Yasuhiro Morimoto

Ultrasonography for Intraoperative Determination of Tumor Thickness and Resection Margin in Tongue Carcinomas

PURPOSEnExact estimation of tumor thickness and the status of the resection margin in tongue carcinoma are important prognostic factors for local recurrence, subclinical nodal metastasis, and survival. This study aims to evaluate the accuracy of intraoral ultrasonography-guided measurement of tumor thickness and define an adequate intraoperative resection margin in squamous cell carcinomas of the tongue.nnnMATERIALS AND METHODSnIn this prospective study, 13 patients with presurgical, biopsy-proven, clinical T1N0 or T2N0 tongue squamous cell carcinomas who underwent a partial glossectomy were examined preoperatively with ultrasonography to assess tumor thickness under general anesthesia. Nine cases underwent resection by a conventional method, whereas we introduced elastic needles with a metal core to mark a deep surgical margin of 10 mm from the deepest tumor invasion front under ultrasonographic monitoring as a new technique in the remaining 4 cases. Each resected specimen was immediately immersed in gelatin solution while maintaining its original shape and orientation and was placed under refrigeration to solidify. Ultrasonographic observations of the gelatin-embedded specimens were performed from the superior surface of the gelatin block.nnnRESULTSnVery fine ultrasonographic images of the resected specimen could be easily obtained without any special skills, and surgical clearance could be verified intraoperatively. The ultrasonographic tumor thickness measurements corresponded well with those of histologic sections, with a consistency ratio of 91.4% to 98.2% (Pearson correlation coefficient = 0.981, P < .05).nnnCONCLUSIONnIntraoperative ultrasonography is a reliable method to objectively evaluate tumor thickness and surgical margin clearance.

Advanced Clinical Usefulness of Ultrasonography for Diseases in Oral and Maxillofacial Regions

Various kinds of diseases may be found in the oral and maxillofacial regions and various modalities may be applied for their diagnosis, including intra-oral radiography, panoramic radiography, ultrasonography, computed tomography, magnetic resonance imaging, and nuclear medicine methods such as positron emission tomography. Of these modalities, ultrasound imaging is easy to use for the detection of noninvasive and soft tissue-related diseases. Doppler ultrasound images taken in the B-mode can provide vascular information associated with the morphology of soft tissues. Thus, ultrasound imaging plays an important role in confirming the diagnosis of many kinds of diseases in such oral and maxillofacial regions as the tongue, lymph nodes, salivary glands, and masticatory muscles. In the present article, we introduce three new applications of ultrasonography: guided fine-needle aspiration, measurement of tongue cancer thickness, and diagnosis of metastasis to cervical lymph nodes.

Correlation of mandibular bone quality with neurosensory disturbance after sagittal split ramus osteotomy

Our aim was to find out whether the quality of bone around the inferior alveolar nerve is correlated with neurosensory disturbance to the nerve after sagittal split ramus osteotomy (SSRO) in patients with mandibular prognathism. Computed tomograms (CT) were taken of 35 patients with mandibular prognathism and 35 without. To assess the density of bone around the inferior alveolar nerve, the width of the buccal cortical bone in the mandibular second molar regions was measured on CT. The Hounsfield units (HU) in the same regions were also measured. The number of HU in the mandible around the second molar regions was significantly higher (p<0.01) in those with neurosensory disturbance (p<0.01). The quality of bone measured by HU is associated with an increased risk of neurosensory disturbance, but the width of buccal bone is not.

Effect of bone quality and position of the inferior alveolar nerve canal in continuous, long-term, neurosensory disturbance after sagittal split ramus osteotomy

OBJECTIVESnTo examine the relationship between the anatomical position and the bone quality of the inferior alveolar nerve (IFAN) canal and long-term neurosensory disturbance (NSD) of the IFAN after a sagittal split ramus osteotomy (SSRO).nnnMATERIAL AND METHODSnCT images were taken of patients with mandibular prognathism. The location of the IFAN and the bone density around the IFAN were measured on CT images. Whether NSD at 6 months and 1 year after SSRO was related to the position and bone quality of the IFAN canal was analyzed.nnnRESULTSnSignificant correlations were found between the anatomical position and the bone quality of the IFAN canal and the period to the resolution of NSD of the IFAN from 3 months to 1 year after SSRO. If the HU values around the IFAN were greater than 300 HU and/or the distance from the buccal aspect of the IFAN canal to the outer buccal cortical margin was less than 6 mm, NSD of the IFAN at 1 year after SSRO was significantly increased.nnnCONCLUSIONnIt is important to pay particular attention to the anatomical position of the IFAN and the bone quality around the IFAN to predict long-term NSD of the IFAN after SSRO.

Assessment of the relationship between the mandibular cortex on panoramic radiographs and the risk of bone fracture and vascular disease in 80-year-olds

OBJECTIVESnThe objective of this study was to assess cortical measurements on panoramic radiographs in 80-year-old subjects to predict bone fracture and vascular disease risks.nnnMETHODSnThe cortical width and shape (normal cortex, mildly to moderately eroded cortex, and severely eroded cortex) were evaluated on 659 panoramic radiographs obtained from 262 men and 397 women, all of whom were 80 years old. At baseline, a general medical examination, including heel bone density, was performed in all subjects. Fractures and vascular disease occurring within 5 years after the baseline examination were determined in 191 subjects and in 108 subjects who died within 5 years after the baseline examination.nnnRESULTSnThere were significant correlations between heel bone density and cortical width (r = 0.435, P < .001) and shape (r = 0.231, P < .001). However, cortical measurements on panoramic radiographs were not significantly associated with the occurrence of fractures and vascular disease within 5 years after the baseline examination.nnnCONCLUSIONSnAmong the elderly, cortical measurements on panoramic radiographs may be associated with bone mineral density and physical activity, but they are not useful markers for the subsequent occurrence of fractures and vascular disease.

Dynamic magnetic resonance sialography for patients with xerostomia.

OBJECTIVEnThe aim was to evaluate the utility of dynamic magnetic resonance (MR) sialographic images as a diagnostic tool for patients with xerostomia as chief complaint.nnnMETHODSnVarious parameters of dynamic MR sialographic images from 40 healthy volunteers were compared with those from 28 patients having dry mouth as chief complaint. Dynamic MR sialographic images were acquired using a 1.5-T full-body MR system and 2-dimensional fast asymmetric spin-echo (2D-FASE) sequences. Acquisition of the optimal section using 2D-FASE sequencing with single-section acquisition of thick sections was repeated every 30 s before and after a few drops of 5% citric acid was placed on the tongue. Student t test was used to examine differences between the healthy volunteer and patient groups regarding the maximum area of salivary gland ducts before and after citric acid stimulation.nnnRESULTSnThe maximum area of the detectable ducts in the patient group was significantly smaller (P < 0.001), whereas the change in detectable duct area was significantly lower (P < 0.001).nnnCONCLUSIONSnThis study suggests that dynamic MR sialographic images and data can be useful in the diagnosis of patients with dry mouth as chief complaint.

Relationship between the curative effects of carbamazepine administration and the neurovascular compression volume of the trigeminal nerve measured using magnetic resonance cisternography.

ObjectivesTo elucidate the relationship between the extent of pain and neurovascular compression (NVC) volume, measured by magnetic resonance (MR) cisternography, in patients with trigeminal neuralgia. In addition, we aimed to evaluate the relationship between NVC volume and the efficacy of carbamazepine administration in patients with trigeminal neuralgia. MethodsMR cisternography was performed on 214 patients with clinical signs and symptoms that suggested trigeminal neuralgia retrospectively. The extent of their pain was evaluated using visual analog scales. Next, only carbamazepine was administered as the initial treatment. For the patients with NVC detectable on MR cisternography, the relationship between the extent or nature of the pain and the neurovascular volume was analyzed. In addition, the correlation between the efficacy of carbamazepine treatment and the NVC volume was evaluated retrospectively. ResultsOf the 214 patients evaluated, 144 were deemed to have NVC. In these 144 patients, a significant difference was found between the NVC volume and the curative effects of 100u2009mg/d carbamazepine. However, no significant correlation was found between the extents of pain by visual analog score or between the daily dosage of carbamazepine and the NVC volume measured by MR cisternography. ConclusionsThree-dimensional MR cisternography is very useful for detecting the site of NVC in patients with trigeminal neuralgia. NVC measured by this technique may indicate the prognosis after initial treatment. The present results suggest that the evaluation of NVC volume by MR cisternography would be useful in choosing the initial treatment for patients with trigeminal neuralgia.

Reflection of 18F-FDG accumulation in the evaluation of the extent of periapical or periodontal inflammation

OBJECTIVESnTo elucidate whether fluorine-18-labeled ((18)F) fluoro-2-deoxy-d-glucose (FDG) accumulation can reflect the extent of periodontal inflammation, periapical inflammation, or dental caries.nnnSTUDY DESIGNn(18)F-FDG accumulations on positron emission tomography (PET)-computed tomography (CT) were retrospectively compared with the size of the bone resorption areas caused by periodontal inflammation, periapical inflammation, or dental caries on panoramic radiographs, CT, and magnetic resonance imaging (MRI) in 44 subjects.nnnRESULTSnA significant correlation was found between the size of the bone resorption area caused by periodontal (r = 0.595, P < .01) or periapical (r = 0.560, P < .01) inflammation and the highest standardized uptake value (SUVmax) of (18)F-FDG accumulation. A significant correlation was found between the periodontal (r = 0.622, P < .01) or periapical (r = 0.394, P < .01) inflammatory findings on MRI and the SUVmax of (18)F-FDG accumulation. The SUVmax of (18)F-FDG around most teeth with caries was under 1.5.nnnCONCLUSIONSn(18)F-FDG accumulation reflects the extent of dental inflammation, not dental caries.

Diagnostic significance of characteristic findings on ultrasonography for the stitch abscess after surgery in patients with oral squamous cell carcinoma

To elucidate the clinical significance of imaging modalities for detection of stitch abscess after surgery in patients with oral squamous cell carcinoma (SCC). In 137 patients with oral SCC suspected of having lymph node metastases, local recurrence of tumor, or stitch abscess after surgery, the characteristic imaging findings related to lymph node metastases, local recurrence of tumor, and stitch abscess on ultrasonography (US), computed tomography (CT), magnetic resonance (MR), and (18)fluorodeoxyglucose (18FDG)-positron emission tomography (PET) images were identified and analyzed. In all six patients with stitch abscess, characteristic findings were demonstrated on US, different from those of metastatic lymph nodes and local recurrence on CT, MRI, and 18FDG-PET images. Our results suggest that ultrasonography may be a very useful tool for diagnosis of postoperative stitch abscess and may help improve the quality of life of oral SCC patients.

Prevalence and imaging characteristics of detectable tonsilloliths on 482 pairs of consecutive CT and panoramic radiographs

BackgroundRecent studies suggest that tonsilloliths are clinically related to halitosis and tonsillar abscess. Based on our empirical knowledge, tonsilloliths are relatively commonly encountered in daily clinical practice. It has been reported that the detection rate of tonsilloliths was under 24% in previous reports, although experience suggests otherwise. The purpose of the study was to evaluate the prevalence and characteristics of tonsilloliths using computed tomography (CT). In addition, the possible causes of low detection rates on panoramic radiographs were evaluated based on comparisons between CT images and panoramic radiographs in order to elucidate the limitations of visualizing the area around the palatine tonsils on panoramic radiographs.Methods482 pairs of CT images and panoramic radiographs were retrospectively assessed with respect to the presence and characteristics of tonsilloliths. In addition, the causes in cases of disagreement between the two modalities were analyzed.ResultsThe detection rate of tonsilloliths was 46.1% using CT scans, unlike previous reports. The characteristics of tonsillolith were dot-like figures with about 300-500 Hounsfield units within the palatine tonsil under the soft palate. The most common length of tonsilloliths was about 3 or 4xa0mm. As the subjects aged, the detection rate increased gradually. A significant difference in the tonsillolith detection rate was found between the over and under 40-year-old groups (pu2009<u20090.0001). However, the detection rate of tonsilloliths was only 7.3% on panoramic radiographs. A significant correlation was observed between the detection rate of tonsilloliths on panoramic radiographs and CT number (Spearman ru2009=u20090.429), size, (Spearman ru2009=u20090.318), and number of tonsilloliths (Spearman ru2009=u20090.333).ConclusionThe present results suggest that tonsilloliths are relatively more common than previously suggested. However, panoramic radiographs detect only a small percentage of palatine tonsilloliths. The low detection rates on panoramic radiographs might be related to the degree of calcification, size, and number of tonsilloliths.