Publications by authors named "Akihiko Iwasa"

Cortical bone thickness is assumed to be a major factor regulating miniscrew stability. We investigated stress distribution in two miniscrews with different thread shapes (type A and B) and in cortical bone of three different thicknesses using three-dimensional (3D) finite element (FE) models. More specifically, 3D FE models of two different miniscrews were created and placed obliquely or vertically into a cylindrical bone model representing different cortical bone thicknesses.

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Background: Idiopathic condylar resorption (ICR) is an aggressive degenerative disease of the temporomandibular joint that is most frequently observed in teenage girls. However, no specific cause of ICR has been identified. To explore the specific causes of the onset and progression of ICR, we performed a survey-based study on ICR in orthodontic patients and described its subjective symptoms, clinical signs, and condylar morphological features.

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Aim And Objective: To present an Apert syndrome patient with midfacial growth deficiency treated with Le Fort III distraction osteogenesis and subsequent two-jaw surgery.

Background: Apert syndrome is expressed as a severe and irregular craniosynostosis, midfacial hypoplasia, and symmetric syndactyly in the fingers and toes. For craniosynostosis syndromes, treatment planning is complex due to the disharmony between facial profile and occlusion.

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Accumulating evidence indicates that the molecular pathways mediating wound healing induce cell migration and localization of cytokines to sites of injury. Macrophages are immune cells that sense and actively respond to disturbances in tissue homeostasis by initiating, and subsequently resolving, inflammation. Hypoxic conditions generated at a wound site also strongly recruit macrophages and affect their function.

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Objectives: To investigate the role of hypoxia-inducible factor 1α (HIF-1α) signaling, the expression profile of M1 and M2 macrophages, and the role of the sphingosine 1-phosphate (S1P)/S1P receptor system in palatal wound healing of heterozygous HIF-1α-deficient (HIF-1α HET) mice.

Materials And Methods: HIF-1α HET and wild-type (WT) littermates underwent palatal tissue excision at the mid-hard palate. Histological analysis, immunostaining, real-time PCR, Western blotting (WB), and cellular migration assays were performed to analyze wound closure and macrophage infiltration.

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Objective: We aimed to identify the immunoregulatory role of the cyclin-dependent kinase inhibitor p21 in the homeostasis of mandibular condylar cartilage affected by mechanical stress.

Materials And Methods: Ten C57BL/6 wild-type (WT) and ten p21 mice aged 8 weeks were divided into the untreated and treated groups. In the treated groups, mechanical stress was applied to the temporomandibular joint (TMJ) through forced mouth opening for 3 hr/day for 7 days.

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The aim of this study was to assess the effect of low-intensity pulsed ultrasound (LIPUS) application on rat temporomandibular joints (TMJs) with early-stage of osteoarthritis-like conditions induced by mechanical overloading. Fifteen-week-old male Wistar rats were divided into two experimental groups and a control group (n = 10 each). Both TMJs of all rats in one experimental group were subjected to mechanical overloading for 5 d, and those in the other experimental group were exposed to LIPUS for 20 min/d after overloading.

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The treatment of severe skeletal anterior open bite is extremely difficult in adults, and orthognathic surgery is generally selected for its treatment. We report the case of an 18-year-old adult patient with skeletal anterior open bite and temporomandibular disorders who was successfully treated using temporary anchorage devices. She had an open bite of -2.

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Enhanced turnover of subchondral trabecular bone is a hallmark of rheumatoid arthritis (RA) and it results from an imbalance between bone resorption and bone formation activities. To investigate the formation and activation of osteoclasts which mediate bone resorption, a Fas-deficient MRL/lpr mouse model which spontaneously develops autoimmune arthritis and exhibits decreased bone mass was studied. Various assays were performed on subchondral trabecular bone of the temporomandibular joint (TMJ) from MRL/lpr mice and MRL+/+ mice.

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Temporomandibular joint osteoarthritis (TMJ-OA) is characterized by progressive degradation of cartilage and changes in subchondral bone. It is also one of the most serious subgroups of temporomandibular disorders. Rebamipide is a gastroprotective agent that is currently used for the treatment of gastritis and gastric ulcers.

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Several autoimmune diseases are known to develop in postmenopausal women. However, the mechanism by which estrogen deficiency influences autoimmunity is unknown. Aromatase is an enzyme that converts androgens to estrogens.

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Background: Topical therapy is effective for dry eye, and its prolonged effects should help in maintaining the quality of life of patients with dry eye. We previously reported that the oral administration of rebamipide (Reb), a mucosal protective agent, had a potent therapeutic effect on autoimmune lesions in a murine model of Sjögren's syndrome (SS). However, the effects of topical treatment with Reb eyedrops on the ocular lesions in the murine model of SS are unknown.

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