Orofacial symptoms suggestive of malignant lesions and the role of imaging: literature review and case presentation.

Among the patients seeking dental treatment, some may present with symptoms that cannot be resolved by dental treatment alone. Patients with orofacial symptoms associated with malignant diseases, which require medical treatment, often visit dental clinics for their initial consultation. Delays in making a definitive diagnosis worsen the patient's prognosis. Therefore, dental clinicians should also be aware of the signs and symptoms associated with malignant diseases. The chief complaints of these patients include numb chin syndrome (NCS), painless swelling of the palate and neck, trismus and temporomandibular disorders, and an enlarged tongue. This article aimed to review these orofacial symptoms and related diseases and describe representative cases of these diseases to obtain a definitive diagnosis via imaging. Panoramic radiograph is widely used in general dentistry, and this article reaffirmed the importance of panoramic radiograph anatomical landmarks in diagnosing the cases presented in this paper.

Analysis of the sublingual artery using contrast-enhanced computed tomography.

INTRODUCTION: This in vivo study aimed to clarify the position of the sublingual artery (SLA) relative to the mandibular bone and to infer the potential risk for injury during dental implant surgery. METHODS: Contrast-enhanced computed tomography images of the mouth of 50 edentulous patients (100 sides) treated at Tokushima University Hospital were reviewed. Curved planar reconstructed images perpendicular to the alveolar ridge were processed and classified into molar, premolar, canine, and incisor regions. The SLA and its branches were identified, and the distance from the mandible to the SLA was measured. RESULTS: The SLA was located close to the mandible (<2 mm) in the molar, premolar, canine, and incisor segments in 12.0% (95% confidence interval 5.6%-18.4%), 20.6% (12.6%-28.7%), 30.5% (21.3%-39.8%), and 41.8% (28.8%-54.9%) cases, respectively. The SLA was located within ±3 mm craniocaudally to the upper wall of the mandibular canal in the molar and premolar regions in 50% of cases and within ±5 mm craniocaudally to the mylohyoid ridge in the canine and incisor regions in the other cases, with no sex or age-related differences. The vertical distance from the alveolar ridge to the SLA was influenced by sex and age owing to alveolar resorption, indicating that the alveolar ridge is not a reliable reference for predicting SLA position. CONCLUSIONS: As the risk of SLA injury always exist during dental implant placement and there is no way to confirm the SLA pathways in a patient, clinicians must avoid injuring the sublingual soft tissue.

Prevalence and imaging characteristics of nasopharyngeal and eustachian tube tonsilloliths in 2244 patients determined using computed tomography.

OBJECTIVES:: Nasopharyngeal tonsilloliths (NT) and eustachian tube tonsilloliths (ET) are not as well-known to radiologists as palatine and lingual tonsilloliths. The aim of this investigation was to determine the prevalence and imaging characteristics of NT and ET using CT and panoramic radiographs. METHODS:: We retrospectively assessed the scans of 2244 patients who underwent consecutive CT and panoramic radiographs of the maxillofacial region. The prevalence, size, number, and position of NT and ET were analysed. RESULTS:: NT and ET were detected in 14 (0.6%) and 6 (0.3%) of 2244 patients on CT, respectively, but they were undetectable on panoramic radiographs. No significant difference was found in the prevalence with respect to sex. Although there was also no significant difference in the prevalence among age groups, tonsilloliths were most commonly noted in patients over 40 years old; they appeared as small and round calcified bodies, ranging from 1 to  3 mm in diameter. All NT were found 0 to 3 mm beneath the nasopharyngeal mucosal surface. CONCLUSIONS:: The prevalence of NT and ET on CT was lower than that of palatine and lingual tonsilloliths. However, since they are encountered more frequently than clinically significant calcifying diseases such as retropharyngeal calcific tendinitis, clinicians should be able to correctly diagnose NT and ET based on their anatomical features.

Lingual tonsillolith: prevalence and imaging characteristics evaluated on 2244 pairs of panoramic radiographs and CT images.

OBJECTIVES: Lingual tonsilloliths are not as well-known to radiologists than palatine tonsilloliths, although they might be common in clinical practice. The aim of this investigation was to clarify the prevalence and imaging characteristics of lingual tonsilloliths using panoramic radiographs and CT images. METHODS: This study included 2244 patients without pathology at the base of tongue who had undergone panoramic radiography and CT of the maxillofacial region. The size, number and position of lingual tonsilloliths relative to the mandible and tongue were evaluated. RESULTS: Lingual tonsilloliths were observed in 33 (1.5%) and 108 (4.8%) of all patients on panoramic radiographs and CT images, respectively. The prevalence was higher in patients aged ≥40 years than in those aged < 40 years (χ2, p < 0.01). They appeared as small, round- or rod-shaped calcified bodies, and they always located closely anterior (1-17 mm) to the anterior border of oropharyngeal airway on panoramic radiographs. Lingual tonsilloliths were superimposed over the surrounding soft tissue inferior to the body of the mandible, posteroinferior to the angle of the mandible and posterior to the mandible in 16 (48.5%), 15 (45.5%) and 1 (3.0%) individual, respectively. A significant correlation was observed between the detectability on panoramic radiographs and size (Spearman's r = 0.961, p < 0.01) of tonsilloliths, as revealed by CT images. CONCLUSION: Lingual tonsilloliths commonly appear on CT. They also appear on panoramic radiography and may superimpose the surrounding soft tissue of the mandible. Although lingual tonsilloliths may resemble other pathological calcifications including submandibular sialoliths and lingual osseous cholistoma, they can be differentiated by carefully observing panoramic radiographs. When clinicians detect calcified bodies near the base of tongue, lingual tonsilloliths should be included in the differential diagnoses.

Prevalence and imaging characteristics of palatine tonsilloliths evaluated on 2244 pairs of panoramic radiographs and CT images.

OBJECTIVES: Palatine tonsilloliths incidentally detected on diagnostic imaging should be differentiated from pathologic calcifications to enable correct diagnosis and treatment. The aim of this study is to clarify the prevalence and imaging characteristics of palatine tonsilloliths on panoramic radiographs. MATERIALS AND METHODS: We retrospectively reviewed 2244 individuals who underwent pairs of consecutive panoramic radiography and computed tomography (CT) of the head and neck region. The imaging characteristics of palatine tonsilloliths on panoramic radiography were compared with the findings from CT, which was considered the gold standard. RESULTS: Tonsilloliths were detected in 300 (13.4 %) and 914 (40.7 %) of the 2244 individuals on panoramic radiographs and CT, respectively. On panoramic radiographs, tonsilloliths were superimposed over the ramus of the mandible at the level coincident with and inferior to the soft palate in 176 (7.8 %) and 90 (4.0 %) individuals, respectively. Tonsilloliths were also superimposed over the surrounding soft tissue inferior to the body of the mandible, postero-inferior to the angle of the mandible, and posterior to the ramus of the mandible in 33 (1.5 %), 26 (1.2 %), and 28 (1.3 %) individuals, respectively. A significant correlation was observed between the detectability on panoramic radiographs and the size (Spearman r = 1.000) and number (Spearman r = 0.991) of tonsilloliths, as revealed by CT images. CONCLUSIONS: The present results suggest that tonsilloliths are commonly detected on panoramic radiographs. Furthermore, they can be superimposed on both the mandible and the surrounding soft tissue. CLINICAL RELEVANCE: Clinicians should include tonsilloliths among the differential diagnoses when calcified bodies are detected on panoramic radiographs.

Intraoral ultrasonography of tongue mass lesions.

OBJECTIVES: To demonstrate the usefulness of intraoral ultrasonography (IOUS) for tongue mass lesions, we analyzed surgery cases excluding squamous-cell carcinoma and leukoplakia and compared IOUS and pathological findings. METHODS: We used the hospital information system and Radiology Information System to evaluate the IOUS and pathological findings of patients who underwent surgeries for tongue masses in the past 11 years. RESULTS: Surgeries for the tongues were performed in 268 cases. Imaging examinations were carried out in 52 (19.4%) cases including 42 (15.7%) cases by IOUS. The pathological results of the surgeries were as follows: 36 cases were inflammatory lesions, 74 cases were tumours, 131 cases were hyperplasia, 8 cases were cystic lesions and 19 cases were other miscellaneous lesions. On the other hand, the number of patients who received IOUS in the same period was 87, and 42 of them had surgeries. In 32 out of the 42 (76.2%) cases, pre-operative IOUS features matched with pathological results. Most of the haemangiomas and lipomas could be diagnosed by IOUS alone. CONCLUSIONS: IOUS of the tongue revealed the nature of the lesions including the border, size, location, depth, the presence or absence of a capsule and the internal structure including vascularity of the mass. The ultrasonographic findings well reflected the histological findings. IOUS is a simple and useful technique that provides additional information beyond inspection, clarifying the internal structure, blood flow and relationships with the adjacent tissues. In this article, we indicated 11 representative cases (fibrous polyp, haemangioma, pyogenic granuloma, lipoma, liposarcoma, chondroma, lymphangioma, schwannoma, neurofibroma, pleomorphic adenoma and amyloidosis) to show the usefulness of IOUS.

Neuroendocrine tumor in the mandible: a case report with imaging and histopathologic findings.

Neuroendocrine tumors (NETs) arise from neuroendocrine cells and are mostly observed in the gastrointestinal tract, pancreas, and lungs. NETs in the oral and maxillofacial region are extremely rare. We report a case of a 59-year-old woman with an NET in the mandible. The patient did not show any symptoms except for remarkable swelling and bleeding. The lesion appeared as a radiolucent honeycomb abnormality with bone destruction on panoramic radiography. The histopathologic diagnosis following a biopsy was NET. Contrast-enhanced computed tomography (CT), 18F-fluorodeoxyglucose positron emission computed tomography (18F-FDG PET/CT), and adrenal scintigraphy-labeled meta-iodobenylguanidine were the modalities added to identify the primary site. Multiple lesions were confirmed in the gastrointestinal tract. Endoscopy was performed to identify the lesions, and several lesions were observed protruding from the mucous membranes. However, the endoscopy specimens did not yield an accurate diagnosis because adequate samples were not acquired. Blood and urine tests revealed no functional activity caused by the tumors. Although the origin was not histopathologically confirmed with endoscopy, this patient was situationally diagnosed with nonfunctional NET originating from the duodenum, as demonstrated by the metastases in the mandible.

Prevalence and imaging characteristics of palatine tonsilloliths detected by CT in 2,873 consecutive patients.

AIM: Tonsilloliths are calcified structures that develop in tonsillar crypts. They are commonly detected in daily clinical practice. The prevalence of tonsilloliths was 16 to 24% in previous reports, but it is inconsistent with clinical experience. The aim of this study is to clarify the prevalence, number, and size distribution of tonsilloliths using computed tomography (CT) in a relatively large number of patients. MATERIALS AND METHODS: We retrospectively reviewed the scans of 2,873 patients referred for CT examinations with regard to tonsilloliths. RESULTS: Palatine tonsilloliths were found in 1,145 out of 2,873 patients (39.9%). The prevalence of tonsilloliths increased with age, and most commonly in patients of ages 50-69. The prevalence in the 30s and younger was statistically lower than in the 40s and older (P < 0.05). The number of tonsilloliths per palatine tonsil ranged from one to 18. The size of the tonsilloliths ranged from 1 to 10 mm. For the patients with multiple CT examinations,the number of tonsilloliths increased in 51 (3.9%) and decreased in 84 (6.5%) of the tonsils. CONCLUSIONS: As palatine tonsilloliths are common conditions, screenings for tonsilloliths during the diagnosis of soft tissue calcifications should be included in routine diagnostic imaging.

Hypothalamic orexin prevents hepatic insulin resistance induced by social defeat stress in mice.

Depression is associated with insulin resistance and type 2 diabetes, although the molecular mechanism behind the pathological link remains unclear. Orexin, a hypothalamic neuropeptide regulating energy and glucose homeostasis, has been implicated in the endogenous antidepressant mechanism. To clarify whether orexin is involved in the coordination between mental and metabolic functions, we investigated the influence of orexin deficiency on social interaction behavior and glucose metabolism in mice subjected to chronic social defeat stress. Chronic stress-induced glucose intolerance and systemic insulin resistance as well as social avoidance were ameliorated by calorie restriction in an orexin-dependent manner. Moreover, orexin-deficient mice maintained under ad libitum-fed conditions after defeat stress exhibited hyperinsulinemia and elevated HOMA-IR (homeostasis model assessment for insulin resistance), despite normal fasting blood glucose levels. In a pyruvate tolerance test to evaluate hepatic insulin sensitivity, chronic stress-induced abnormal glucose elevation was observed in orexin-deficient but not wild-type mice, although both types of mice were susceptible to chronic stress. In addition, insulin-induced phosphorylation of Akt in the liver was impaired in orexin-deficient but not wild-type mice after chronic stress. These results demonstrate that the central physiological actions of orexin under ad libitum-fed conditions are required for the adaptive response to chronic defeat stress, which can prevent the development of hepatic insulin resistance but not social avoidance behavior. Moreover, calorie restriction, a paradigm to strongly activate orexin neurons, appears to prevent the persistence of depression-like behavior per se, leading to the amelioration of impaired glucose metabolism after chronic stress; therefore, we suggest that hypothalamic orexin system is the key for inhibiting the exacerbating link between depression and type 2 diabetes.

Preoperative evaluation of patients with squamous cell carcinoma of the oral cavity: fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography and ultrasonography versus histopathology.

BACKGROUND: The purpose of this retrospective study was to compare fluorine-18 fluorodeoxyglucose positron emission tomography/computed tomography (PET/CT) and ultrasonography (US) in the staging of patients with squamous cell carcinoma of the oral cavity. METHODS: We compared preoperative evaluations regarding lymph nodes using PET/CT, US, and both methods. The cutoff for the maximum standardized uptake value (SUV(max)) in PET/CT was set at 2.7 by a receiver operating characteristic analysis that was based on the histopathological diagnosis. US was used to examine internal structural changes on B-mode and hilar vascularity on power Doppler. RESULTS: The performance of PET/CT and US in combination was better than that of each modality separately. However, there were histopathological changes that could not be detected on PET/CT or US. PET/CT could not detect nodes with necrotic or cystic changes. US could not detect lymph nodes that did not have abnormal structures. CONCLUSIONS: PET/CT and US are complementary tools to evaluate preoperative patients.

Mechanical and clinical performance of pulse-inversion tissue harmonic imaging in the superficial region.

PURPOSE: To compare image quality between fundamental imaging (FI; transmitted and received frequencies 8.0 and 9.0 MHz, respectively) and pulse-inversion tissue harmonic imaging (PI-THI; transmitted frequencies 4.0 and 4.5 MHz, respectively) within 40 mm of the surface of the probe, we tested axial, lateral, and contrast resolution. METHODS: The axial and lateral resolution were tested by use of a tissue-mimicking test object. For contrast resolution, milk agar blocks of different concentration were used for the comparison test. RESULTS: The lateral resolution was significantly improved by use of PI-THI at a depth of 20 to 40 mm from the surface of the phantom. Axial resolution was not reduced by use of PI-THI compared with FI. The value of the contrast index was higher in PI-THI than in FI. The researchers also evaluated the two modes clinically, by comparing the visibility of 170 cervical lymph nodes (identification of lymph node, echogenic hilus, parenchymal echogenicity). The results revealed significant advantages of PI-THI over FI for three features. CONCLUSION: This study suggests that PI-THI might be mechanically and clinically useful in the superficial region.