The A7 cell group in the dorsolateral pons provides noradrenergic innervation of the spinal cord. Activation of this descending pathway (the A7 descending system) produces bi-directional effects on nociceptive processing in the dorsal horn, which are facilitation mediated by α1-adrenoceptor and inhibition via α2-adrenoceptor. Peripheral nerve injury sometimes results in neuropathic pain. Hypersensitivity of dorsal horn neurons under neuropathic conditions is linked to activity in descending pathways from the brain. The aim of this study was to examine the involvement of the A7 descending system under neuropathic conditions. Experiments were performed on male Sprague-Dawley rats (n=35). Bilateral lesions of the A7 area were performed by microinjection of kainic acid. The tibial and common peroneal the nerves were sectioned produce neuropathic conditions (spared nerve injury, SNI). For estimating mechanical allodynia, mechanical hypoalgesia and cold allodynia, paw withdrawal threshold (PWT), paw withdrawal latency (PWL) and paw withdrawal frequency (PWF) were measured. PWTs significantly decreased following A7 lesions. After SNI, PWTs signifi cantly decreased in A7-lesioned and sham-lesioned rats. However, no signifi cant difference was observed between the decreased rates of PWTs in A7-lesioned and sham-lesioned rats. PWLs signifi cantly increased in sham-lesioned rats compared with A7-lesioned group. PWFs signifi cantly increased in the A7-lesioned and sham-lesioned rats. Intrathecal injection of prazosin, an α1-adrenoceptor antagonist, failed to change the PWT, PWL and PWF in non-A7-lesioned neuropathic rats. These results suggest that (1) the A7 descending inhibitory system has tonic activity under normal conditions, and (2) this system functions in a complex manner during the neuropathic pain state.
Globalization in dental education is an important issue in Japan. However, implementing strategies for globalization related to aspects such as infrastructure, educational goals and content, educational methodologies, and standards is not easy. The dental training programmes at the Faculty of Dentistry at The University of Hong Kong can offer some insight into the process. While The University of Hong Kong is world-renowned and has embraced globalization, it is located in Asia, where English is not the native language. The latter reflects the same situation as in Japan, but the Hong Kong and Japanese dental schools differ considerably in the medium of education, teaching styles, undergraduate curriculum, postgraduate education system, character of the students, and duties of the academic staff. Dental education at The University of Hong Kong may thus provide a role model for the planning and integration of globalization within the tertiary dental education system in Japan.
The Invisalign system is widely used to treat mild to moderate tooth crowding. Recently, Invisalign appliances have been used in orthodontic patients with increasingly complex malocclusions. When using an Invisalign appliance to correct severe tooth crowding, root positions must be carefully controlled during extraction space closure. We report our treatment of a 34-year-old man who presented with a Class I relationship, a midline deviation, severe overjet, and severe tooth crowding in the maxillary and mandibular anterior regions. The treatment plan involved extraction of the maxillary and mandibular fi rst premolars on both sides. We treated this patient with severe anterior tooth crowding using an Invisalign appliance combined with a fi xed appliance with power arms and elastics. Treatment by Invisalign as an application of computational calculated result, especially in extraction cases, doctors should have professional skill and experience as an orthodontist.
The osseointegration capacity of implant surfaces deteriorates over time. However, the treatment of titanium surfaces with ultraviolet (UV) light restores the original properties of the surface and causes considerable acceleration in the process of osseointegration. This study reviews two recent findings: the aging-like time-dependent biological degradation of titanium surfaces and the discovery of UV photofunctionalization as a solution to this phenomenon. This technology and the associated knowledge herald a new age of implant treatment and provide a novel concept of osseointegration in the science and therapeutics of implant dentistry. In addition, we expect to revolutionize clinical implant therapy through these new concepts.
過去10年, 免疫学では自然免疫系分野における進展が目覚しい. 自然免疫はマクロファージや好中球, 樹状細胞などの貪食系細胞が主役の免疫細胞集団である. 自然免疫細胞は炎症応答を引き起こすことによってもう一つの免疫系である獲得免疫系の活性化を促す. これら二つの免疫系の緊密な相互作用によって我々の体は病原性微生物の攻撃から保護されている. この時, マクロファージ活性化のオン・オフは厳密にコントロールされる必要がある. 前半では, 転写因子レベルや受容体レベルなど様々な仕組みの制御メカニズムについて概説する. また, 自然免疫には体の中のゴミ掃除など感染防御以外にも重要な役割を有しており, 通常とは異なる分化誘導の存在が議論されているが, 詳細なメカニズムはまだ不明である. 後半では今後免疫研究の中心課題となるオルタナティブマクロファージの分化機構について概説する.
閉塞性睡眠時無呼吸は, 様々な診療科が関与すべき全身性疾患である. 歯科医師は, 病態生理解明, 顎顔面形態解析による原因検索, 口腔内装置や顎顔面手術, 歯科矯正による治療など, すでに重要な役割を果たしている. 今後, 歯科的, 歯科矯正的なアプローチによりこの疾患の予防まで視野に入れた研究の発展が期待される.
後天的に開咬を生じる原因として, 臼歯の挺出や舌癖, 指しゃぶりなどが挙げられる. なかでも第二大臼歯萌出時期, 一過性にみられる開咬については咬合力によって改善される場合が一般的である. 本症例は初診時年齢15歳4か月の女性で「物が咬めない」ということを主訴に来院した. 患者は以前, 顎関節に疼痛およびクリック音を自覚し一般歯科にて13歳頃よりスプリント療法をうけている. スプリント療法後, 顎関節の症状は改善されたが物が噛み切れなくなったため矯正歯科を受診した. 口腔内所見は第二大臼歯以外すべての部位に咬合接触が認められず, いわゆるtotal open-biteであったが犬歯の咬頭には咬耗が認められた. 今回, 上顎両側第二大臼歯を抜去しマルチブラケット装置による治療を行ったところ, 短期間で良好な結果を得られたため報告する.
歯科恐怖症患者は恐怖心により歯科治療が困難となり, 十分な治療を受けられない, 治療を拒否されるなど, 治療を諦める例も少なくない. そのため口腔内の健康が損なわれ, 生活のQOLが低下し大きな問題となっている. 当講座では地域歯科医院や院内から紹介された多くの歯科恐怖症患者に対して個々に適した方法で治療を行い, 患者より満足を得ている. しかし, 歯科恐怖症患者の治療には多くの時間とマンパワーを要するのが現状であり問題点も多い. そこで本稿では, 歯科恐怖症患者の治療の実態と問題点についてその概要を説明する.
我々が, 日常の臨床にて向き合っている歯 (歯根膜・歯髄) から獲得出来る細胞は再生医療の分野においても注目され, 歯根膜や歯髄そのものを再生する研究や有効活用する研究は盛んに行われている. 歯 (歯根膜・歯髄) 由来細胞はheterogeneityな細胞集団でありそれらの能力について未だ解明されていない部分も多い. また, 歯の形態異常や重度の歯周疾患を特徴とする全身疾患のある患者において歯 (歯根膜・歯髄) を採取し, 細胞の特徴を把握することが出来れば, 歯周疾患や外傷, 矯正歯科治療などにおける歯周組織の再生および恒常性の維持に必要な間葉系幹細胞の遊走制御やrecruitmentの機構を解明することも期待できる. そこで本稿は, 歯 (歯根膜・歯髄) 由来細胞の分離培養方法について報告する.
With super aged society in Japan, the death rate from choking due to blockage of the oropharynx has increased; it is now greater than that from traffi c accidents and it is believed that this rate will continue to increase. The shape and function of the oropharyngeal crossing with the respiratory tract are most infl uential in ensuring that food is carried from the oral cavity to the pharynx and the esophagus. We sought to clarify the changes in the shape and features of the oropharyngeal airway from teenagers to those in their 70 s. A total of 57 patients were grouped by age (teenagers, 20s, 30s, 40s, 50s, 60s and 70s), and all underwent cone beam computed tomography (CBCT) to measure the oropharynx volume, height, cross-sectional area, and length of the superior and inferior extremities. Kruskal-Wallis analysis indicated that the volume and height of the oropharynx did no signifi cant difference among age groups, but there was a different tendency when cross-sectional areas of the superior and inferior extremities were compared between younger and older patients. Further, the shape of the inferior extremity was also different features between younger and older patients. In humans, the oropharyngeal airway plays an important role in carrying food through the esophagus and facilitating phonation. Ideally, it is important for this airway to maintain a constant volume and height. Recently, there has been an increase in the incidence of oropharyngeal airway blockage accidents among the elderly. Declines in feeding and swallowing functions and changes in the form of the oropharynx are major factors in these accidents.
： Due to Japan ʼ s rapidly aging population, patients with some kind of severe systemic disease are increasingly going to the dental offi ce. As such, society ʼ s need of dentists who can treat these types of patients is higher than before. Unfortunately, sometimes general practitioners are unable to give these patients appropriate care because of the high risk of their treatment. So, a community dental network between dental offi ces and the hospital is becoming necessary. I have received many referrals to treat such high-risk patients for many years while work at several hospitals. I would like to talk about my history and the achievements I made in creating a community dental network, and make some suggestions based on my experiences.
: In clinical practice, teeth with hypoplasia, devitalization, or caries are preferentially extracted for convenience as part of orthodontic treatment strategy. In such cases, to obtain ideal esthetic results, tooth shape, the contours of gingival margins and function should be considered before starting orthodontic treatment. 27-year-3-month-old female whose chief complaints were crowding, maxillary protrusion and midline deviations of upper and lower. She had a skeletal class II with hopeless upper right lateral incisor. The treatment objectives were to establish a Class I molar relationship, and to obtain proper interdigitation and an ideal overbite and overjet. Orthodontic treatment involved the extraction of the upper right lateral incisor, upper left fi rst premolar, and lower second premolars on both sides, and the use of an edgewise appliance. In the extraction case of incisor, the orthodontists should be aware of the tooth morphology and the morphology of gingival contours. When aligning the fi rst premolar as the canine, it is common to avoid cuspal interference by reforming the lingual cusp of the fi rst premolar. Moreover, in this case, maxillary right canine gingival recession may happen for thin alveolar bone. However, we were eventually able to avoid cuspal interference, recession by performing tooth movement only, and achieved good function without interference. However, it is also important to note that the observation of stable occlusion.
低侵襲インプラントに至るまでのインプラント治療の歴史的変遷とともに，当 科で行っている低侵襲インプラントの治療例について解説した． 日進月歩のインプラント治療をできるだけ低侵襲に行うことは，患者と術者の双方に非常に 有益性が高いことから，個々の患者の要望に応じた患者主導型(患者中心型)の治療を行うう えで，低侵襲インプラントは今後もますます需要が高まると思われる．
Many aspects of the coordination of lip and mandibular movements in the process of eating have not yet been clarifi ed. This time, aiming to objectively evaluate lip and mandibular movements when chewing, the movements of the corners of the mouth and the mandible during mastication were measured three-dimensionally and analyzed. The subjects were 20 healthy women with individual normal occlusion. The test food was a commercially-available biscuit with a weight of 1 g. With six measuring points set for the lips and pogonion, the movements at those measuring points were captured with two CCD cameras during mastication, and the resulting images were analyzed with a three-dimensional motion analysis system. The analysis result showed that Xand Z-axis movements occurred on the working-side corner of the mouth, with Z-axis movements preceding X-axis movements, while on the balancing-side corner of the mouth, Xand Z-axis movements occurred simultaneously. Data on the amount, time taken, and speed of movements measured at each anatomical landmark showed that the working-side corner of the mouth moved a greater distance at a faster pace and, therefore, in less time than that of the balancing-side corner of the mouth. This is conceivably due to the aforementioned differences in Xand Z-axis movements of the working-side and balancing-side corners of the mouth. Further comparisons and studies with expansion of the subjects to include children will be necessary.
To clarify 1) how the signal fading effect occurs and 2) the diagnostic quality of the signal fading image in caries diagnosis. The Digora Optime (Soredex, Helsinki, Finland) system was used. Aluminum step wedges of 1 to 10 mm thickness and 1-mm-thick lead were used. Exposed photo-stimulated phosphor imaging plates (PSP-IPs) were scanned at six different intervals: immediately, 3, 6, 24, 72, and 144 h. Two kinds of scanning modes were used: with and without auto enhancement correction (AEC). The gray value difference between the immediate and delayed scanning images in the same objective area was calculated as the signal fading effect value (FEV). Thirty extracted upper premolar teeth (carious: 42 surfaces) were used. Immediate, 3, 24, and 72 h delayed scan images were created. Four observers assessed them. The Friedman test was used for statistical analysis and statistical significance was p<0. 05. Analysis of the without AEC image revealed that the signal fading had the same gray value change. This change was not related to the initial gray value. In the processing of AEC, the middle part of the gray value tended to be more enhanced. Significant differences in gray value changes were observed after 3 h, but no statistically significant difference was seen in the caries diagnosis. The area under the receiver operating characteristic (ROC) curve (Az) from immediate, 3, 24, and 72 h delayed images was 0. 61±0. 17, 0. 56±0. 04, 0. 67±0. 04, and 0. 58±0. 06.
The interactions between orofacial muscles and skeletal patterns are widely recognized as significant factors in craniofacial growth. Many studies have suggested that the vertical facial growth pattern correlates with occlusal forces and the activity of masticatory muscles. In particular, it has been suggested that occlusal forces produced by masticatory muscles are converted into physiological stress at the condyle in the form of functional strain. In such circumstances, the dimensions and morphology of the condyle ought to be affected. The aim of this study is to test the hypothesis that low-angle subjects with larger occlusal forces tend to have mandibular condyles with a larger surface area than high-angle subjects. Cone-beam computed tomographic scans were obtained from 14 Japanese adult subjects (17 to 33 years old, 7 high angle and 7 low angle) at 60 kV and 10 mA. Occlusal force was measured by pressure-indicating fi lms, and the surface area of the condyle was calculated from axial CT data. The correlation between occlusal conditions and the surface area of condyles was compared between the two facial groups. We found that the low-angle group had a signifi cantly larger surface area and volume of condyles than the high-angle group and that there was a positive correlation between occlusal forces and condylar surface area. Our fi ndings demonstrate that occlusal force is one of the important factors that affect the mechanical environment of the condyle.
As society has aged, the proportion of individuals aged ≥75 years has increased, resulting in a higher number of patients with underlying comorbidities presenting for dental care. However, dental care in Japan is not currently capable of accommodating such changes, and it is incumbent upon universities to train new dentists for the requisite skills. The system must be able to deal with three challenges: (1) provide satisfactory and safe dental care for patients with underlying comorbidities; (2) maintain close cooperation with physicians; and (3) maintain and restore oral function. Showa University is working quickly to reform its dental education system with these challenges in mind.
CT画像解析ソフトウェアの普及に伴って，顎変形症に対するコンピュータ画面上での三次元診断や手術シミュレーションが可能となっているが，画面上でのシミュレーションで骨片移動時の骨干渉の部位ならびに骨片の変位量などを全て正確に診断することは困難である．したがって，顎矯正手術では，頭部骨格模型を用いたモデルサージャリーによる，より実践的な手術シミュレーションが必要である．われわれは，矯正歯科学講座の協力を得てCTの撮像データと歯列模型のスキャンデータとを画像解析ソフト上で組み合わせ，歯列情報を癒合させた三次元頭部骨格モデルを作製して手術シミュレーションを行っている．この方法の利点は高い精度で歯列の位置を頭部骨格模型上に再現でき，また，咬合関係を主体とした顎矯正手術のシミュレーションができることである．今回はわれわれが行っている三次元モデルを用いた術前診断と治療について代表症例を供覧しながら紹介する．
