Search

Background: Masseter muscle activity during wakefulness may be associated with temporomandibular disorder (TMD)‐related symptoms, psychosocial status and pain‐related disability; however, this relationship is unclear. Objectives: This study aimed to determine the relationship between masseter muscle electromyography (EMG) burst/duration during wakefulness and TMD‐related symptoms, psychosocial status and pain‐related disability. Methods: Sixty participants were assessed masseter muscle activity during wakefulness using a data‐logger‐type ultraminiature EMG system and TMD‐related symptoms, psychosocial status and pain‐related disability through Axis I and II of the diagnostic criteria for TMD (DC/TMD). EMG bursts lasting longer than 0.25 s but less than 2.0 s and those lasting longer than 2.0 s were classified as phasic and tonic bursts, respectively. Results: Participants with palpation‐related pain in the temporalis and masseter muscles, as assessed through the DC/TMD examination form in Axis I, had more bursts (number/h) (p =.035 and p =.009, respectively) and longer duration (time/h) (p =.013 and p =.004, respectively) of tonic bursts of the masseter muscle during wakefulness. Participants with palpation‐related pain in the masseter muscles had higher oral behaviour scores during wakefulness using Axis II (p =.001), which affected the number and duration of tonic bursts of the masseter muscle activity during wakefulness (p =.011 and p =.007, respectively). Conclusion: As tonic bursts mainly reflect clenching, individuals with pain in the masseter muscles by palpation may have a high frequency and longer duration of clenching, as well as a high frequency of oral behaviours during wakefulness. [ABSTRACT FROM AUTHOR]

The international economic order is undergoing significant change. Most recently, key countries have been seeking to increase their level of economic security, including through increased industrial subsidies. Regulating subsidies is controversial, but undisciplined subsidy payments could be harmful for the healthy functioning of markets and balanced development among nations. In this regard, the GATT-WTO has regulated subsidies, but it has not been fully functional in recent years, and reform efforts do not appear to be bearing fruit soon. Therefore, in parallel with WTO reform efforts, reliance on other approaches, such as discipline through free trade agreements (FTAs), should be considered. Disciplining subsidies through FTAs is inherently difficult, given the cross-border nature of subsidies on the one hand and the geographical limitations of the FTA's scope of application on the other. In recent years, however, such disciplines in FTAs have begun to appear, starting with EU FTAs. Thus, this article explores the possibilities and limitations of the discipline of subsidies through FTAs, using Japan's FTAs as a case study, to approach the path to international control of subsidies. Accordingly, this article first reviews the range of related issues and developments, including characteristics of subsidies, the rationale for subsidy discipline in trade agreements, recent challenges to multilateral subsidy discipline, the current status of subsidy discipline through FTAs, and the background of subsidy discipline in EU FTAs. The article then identifies the WTO-plus elements that are distinct to subsidy disciplines in EU FTAs and discusses their implications. Through these, it highlights the perspectives needed when considering subsidy discipline through FTAs, examines Japan's FTAs in light of these perspectives, and presents the findings and implications thereof. Considerations are given to Japan's FTA/trade policy as a background for its subsidy discipline through FTAs, the current status and characteristics of subsidy disciplines in Japan's FTAs, the Agreement Between the European Union and Japan for an Economic Partnership's (JPN-EU) subsidy-related provisions as drastic change, the effects on the Asia-Pacific region, and future prospects. [ABSTRACT FROM AUTHOR]

To evaluate miniscrew stability and perform a histomorphometric analysis of the bone around the miniscrew under a load corresponding to orthopedic force. Thirty-two miniscrews were implanted into eight rabbit tibias. Auxiliary group rabbits received auxiliary devices with miniscrews (n = 8, 28 days; n = 8, 56 days), and those in the nonauxiliary control group received miniscrews without auxiliary devices (n = 8, 28 days; n = 8, 56 days). Elastics were placed between miniscrews to apply a load of 5 N. Miniscrew stability was evaluated using a Periotest. Bone-to-implant contact (BIC) and spike implantation depth were measured histomorphologically. Periotest values in the auxiliary group were significantly lower than those in the nonauxiliary group at all time periods. There was no significant difference in BIC between the auxiliary and nonauxiliary groups at 28 or 56 days postimplantation. The implantation spike depth in the auxiliary group was significantly greater at 56 days compared to that at 28 days. Newly formed bone was observed around the spike of the auxiliary device at 56 days. The results suggest that the use of miniscrews in conjunction with auxiliary devices provides stable skeletal anchorage, which may be useful in orthopedic treatments. [ABSTRACT FROM AUTHOR]

Purpose: To observe the long-term postoperative bone formation and eruption of adjacent teeth after octacalcium phosphate granule and atelocollagen complex (OCP/Col) grafting in the treatment of alveolar cleft of patients with unilateral cleft lip with or without cleft palate (UCL ± P).Methods: Four patients with UCL ± P who underwent OCP/Col grafting (OCP group), and 55 patients with UCL ± P who underwent autologous bone grafting (AB group) were enrolled in this study. OCP/Col or autologous bone grafting was performed before the eruption of canines or lateral incisors in mixed dentition, followed by orthodontic management. Patients in the OCP group underwent radiography before and after surgery at 1, 2, 3, 6, and over 30 months postoperatively. The volume and area of the bony defect in the alveolar cleft area were compared between the OCP and AB groups before and after 6 months of surgery.Results: The bone bridge in all patients in the OCP/Col group was successfully formed, and by 6 months postoperatively, the permanent teeth adjacent to the alveolar cleft had erupted at the site of the OCP/Col complex graft. Comparison of the pre- and postoperative bone defects between the 2 groups revealed almost the same extent of bone bridge formation.Conclusions: OCP/Col grafting could be considered as an alternative to autologous bone grafting as it yielded successful bone bridge formation and facilitated permanent tooth eruption. [ABSTRACT FROM AUTHOR]

Objectives: Maxillofacial morphology and malocclusion are related to maximum occlusal force (MOF). Although it has been reported that MOF was related to handgrip strength (HS), the relationships between maxillofacial morphology/malocclusion and HS remain unclear. This study aimed to examine the relationships between maxillofacial morphology, malocclusion and HS.Setting and Sample Population: Eighty-five women with malocclusion, aged 18-40 years, were selected.Materials and Methods: Lateral cephalometric radiographs (SNA, SNB, ANB, mandibular plane-FH, and gonial angles, overjet and overbite), the Peer Assessment Rating (PAR) index and HS were measured. Subjects were classified by the Japanese normal mean value of cephalometric analysis or the reference value which was defined by degree of malocclusion in each PAR index measurement item (small/low: value < mean/reference value, large/high: value ≧ mean/reference value). Measurements were then compared between groups.Results: HS of the large-gonial angle group was lower than that of the small-gonial angle group. In the small-overbite group or high-transverse (PAR index score showing crossbite/scissor bite in the canine and molars) group, HS in the large-gonial angle group was significantly lower than that in the small-gonial angle group.Conclusions: Our results suggest that gonial angle is the largest factor affecting HS. HS may be especially low in those subjects with a large gonial angle and a small overbite or a crossbite/scissor bite in the molar section. [ABSTRACT FROM AUTHOR]

Background: Gastroesophageal reflux disease may be an important risk factor for awake bruxism. Additionally, it has been known that a psychological stress task affects masseter muscle activity, and autonomic nervous system (ANS) activity modulation induces masseter muscle activity. Objectives: This study aimed to investigate whether task‐induced stress and experimental oesophageal acid infusion increase masseter muscle activity and alter ANS activity, compared to rest task and oesophageal saline infusion, respectively. Methods: Polygraphic monitoring, consisting of electromyography of the masseter muscle and electrocardiography, was performed in 12 healthy adult men during 30‐min interventions with intra‐oesophageal saline or acid infusion, while reading a book quietly, as rest, and while performing calculation, as a stress task. Results: At rest, masseter muscle activity and parasympathetic nervous system (PNS) activity during acid infusion were significantly higher (P =.019) and lower (P =.021) than during saline infusion, respectively. During saline infusion, both masseter muscle activity and sympathetic nervous system (SNS) activity or PNS activity while performing the calculation task were higher (P =.022 and.012, respectively) or lower (P =.007) than those during the reading task, respectively. In two‐way repeated‐measures ANOVA, intra‐oesophageal infusion (saline or acid) significantly affected masseter muscle activity (P =.008) and PNS activity (P =.021). However, performing tasks (reading or calculation) significantly affected only PNS activity (P =.028). Conclusion: Intra‐oesophageal acid infusion significantly increased masseter muscle activity and decreased PNS activity. In contrast, stress task not only significantly decreased PNS activity, but only modestly increased masseter muscle activity and SNS activity. [ABSTRACT FROM AUTHOR]

Objectives: To measure the root lengths of maxillary central incisors (U1) and evaluate the relationship among U1 root length, tooth movement, and type of treatment appliance in patients with unilateral cleft lip and palate over a long-term follow-up period. Materials and Methods: Occlusal radiographs of 30 patients with unilateral cleft lip and palate, acquired less than 6 months before secondary alveolar bone grafting (SBG, T1) and after edgewise treatment (T2), were measured for U1 root length (R1 and R2, root lengths at T1 and T2, respectively). Frontal and lateral cephalometric radiographs acquired at eruption of U1 (T0), T1, and T2 were evaluated to determine the inclination and position of U1. Results: The average values of R1 and R2 on the cleft side were significantly lower than those on the noncleft side. Frontal cephalometric analysis revealed that the horizontal distance of the root apex from the median vertical line at T0 on the cleft side was significantly smaller than that on the noncleft side and was correlated with short U1 root length on the cleft side. On the other hand, R1 in patients treated with maxillary protraction appliances between T0 and T1 was significantly shorter than that in patients without maxillary protraction appliances. However, none of the changes in cephalometric measurements were correlated with root length. Conclusions: In patients with unilateral cleft lip and palate, the short root length of cleft-adjacent central incisors might be associated with the horizontal position of the root apex. In addition, orthodontic treatment with a maxillary protraction appliance before secondary alveolar bone grafting might be associated with short U1 root length. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the relationship between external apical root resorption (EARR) of the maxillary central incisors (U1), horizontal orthodontic tooth movement, and quantity of grafted bone in subjects with unilateral cleft lip and palate (UCLP) over an average duration of 8 years. Materials and Methods: Thirty subjects with UCLP were evaluated for EARR of U1 after edgewise treatment (T2). The teeth were classified as having no EARR, moderate EARR (combined into ‘‘no/ moderate’’ EARR), or severe EARR. Frontal cephalometric radiographs acquired at eruption of U1 (T0), less than 6 months before secondary alveolar bone grafting (T1), and T2 were evaluated to determine the horizontal inclination (U1-axis angle) and distance of the root apex from the median line (U1-root–VL distance). On the cleft side, the quantities of grafted bone at less than 12 months postsecondary bone grafting and at T2 were evaluated using the alveolar bone graft (ABG) scale. Results: Cleft-adjacent teeth exhibitedmore severeEARRthan did teeth on the noncleft side. The cleft side exhibited greater changes in U1-axis angle and U1-root–VL distance between T0 and T2 than did the noncleft side.Onthe cleft side, theABGscoreatT2 inthesevereEARRgroupwas significantly lower than that in the no/moderate EARR group. These measurements were correlated with EARR grade. Conclusions: Cleft-adjacent U1 exhibited more severe EARR than did the U1 on the noncleft side, which might be associated with orthodontic treatment-induced changes in horizontal inclination and root apex movement. On the cleft side, severity of EARR may be correlated with the success of ABG. [ABSTRACT FROM AUTHOR]

The article reviews the blocking legislation enacted by the European Community (EC) and the Japanese government to counter the U.S. Anti-Dumping Act of 1916. It provides an overview of the events that led to the enactment of the blocking legislation. The ruling by the World Trade Organization on the cases filed by the EC and the Japanese government against the U.S. anti-dumping law is discussed.

Purpose: This study aimed to elucidate the relationship between diurnal masseter muscle activity and awareness of diurnal awake bruxism (d-AB) by conducting a comparative analysis of electromyographic (EMG) data from individuals with and without awareness of diurnal awake bruxism (d-AB), utilizing EMG data gathered from multiple subjects., Methods: Unilateral masseter electromyography (EMG) recordings were performed during the daytime using an ultraminiature wearable EMG device. A total of 119 participants (59 with awareness of diurnal tooth clenching [d-TC] and 60 without awareness of d-TC) were included. Waveforms longer than 0.25 s with the two amplitude conditions, exceeding twice the baseline and >5% of maximum voluntary clenching, were extracted. In addition, the number of bursts and episodes (groups of bursts), burst duration, and burst peak amplitude were calculated for each participant., Results: There were no significant differences in the EMG parameters between the groups with and without awareness of d-TC. Additionally, the frequency distribution of the number of EMG waveforms exhibited wide ranges and substantial overlap between the two groups., Conclusions: The variability in the number of bursts and episodes, burst peak amplitude, and burst duration among subjects suggests the need for an objective classification of d-AB severity based on EMG values. The absence of significant differences and large overlap in frequency distributions between the groups with and without awareness of d-TC indicate difficulty in predicting muscle activity solely based on awareness of d-AB.