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Objectives: The purpose of this study was to perform a three-dimensional analysis on the pharyngeal airway of supine patients who have undergone mandibular setback surgery, using multislice computed tomography (MSCT). We also measured the respiratory disturbance index pre- and post-surgery, using a portable sleep monitor. Materials and Methods: The subjects included two males and nine females who were diagnosed with mandibular prognathism at Hiroshima University Hospital and were scheduled to undergo the bilateral sagittal split osteotomy. Using a CT scanner, baseline MSCT images were obtained from the subjects before surgery for morphological analysis, and then the two further scans were obtained after mandibular setback surgery. All patients were provided with at-hoeme sleep monitor to use it both at baseline and approximately 1 year after surgery. Results: Middle and epiglottis pharyngeal space and cross-sectional area were significantly decreased immediately after setback surgery, but did not change further over the 1-year period. Mandibular setback was not associated with the development of sleep breathing disorder (SBD) during the 1-year follow-up period. Conclusion: We found no evidence that the reduction in the pharyngeal airway space immediately after mandibular setback surgery recovered significantly during the follow-up period, although mandibular setback was not associated with development of SBD.

Temporomandibular disorders are typically accompanied by a number of clinical manifestations that involve pain and dysfunction of the masticatory muscles and temporomandibular joint. The most important subgroup of articular abnormalities in patients with temporomandibular disorders includes patients with different forms of articular disc displacement and deformation. Here, we propose a fully automated articular disc detection and segmentation system to support the diagnosis of temporomandibular disorder on magnetic resonance imaging. This system uses deep learning-based semantic segmentation approaches. Two hundred and seventeen magnetic resonance images obtained from patients with normal or displaced articular discs were used to evaluate three deep learning-based semantic segmentation approaches: our proposed encoder-decoder CNN named 3DiscNet (Detection for Displaced articular DISC using convolutional neural NETwork), U-Net, and SegNet-Basic. Of the three algorithms, 3DiscNet and SegNet-Basic showed comparably good metrics (Dice coefficient, sensitivity, and PPV). This study provides a proof-of-concept for a fully automated segmentation methodology of the articular disc on MR images with deep learning, and obtained promising initial results indicating that it could potentially be used in clinical practice for the assessment of temporomandibular disorders.

Objective: Patients with medication-related osteonecrosis of the jaw (MRONJ) often visit their dentists at advanced stages and subsequently require treatments that greatly affect quality of life. Currently, no clear diagnostic criteria exist to assess MRONJ, and the definitive diagnosis solely relies on clinical bone exposure. This ambiguity leads to a diagnostic delay, complications, and unnecessary burden. This article aims to identify imaging modalities’ usage and findings of MRONJ to provide possible approaches for early detection. Methods: Literature searches were conducted using PubMed, Web of Science, Scopus, and Cochrane Library to review all diagnostic imaging modalities for MRONJ. Results: Panoramic radiography offers a fundamental understanding of the lesions. Imaging findings were comparable between non-exposed and exposed MRONJ, showing osteolysis, osteosclerosis, and thickened lamina dura. Mandibular cortex index Class II could be a potential early MRONJ indicator. While three-dimensional modalities, CT and CBCT, were able to show more features unique to MRONJ such as a solid type periosteal reaction, buccal predominance of cortical perforation, and bone-within-bone appearance. MRI signal intensities of vital bones are hypointense on T1WI and hyperintense on T2WI and STIR when necrotic bone shows hypointensity on all T1WI, T2WI, and STIR. Functional imaging is the most sensitive method but is usually performed in metastasis detection rather than being a diagnostic tool for early MRONJ. Conclusion: Currently, MRONJ-specific imaging features cannot be firmly established. However, the current data are valuable as it may lead to a more efficient diagnostic procedure along with a more suitable selection of imaging modalities.

We aimed to assess stroke lesions, which play a key role in determining swallowing dysfunction, and findings of videofluoroscopy (VF), which provides the most accurate instrumental assessment for evaluating swallowing function, in patients with acute stroke. We enrolled 342 patients with first-time acute stroke (age 70.4 ± 12.6 years, 142 female). Patients with dementia and altered mental status due to severe stroke were excluded. All patients underwent cranial magnetic resonance imaging to identify the location of stroke lesion, VF, and tongue pressure measurement. Aspiration was detected in 45 (13.2%) patients. Multivariate analysis identified parietal lobe lesion and the National Institutes of Health Stroke Scale (NIHSS) score as independent significant factors for aspiration (odds ratio 6.33, 95% confidence interval [CI] 2.25–17.84, p

To develop and assess a dysphagia training method involving lollipop sucking training in older adults with dementia, clarify its effectiveness for improving oral function.Twenty-five older adults with dementia (5 males and 20 females, mean age 90.8 ± 6.7 years) were participated in this study. Participants were trained in lollipop sucking once a day, 3 times a week for 6 months. Mini-Mental State Examination (MMSE), Barthel Index (BI), Candy Sucking Test (CST), and BMI values were measured before and after the training. Participants were grouped into those who achieved0.1 g/min increase in CTS value after the training (increase group) and those who did not (nonincrease group).No significant change was observed after the training. The increase group contained 4 patients and the non-increase group contained 21 patients. There were no significant differences in MMSE, BI, or BMI between the two groups before and after the training. However, the CST values of the increase group before the training (0.31 ± 0.13 g/min) were significantly lower than non-increase group (0.69 ± 0.27 g/min) (p 0.01). Respective changes in BMI before and after training were 1.13 ± 0.85 kg/m² and -0.53 ± 1.76 kg/m² in the increase and non-increase, and the difference in these changes was statistically significant (p = 0.04).Our new rehabilitation method was well accepted by older adults with dementia, and there was an improvement in oral function as a result of the rehabilitation, which had some good influence on weight gain.

The purpose of the present study was to measure the regional effects of the mandibular advancement appliance (MAA) on the upper airway of supine subjects with obstructive sleep apnea (OSA) using multislice computed tomography (MSCT). The subjects included 8 males and 5 females who were diagnosed with mild to moderate OSA and were referred to the Orthodontic Clinic of Hiroshima University Hospital, where they underwent MAA therapy. Using a CT scanner, baseline MSCT images were obtained from the subjects without the MAA for morphological analysis, and then the experimental images were obtained while wearing the MAA. To measure the anteroposterior diameter, width, and cross-sectional area of the oropharynx region of interest (ROI), five distance variables were first defined on each multiplanar reconstruction (MPR) image using OsiriX. Additionally, the volumes of the upper airway, bony hard tissue, and soft tissue (soft palate and tongue) in the oro-hypopharyngeal region were measured. In most of the assessed airway size variables, significant increases in the anteroposterior diameter and width were observed after MAA therapy. Regarding the upper airway cross-sectional area, all the upper airway size variables exhibited significant increases. In the volumetric analysis, a significant increase was observed in airway volume, whereas the soft tissue volume in the oro-hypopharyngeal region did not show the significant decrease after MMA therapy. However, from a different point of view, the volumes of the upper airway and soft tissue significantly increased and decreased, respectively, as demonstrated by the calculated ratio for the oro-hypopharyngeal region. We demonstrated that the proportional size of the soft tissue volume, i.e., the soft palate and tongue in the oro-hypopharyngeal region, significantly decreased during use of an MAA. This forward displacement of the soft tissue thereby increases the retroglossal airway space (except the nasopharynx) three-dimensionally.

The videofluoroscopic swallowing study (VFSS) is commonly considered the gold standard for assessing a patient’s swallowing ability. Most dysphagic patients arrange food to make it thicker or softer and thus easier and safer to swallow. A popular point of discussion, even argument, about VFSS among clinicians is whether to use barium sulfate in isolation or in combination with real food. No firm answer has emerged from these discussions, and proponents of both perspectives have seemingly valid points. The aim of the present study was to review whether there were differences between the results using liquid or solid foods in VFSS. We performed a literature search and interpreted the data acquired according to a systematic method. After data extraction and interpretation, we were left with 14 publications that were considered relevant. Most of the research showed that the rate of aspiration was higher with liquids than with solid foods. According to the results of VFSS by using the various textured-foods, the aspiration risk was highest with two-phase food diet such as the mixtures of liquid and solid foods. However, descriptions of their results were often inadequate although many test foods were used for the VFSS. There were a few publications containing the detailed information of the food textures. As the VFSS images provide valuable data, the methods and the results should be described in as much detail as possible to help readers of the articles. Most patients make allowances for the differences in thin liquids, thick liquids, and solid foods. Hence, writing the details of test food textures would lead to improve the quality of the VFSS in the future.

Objective: To investigate any change in deglutitive tongue movement following the correction of malocclusion by orthognathic surgery. Materials and Methods: The subjects were nine patients with mandibular protrusion. A control group consisted of 10 individuals with a similar age range and normal occlusion. Swallowing events before and after mandibular setback via sagittal split ramus osteotomy were recorded by cineradiography, and the tongue movement was analyzed. Time and linear measurements were compared before and after surgical treatment by the Wilcoxon signed rank test; control and test subjects were compared with the Mann-Whitney U-test. Results: Tongue-palate contact and the tongue-tip position changed after orthognathic surgery and became similar to those of the controls. Movements of the anterior and middorsal regions of the tongue did not change after orthognathic surgery and remained different from those of the controls. Conclusion: Our findings suggest that tongue-palate contact and tongue-tip position during deglutition adapted to the corrected oral and maxillofacial morphology, but the anterior and middorsal regions of the tongue during deglutition may have been affected by pharyngeal constrictors rather than by the oral and maxillofacial morphology.

Maximum tongue pressure (MTP) measurement is a convenient, less invasive assessment that has been developed to quantify tongue strength; however, it is unclear whether MTP is useful for the detection of swallowing disorders in amyotrophic lateral sclerosis (ALS) patients. The purpose of this study was to clarify the relationship between MTP and the characteristics of swallowing disorders on videofluorography and to determine the usefulness of tongue pressure measurement for the assessment of swallowing function in ALS patients. Twenty-five ALS patients were evaluated according to the ALS functional rating scale-revised (ALSFRS-R), and their ability to swallow yogurt was observed via videofluorography. MTP was measured using a device (TPM-01, JMS, Hiroshima) equipped with a balloon probe. Then, the relationships between the ALSFRS-R score, swallowing function, and MTP were analyzed. MTP was significantly lower in the subjects with reduced tongue function (p = 0.002) or with pharyngeal residue (p = 0.006) than in the subjects with normal characteristics. Bolus formation and oral transit time and pharyngeal transit time were significantly prolonged among those with reduced MTP. MTP at a cut-off value of 21.0 kPa was associated with a full score on the bulbar-related items of the ALSFRS-R. MTP may serve as a new diagnostic tool for the early detection of swallowing dysfunction in ALS patients, because of its good relationship with their swallowing characteristics.

Orthodontic setup models are usually limited to the display of teeth, with no information about the roots. The purpose of this article is to present a method for visualizing the tooth roots in setup models by integrating information from cone-beam computed tomography and a laser scanner. The reproducibility of the integration was evaluated.The records of 5 patients were used in this study. Three-dimensional digital models were generated from the dental casts. Tooth models were generated from the cone-beam computed tomography slices. The 3-dimensional models were superimposed on the crowns of the teeth in the tooth models and integrated. The integrated 3-dimensional tooth model and 3-dimensional setup model were registered. The reproducibility of the integration was evaluated for each tooth. Unpaired Student t tests were performed on the data between the anterior and posterior teeth, and between the right and left teeth.The discrepancy among the integrated 3-dimensional models at the final positions after we used this technique was 0.025 ± 0.007 mm. There was a significant difference in the distance between the anterior and posterior teeth (P 0.05). However, the average distances between the anterior and posterior teeth were small: 0.023 ± 0.007 and 0.028 ± 0.007 mm, respectively. No significant difference was found between the right and left teeth (P = 0.831).The methods presented in this study provide a reproducible visualization of tooth roots in virtual setup models by registering accurate crown models to cone-beam computed tomography scans.

The aim was to evaluate the possibility of radiographic prediction of the prognosis of simple bone cysts (SBCs) of the jaws.The relationship between the radiographic findings and treatment outcome (healing or recurrence) was investigated in 31 cases treated in the authors' hospital and 108 published cases.In 17 of our 31 cases, the lesions had radiographic findings of a preserved lamina dura adjacent to the lesion, with a smooth margin, and no or smooth bone expansion, and all of them healed after surgery. In the other 14 cases, there was resorption of the lamina dura, a scalloped margin, nodular bone expansion, root resorption, a sclerotic mass or multiple cavities, and nine cases of recurrence. Although there was incomplete information in the published case studies, similar results were noted.It was concluded that there was a relationship between the radiographic features of the lesions and prognosis. Radiographic examination should be used not only for discovering and diagnosing the lesions, but also for predicting possible prognosis.

Food flow in the oropharynx changes when the head is rotated. The purpose of this study was to evaluate morphological differences in the upper and lower piriform sinuses in head-on (HO) versus head-rotated (HR) positions. Ten healthy adult volunteers with no previous history of dysphagia were subjected to cone-beam computed tomography (CBCT) in the HO and HR positions. Binary CBCT images were created at 50% gray scale to examine morphological changes in the lower piriform sinuses. Upon rotation to the right, the cross-sectional area of the left lower piriform sinus increased significantly (P = 0.037). The depth of the right lower piriform sinus also increased significantly (P = 0.011) upon rotation. The volume of the lower piriform sinuses increased significantly on both sides (right, P = 0.009; left, P = 0.013). The upper piriform sinuses acquired a teardrop shape, with the rotated side narrowed and opposite side enlarged. These results suggest that changes in food flow during head rotation result mainly from changes in the size and shape of the upper piriform sinuses.

Objectives To evaluate the structure of the lateral pharyngeal recess (LPR) and surrounding structures in computed tomography (CT) images obtained from subjects in the supine and upright positions.

To compare the responses of oropharyngeal structures to gravity while sitting upright or lying down in a supine position.Seven subjects were evaluated by cone beam CT (CBCT) while in the upright position and by a four-row multidetector helical CT (MDCT) while in the supine position. All of the voxel sizes were adjusted to be 0.3x0.3x0.3 mm3 in the x-y-z axis. The posterior nasal spine, basion and fourth cervical bone were used as references to measure positional changes in the oropharyngeal structures between the upright and supine positions. The smallest areas in the oropharynx were also evaluated.The soft palate, epiglottis and entrance of the oesophagus moved caudally with the positional change from supine to sitting upright, and moved posteriorly when the position changed from an upright to a supine position. The hyoid bone moved caudally but not posteriorly in response to the same positional changes. The width and length of the smallest area present in the oropharynx was larger in the upright position than in the supine position.Gravity can produce movements in oropharyngeal structures in response to postural changes between sitting upright and lying in the supine position.

OBJECTIVES: To clarify the influence of aging and denture use on swallowing in healthy edentulous people aged 75 and older. DESIGN: A cross-sectional research design was used with participants from Hiroshima University Hospital, Hiroshima University, and Hiroshima City. SETTING: Participants were examined in Hiroshima University Hospital, Hiroshima, Japan. PARTICIPANTS: Thirteen edentulous elderly volunteers (7 male, 6 female; aged 75–86, mean age 81.2) and 19 dentulous elderly volunteers (12 male, 7 female; aged 80–87, mean age 81.2) as a control group participated in this study. Participants reported no clinical symptoms relating to dysphagia, neurological impairments, or degenerative diseases. MEASUREMENTS: Participants were asked to swallow a 10-mL barium sulfate solution three times. Edentulous older people were asked to swallow the solution while wearing dentures and with dentures removed. Functional swallowing was recorded on cine-film with a digital subtraction angiography system. Lateral cinefluorography images were obtained from seated subjects. Using a cine-projector, visual images were evaluated qualitatively and quantitatively. RESULTS: No participants exhibited aspiration. The occurrence of laryngeal penetration in the edentulous older people not wearing dentures was the only significant difference (P

Background. Although age-related changes resulting in slowing of the swallowing reflex and a decline in the neuromuscular control system have been reported, there have been few reports on swallowing function in dentate elderly persons. The purpose of this study was to clarify the primary influence of aging on swallowing in healthy dentate elderly persons older than 80 years who have more than 20 teeth. Methods. Dentate elderly persons (12 male, 7 female; mean age: 81.2 years) and dentate young participants (9 male, 5 female; mean age: 26.8 years) as a control group participated voluntarily. Participants reported no clinical symptoms relating to dysphagia, neurologic impairments, or degenerative diseases, and were asked to swallow 10 ml of barium sulfate solution (10% w/v) three times. Functional swallowing was recorded on 35 mm cinefilm at 30 frames per second with a digital subtraction angiography system. Lateral images of cinefluorography of seated participants’ mouth, pharynx, and larynx were obtained. Visual image analysis for qualitative and quantitative evaluation was made with a cine projector. Results. No participants exhibited aspiration during three trials. Occurrence and frequencies of piecemeal deglutition, premature loss of liquid, oral and pharyngeal residues, and laryngeal penetration were significantly greater in dentate elderly persons (p , .05) than in the dentate young participants. Oral transit time, pharyngeal delay time, and pharyngeal transit time in dentate elderly persons were prolonged significantly compared with those in dentate young participants (p , .01). Conclusion. Physiological swallowing functions deteriorate even in healthy dentate elderly persons. This deterioration may be explained primarily by the influence of aging on swallowing.

Metastatic retinoblastoma of the jaws is very rare. We present a 4-year-old boy with metastatic retinoblastoma that involved both the maxilla and mandible simultaneously. Enhanced CT indicated bone-destructive masses with partially non-enhanced area and enhanced margin in the right maxilla and left mandible. MRI showed well-delineated masses that were isointense on T(1) weighted images and hyperintense on T(2) weighted images. Four weeks after chemotherapy and bone marrow transplantation, the size of lesions remarkably decreased. The patient died 19 months later with extensive tumour metastases despite additional chemotherapy. In this case, the dental crypt of a permanent tooth was considered the potential target through which retinoblastoma metastasized to the jaws.

This paper reports the case of a 47-year-old woman with dysphagia due to amyotrophic lateral sclerosis (ALS). Swallowing impairment was improved for 9 months by the application of a palatal plate prosthesis. The patient’s swallowing condition was evaluated by the swallowing function of ALS severity scale and cinefluoroscopy. The effect on ALS patients of oral prostheses as an aid to swallowing is discussed herein.

We reported previously that patients with anterior open bite had tongue tip protrusion, slower movement of the rear part of the dorsal tongue, and earlier closure of the nasopharynx during deglutition. In the present study, the relationship between this characteristic tongue movement and maxillofacial morphology in patients with anterior open bite was investigated. The subjects were 10 female patients with anterior open bites and 10 women with normal overbites as controls. Maxillofacial morphology was measured by cephalometric radiography, and tongue movement during deglutition was analyzed by cineradiography. The relationship between each value obtained by cephalometric radiography and cineradiography was evaluated by simple correlation analysis. In the patients with anterior open bite, there were significant correlations between mandibular plane angle, ramus height of the mandible, or anteroposterior dimension of the maxilla and movement of the front part of the dorsal tongue during deglutition. Furthermore, there were also significant correlations in these patients between mandibular plane angle, gonial angle, or ramus height of the mandible and the change in the contact between tongue and palate during deglutition. The controls did not have the correlations like these. Our study suggests that characteristic tongue movements during deglutition in patients with anterior open bites are closely related to their morphological features.

The purpose of this study was to clarify quantitatively the differences in tongue-tip motion among the dentulous elderly people and also among the elderly edentulous, both with and without their dentures and, to identify the influence of tooth loss and denture wear on tongue-tip motion. Fourteen young dentulous people, 12 elderly dentulous people and 13 elderly edentulous people participated in this study. Subjects were asked to swallow a 10 mL barium sulfate solution three times. The elderly edentulous people were asked to swallow the solution while wearing dentures and with dentures removed. Functional swallowing was recorded on cine-film with a digital subtraction angiography system. Lateral cinefluorography images were obtained from seated subjects. Using a cine-projector, the movements of the tongue surface were traced as dots and lines frame by frame on a single tracing sheet within a definite period of time from the beginning of the oral phase to the end of the pharyngeal phase. With counting the number of 'trajectories' of tongue-tip motion, tongue movements were classified as 'stable' and 'hyperactive' types. The results was that significantly more 'hyperactive' type subjects were found among the elderly edentulous who were not wearing dentures (12 of 13) compared with the dentulous young (1 of 14), the elderly dentulous (1 of 13) or the elderly edentulous wearing dentures (1 of 13) (P < 0.001). The tongue-tip motion for the 'hyperactive' type was very complex and the tongue-tip anchoring against the palate was always instable.

Purpose The goal was to suggest guidelines for the treatment of developing tooth buds located on the fracture line of mandibular fractures. Patients and Methods The long-term radiographic follow-up records of 28 patients with mandibular fractures involving 66 tooth buds were examined for the occurrence of abnormalities in development or eruption. The fates of the involved teeth were compared according to the fracture conditions and other factors, and the cause of the abnormalities was surveyed. Results Abnormal findings were observed in 30 of 66 developing teeth (45%); these included deficient root formation, abnormal bend of the root, nodule formation on the root, partial obliteration of the pulp cavity, impaction, growth arrest, and external resorption. No relationship was found between the presence of abnormalities and the condition of the fracture or the developmental stage of the tooth buds. However, infection, rotation of the tooth bud, and a surgical wire passing through the follicular space were associated with arrested growth and impaction. Conclusions The tooth buds present on the fracture line should be preserved except in cases of infection, and careful attention should be paid to avoiding further injury to the tooth bud and the soft tissues of the follicle at the time of surgery.