Butyric acid as a histone deacetylase (HDAC) inhibitor is produced by a number of periodontal and root canal microorganisms (such as Porphyromonas, Fusobacterium, etc.). Butyric acid may affect the biological activities of periodontal/periapical cells such as osteoblasts, periodontal ligament cells, etc., and thus affect periodontal/periapical tissue destruction and healing. The purposes of this study were to study the toxic effects of butyrate on the matrix and mineralization marker expression in MG-63 osteoblasts. Cell viability was determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cellular apoptosis and necrosis were analyzed by propidium iodide/annexin V flow cytometry. The protein and mRNA expression of osteoprotegerin (OPG) and receptor activator of nuclear factor kappa-B ligand (RANKL) were analyzed by Western blotting and reverse transcriptase-polymerase chain reaction (RT-PCR). OPG, soluble RANKL (sRANKL), 8-isoprostane, pro-collagen I, matrix metalloproteinase-2 (MMP-2), osteonectin (SPARC), osteocalcin and osteopontin (OPN) secretion into culture medium were measured by enzyme-linked immunosorbant assay. Alkaline phosphatase (ALP) activity was checked by ALP staining. Histone H3 acetylation levels were evaluated by immunofluorescent staining (IF) and Western blot. We found that butyrate activated the histone H3 acetylation of MG-63 cells. Exposure of MG-63 cells to butyrate partly decreased cell viability with no marked increase in apoptosis and necrosis. Twenty-four hours of exposure to butyrate stimulated RANKL protein expression, whereas it inhibited OPG protein expression. Butyrate also inhibited the secretion of OPG in MG-63 cells, whereas the sRANKL level was below the detection limit. However, 3 days of exposure to butyrate (1 to 8 mM) or other HDAC inhibitors such as phenylbutyrate, valproic acid and trichostatin stimulated OPG secretion. Butyrate stimulated 8-isoprostane, MMP-2 and OPN secretion, but not procollagen I, or osteocalcin in MG-63 cells. Exposure to butyrate (2–4 mM) for 3 days markedly stimulated osteonectin secretion and ALP activity. In conclusion, higher concentrations of butyric acid generated by periodontal and root canal microorganisms may potentially induce bone destruction and impair bone repair by the alteration of OPG/RANKL expression/secretion, 8-isoprostane, MMP-2 and OPN secretion, and affect cell viability. However, lower concentrations of butyrate (1–4 mM) may stimulate ALP, osteonectin and OPG. These effects are possibly related to increased histone acetylation. These events are important in the pathogenesis and repair of periodontal and periapical destruction.

Using a specialized oral device to perform myofunctional therapy during sleep may improve the breathing during sleep of children with obstructive sleep apnea.

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of transforming growth factor-b1 on plasminogen activation in stem cells from the apical papilla: role of activating receptorlike kinase 5/Smad2 and mitogen-activated protein kinase kinase (MEK)/extracellular signal-regulated kinase (ERK) signalling.

Platelets play crucial roles in thrombosis and hemostasis through platelet activation and aggregation that are crucial in cardiovascular diseases. Hydroquinone (HQ) and its derivatives are present in many dermatological creams, paints, motor fuels, air, microorganisms, and plant products like wheat bread, fruit, coffee, and red wine. The effect of HQ on humans is not clear. In this study, we found that HQ (>25 μM) inhibited arachidonic acid (AA)‐induced platelet aggregation. HQ suppressed AA‐induced thromboxane B2 production of platelets. HQ (>10 μM) also attenuated ex vivo platelet‐rich plasma aggregation. HQ prevented the interleukin (IL)‐1β‐induced 8‐isoprostane, and PGE2 production, but not IL‐8 production of pulp cells. These results indicate that HQ may have an antiplatelet effect via inhibition of thromboxane production. HQ has antioxidative and anti‐inflammatory effects, and possible inhibition of COX. Exposure and consumption of HQ‐containing products, food or drugs may have antiplatelet, antioxidative, and anti‐inflammatory effects.

Background/purpose The prematurely born and obstructive sleep apnea (OSA) could affect craniofacial and airway growth. The purpose of this study is to compare the differences in craniofacial and airway morphology between preterm and full-term children both with OSA problem. Materials and methods The differences in craniofacial and airway morphology between preterm children and full-term children both with OSA problem during the prepubertal (age 6–10) and pubertal (age 11–14) period were measured using lateral cephalometric radiograph. Results In the prepubertal period, effective maxillary length, and length from Go to Gn were smaller in the preterm group (n = 6) compared to the full-term (n = 8). The length of the soft palate was smaller and the distance soft palate-posterior side of nasopharynx was longer in preterm children. During puberty, (1) position of maxilla relative to cranial base: there was an anteroposterior maxilla and a mandibular discrepancy, a convexity of facial profile, (2) the distance from point A to nasion perpendicular, the distance from Pog to nasion perpendicular, and the ratio of effective maxillary length/effective mandibular length were smaller in the preterm group (n = 5) compare to the full-term (n = 6). Conclusion During prepuberty, the preterm children had a significantly shorter effective maxillary and mandibular length but the catch up growth resulted during the pubertal period in reduction in facial profile convexity and more important mandibular vertical growth toward a dolichocephalic profile. Due to preterm birth, OSA children have a different craniofacial morphology compared to the full-term. When using an oral device for passive myofunctional therapy, the treatment outcome maybe different.

Butyric acid as a histone deacetylase (HDAC) inhibitor was produced by a number of periodontal and root canal microorganisms (such as Porphyromonas, Fusobacterium etc.). Butyric acid may affect the biological activities of periodontal/periapical cells such as osteoblasts, periodontal ligament cells etc., and thus affect periodontal/periapical tissue destruction and healing. The purposes of this study were to study the toxic effects of butyrate on matrix and mineralization markers’ expression of MG-63 osteoblasts. Cell viability and proliferation were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) assay. Cellular apoptosis and necrosis were analyzed by propidium iodide/Annexin V flow cytometry. Protein and mRNA expression of OPG, and RANKL were analyzed by western blotting and RT-PCR. OPG, soluble RANKL (sRANKL), 8-isoprostane, pro-collagen I, MMP-2, osteonectin (SPARC), osteocalcin and osteopontin secretion into culture medium were measured by enzyme-linked immunosorbant assay. Histone H3 acetylation levels were evaluated by immunofluorescent staining (IF) and western blot. We found that butyrate induced morphologic changes of growing MG-63 cells, with bigger and flattened in appearance. Butyrate activated histone H3 acetylation of MG-63 cells. Exposure of MG-63 cells to butyrate partly decreased cell number with no marked increase in apoptosis and necrosis. Butyrate stimulated RANKL protein expression, whereas it inhibited OPG protein expression. Butyrate also inhibited the secretion of OPG in MG-63 cells, whereas sRANKL level was below detection limit. Butyrate stimulated 8-isoprostane, MMP-2 and osteopontin secretion, but not procollagen I, osteonectin, osteocalcin in MG-63 cells. In conclusion, butyric acid generated by periodontal and root canal microorganisms may potentially induce bony destruction and impair bone repair by alteration of OPG/RANKL expression/secretion, 8-isoprostane, MMP-2, and osteopontin secretion, and affect cell proliferation. These effects are possibly related to increased histone acetylation. These events are important in the pathogenesis of periodontal and periapical destruction.

We conducted this retrospective study to identify potential clinical, polysomnographic, and cephalometric predictors for the treatment outcomes of a tongue-beaded oral appliance (OA) in children with obstructive sleep apnea syndrome (OSAS). In total, 63 patients—50 boys and 13 girls ranging in age from 4 to 16 years—underwent OA treatment nightly for at least 6 months. A baseline digital lateral cephalometric radiograph was obtained for each patient. Multivariate logistic regression analysis was performed to examine predictors for the treatment outcome based on the clinical and cephalometric measurements. Overall, 28 patients responded to the treatment (post-treatment improvement >50% or apnea–hypopnea index (AHI) < 1/h), and 35 did not (post-treatment improvement <50% and AHI ≥ 1/h). Significantly larger cranial base angle (SNBa), smaller lower gonial angle (LGo Angle), and shorter length of anterior cranial base (SN) were found in responders. Smaller lower gonial angle (LGo Angle) and smaller anterior cranial base (SN) predict a favorable outcome for pediatric OSAS using a tongue-beaded OA. This finding will equip practitioners with additional insights when selecting suitable candidates for OA therapy in pediatric patients.