy modifies the postoperative volume of rhinosinusal aerial spaces and individual segmentation on CBCT images is a useful tool to analyze the changes.

Clinical indications and radiation doses of cone beam computed tomography in orthodontics.

Cone beam computed tomography can be used in pediatric population when a tridimensional analysis of dental and maxillofacial bone structures is required. Even though CBCT is considered a low dose radiological examination, ionizing radiation is a known human carcinogenic factor. Furthermore, biological effects are more important in young patients because of their higher radiosensitivity. Orthodontic treatment is typically initiated at young ages and the most common radiographs at this age are dental. This makes it important to quantify the effects of diagnostic radiographs, in particular of CBCT, due to the fact that the radiation doses are higher compared to conventional radiological methods. So far, the carcinogenic response after low dose radiation exposure is not fully understood in the scientific literature. The aim of our review was to emphasize the main indications of CBCT in orthodontics and to evaluate the radiation doses and potential risks of CBCT irradiation of pediatric patients.

Early and long-term changes in the muscles of the mandible following orthognathic surgery.

OBJECTIVES: The aim of the present study is to evaluate the early and long-term postoperative dimensional changes of the muscles of the mandible in patients with orthognathic surgery for class II and class III malocclusions by using ultrasonography (US). MATERIAL AND METHODS: Twenty-six patients who underwent bimaxillary orthognathic surgery for class II or class III malocclusions (14 and 12 patients, respectively) were ultrasonographically examined. The length, width, and cross-sectional area of the masseter and suprahyoid muscles were measured at three different time points: T0 (preoperatively), T1 (early postoperatively at 1 month after the surgery), and T2 (late postoperatively at 9 months). A repeated measures ANOVA was used to calculate statistically significant dimensional changes of the mandibular muscles. RESULTS: Statistically significant dimensional changes were found postoperatively in class II malocclusion patients only. The digastric muscle showed higher values for the length and lower values for the width (p < .05) at T1. The geniohyoid muscles were higher in length at T1 and lower in cross-sectional area (CSA) (p < .05) at T2. A decreased measured length and an increased measured width were found in case of the mylohyoid muscle (p < .05) at T2. The early and long-term postoperative dimensional changes of the masseter muscle were not statistically significant. CONCLUSIONS: The mandibular muscles showed a variable adaptive response to the orthognathic surgery. US should be considered for the long-term follow-up of muscular dimensional changes in class II malocclusion patients. CLINICAL RELEVANCE: From a clinical perspective, US is a reliable, non-invasive, and widely available method, which allows monitoring the postoperative muscular changes occurring in class II malocclusion patients.

Low-dose radiations derived from cone-beam CT induce transient DNA damage and persistent inflammatory reactions in stem cells from deciduous teeth.

OBJECTIVES: Cone-beam CT (CBCT), a radiographic tool for diagnosis, treatment, and follow-up in dental practice, was introduced also in pediatric radiology, especially orthodontics. Such patients subjected to repetitive X-rays examinations may receive substantial levels of radiation doses. Ionizing radiation (IR), a recognized carcinogenic factor causing DNA double-strand breaks (DSBs) could be harmful to undifferentiated cells such as dental pulp stem cells (DPSCs) since inaccurately repaired or unrepaired DSBs may lead to malignant transformation. The H2AX and MRE11 proteins generated following DSBs formation and pro-inflammatory cytokines (CKs) secreted after irradiation are relevant candidates to monitor the cellular responses induced by CBCT. METHODS: DPSCs were extracted from human exfoliated deciduous teeth and their phenotype was assessed by immunocytochemistry and flow-cytometry. Cells were exposed to IR doses: 5.4-107.7 mGy, corresponding to 0.5-8 consecutive skull exposures, respectively. H2AX and MRE11 were detected in whole cells, while IL-1α, IL-6, IL-8, TNFα in supernatants, using enzyme-linked immunosorbent assay (ELISA) at different time points after exposure. RESULTS: The phosphorylation level of H2AX in DPSCs increased considerably at 0.5 h after exposure (p < 0.001 for 3, 5, 8 skull exposures and p < 0.05 for 1 skull exposure, respectively). MRE11 response could only be detected for the highest IR dose (p < 0.001) in the same interval. CKs secretion increased upon CBCT exposure according to doses and time. CONCLUSIONS: The DPSCs exposure to CBCT induces transient DNA damage and persistent inflammatory reaction in DPSCs drawing the attention on the potential risks of IR exposures and on the importance of dose monitoring in pediatric population.

Estimation of the radiation dose for pediatric CBCT indications: a prospective study on ProMax3D.

BACKGROUND: An increasing number of CBCT units and a wide variability of radiation doses have been reported in dentistry lately. AIM: To estimate the effective, cumulative, and organ absorbed doses in children exposed to CBCT over 2 years. DESIGN: A prospective study was conducted in children who underwent CBCT diagnostic imaging with the ProMax3D machine. Organ and effective doses were calculated by Monte Carlo simulation using 5- and 8-year-old pediatric voxel phantoms. Extrapolation procedures were applied to estimate doses for other ages and CBCT protocols used in clinical conditions. RESULTS: The median effective dose was 137.9 µSv, and the median cumulative dose was 231.4 µSv. Statistically significant differences in the effective doses and cumulative doses were found for various indications of CBCT in children (P < 0.001). The median absorbed organ dose for brain and thyroid was significantly higher for the clinical condition that required large FOVs (2.5 mGy and 1.05 mGy, respectively) compared to medium (0.19 and 0.51 mGy) and small FOVs (0.07 and 0.24 mGy; P < 0.05). The radiation dose of salivary glands did not vary significantly with FOV. CONCLUSION: The results revealed the variation of CBCT doses and the influence of FOV size in pediatric exposure.

In quest of optimal drug-supported and targeted bone regeneration in the cranio facial area: a review of techniques and methods.

Craniofacial bone structures are frequently and extensively affected by trauma, tumors, bone infections and diseases, age-related degeneration and atrophy, as well as congenital malformations and developmental anomalies. Consequently, severe encumbrances are imposed on both patients and healthcare systems due to the complex and lengthy treatment duration. The search for alternative methods to bone transplantation, grafting and the use of homologous or heterologous bone thus responds to one of the most significant problems in human medicine. This review focuses on the current consensus of bone-tissue engineering in the craniofacial area with emphasis on drug-induced stem cell differentiation and induced bone regeneration.

The accuracy of alveolar crest dimensions measurement for dental implants. In vitro study.

OBJECTIVES: The aim of this study was to evaluate the accuracy of radiological examination methods in quantitative preimplantar bone assessment. MATERIAL AND METHOD: The study was carried out on a dry cranium, totally edentate. There have been radiological appreciated the height of the alveolar process and its width, both to the maxilla and the mandible. Also, it has been established the distance between the free edge of the alveolar crest and the superior edge of the mandibular canal. The values radiological measured have then been compared with those obtained through direct measurement of these dimensions on the cranium. RESULTS: The results were performed in tables and diagrams. The greatest deviation from the real values was at the panoramic radiography, while the computer tomography was the most accurate examination among the radiological techniques used in this study. The panoramic radiography doesn't give information about the alveolar crest thickness, about it's declivity and the alveolar crest measurement generates significant errors. Linear tomography implies a difficult technique, but it has the advantage of a low irradiation,a wider accessibility and a lower cost than the CT. Computer tomography is the most accurate preimplantar evaluation technique but it has the disadvantage of a high patient radiation. CONCLUSIONS: The panoramic radiography represents an insufficient method for appreciating the preimplantar bone status. That's why it has to be supplemented with other radiological examinations, especially at the cases with alveolar crest atrophy, to avoid accidental penetration of adjacent structures.