Analysis of subgingival microbiota in monozygotic twins with different severity and progression risk of periodontitis

The study aims to reveal the composition of subgingival bacteria in monozygotic twins with discordant in severity and progression risk of periodontitis. Microbiome analysis indicated that most bacteria were heritable but differed in their abundance and immune response. The dysbiotic bacteria can be considered as risk markers for periodontitis progression

Treatment of Bucco-Accessory Root Canal of a Maxillary Incisor with a Combination of Cone Beam Computed Tomography and Continuous Supersonic Wave Condensation

Objective: A novel treatment for bucco-accessory root canal (bARC), which is difficult to treat by regular endodontic therapy, is discussed. Clinical Presentation and Intervention: A bARC in the maxillary right incisor with symptomatic irreversible pulpitis was detected using cone beam computed tomography (CBCT) after conventional dental radiography. The pulp was extirpated and the canal enlarged using rotary files and chemo-mechanical reagents. The main root canal and bARC were obturated with thermoplastic gutta-percha using continuous wave condensation. Postoperative CBCT revealed a completely treated bARC. Conclusion: A combination of CBCT and continuous wave condensation is ideal for bARCs in incisors

Use of Highly Accurate Devices for a First Lower Premolar Endodontic Treatment with Multiple Root Canals

This case report highlights the importance of using a dental operating microscope (DOM) and ultrasonic endodontic tips (UETs) to locate all root canals in the lower first premolar. A 53-year-old woman presented to our clinic with pain in the lower right first premolar. After a detailed search using a DOM and UETs, three root canals were found, prepared with rotary HyFlex endodontic files, and obturated using the lateral condensation technique. At the five-year follow-up after treatment, the tooth was completely restored and fulfilling its function, with no signs or symptoms of any post-treatment flare-up

Correction and lengthening for deformities of the forearm in multiple cartilaginous exostoses

金沢大学医学部附属病院整形外科Background. Multiple cartilaginous exostoses cause various deformities of the epiphysis. In exostoses of the ulna, the ulna is shortened and the radius acquires varus deformity, which may lead to dislocation of the radial head. In this study, we present the results of exostoses resection, with correction and lengthening with external fixators for functional and cosmetic improvement, and prevention of radial head dislocation. Methods. We retrospectively reviewed seven forearms of seven patients who had deformities of the forearm associated with multiple cartilaginous exostoses. One patient had dislocation of the radial head. Operative technique was excision of osteochondromas from the distal ulna, correction of the radius, and ulnar lengthening with external fixation up to 5 mm plus variance. We evaluated radiographs and the range of pronation and supination. Furthermore, we conducted a follow-up of ulnar length after the operation. Results. Dislocation of the radial head of one patient was naturally reduced without any operative intervention. At the most recent follow-up, six of the seven patients showed full improvement in pronation-supination. Ulnar shortening recurred with skeletal growth of four skeletally immature patients; however, it did not recur in one skeletally mature patient. Overlength of 5 mm was negated by the recurrence of ulnar shortening about 1.5 years after the operation. Conclusions. We treated seven forearms of seven patients by excision of osteochondromas, correction of radii, and gradual lengthening of ulnas with external fixators. The results of the procedure were satisfactory, especially for function of the elbow and wrist. However, we must consider the possible recurrence of ulnar shortening within about 1.5 years during skeletal growth periods in immature patients. © 2006 The Japanese Orthopaedic Association

High Mobility Group Box 1 Expression in Oral Inflammation and Regeneration

High mobility group box 1 (HMGB1) is a non-histone DNA-binding protein of about 30 kDa. It is released from a variety of cells into the extracellular milieu in response to inflammatory stimuli and acts on specific cell-surface receptors, such as receptors for advanced glycation end-products (RAGE), Toll-like receptor (TLR)2, TLR4, with or without forming a complex with other molecules. HMGB1 mediates various mechanisms such as inflammation, cell migration, proliferation, and differentiation. On the other hand, HMGB1 enhances chemotaxis acting through the C-X-C motif chemokine ligand (CXCL)12/C-X-C chemokine receptor (CXCR)4 axis and is involved in regeneration. In the oral cavity, high levels of HMGB1 have been detected in the gingival tissue from periodontitis and peri-implantitis patients, and it has been shown that secreted HMGB1 induces pro-inflammatory cytokine expression, such as interleukin (IL)-1 beta, IL-6, and tumor necrosis factor (TNF)-alpha, which prolong inflammation. In contrast, wound healing after tooth extraction or titanium dental implant osseointegration requires an initial acute inflammation, which is regulated by secreted HMGB1. This indicates that secreted HMGB1 regulates angiogenesis and bone remodeling by osteoclast and osteoblast activation and promotes bone healing in oral tissue repair. Therefore, HMGB1 can prolong inflammation in the periodontal tissue and, conversely, can regenerate or repair damaged tissues in the oral cavity. In this review, we highlight the role of HMGB1 in the oral cavity by comparing its function and regulation with its function in other diseases. We also discuss the necessity for further studies in this field to provide more specific scientific evidence for dentistry

Microbiome composition comparison in oral and atherosclerotic plaque from patients with and without periodontitis

There is no conclusive evidence regarding a causal relationship between periodontitis and atherosclerosis. In this study, we examined the microbiome in the oral cavity and atheromatous plaques from atherosclerosis patients with or without periodontitis to investigate the role of oral bacteria in the formation of atheromatous plaques. We chose four patients with and without periodontitis, who had undergone carotid endarterectomy. Bacterial samples were extracted from the tongue surface, from periodontal pocket (during the oral examination), and from the atheromatous plaques (APs). We investigated the general and oral conditions from each patient and performed next-generation sequencing (NGS) analysis for all bacterial samples. There were no significant differences between both groups concerning general conditions. However, the microbiome patterns of the gingival pocket showed differences depending on the absence or presence of periodontitis, while those of the tongue surface were relatively similar. The microbiome pattern of the atheromatous plaques was entirely different from that on the tongue surface and gingival pocket, and oral bacteria were seldom detected. However, the microbiome pattern in atheromatous plaques was different in the presence or absence of periodontitis. These results suggested that oral bacteria did not affect the formation of atheromatous plaques directly

The fungal metabolite (+)-terrein abrogates osteoclast differentiation via suppression of the RANKL signaling pathway through NFATc1

Pathophysiological bone resorption is commonly associated with periodontal disease and involves the excessive resorption of bone matrix by activated osteoclasts. Receptor activator of nuclear factor (NF)-κB ligand (RANKL) signaling pathways have been proposed as targets for inhibiting osteoclast differentiation and bone resorption. The fungal secondary metabolite (+)-terrein is a natural compound derived from Aspergillus terreus that has previously shown anti-interleukin-6 properties related to inflammatory bone resorption. However, its effects and molecular mechanism of action on osteoclastogenesis and bone resorption remain unclear. In the present study, we showed that 10 µM synthetic (+)-terrein inhibited RANKL-induced osteoclast formation and bone resorption in a dose-dependent manner and without cytotoxicity. RANKL-induced messenger RNA expression of osteoclast-specific markers including nuclear factor of activated T-cells cytoplasmic 1 (NFATc1), the master regulator of osteoclastogenesis, cathepsin K, tartrate-resistant acid phosphatase (Trap) was completely inhibited by synthetic (+)-terrein treatment. Furthermore, synthetic (+)-terrein decreased RANKL-induced NFATc1 protein expression. This study revealed that synthetic (+)-terrein attenuated osteoclast formation and bone resorption by mediating RANKL signaling pathways, especially NFATc1, and indicated the potential effect of (+)-terrein on inflammatory bone resorption including periodontal disease