Objective assessment of mastication predominance in healthy dentate subjects and patients with unilateral posterior missing teeth.

We aimed to investigate mastication predominance in healthy dentate individuals and patients with unilateral posterior missing teeth using objective and subjective methods. The sample comprised 50 healthy dentate individuals (healthy dentate group) and 30 patients with unilateral posterior missing teeth (partially edentulous group). Subjects were asked to freely chew three kinds of test foods (peanuts, beef jerky and chewing gum). Electromyographic activity of the bilateral masseter muscles was recorded. The chewing side (right side or left side) was judged by the level of root mean square electromyographic amplitude. Mastication predominance was then objectively assessed using the mastication predominant score and the mastication predominant index. Self-awareness of mastication predominance was evaluated using a modified visual analogue scale. Mastication predominance scores of the healthy dentate and partially edentulous groups for each test food were analysed. There was a significant difference in the distribution of the mastication predominant index between the two groups (P < 0·05). The mastication predominant score was weakly correlated with self-awareness of mastication predominance in the healthy dentate group, whereas strong correlation was observed in the partially edentulous group (P < 0·05). The results suggest that the individuals with missing unilateral posterior teeth exhibited greater mastication predominance and were more aware of mastication predominance than healthy dentate individuals. Our findings suggest that an objective evaluation of mastication predominance is more precise than a subjective method.

The effect of intermittent use of occlusal splint devices on sleep bruxism: a 4-week observation with a portable electromyographic recording device.

This randomised controlled study investigated the effect of intermittent use of occlusal splints on sleep bruxism compared with that of continuous use by measuring masseter muscle electromyographic activity using a portable electromyographic recording system. Twenty bruxers were randomly allocated to the continuous group and intermittent group. Subjects in the continuous group wore stabilisation splints during sleep for 29 nights continuously, whereas those in the intermittent group wore splints during sleep every other week, that is they used splints on the 1st-7th, 15th-21st and 29th nights. Electromyographic activity of the masseter muscle during sleep was recorded for the following six time points: before (baseline), immediately after, and 1, 2, 3 and 4 weeks after the insertion of a stabilisation splint. The number of nocturnal masseter electromyographic events, duration and the total activity of sleep bruxism were analysed. In the continuous group, nocturnal masseter electromyographic events were significantly reduced immediately and 1 week after the insertion of the stabilisation splint, and duration was reduced immediately after the insertion (P < 0·05, Dunnett's test), but no reduction was observed at 2, 3 and 4 weeks after insertion. In the intermittent group, nocturnal masseter electromyographic events and duration were significantly reduced immediately after and also 4 weeks after insertion of the stabilisation splint (P < 0·05, Dunnett's test). The obtained results of the present exploratory trial indicate that the intermittent use of stabilisation splints may reduce sleep bruxism activity for a longer period compared with that of continuous use.

Bio-psycho-social assessment of occlusal dysaesthesia patients.

Dentists occasionally experience occlusal dysaesthesia (OD) patients, who complain of bite discomfort without evident occlusal abnormalities. It is suggested that this condition is related to somatosensory abnormalities of the trigeminal system and/or psychological problems such as somatoform disorders. The aim of this study was to investigate the characteristics of OD with a bio-psycho-social approach. Twelve OD patients (10 women, two men; mean age 54.7 years) and twelve healthy volunteers (10 women, two men; mean age 54.8 years) were selected. They were assessed using (i) interdental thickness discrimination ability test using 2-, 5- and 10-mm-thick standard blocks and 12 test blocks that were thinner or thicker than the corresponding standard block and (ii) psychological tests: General Health Questionnaire (GHQ60) and Profile of Mood States (POMS) brief-form. There was no significant difference in the interdental thickness discrimination ability between OD patients and controls (mixed-model anova, P=1.000). Regarding psychological tests, there were no significant differences between OD patients and controls in the total scores for either GHQ60 (P=0.143) or POMS brief-form (P=0.319) (Wilcoxon's test). However, OD patients showed significant differences from controls in several subscales, that is, 'somatic symptoms' (P=0.039) and 'severe depression' (P=0.039) for GHQ60 and 'depression-dejection' (P=0.014) and 'vigour' (P=0.008) for POMS brief-form (Wilcoxon's test). These results suggest there is no difference in interdental thickness discrimination ability between OD patients and normal controls, but OD patients tend to score higher on psychosomatic distress.

Rehabilitation of occlusion - science or art?

The primary objective of rehabilitating occlusion is to improve stomatognathic function in patients experiencing dysfunction in mastication, speech, and swallowing as a consequence of tooth loss. The procedure of occlusal treatment involves improving the morphology and the stomatognathic function. Several practical methods and morphological endpoints have been described in occlusal rehabilitation. We made a selection of these (mandibular position, occlusal plane, occlusal guidance, occlusal contact, face-bow transfer, use of an adjustable articulator and occlusal support) and performed a literature review to verify the existence of compelling scientific evidence for each of these. A literature search was conducted using Medline/PubMed in March 2011. Over 400 abstracts were reviewed, and more than 50 manuscripts selected. An additional hand search was also conducted. Of the many studies investigating stomatognathic function in relation to specific occlusal schemes, most studies were poorly designed and of low quality, thus yielding ambiguous results. Overall, there is no scientific evidence that supports any specific occlusal scheme being superior to others in terms of improving stomatognathic function, nor that sophisticated methods are superior to simpler ones in terms of clinical outcomes. However, it is obvious that the art of occlusal rehabilitation requires accurate, reproducible, easy and quick procedures to reduce unnecessary technical failures and/or the requirement for compensatory adjustments. Therefore, despite the lack of scientific evidence for specific treatments, the acquisition of these general skills by dentists and attaining profound knowledge and skills in postgraduate training will be necessary for specialists in charge of complicated cases.

White matter alteration of the cingulum in Parkinson disease with and without dementia: evaluation by diffusion tensor tract-specific analysis.

BACKGROUND AND PURPOSE: In PD, the neurodegenerative process begins in the brain stem and extends to the limbic system and finally into the cerebral cortex. We used diffusion tensor tractography to investigate the FA of the cingulate fiber tracts in patients with PD with and without dementia. MATERIALS AND METHODS: Fifteen patients with PD, 15 patients with PDD, and 15 age-matched healthy controls underwent diffusion tensor imaging with a 3T MR imager. Diffusion tensor tractography images of the anterior and posterior cingulate fiber tracts were generated. Mean diffusivity and FA were measured along the tractography of the anterior and posterior cingulate fiber tracts. One-way ANOVA with the Scheffé post hoc test was used to compare results among the groups. RESULTS: FA was significantly lower in patients with PDD than in healthy controls in both the anterior and the posterior cingulate fiber tracts (P = .003, P = .015) and significantly lower in patients with PD than in healthy controls (P = .003) in the anterior cingulate fiber tract. There were no significant mean diffusivity differences among the groups. MMSE and FA values of the anterior cingulate fiber tracts in patients with PDD were significantly correlated (r = 0.633, P < .05). CONCLUSIONS: The reduced FA in patients with PD and PDD might reflect neuropathologic changes such as Lewy body pathology in the cingulate fibers. This abnormality might contribute to the dementing process in PD.

Dynamic alteration of regional cerebral blood flow during carotid compression and proof of reversibility.

BACKGROUND: It is difficult to non-invasively visualize changes in regional cerebral blood flow caused by manual compression of the carotid artery. PURPOSE: To visualize dynamic changes in regional cerebral blood flow during and after manual compression of the carotid artery. MATERIAL AND METHODS: Two healthy volunteers were recruited. Anatomic features and flow directions in the circle of Willis were evaluated with time-of-flight magnetic resonance angiography (MRA) and two-dimensional phase-contrast (2DPC) MRA, respectively. Regional cerebral blood flow was visualized with territorial arterial spin-labeling magnetic resonance imaging (TASL-MRI). TASL-MRI and 2DPC-MRA were performed in three states: at rest, during manual compression of the right carotid artery, and after decompression. In one volunteer, time-space labeling inversion pulse (Time-SLIP) MRA was performed to confirm collateral flow. RESULTS: During manual carotid compression, in one volunteer, the right thalamus changed to be fed only by the vertebrobasilar system, and the right basal ganglia changed to be fed by the left internal carotid artery. In the other volunteer, the right basal ganglia changed to be fed by the vertebrobasilar system. 2DPC-MRA showed that the flow direction changed in the right A1 segment of the anterior cerebral artery and the right posterior communicating artery. Perfusion patterns and flow directions recovered after decompression. Time-SLIP MRA showed pial vessels and dural collateral circulation when the right carotid artery was manually compressed. CONCLUSION: Use of TASL-MRI and 2DPC-MRA was successful for non-invasive visualization of the dynamic changes in regional cerebral blood flow during and after manual carotid compression.

Comparison of gadobenate dimeglumine with gadopentetate dimeglumine for magnetic resonance imaging of liver tumors.

RATIONALE AND OBJECTIVES: To compare gadobenate dimeglumine (Gd-BOPTA) with gadopentetate dimeglumine (Gd-DTPA) for magnetic resonance imaging of the liver. METHODS: The contrast agent Gd-BOPTA or Gd-DTPA was administered at a dose of 0.1 mmol/kg to 257 patients suspected of having malignant liver tumors. Dynamic phase images, spin-echo images obtained within 10 minutes of injection, and delayed images obtained 40 to 120 minutes after injection were acquired. All postcontrast images were compared with unenhanced T1-weighted and T2-weighted images obtained immediately before injection. A full safety assessment was performed. RESULTS: The contrast efficacy for dynamic phase imaging was moderately or markedly improved in 90.9% (110/121) and 87.9% (109/124) of patients for Gd-BOPTA and Gd-DTPA, respectively. At 40 to 120 minutes after injection, the cor- responding improvements were 21.7% (26/120) and 11.6% (14/121) for spin-echo sequences and 44.5% (53/119) and 19.0% (23/121) for breath-hold gradient-echo sequences, respectively. The differences at 40 to 120 minutes after injection were statistically significant (P < 0.02). Increased information at 40 to 120 minutes after injection compared with information acquired within 10 minutes of injection was available for 24.0% (29/121) of patients with Gd-BOPTA and for 14.5% (18/124) of patients with Gd-DTPA (P < 0.03). Adverse events were seen in 4.7% (6/128) and 1.6% (2/127) of patients receiving Gd-BOPTA and Gd-DTPA, respectively. The difference was not statistically significant. CONCLUSIONS: The efficacy of Gd-BOPTA is equivalent to that of Gd-DTPA for liver imaging during the dynamic phase and superior during the delayed (40-120 minutes) phase of contrast enhancement. Both agents are safe for use in magnetic resonance imaging of the liver.

Magnetic resonance cholangiopancreatography in assessing the cause of acute pancreatitis in children.

Magnetic resonance cholangiopancreatography (MRCP) is a new noninvasive method of obtaining images of the pancreaticobiliary tract. Recent advances in MR technology and image quality have made it easy to diagnose structural abnormalities of the pancreaticobiliary tract (SAPBT) in children. To examine the usefulness of MRCP in assessing the cause of acute pancreatitis in children, we performed MRCP in 16 patients with acute pancreatitis. The study population was divided into two groups according to the cause of acute pancreatitis as follows: group 1 consisted of seven patients sonographically diagnosed with choledochal cysts; and group 2 consisted of nine patients with no obvious cause of acute pancreatitis. Non-breath-hold MRCP using the half-Fourier, single-shot, fast spin-echo imaging method was performed within 7 days after the onset of pancreatitis. Abnormal union of the pancreaticobiliary junction was detected in six of seven group 1 patients and in one of nine group 2 patients. Pancreatic divisum was detected in one patient of group 1, but could not be confirmed in one patient of group 2. Dilatation of the main pancreatic duct was detected in one patient of group 1 and in three patients of group 2. Our results suggest that MRCP is a useful, noninvasive method of identifying and ruling out SAPBT as a cause of acute pancreatitis in children with early-stage pancreatitis.

Papillonodular type of cystic partially differentiated nephroblastoma: a case report.

We report a case of the papillonodular type of cystic partially differentiated nephroblastoma (CPDN), an extremely rare renal neoplasm that occurs in newborns and infants. The papillonodular type of CPDN is a variant of the conventional form of CPDN. MRI clearly demonstrated the gross pathologic features, distinguishing it from other renal multilocular cystic tumors.

A case of inflammatory breast cancer following augmentation mammoplasty with silicone gel implants.

A 54-year-old-woman who underwent augmentation mammoplasty with silicone gel implants 30 years previously, visited our hospital with complaints of bloody nipple discharge, redness and itching of her right breast. Cancer of the right breast was diagnosed by dynamic magnetic resonance imaging (MRI) examination with Gadolinium (Gd)-DTPA enhancement. Radical mastectomy was subsequently performed. The histopathological findings demonstrated scirrhous and inflammatory breast cancer with invasion of dermal lymphatics.

Clinical late phase II trials of MultiHance (Gd-BOPTA) for the magnetic resonance imaging of liver tumors in Japan.

OBJECTIVE: The purpose of the study was to evaluate the safety and efficacy of Gd-BOPTA for liver imaging and to determine the most appropriate clinical dose to administer. METHODS: Gd-BOPTA was administered at a dose of 0.05 (group A), 0.1 (group B), or 0.2 (group C) mmol/kg to 201 patients suspected of having malignant liver tumors who had been referred for magnetic resonance imaging. Dynamic phase images (T1-weighted gradient echo sequences obtained during breath-hold), images obtained within 10 min of Gd-BOPTA injection (spin echo images) and delayed images obtained at 40-120 min after Gd-BOPTA injection (T1-weighted spin echo and gradient echo sequences during breathhold) were acquired. All post-contrast images were compared with pre-contrast images (T1- and T2-weighted sequences) obtained immediately prior to Gd-BOPTA administration. Safety was assessed in terms of the incidence of adverse events. RESULTS: The contrast efficacy for the dynamic study was classified as ( ) in 39.7% (27/68), 55.4% (36/65), and 47.0% (31/66) for groups A, B, and C, respectively. The contrast efficacy within 10 min of the injection was classified as ( ) in 7.6% (5/66), 16.9% (11/65), and 12.5% (8/64) for groups A, B, and C, respectively. The contrast efficacy at 40-120 min post-injection was classified as ( ) in 4.4% (3/68), 21.5% (14/65), and 20.0% (13/65) for groups A, B, and C, respectively with significant differences noted between groups A and B and groups A and C. As regards safety, the overall incidence of adverse reactions was 3.5% (7/199). CONCLUSION: Gd-BOPTA is a safe and efficacious contrast agent for use in both dynamic phase imaging and delayed (40-120 min) static imaging. A dose of 0.1 mmol/kg Gd-BOPTA appears to be the ideal dose for use in liver imaging in Japan.

Evaluation of gadobenate dimeglumine in hepatocellular carcinoma: results from phase II and phase III clinical trials in Japan.

To evaluate the clinical efficacy of gadobenate dimeglumine (Gd-BOPTA)-enhanced magnetic resonance imaging for hepatocellular carcinoma (HCC), we reviewed the results of clinical phase II and III trials in Japan. Gd-BOPTA was administered at a dose of 0.1 mmol/kg to 139 patients who were suspected to have HCC. Dynamic phase images [breath-hold T1-weighted gradient echo (GRE)], spin-echo (SE) images obtained within 10 minutes of injection, and delayed breath-hold GRE images obtained 40-120 minutes after injection were evaluated. All post-contrast images were compared with T1- and T2-weighted pre-contrast images. The contrast efficacy for the dynamic study was classified as ( ) or (++) in 92.1% (128/139), in 43.1% (59/137) with SE within 10 minutes of injection, and in 43.2% (60/139) with breath-hold GRE at delayed phase. The increase in lesion-liver contrast-to-noise ratio was best at the arterial phase of dynamic breath-hold GRE. Liver signal-to-noise ratio showed a mean 52.3% increase in delayed phase. Additional information at delayed phase compared with images acquired within 10 minutes of injection (including the dynamic study) was classified as ( ) or (++) in 28.1% (39/139). With regard to safety, the overall incidence of adverse reactions was 5.0% (7/141) of the patients who were suspected to have HCC, all of whom recovered within 12 hours without any sequelae. No clinically important changes were observed in the blood and urine laboratory tests. It was concluded that Gd-BOPTA was well tolerated and effective in both dynamic study and delayed static imaging for the diagnosis of HCC.

MR images of ovarian carcinosarcoma.

The MR imaging of an ovarian carcinosarcoma is described. The tumor was heterogeneous and showed very high-intensity on T2-weighted images and iso-intensity on T1-weighted images, with visible enhancement. Even though signal intensities were somewhat different from those of ovarian adenocarcinoma, the preoperative diagnosis of ovarian carcinosarcoma is still difficult.

[Cystic lesions of the pancreas].

The number of the literature and classification of the cystic pancreatic diseases is increasing recently. We describe MR cholangiopancreatography (MRCP) findings of the cystic pancreatic diseases according to the clinical oriented classification. Intraductal papillary tumor, mucinous cystadenoma and serous cystadenoma showed characteristic MRCP findings. However small non-neoplastic true cysts are difficult to differentiate from cystic tumors even by MRCP.

[2D-FASE MRCP for pediatrics with congenital biliary dilatation: usefulness of non-breath-hold one-shot MRCP].

The usefulness of magnetic resonance cholangiopancreatography (MRCP) using the non-breath-hold one-shot technique was evaluated. Ten children suffering from congenital biliary dilatation (CBD) were included. Four of them were preoperative cases, and the remaining six postoperative. All MR images taken were compared with endoscopic retrograde cholangiopancreatography or intraoperative cholangiography. MR images using the non-breath-hold one-shot technique clearly showed the confluence of the common bile duct and the main pancreatic duct in seven of the cases. The confluence of the common bile duct and main pancreatic duct was obscure in the other three cases, mainly due to motion artifact. These results show that this non-breath-hold one-shot technique is useful for diagnosis and postoperative follow-up of congenital biliary dilatation in children.