Deep learning with convolution neural network detecting mesiodens on panoramic radiographs: comparing four models.

The aim of this study was to develop an optimal, simple, and lightweight deep learning convolutional neural network (CNN) model to detect the presence of mesiodens on panoramic radiographs. A total of 628 panoramic radiographs with and without mesiodens were used as training, validation, and test data. The training, validation, and test dataset were consisted of 218, 51, and 40 images with mesiodens and 203, 55, and 61 without mesiodens, respectively. Unclear panoramic radiographs for which the diagnosis could not be accurately determined and other modalities were required for the final diagnosis were retrospectively identified and employed as the training dataset. Four CNN models provided within software supporting the creation of neural network models for deep learning were modified and developed. The diagnostic performance of the CNNs was evaluated according to accuracy, precision, recall and F1 scores, receiver operating characteristics (ROC) curves, and area under the ROC curve (AUC). In addition, we used SHapley Additive exPlanations (SHAP) to attempt to visualize the image features that were important in the classifications of the model that exhibited the best diagnostic performance. A binary_connect_mnist_LeNet model exhibited the best performance of the four deep learning models. Our results suggest that a simple lightweight model is able to detect mesiodens. It is worth referring to AI-based diagnosis before an additional radiological examination when diagnosis of mesiodens cannot be made on unclear images. However, further revaluation by the specialist would be also necessary for careful consideration because children are more radiosensitive than adults.

Efficacy of Essential Oils in Relieving Cancer Pain: A Systematic Review and Meta-Analysis.

Over 80% of patients affected by cancer develops cancer-related pain, one of the most feared consequences because of its intractable nature, particularly in the terminal stage of the disease. Recent evidence-based recommendations on integrative medicine for the management of cancer pain underline the role of natural products. The present systematic review and meta-analysis aims at appraising for the first time the efficacy of aromatherapy in cancer pain in clinical studies with different design according to the most updated Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 recommendations. The search retrieves 1002 total records. Twelve studies are included and six are eligible for meta-analysis. The present study demonstrates significant efficacy of the use of essential oils in the reduction of the intensity of pain associated with cancer (p < 0.00001), highlighting the need for earlier, more homogeneous, and appropriately designed clinical trials. Good certainty body of evidence is needed for effective and safe management of cancer-related pain using essential oils by establishment of a step-by-step preclinical-to-clinical pathway to provide a rational basis for clinical use in integrative oncology. PROSPERO registration: CRD42023393182.

Macroscopic Anatomy of the Layered Structures of Facial Muscles and Fasciae in the Temporal-Malar-Mandible-Neck Region.

The layered structures of facial muscles and their topographical relationship with facial fasciae are still not fully understood. This study aimed to clarify the layered structures of facial muscles and fasciae in the temporal-malar-mandible-neck region. Thirty-four human cadavers were examined during gross anatomy courses at Niigata University (2017-2020). The face was composed of 3-layered (deep, middle, and superficial) fasciae and 4-layered facial muscles (first superficial, second superficial, third, and fourth muscle layers) according to the attachment of muscles and their topographical relationship with the fasciae. The deep fascia covered the temporal and masseter muscles. The parotid gland and facial nerves were enveloped in the middle fascia. The superficial fascia was continuous with the second superficial muscle layer. The connection between fourth and superficial muscles was at the malar and buccal areas, where the platysma blended with the masseter and the plural muscles blended with the buccinator. Our findings suggest that cooperation between the 4-layered structure of the facial muscles surrounding the apertures of the eyes and mouth and the superficial fascia enables humans to produce complex facial expressions. Furthermore, the spread of inflammation in the face may be owing to the layered facial muscles and fasciae, as these layered structures separate tissues into multiple compartments.

Analgesic Characteristics of NanoBEO Released by an Airless Dispenser for the Control of Agitation in Severe Dementia.

Chronic pain is one of the most common causes of the need for clinical evaluation, acquiring more importance in the elderly with cognitive impairment. Reduced self-reporting capabilities cause unrelieved pain contributing to the development of agitation. Safe and effective pain treatment can afford the management of agitation without the serious increase in death risk associated with neuroleptics. To this aim, the essential oil of bergamot (BEO), proven by rigorous evidence to have strong preclinical anti-nociceptive and anti-allodynic properties, has been engineered (NanoBEO, patent EP 4003294) to allow randomized, double-blind, placebo-controlled trials (BRAINAID, NCT04321889). The present study: (1) assesses the analgesic effects of a single therapeutic dose of NanoBEO, as supplied by an airless dispenser for clinical translation, in models of inflammatory, neuropathic, and sensitization types of pain relevant to clinic; (2) provides a dose-response analysis of the efficacy of NanoBEO on scratching behavior, a typical behavioral disturbance occurring in dementia. A single therapeutic dose of NanoBEO confirms efficacy following thirty minutes pre-treatment with capsaicin and on the central sensitization phase induced by formalin. Moreover, it has an ID50 of 0.6312 mg and it is efficacious on static and dynamic mechanical allodynia. Altogether, the gathered results strengthen the potential of NanoBEO for clinical management of pain and agitation.

General rules for clinical and pathological studies on oral cancer (2nd edition): a synopsis.

For doctors and other medical staff treating oral cancer, it is necessary to standardize the basic concepts and rules for oral cancer to achieve progress in its treatment, research, and diagnosis. Oral cancer is an integral part of head and neck cancer and is treated in accordance with the general rules for head and neck cancer. However, detailed rules based on the specific characteristics of oral cancer are essential. The objective of this article was to contribute to the development of the diagnosis, treatment, and research of oral cancer, based on the correct and useful medical information of clinical, surgical, pathological, and imaging findings accumulated from individual patients at various institutions. Our general rules were revised as the UICC was revised for the 8th edition and were published as the Japanese second edition in 2019. In this paper, the English edition of the "Rules" section is primarily presented.

A soybean quantitative trait locus that promotes flowering under long days is identified as FT5a, a FLOWERING LOCUS T ortholog.

FLOWERING LOCUS T (FT) is an important floral integrator whose functions are conserved across plant species. In soybean, two orthologs, FT2a and FT5a, play a major role in initiating flowering. Their expression in response to different photoperiods is controlled by allelic combinations at the maturity loci E1 to E4, generating variation in flowering time among cultivars. We determined the molecular basis of a quantitative trait locus (QTL) for flowering time in linkage group J (Chromosome 16). Fine-mapping delimited the QTL to a genomic region of 107kb that harbors FT5a We detected 15 DNA polymorphisms between parents with the early-flowering (ef) and late-flowering (lf) alleles in the promoter region, an intron, and the 3' untranslated region of FT5a, although the FT5a coding regions were identical. Transcript abundance of FT5a was higher in near-isogenic lines for ef than in those for lf, suggesting that different transcriptional activities or mRNA stability caused the flowering time difference. Single-nucleotide polymorphism (SNP) calling from re-sequencing data for 439 cultivated and wild soybean accessions indicated that ef is a rare haplotype that is distinct from common haplotypes including lf The ef allele at FT5a may play an adaptive role at latitudes where early flowering is desirable.

Long-term outcomes of salvage transurethral high-dose-rate brachytherapy combined with external beam radiation therapy for anastomotic recurrence of prostate cancer after radical prostatectomy: A retrospective analysis.

BACKGROUND: High-dose-rate brachytherapy (HDR-BT) delivers high-dose radiation to local lesions within a short treatment period. There are no reports of salvage transurethral HDR-BT for biochemical recurrence (BCR) after radical prostatectomy. Thus, we aimed to evaluate the usefulness of salvage transurethral HDR-BT with external beam radiation therapy (EBRT) for anastomotic prostate cancer recurrence. METHODS AND MATERIALS: Patients with postoperative prostate cancer who underwent salvage transurethral HDR-BT with EBRT for anastomotic recurrence at our hospital between January 2002 and July 2009 were retrospectively evaluated. The Kaplan-Meier method was used to estimate biochemical freedom from failure (bFFF), cause-specific survival (CSS), and overall survival (OS) rates. RESULTS: Nine patients were included in this study. The median follow-up period and age were 13.1 (range 4.3-18.4) years and 67 (range 63-78) years, respectively. The dose of HDR-BT ranged from 13 to 24 Gy per 2 to 5 fractions, while that of EBRT ranged from 30 to 44 Gy per 15 to 22 fractions. The 1-year, 5-year, and 10-year bFFF rates were 77.8%, 41.7%, and 13.9%, respectively. The 10-year and 15-year CSS rates were 100% each. The 10-year and 15-year OS rates were 100% and 64.3%, respectively. Six patients were diagnosed with BCR. Two patients experienced Grade 3 hematuria as a late adverse event. There was no exacerbation of urinary incontinence. CONCLUSIONS: No prostate cancer-related deaths were observed, even after a long-term follow-up. Salvage transurethral HDR-BT after radical prostatectomy is safe and feasible and may be a useful treatment option.

Long-term outcomes of high-dose-rate brachytherapy and external beam radiotherapy without hormone therapy for high-risk localized prostate cancer.

PURPOSE: Until March 2018, patients with high-risk localized prostate cancer had been administered high-dose-rate brachytherapy (HDR-BT) combined with external beam radiotherapy (EBRT) without additional hormone therapy (HT) at our institution. In this study, we aimed to evaluate long-term outcomes of this treatment. MATERIALS AND METHODS: Patients with prostate cancer who received HDR-BT and EBRT between April 1997 and March 2021 and who were followed up for at least 6 months were included in the study. High-risk groups were classified into five levels according to the National Comprehensive Cancer Network guidelines. The EBRT and HDR-BT doses were 39-45 Gy/13-25 fractions. and 16.5-22 Gy/2-4 fractions, respectively. None of the patients received HT during initial treatment. The Kaplan-Meier method was used to estimate biochemical freedom from failure (bFFF), cause-specific survival (CSS), and overall survival (OS) rates. Biochemical failure was also determined. RESULTS: Seventy-two patients were enrolled in the study, with a median follow-up of 91.9 months. The median age and initial prostate-specific antigen (iPSA) level were 71 years and 10.95 ng/mL, respectively. The median biologically effective dose for HDR-BT plus EBRT was 270.3 Gy. The 5- and 7-year bFFF, CSS, and OS rates were 85.2 and 74.2%, 100 and 100%, and 95.7 and 91.9%, respectively. Only the iPSA ≤ 20 group was associated with the higher bFFF rate. The 7-year bFFF rates in the groups with iPSA ≤ 20 and iPSA > 20 were 86.6 and 48.6%, respectively. CONCLUSION: HDR-BT plus EBRT without HT might be an alternative treatment option for patients with high-risk localized prostate cancer and iPSA levels ≤ 20. Further studies are required to validate the efficacy of this treatment strategy.

Role of Spinal Cholecystokinin Octapeptide, Nociceptin/Orphanin FQ, and Hemokinin-1 in Diabetic Allodynia.

A complication of diabetes is neuropathic pain, which is difficult to control with medication. We have confirmed that neuropathic pain due to mechanical allodynia in diabetic mice is mediated by a characteristic neuropeptide in the spinal cord. We evaluated the strength of mechanical allodynia in mice using von Frey filaments. When mice were intravenously injected with streptozotocin, mechanical allodynia appeared 3 days later. Antibodies of representative neuropeptides were intrathecally (i.t.) administered to allodynia-induced mice 7 days after the intravenous administration of streptozotocin, and allodynia was reduced by anti-cholecystokinin octapeptide antibodies, anti-nociceptin/orphanin FQ antibodies, and anti-hemokinin-1 antibodies. In contrast, i.t.-administered anti-substance P antibodies, anti-somatostatin antibodies, and anti-angiotensin II antibodies did not affect streptozotocin-induced diabetic allodynia mice. Mechanical allodynia was attenuated by the i.t. administration of CCK-B receptor antagonists and ORL-1 receptor antagonists. The mRNA level of CCK-B receptors in streptozotocin-induced diabetic allodynia mice increased in the spinal cord, but not in the dorsal root ganglion. These results indicate that diabetic allodynia is caused by cholecystokinin octapeptide, nociceptin/orphanin FQ, and hemokinin-1 released from primary afferent neurons in the spinal cord that transmit pain to the brain via the spinal dorsal horn.

Variation in arterial supply to the floor of the mouth and assessment of relative hemorrhage risk in implant surgery.

OBJECTIVES: Bleeding in the floor of the mouth during implant surgery is attributed to arterial injuries in the sublingual space: clinicians may injure the submental and sublingual arteries, which originate from the facial and lingual arteries, respectively. This study aimed to clarify the three-dimensional courses of submental and sublingual arteries and their topographic relation to the mandible. MATERIALS AND METHODS: During the gross anatomy course at the Faculty of Dentistry and Graduate School, Niigata University (2009-2011), we investigated the relationship between the courses of submental and sublingual arteries and their dividing patterns of the mylohyoid muscle, sublingual gland, and mandible using 27 human cadavers. RESULTS: The courses of submental and sublingual arteries were divided into four patterns: (1) the sublingual space was supplied by the sublingual artery (type I: 63%), (2) it was supplied by both the sublingual and submental arteries (type II: 5.6%), (3) it was supplied by the submental artery without the sublingual artery (type III: 29.6%), and (4) type III without the deep lingual artery originated from the lingual artery (type IV: 1.8%). In type II, III, and IV, the submental artery perforates the mylohyoid muscle or takes a roundabout route to travel near the surface of the mandible. The percentage occurrence of arteries traveling between the sublingual gland and mandible in type II, III, and IV (55%) is higher than that in type I (8.8%). CONCLUSION: Susceptibility of the submental artery in type II, III, and IV to injury during implant surgery is suggested.

Visual evaluation for the elasticity of suprahyoid muscles using sonographic elastography during tongue pressure measurement: A pilot study.

BACKGROUND: Suprahyoid muscles behavior during the tongue lifting movement has not yet been elucidated. OBJECTIVE: The purpose of this study was to investigate the potential of elastography imaging to examine developmental oral dysfunction in children and oral hypofunction in older adults using sonography. METHODS: Tongue pressure was measured using a manometer with a probe. The tongue pressure was measured with simultaneously scanning the geniohyoid muscle (GHM) and the anterior belly of the digastric muscle (DGM) using sonographic elastography. Sagittal images of the GHM and coronal images of the DGM were used for the strain ratio measurement. The strain ratio of the muscles was measured three times for each subject with the tongue pressure values of 0-30 kPa. RESULTS: The strain ratio of the GHM were higher than those of the DGM at tongue pressure of 10, 20 and 30 kPa. The strain ratio of the GHM increased as the tongue pressure increased in all participants. In contrast, the strain ratio of the DGM tended to slowly decrease as tongue pressure increased in female participants. CONCLUSION: Sonographic elastography is useful for visual and quantitative evaluation of elastic properties in suprahyoid muscles during tongue lifting movements.

Masticatory muscle tendon-aponeurosis hyperplasia that was initially misdiagnosed for polymyositis: a case report and review of the literature.

BACKGROUND: Masticatory muscle tendon-aponeurosis hyperplasia (MMTAH) is a relatively newly identified clinical condition that manifests as trismus with a square-shaped mandible. Herein, we report a case of MMATH that was initially misdiagnosed for polymyositis due to trismus and simultaneous lower limb pain, with literature review. CASE PRESENTATION: A 30-year-old woman had a history of lower limb pain after exertion for 2 years. Initial physical examination had been performed at the Department of General Medicine in our hospital. There was also redness in the hands and fingers. Although polymyositis was suspected, it was denied. The patient visited our department for right maxillary wisdom tooth extraction. Clinical examination revealed that the patient had a square-shaped mandible. The maximal mouth opening was 22 mm. There was no temporomandibular joint pain at the time of opening. Furthermore, there was awareness of clenching while working. Panoramic radiography revealed developed square mandibular angles with flattened condyles. Computed tomography showed enlarged masseter muscles with high-density areas around the anterior and lateral fascia. Magnetic resonance imaging also showed thickened tendons and aponeuroses on the anterior surface and inside bilateral masseter muscles. Finally, the patient was diagnosed with MMTAH. Bilateral aponeurectomy of the masseter muscles with coronoidectomy and masseter muscle myotomy was performed under general anesthesia. The maximum opening during surgery was 48 mm. Mouth opening training was started on day 3 after surgery. Histopathological examination of the surgical specimen showed that the muscle fibers were enlarged to 60 µm. Immunohistochemistry testing for calcineurin, which was associated with muscle hypertrophy due to overload in some case reports, showed positive results. Twelve months after surgery, the mouth self-opening and forced opening were over 35 mm and 44 mm, respectively. CONCLUSIONS: Herein, we report a case of MMATH. Lower limb pain due to prolonged standing at work and overload due to clenching were considered risk factors for symptoms onset of MMATH.

Diagnostic application of intraoral ultrasonography to assess furcation involvement in mandibular first molars.

OBJECTIVES: The objectives were to clarify if intraoral ultrasonography (USG) is: (1) more accurate than conventional periodontal examinations in detection of furcation involvement, and (2) comparable to conventional periodontal examinations in accurate horizontal classification of furcation involvement in comparison to cone beam computed tomography (CBCT). METHODS: The buccal furcation in 61 lower first molars were evaluated with conventional periodontal examinations, intraoral USG and CBCT. The presence and classification of the horizontal depth of furcation involvement were defined clinically by assessment with a Nabers periodontal probe and a periapical radiograph with reference to the bone loss under the fornix. The horizontal depth of furcation involvement was measured in intraoral USG and CBCT images. Based on the measurements, presence diagnosis and horizontal classification were performed. Results from conventional periodontal examinationsand intraoral USG were compared with those from CBCT. RESULTS: κ value (κ) for agreement of presence diagnosis of furcation involvement between intraoral USG and CBCT was 0.792, while agreement with conventional periodontal examinations was 0.225. Diagnostic accuracy of intraoral USG exhibited higher values (sensitivity: 98.3%, accuracy: 98.4 %) than conventional periodontal examinations (81.4% and 81.9 %). Weighted κ statistics showed substantial agreement in the classification between intraoral USG and CBCT (κ = 0.674). High agreement (ICC: 0.914) for the measurement of horizontal depth of furcation involvement was found between intraoral USG and CBCT. CONCLUSIONS: Intraoral USG may be a reliable diagnostic tool for assessment of furcation involvement of mandibular molars with a similar performance to CBCT, but without ionizing radiation.

The Relationship between the Contouring Time of the Metal Artifacts Area and Metal Artifacts in Head and Neck Radiotherapy.

(1) Background: The impacts of metal artifacts (MAs) on the contouring workload for head and neck radiotherapy have not yet been clarified. Therefore, this study evaluated the relationship between the contouring time of the MAs area and MAs on head and neck radiotherapy treatment planning. (2) Methods: We used treatment planning computed tomography (CT) images for head and neck radiotherapy. MAs were classified into three severities by the percentage of CT images containing MAs: mild (<25%), moderate (25−75%), and severe (>75%). We randomly selected nine patients to evaluate the relationship between MAs and the contouring time of the MAs area. (3) Results: The contouring time of MAs showed moderate positive correlations with the MAs volume and the number of CT images containing MAs. Interobserver reliability of the extracted MAs volume and contouring time were excellent and poor, respectively. (4) Conclusions: Our study suggests that the contouring time of MAs areas is related to individual commitment rather than clinical experience. Therefore, the development of software combining metal artifact reduction methods with automatic contouring methods is necessary to reducing interobserver variability and contouring workload.

Comparing the Diagnostic Accuracy of Ultrasonography, CT, MRI, and PET/CT in Cervical Lymph Node Metastasis of Oral Squamous Cell Carcinoma.

(1) Background: In oral cancer staging, ultrasonography (US), computed tomography (CT), magnetic resonance imaging (MRI), and 2-deoxy-2-[fluorine-18]fluoro-D-glucose (FDG) with positron emission tomography/computed tomography (PET/CT) are routinely used in clinical practice. The present study is a retrospective examination of the diagnostic accuracy of cervical lymph node metastasis using US, CT, MRI, and PET/CT, with histopathological diagnosis as a reference, to compare the different diagnostic imaging modalities. (2) Methods: The participants included 16 patients with oral squamous cell carcinoma who underwent US-, CT-, MRI-, and PET/CT-based preoperative diagnostic imaging and simultaneous primary lesion resection and neck dissection, including 82 level regions and 424 lymph nodes. We compared the sensitivity, specificity, accuracy, positive predictive value, and negative predictive value of each imaging modality based on the imaging results and the pathology results of metastasis. (3) Results: Of the four diagnostic imaging modalities, PET/CT exhibited the highest sensitivity but the lowest specificity and accuracy. US, CT, and MRI had high specificities. Comparing each level region and lymph node showed that differences were observed in PET/CT. (4) Conclusions: PET/CT to diagnose lymph node metastasis requires a comprehensive evaluation because it produces more false positives than other diagnostic imaging modalities. Using US, CT, and MRI, which have excellent spatial resolution, improves diagnostic accuracy at the lymph node level.

Enhanced behavioral response to serotonin-related agonists in postweaning protein malnourished mice.

We investigated whether postweaning protein malnutrition (PM) affects serotonergic systems. Mice were fed a PM diet or normal protein (control) diet from weaning (21 d of age). Twenty days later, we tested for behavioral effects of the selective serotonin (5-HT)(1A) receptor agonist 8-hydroxy-N,N-dipropyl-2-aminoteralin (8-OH-DPAT) and the 5-HT releaser d-fenfluramine. The number of head weaving responses induced by 8-OH-DPAT or d-fenfluramine in the PM mice was significantly increased compared with the control diet group. The effects of 8-OH-DPAT and d-fenfluramine were blocked by pretreatment with the selective 5-HT(1A) receptor antagonist WAY-100635 (0.01 mg/kg). However, postpubertal (56 d of age) mice fed with the PM diet did not show an enhancement of the 8-OH-DPAT-induced head weaving response. These results indicate the occurence of a supersensitivity of postsynaptic 5-HT(1A) receptor in the postweaning PM group. Moreover, they highlight the postweaning stage as a vulnerable period to malnutrition-induced alterations in central serotonergic systems.

Orofacial pain related to traumatic neuroma in a patient with multiple TMJ operations.

The diagnosis of orofacial pain associated with temporomandibular disorders after repeated temporomandibular joint (TMJ) surgeries can be quite difficult. This case report describes a 52-year-old woman who had previously undergone five TMJ surgeries and developed divergent pain caused by a trigger point in the left preauricular area. Computed tomography and magnetic resonance imaging could not be used to identify a lesion because of metallic artifacts from a TMJ prosthesis. However, sonography indicated the location of the suspected lesion. Moreover, a neurological examination performed with local anesthesia was clinically effective in ruling out other diagnoses of orofacial pain. Ultimately, a histopathological examination of a biopsy specimen from the painful site confirmed the lesion to be a traumatic neuroma. This case report suggests the value of including traumatic neuroma in the differential diagnosis of patients with a history of previous TMJ surgery who present with orofacial pain in the region of the TMJ.

Examination of factors affecting condylar bone changes following surgical-orthodontic treatment.

OBJECTIVE: To identify factors affecting condylar bone changes following surgical-orthodontic treatment. METHODS: A total of 200 patients with dentofacial deformities were classified into skeletal Classes I, II, and skeletal Class III groups consisting of 61 and 139 subjects, respectively. Temporomandibular joints (TMJs) were evaluated using clinical findings and computed tomography images before treatment, immediately before surgery, and 6 months after surgery. RESULTS: Condylar bone changes occurred at a significantly higher rate after surgery in both groups. Factors related to condylar bone changes following surgical-orthodontic treatment included skeletal Class I or II, disc displacement, and condylar bone changes before treatment. There were three cases with condylar bone changes after surgery that were diagnosed with condylar resorption and skeletal Class II and anterior disc displacement before surgery. CONCLUSION: Condylar resorption could occur when the load on the condyle increases after orthognathic surgery and exceeds the permissible limit.

A comparative study between CT, MRI, and intraoral US for the evaluation of the depth of invasion in early stage (T1/T2) tongue squamous cell carcinoma.

OBJECTIVES: This study aimed to clarify the accuracy of intraoral ultrasonography (US), computed tomography (CT), and magnetic resonance imaging (MRI) in preoperative image depth of invasion (DOI) measurement of T1/T2 tongue cancer through comparison with histopathological measurements. METHODS: Imaging of the primary lesions was performed at our hospital; the lesions were classified into T1 and T2 based on the 8th edition of the AJCC/UICC, and surgery performed. There was histopathological confirmation of lesions as squamous cell carcinoma in 48 patients with tongue cancer. T3 and T4 cases, cases in which preoperative chemotherapy and radiation therapy were performed, and cases where biopsy was performed before imaging were excluded. The radiological DOI in US, CT, and MRI and the histopathological DOI as base were comparatively investigated and statistical analyses were performed by Bland-Altman analysis and Spearman's rank correlation coefficient. RESULTS: Bland-Altman analysis showed that the US radiological DOI was overestimated by an average of 0.2 mm compared to the histopathological DOI, while CT and MRI radiological DOI were overestimated by an average of 2-3 mm. The comparison of CT and MRI revealed that the difference between the MRI and histopathological DOI, as well as the 95% limit of agreement, were smaller than those of the CT radiological DOI. CONCLUSIONS: US is the most accurate preoperative diagnostic tool for T1 and T2 squamous cell carcinoma; CT and MRI tend to have an overestimation of about 2-3 mm and so caution is required.

Posterior superior alveolar nerves contribute to sensation in the anterior teeth.

BACKGROUND: There is no available data on the occurrence rate of a converged alveolar canal, the detailed three-dimensional (3D) courses of alveolar canals/grooves (ACGs), or the contribution of each superior alveolar nerve to each area in the maxilla. This study aimed to clarify the 3D courses of ACGs, the relationship between ACGs and superior alveolar nerves, and the contribution of posterior superior alveolar nerves (PSANs) using computed tomography (CT) with histological analysis. METHODS: During the gross anatomy course at Niigata University, we investigated nine human cadavers. RESULTS: All anterior and posterior ACGs converged into the common alveolar canal, which contained blood vessels and several nerve bundles surrounded by perineurium, located at the nasal floor near the pyriform aperture. Histometrical analysis clarified that 16.3% of the nerve bundles in this canal were derived from PSANs, and 67% of the bundles were dispersed while they coursed down to the nasal floor. There seems to be no relationship between the density of nerve bundles in the canal and the number of remaining anterior teeth. CONCLUSIONS: Data obtained from observing the detailed 3D courses of anterior and posterior ACGs, and their relationship with superior alveolar nerves, suggest that PSANs partially contribute to the nociception of the anterior teeth.