Hyperspectral imaging for monitoring of free flaps of the oral cavity: A feasibility study.

OBJECTIVES: Hyperspectral imaging (HSI) provides spectral information about hemoglobin, water and oxygen supply and has thus great potential in perfusion monitoring. The aim of the present study was to investigate the feasibility of HSI in the postoperative monitoring of intraoral free flaps. METHODS: The 14 patients receiving reconstructive head and neck surgery with a radial forearm free flap were included. HSI was performed intraoperatively (t0), on Day 1 (t1), 2 (t2), 3-6 (t3), 7-9 (t4), 10-11 (t5) and 12-15 (t6) postoperatively. Flap tissue perfusion was assessed on defined regions of interest by calculating the perfusion indices Tissue Hemoglobin Index (THI), hemoglobin oxygenation (StO2 ), Near Infrared Perfusion Index (NIR Perfusion Index) and Tissue Water Index (TWI). RESULTS: Image quality varied depending on location of the flap and time of measurement. StO2 was >50 intraoperatively and >40 on t1 for all patients. A significant difference was found solely for TWI between t0 and t2 and t0 and t4. No flap loss occurred. CONCLUSIONS: The use of HSI in the monitoring of intraoral flaps is feasible and might become a valuable addition to the current clinical examination of free flaps.

Effects of vocal fold lesions on particle deposition in a mouth-throat model: A numerical study.

OBJECTIVE: Dysphonia is very common worldwide and aerosol drug inhalation is an important treatment for patients with dysphonia. This study aimed to explore the effects of vocal fold (VF) lesions on the particle deposition pattern using computational modeling. METHODS: A realistic mouth-throat (MT) model of a healthy adult was constructed based on computed tomography images. Small and large vocal fold lesions were incorporated in the original model. A steady inhalation flowrate of 15 and 30 liter per minute (LPM) was used as the velocity inlet and monodisperse particles with diameters of 5 to 10 µm were simulated. RESULTS: Particles of larger size are more likely to be deposited in MT models, most of them distributed in oral cavity, oropharynx and supraglottis. The ideal sizes at 30 LPM ranged over 7-10 µm for healthy VFs and 6-8 µm for VF lesions. The best sizes at 15 LPM ranged over 6-8 µm for healthy VFs and 8-9 µm for VF lesions. CONCLUSION: Based on this study, VF lesions influence the deposition pattern in the glottis obviously. The ideal sizes differ at the flow rates of 15 and 30 LPM.

Activation of Cerebellum, Basal Ganglia and Thalamus During Observation and Execution of Mouth, hand, and foot Actions.

Humans and monkey studies showed that specific sectors of cerebellum and basal ganglia activate not only during execution but also during observation of hand actions. However, it is unknown whether, and how, these structures are engaged during the observation of actions performed by effectors different from the hand. To address this issue, in the present fMRI study, healthy human participants were required to execute or to observe grasping acts performed with different effectors, namely mouth, hand, and foot. As control, participants executed and observed simple movements performed with the same effectors. The results show that: (1) execution of goal-directed actions elicited somatotopically organized activations not only in the cerebral cortex but also in the cerebellum, basal ganglia, and thalamus; (2) action observation evoked cortical, cerebellar and subcortical activations, lacking a clear somatotopic organization; (3) in the territories displaying shared activations between execution and observation, a rough somatotopy could be revealed in both cortical, cerebellar and subcortical structures. The present study confirms previous findings that action observation, beyond the cerebral cortex, also activates specific sectors of cerebellum and subcortical structures and it shows, for the first time, that these latter are engaged not only during hand actions observation but also during the observation of mouth and foot actions. We suggest that each of the activated structures processes specific aspects of the observed action, such as performing internal simulation (cerebellum) or recruiting/inhibiting the overt execution of the observed action (basal ganglia and sensory-motor thalamus).

Ultrasound imaging for evaluation of impalement-related injuries to the oral cavity in pediatric patients: a case series study.

BACK GROUND: An impalement-related injury to the oral cavity is common in pediatric patients at emergency department. A computed tomography evaluation is not always suitable in these cases. Herein, we aimed to present oral sonography findings from six pediatric patients presenting with impalement-related injury to the oral cavity. CASE SERIES: All included patients were younger than 4 years and sustained injuries with a toothbrush, chopstick, water gun, and fork to the tonsils, submandibular gland area, uvula, and under the tongue. CONCLUSION: Ultrasound imaging appeared useful in helping diagnose impalement-related injuries lateral to the midline.

Ultrasound protocol in odontogenic infections: a new proposal.

BACKGROUND: Point-of-care-ultrasound can be applied to preview a difficult airway, detect the presence of fluid collection, and soft-tissue edema, and guide the drainage location, although is rarely used. The purpose of this study is to validate a protocol for the assessment of these clinical features on patients with severe odontogenic infections. MATERIAL AND METHODS: This was a single-group prospective cohort study (n=20) including patients with the diagnosis of deep-neck propagation of odontogenic infection. A transcervical linear high-frequency probe transducer (13-6 MHz) was used to scan the structures of the upper airway and the infectious collections. The drainage was guided by ultrasound and the patients were daily evaluated, according to the protocol. The data were extracted and the airway volume, midline deviation, and other important data such as length of hospital stay, dysphagia, voice alteration, raised floor of the mouth, dyspnea, and neck swelling were registered. RESULTS: The ultrasound examination was correlated with multiple clinical findings, such as dyslalia (p=0,069), dysphagia (p=0,028), dyspnea (p=0,001), among others. This protocol has an advantage as it can be used at bedside evaluation, allowing the assessment of severe and unstable patients, and predicting the increase of the hospitalization time (p=0,019). CONCLUSIONS: This protocol is reliable for the assessment of the upper airway, even in an emergency, predicting not only the severity of the clinical features but aids in the determination of the length of the hospitalization time.

Reduction of scratch or dirt artifacts on intraoral radiographs using dual imaging plates in image processing.

OBJECTIVES: Artifacts including scratches and dirt artifacts on the digital intraoral radiographs finally contribute to making inaccurate diagnoses. The aim of this study was to reduce the incidence of artifacts using dual imaging plates (DIPs) in imaging processing. METHODS: Conventional X-rays were taken of a porcine mandible embedded in acrylic resin using a DIP which consists of a front IP (FIP) and a back IP (BIP) with some scratches and dirt. The two images of the FIP and BIP were then synthesized and averaged to obtain a conventional DIP image. The following image processing method was used to make a DIP with artifact reduction (DIP+AR) image. A subtraction image of the FIP and BIP was constructed and the standard deviation (SD) was calculated. If the pixel value was over 3SD on the subtraction images, the pixel value of the DIP was swapped with the value on the opposite side of the non-artifact pixel. The conventional and DIP+AR images were also subjectively evaluated. RESULTS: Image processing to create a DIP+AR image was able to reduce the number of artifacts. Medians of number of artifacts evaluated were 2.00 [interquartile range (IQR), 2.50] in DIP images and 0.67 (IQR, 1.29) in DIP+AR images, indicating a significant reduction of number of artifacts in DIP+AR images. CONCLUSIONS: DIP+AR image processing can reduce the incidence of artifacts caused by scratches and dirt, and could extend the lifespan of the IP and contribute accurate diagnosis in oral radiology.

The impact of cone beam computer tomography field of view on the precision of digital intra-oral scan registration for static computer-assisted implant surgery: A CBCT analysis.

OBJECTIVES: Registration of intra-oral surface scans to cone beam computer tomography (CBCT) is critical in the digital workflow for static computer-aided implant surgery (sCAIS). This study aimed to assess the impact of CBCT field of view (FoV) on the precision of digital intra-oral scan registration. MATERIALS AND METHODS: Cone beam computer tomography data and intra-oral scans from 20 patients were included. Small FoV CBCT's were created by digitally segmenting a large FoV into three sextants. Virtual implant planning was performed. Digital intra-oral scans were repeatedly registered onto their corresponding large and small FoV CBCT datasets. The distances and angulations between the matching implant positions of each repeated registration were used to determine the precision of the registration process. Wilcoxon Signed Rank Paired Tests were used to compare the differences between large FoV and small FoV. The threshold for statistical significance was set at p = .05. RESULTS: Differences in 3D implant position based on the registration precision between small FoV and large FoV present at both the implant entry point (0.37 ± 0.25 mm vs 0.35 ± 0.23 mm, p = .482) and implant tip (0.49 ± 0.34 mm vs 0.37 ± 0.24 mm, p < .001). Differences in overall angular precision were observed between small FOV and large FoV (1.43 ± 1.36° vs 0.51 ± 0.38°, p < .001). CONCLUSION: CBCT with a small FoV is accompanied by greater precision errors in intra-oral scan registration. However, when sufficient well-distributed teeth are visible in small FoV CBCT, the precision of digital intra-oral scan registration appears to be within clinically acceptable limits for sCAIS.

Creation of Digital Virtual Patient by Integrating CBCT, Intraoral Scan, 3D Facial Scan: An Approach to Methodology for Integration Accuracy.

ABSTRACT: The purpose of this paper was to introduce a method for creating a digital virtual patient by combining cone-beam computed tomography (CBCT), intraoral scan, and facial scan with a high accuracy of integration. CBCT scan, facial scan, and intraoral scan were obtained from initial visit. The virtual patient was created using the integration of these imaging modalities. Once the virtual patient was generated, digital workflow could be applied to initial patient consultation, diagnosis, treatment planning, virtual tooth setup, virtual treatment simulation, and post-treatment evaluation. integration of digital technology allows clinicians to improve diagnosis and treatment outcome. in addition, it allows for favorable patient communication. This technique eliminates the traditional impression process and complicated laboratory procedures for evaluating patient's occlusion during smile and habitual resting position. Based on this protocol, it is possible to create a digital virtual patient using CBCT, intraoral scan, and facial scan with a high accuracy of integration. it would be helpful for precision diagnosis and accurate treatment as well as favorable communication with patient.

Relationships between diaphragm ultrasound, spirometry, and respiratory mouth pressures in children.

Diaphragm ultrasound (DUS) is a noninvasive method of evaluating the diaphragm's structure and function. This study explored the relationships between DUS, spirometry, and respiratory mouth pressures in 10 healthy children (median age: 11 [range: 7-14 years]; 5 females, 5 males). Thickening fraction correlated with maximal inspiratory pressure (MIP) (Spearman's rho [rs] = 0.64, p = 0.05). During quiet breaths, excursion time correlated with MIP (rs = 0.78, p = 0.01) while velocity correlated with maximal expiratory pressure (rs = -0.82, p = 0.01). During deep breaths, MIP correlated with excursion (rs = 0.64, p = 0.05) and time (rs = 0.87, p = 0.01). Excursion time during deep breaths also correlated with forced vital capacity (rs = 0.65, p = 0.04). Our findings suggest that DUS parameters are closely related to spirometry and respiratory mouth pressures in healthy children and further support the use of DUS as a noninvasive method of respiratory assessment.

Correlation and mechanism between cardiac magnetic resonance imaging and oral streptococcus count in patients with primary microvascular angina pectoris.

BACKGROUND: Although primary microvascular angina (PMVA) can be diagnosed clinically, the etiology and pathophysiology of PMVA remain unclear. The effects of conventional clinical medications (aspirin, statins, and nitrates) are unsatisfactory, and PMVA can lead to serious cardiovascular events. The present study was designed to analyze the correlation between the load perfusion cardiovascular magnetic resonance imaging (CMR) results and the Streptococcus sanguinis(S sanguinis) count and the correlations between the S sanguinis count in oral cavity subgingival plaque and changes in the plasma levels of platelet alpha-granule membrane glycoprotein 140 (GMP-140), fibrinopeptide A (FPA), von Willebrand factor (vWF), and homocysteine (Hcy) in patients with PMVA after increased anti-infective treatment of the oral cavity. This study also discusses the pathogenesis of PMVA from this perspective. The differences in the S sanguinis count in oral cavity subgingival plaque and oral health status between healthy people and PMVA patients will be compared, and the correlation between the oral cavity health status and disease in PMVA patients will be analyzed. METHODS: The present randomized controlled trial with a parallel control group will be conducted in 68 PMVA patients diagnosed by the in-patient cardiology department. The selected patients will be randomly divided into 2 groups, one receiving routine drug treatment and the other a combination of anti-infective treatments. The normal control group will comprise 30 healthy people with no infectious oral cavity disease matched by age and sex. We will conduct CMR, and the presence of S sanguinis in subgingival plaques will be used to determine the bacterial count in PMVA patients. Blood samples will also be collected to determine the levels of GMP-140, FPA, vWF, and Hcy. S sanguinis in the subgingival plaque of PMVA patients will be further analyzed after increasing the oral cavity anti-infective treatment; the resulting changes and their correlations with changes in GMP-140, FPA, vWF, and Hcy levels will be assessed. Additionally, the differences in the S sanguinis count and the oral cavity health status of oral cavity dental plaque between healthy people and PMVA patients will be determined, and the correlation between the oral cavity conditions and PMVA will be analyzed. The relationship between the perfusion CMR results and the oral cavity S sanguinis count of PMVA patients, and the potential pathogenesis, will be explored. We will use the SPSS19.0 statistical software package to analyze the data. The measurements will be expressed as means±standard deviation. Student t test will be used for intergroup comparisons, a relative number description will be used for the count data, and the chi-square test will be used for intergroup comparisons. Multivariate logistic regression will be performed to identify associations. A P value < .05 will be considered significant. DISCUSSION: In this study, the correlation between the perfusion CMR results and the S sanguinis count in oral cavity subgingival plaque of PMVA patients will be analyzed. Changes in the levels of GMP-140, FPA, vWF, and Hcy of PMVA patients after receiving increased oral cavity anti-infective treatment will be explored, and the difference in the S sanguinis count in oral cavity subgingival plaque and the oral cavity health status between healthy people and PMVA patients will be compared. ATRIAL REGISTRATION: Chinese Clinical Trial Registry, (http://www.chictr.org.cn/showprojen.aspx?proj=45091).

PET Imaging of Oral Cavity and Oropharyngeal Cancers.

Fluorine-18 fluorodeoxyglucose PET/computed tomography (18F-FDG PET/CT) plays an important role in the staging, treatment planning, treatment response assessment, detecting recurrent disease, and predicting prognosis in patients with oral cavity and oropharyngeal squamous cell carcinoma. PET/CT has advantage especially in the detection of nodal, distant metastatic disease and second primary malignancy. PET/MR provides superior soft tissue contrast while decreasing radiation exposure, which is advantageous in evaluation of the primary tumor.

Tongue and mouth imagery questionnaire (TMIQ) for assessing motor imagery vividness of the temporomandibular region: A reliability and validity case-control study.

BACKGROUND: To date, no validated assessment of motor imagery (MI) ability with temporomandibular disorders (TMD) exists preventing identification of good imagers and appropriate MI use during TMD rehabilitation. OBJECTIVE: To assess the reliability and construct validity of the previously developed Tongue and Mouth Imagery Questionnaire (TMIQ) compared with the gold-standard Kinaesthetic and Visual Imagery Questionnaire (KVIQ-10). METHODS: Both KVIQ-10 and TMIQ assess MI ability using vividness (i.e. clarity/brightness for visual MI, V MI; or intensity for kinesthetic MI, K MI) of MI using a 5-point Likert scale (1: no image/sensation, 5: clear/intense image/sensation). The KVIQ-10 was administered once (test) and the TMIQ twice (test-retest) to heathy participants and patients with TMD. Questionnaire validity was investigated using concurrent validity (Pearson correlation and paired t test); TMIQ-test-retest reliability (intraclass correlation coefficients, ICCs); internal consistency (Cronbach ⍺) and the factorial structure (principal factor extraction). RESULTS: A total of 94 participants were included (n = 47 per group). The mean vividness scores of the KVIQ-10 and the TMIQ were significantly correlated, and not significantly different for both groups indicating concurrent validity. ICCs in the control group (range: 0.82-0.90), and in the TMD group (range: 0.75-0.82) indicated good reproducibility. The Cronbach ⍺ values were all above 0.94, indicating excellent reliability. Two factors were extracted corresponding to V MI and K MI, and explained 66% of total variance. CONCLUSION: The TMIQ is a valid and reproducible MI questionnaire showing excellent internal consistency and, therefore, can be used to assess imagined movements of the TM region in healthy individuals and patients with TMD.

MR imaging of Oral Cavity and Oropharyngeal Cancer.

MR imaging is the modality of choice in the evaluation of oral cavity and oropharyngeal cancer. Routine postcontrast MR imaging is important for the accurate localization and characterization of the locoregional extension of oral cavity and oropharyngeal cancers. The anatomy of the oral cavity and oropharynx is complex; accurate interpretation is vital for description of the extension of the masses. Understanding the new changes in the eighth edition of the American Joint Committee on Cancer staging system. MR imaging is the imaging modality of choice for detection of perineural spread.

Functional Connectivity and Speech Entrainment Speech Entrainment Improves Connectivity Between Anterior and Posterior Cortical Speech Areas in Non-fluent Aphasia.

BACKGROUND: Speech entrainment (SE), the online mimicking of an audio-visual speech model, has been shown to increase speech fluency in individuals with non-fluent aphasia. One theory that may explain why SE improves speech output is that it synchronizes functional connectivity between anterior and posterior language regions to be more similar to that of neurotypical speakers. OBJECTIVES: The present study tested this by measuring functional connectivity between 2 regions shown to be necessary for speech production, and their right hemisphere homologues, in 24 persons with aphasia compared to 20 controls during both free (spontaneous) speech and SE. METHODS: Regional functional connectivity in participants with aphasia were normalized to the control data. Two analyses were then carried out: (1) normalized functional connectivity was compared between persons with aphasia and controls during free speech and SE and (2) stepwise linear models with leave-one-out cross-validation including normed functional connectivity during both tasks and proportion damage to the left hemisphere as independent variables were created for each language score. RESULTS: Left anterior-posterior functional connectivity and left posterior to right anterior functional connectivity were significantly more similar to connectivity of the control group during SE compared to free speech. Additionally, connectivity during free speech was more associated with language measures than connectivity during SE. CONCLUSIONS: Overall, these results suggest that SE promotes normalization of functional connectivity (i.e., return to patterns observed in neurotypical controls), which may explain why individuals with non-fluent aphasia produce more fluent speech during SE compared to spontaneous speech.

CD3-positive plasmablastic lymphoma reported in two cases: A potential diagnostic caveat.

Plasmablastic lymphoma (PBL) is a rare aggressive subtype of mature large B cell lymphoma involving almost exclusively the extranodal regions particularly the oral cavity, frequently described in immunocompromised patients. PBL is characterized histologically by diffuse proliferation of large neoplastic cells resembling B immunoblasts or plasmablasts. The diagnosis of PBL can be difficult due to its ambiguous histopathological features mimicking most large cell lymphomas and lacking a distinctive immunophenotypic pattern. They typically lack expression of CD20 and CD79a but may express plasma cell marker, CD138. Aberrant immunoexpression of CD3, a T-cell marker in PBL in the absence of other B-cell markers is exceptionally rare, may potentially lead to incorrect interpretation. Herein, we report a case series of CD3-positive PBL of oral cavity in two individuals, which were initially misdiagnosed as high-grade T-cell lymphomas including extranodal NK/T-cell lymphoma, nasal type. Useful distinguishing clinical settings, histomorphological features, immunohistochemistry and molecular expression profiles of PBL are discussed.

Imaging of the fetal oral cavity, airway and neck.

Magnetic resonance imaging has proved to be an extraordinarily useful adjunct modality in assessment of the fetal face, oral cavity, head and neck because of its soft-tissue contrast, utility for acquiring more precise planar imaging and the inherent advantage of contrast provided by fluid-filled structures, including the oropharyngeal cavity, nasal passages and vascular structures. In this review, the author presents an organized approach to assessing normal anatomical structures of the fetus. The author presents cystic and solid lesions as well as structural and developmental abnormalities and discusses potential concomitant abnormalities. Prenatal consultation, patient counseling and delivery considerations are included.

Prediction of the treatment outcome using machine learning with FDG-PET image-based multiparametric approach in patients with oral cavity squamous cell carcinoma.

AIM: To investigate the value of machine learning-based multiparametric analysis using 2-[18F]-fluoro-2-deoxy-d-glucose positron-emission tomography (FDG-PET) images to predict treatment outcome in patients with oral cavity squamous cell carcinoma (OCSCC). MATERIALS AND METHODS: Ninety-nine patients with OCSCC who received pretreatment integrated FDG-PET/computed tomography (CT) were included. They were divided into the training (66 patients) and validation (33 patients) cohorts. The diagnosis of local control or local failure was obtained from patient's medical records. Conventional FDG-PET parameters, including the maximum and mean standardised uptake values (SUVmax and SUVmean), metabolic tumour volume (MTV), and total lesion glycolysis (TLG), quantitative tumour morphological parameters, intratumoural histogram, and texture parameters, as well as T-stage and clinical stage, were evaluated by a machine learning analysis. The diagnostic ability of T-stage, clinical stage, and conventional FDG-PET parameters (SUVmax, SUVmean, MTV, and TLG) was also assessed separately. RESULTS: In support-vector machine analysis of the training dataset, the final selected parameters were T-stage, SUVmax, TLG, morphological irregularity, entropy, and run-length non-uniformity. In the validation dataset, the diagnostic performance of the created algorithm was as follows: sensitivity 0.82, specificity 0.7, positive predictive value 0.86, negative predictive value 0.64, and accuracy 0.79. In a univariate analysis using conventional FDG-PET parameters, T-stage and clinical stage, diagnostic accuracy of each variable was revealed as follows: 0.61 in T-stage, 0.61 in clinical stage, 0.64 in SUVmax, 0.61 in SUVmean, 0.64 in MTV, and 0.7 in TLG. CONCLUSION: A machine-learning-based approach to analysing FDG-PET images by multiparametric analysis might help predict local control or failure in patients with OCSCC.

Dental pathologies in tumor patients with bone metastases or multiple myeloma scheduled for antiresorptive therapy.

Background: Medication-related osteonecrosis of the jaw (MRONJ) is a potentially severe complication of mainly antiresorptive drugs. We evaluated the frequency of dentoalveolar pathologies in patients scheduled for antiresorptive therapy in a 'real-world' setting, also including patients with poor oral health potentially requiring tooth extractions and/or other dentoalveolar surgery. This approach is in contrast to the setting of recent randomized trials with restrictive exclusion criteria. Patients & methods: We prospectively included patients suffering from solid tumors with osseous metastases or multiple myeloma. Screening for dentoalveolar pathologies was done prior to initiation of antiresorptive therapy at the specialized MRONJ clinic of the University Hospital for Cranio-Maxillofacial and Oral Surgery, Innsbruck, Austria. Results: 119 subjects could be included. In 76 patients (63.9%), a dental focus was revealed including deep caries (24.4% of patients), chronic apical periodontitis (26.9%), periodontal disease (45.8%), root remnants (16%), jaw cysts (2.5%), partially impacted teeth (5.0%) and peri-implantitis (5.0%). Conclusion: Considering the high number of dentoalveolar pathologies (63.9%), systematic dental focus screening prior to initiation of antiresorptive therapy is of utmost importance to lower the risk for MRONJ.

Magnetic Resonance Imaging of the Oral Cavity and Oropharynx.

ABSTRACT: Understanding oral cavity and oropharyngeal anatomy is important to identify various pathologies that may afflict them. This article reviews normal magnetic resonance imaging anatomy of these vital spaces and structures, with special attention to the complex musculature, mucosal surfaces, relevant osseous structures, salivary glands, and nerves. Anatomic awareness of these spaces and critical potential pathways for perineural tumoral spread are important to recognize to improve diagnostic evaluation and treatment.

Update on MRI for Oral Cavity.

ABSTRACT: Magnetic resonance imaging (MRI) is the imaging modality of choice to evaluate the complex anatomy and pathology of the oral cavity. In this article, an overview of MRI findings of common benign lesions in the oral cavity including congenital, vascular, and inflammatory/infectious lesions will be reviewed. In addition, MRI findings of common benign and malignant oral cavity tumors will be presented.