Skeletal Anterior Open Bite Attenuates the Chewing-Related Increase in Brain Blood Flow.

The masticatory function of patients with skeletal anterior open bite (OPEN) is reported to be impaired compared with that of patients with normal occlusion (NORM). In this study, we compared brain blood flow (BBF) in patients with OPEN and NORM and investigated the factors related to BBF during mastication in patients with OPEN. The study included 17 individuals with NORM and 33 patients with OPEN. The following data were collected: number of occlusal contacts, jaw movement variables during mastication, and BBF measured with functional near-infrared spectroscopy during chewing. The number of occlusal contacts, maximum closing and opening speeds, closing angle, and vertical amplitude were smaller in the OPEN than in the NORM group. Interestingly, BBF increased less in the OPEN group. Correlation analysis revealed that several parameters, including number of occlusal contacts and closing angle, were correlated with changes in BBF during mastication. These results suggest that not only occlusion but also jaw movement variables and factors related to masticatory muscles contribute to the chewing-related increase in BBF. In conclusion, BBF increases less during mastication in patients with OPEN than in those with NORM. In addition, the higher increase in BBF is correlated with jaw movement. Together, we discovered that OPEN exhibits significant adverse effects not only on masticatory function but also on brain function.

A New Implantation Method for Orthodontic Anchor Screws: Basic Research for Clinical Applications.

This study aimed to determine whether the positional relationship between the underside of the screw head and the surface of the alveolar bone could alter the stress on the two surfaces and affect the stability of implanted anchor screws. First, in order to confirm the extent of the gap between the mini-screw and the bone surface, a mini-screw was placed in the palate of rabbits and examined histologically. As a result, in the conventional screw implantation procedure, oral mucosa between the base of the screw head and the bone creates a spatial gap. Removal of the oral mucosa eliminates this gap. Then, we compared the positional difference of the screw in a contact and gap group by analyzing stress distribution on the bone and screw. Analysis using the finite element method showed that more stress was loaded on both the bone and screw in the gap group than in the contact group. Cortical bone thickness did not affect stress in either group. The effects of different load strengths were similar between groups. A surgical procedure in which mucosal coverings are removed so that implanted anchor mini-screws are in contact with the bone surface was found to reduce the stress load on both the bone and screw. This procedure can be used to prevent undesirable dislodgement of implanted mini-screws.

Combination of Two Rapid Ophthalmic Test Kits for Improved Diagnosis in Cases of Severe Binocular Conjunctivitis.

INTRODUCTION: Diagnosis of conjunctivitis can be sometimes difficult, especially in cases of severe conjunctivitis and those involving both eyes. In this study, we performed commercial tests for adenovirus (Capilia Adeno Eye®) and total tear IgE (Allerwatch®) in a single visit in patients with bilateral conjunctivitis to examine if, and by how much, the combination of these two tests would improve the diagnostic accuracy of conjunctivitis. METHODS: The study included sixty patients with relatively severe conjunctivitis in both eyes within a week of consulting our clinic and who had no previous treatment. Capilia Adeno Eye® and Allerwatch® tests were performed. RESULTS: A significantly higher number of cases (55/60) were diagnosed when both tests were evaluated than with either test (Capilia Adeno Eye® (12/60; p < 0.001) or Allerwatch® (44/60; p < 0.005)) alone. The positivity rate of Allerwatch® was significantly higher than that of Capilia Adeno Eye® (p < 0.001). The diagnosis rate of atopic keratoconjunctivitis was 100% in patients with allergic conjunctivitis, but there was no significant difference in positivity compared with other types of allergic conjunctivitis. CONCLUSIONS: Testing patients with both Capilia Adeno Eye® and Allerwatch® improves the diagnostic accuracy for conjunctivitis and can diagnose more than 90% of cases. Detection of adenovirus antigen and IgE in tears, using these simple and rapid methods, will be useful for early diagnosis and prevention of adenoviral conjunctivitis.

The effect of basic fibroblast growth factor on regeneration in a surgical wound model of rat submandibular glands.

This study developed an animal model of surgically wounded submandibular glands (SMGs) and investigated the effects of collagen gel with basic fibroblast growth factor (bFGF) on tissue regeneration of surgically wounded SMGs in vivo. The animal model was produced by creating a surgical wound using a 3-mm diameter biopsy punch in SMGs. The wound was filled with collagen gel with bFGF (bFGF group) or without bFGF (control group). In the animal model of surgically wounded SMGs, salivary glands without scar tissue around the wound area were observed with smaller areas of collagen gel. Small round and spindle-shape cells invaded the collagen gel in both groups after operation day (AOD) 5, and this invasion dramatically increased at AOD 7. Host tissue completely replaced the collagen gel at AOD 21. The invading immune cells in the group treated with collagen gel with bFGF were positive for vimentin, α-smooth muscle actin (αSMA), CD49f, c-kit and AQP5 at AOD 7. Similarly, the mRNA expression of vimentin, αSMA, CD49f, keratin19 and AQP5 was also increased. This study suggests that the use of collagen gels with bFGF improves salivary gland regeneration.

A comparative study of the effects of 4-META/MMA-TBB resin and cyanoacrylate on wound healing of skin defects.

The purpose of this study was to investigate the healing process of wounded skin following the application of cyanoacrylate or a 4-(2-methacryloxyethyl) trimellitic anhydride/methyl methacrylate-tributylborane resin (4-META resin). Those materials were applied to skin wound areas in rats, and the regenerating tissues were biopsied and examined at days 1, 3, 5, 7, and 14. Paraffin-embedded specimens were sectioned and stained with hematoxylin and eosin or with Azan-Mallory stain. Sections were also immunohistochemically stained with Pan-cytokeratin and CD68 antibodies. In cyanoacrylate-treated wounds, CD68-positive cells were observed in the connective tissue and their number increased up to day 5. The wound surface was completely covered by epithelial tissue at day 14. In 4-META resin-treated wounds, CD68-positive cells appeared in the soft-tissue hybrid layer (STHL) and epithelial tissue had migrated under the STHL by day 5. The wound surface was completely covered by epithelial tissue at day 7. CD68-positive cells were distributed over the entire area of the cyanoacrylate-treated wounds, but accumulated under the STHL in the 4-META resin-treated wounds. In conclusion, the results suggest that covering skin defects with a 4-META resin is an effective strategy to promote wound healing compared to cyanoacrylate.