Toll‐like receptors 2 and 5 in human gingival epithelial cells co‐operate with T‐cell cytokine interleukin‐17

Background/aim: Periodontitis begins as the result of perturbation of the gingival epithelial cells caused by subgingival bacteria interacting with the epithelial cells via pattern recognition receptors. Toll‐like receptors (TLRs) have been shown to play an important role in the recognition of periodontal pathogens so we have studied the interaction of TLR ligands with TLR2 and TLR5 for cytokine production in the cultures of gingival epithelial cells. Methods: Immunohistochemistry was used for the localization of TLR2 and TLR5 in tissue specimens. Enzyme‐linked immunosorbent assays were performed to detect the levels of interleukin‐1β (IL‐1β) and tumor necrosis factor‐α (TNF‐α), released from gingival epithelial cell cultures following stimulation with TLR ligand alone or in combination with IL‐17. Results: Both TLR2 and TLR5 were increased in periodontitis (2128 ± 159 vs. 449 ± 59 and 2456 ± 297 vs. 679 ± 103, respectively, P < 0.001) including gingival epithelial cells that stained strongly. Cultured gingival epithelial cells stimulated with their respective ligands (HKLM, a TLR2 ligand that is also found in Porphyromonas gingivalis, and flagellin, a TLR5 ligand that is also found in Treponema denticola) produced both IL‐1β and TNF‐α. To mimic T‐cell help, IL‐17 was added. This further greatly enhanced TLR ligand‐induced IL‐1β (P < 0.001) and TNF‐α (P < 0.01) production. Conclusions: These findings show how pathogen‐associated molecular patterns, shared by many different periodontopathogenic bacteria, stimulate the resident gingival epithelial cells to inflammatory responses in a TLR‐dependent manner. This stimulation may be particularly strong in periodontitis and when T helper type 17 cells provide T‐cell help in intercellular cooperation.     

Comparison of CCL28, interleukin‐8, interleukin‐1β and tumor necrosis factor‐alpha in subjects with gingivitis,chronic periodontitis and generalized aggressive periodontitis

Background and Objective: Cytokines produced by various cells are strong local mediators of inflammation. Mucosa‐associated epithelial chemokine (CCL28), interleukin‐8 (IL‐8), interleukin‐1beta (IL‐1β) and tumor necrosis factor‐alpha (TNF‐α) are major cytokines that play important roles in the periodontal inflammatory process. In this study we aimed to compare the levels of CCL28, IL‐8, IL‐1β and TNF‐α in the gingival crevicular fluid of both periodontally healthy subjects and in subjects diagnosed with gingivitis, chronic periodontitis and generalized aggressive periodontitis. Material and Methods: A total of 84 subjects participated in the study: 21 subjects had gingivitis, 21 subjects had chronic periodontitis, 21 subjects had generalized aggressive periodontitis and 21 were periodontally healthy. The levels of CCL28, IL‐8, IL‐1β and TNF‐α were analyzed using enzyme‐linked immune sorbent assay (ELISA). Results: The total levels of CCL28 and IL‐8 in the gingival crevicular fluid of the generalized aggressive periodontitis group (324.74 ± 42.62 pg/30 s, 487.62 ± 49.21 pg/30 s) were significantly higher than those of the chronic periodontitis group (268.81 ± 28.64 pg/30 s, 423.65 ± 35.24 pg/30 s), the gingivitis group (146.35 ± 17.46 pg/30 s, 310.24 ± 48.20 pg/30 s) and the periodontally healthy group (92.46 ± 22.04 pg/30 s, 148.41 ± 24.64 pg/30 s). Similarly, the total levels of IL‐1β and TNF‐α in the generalized aggressive periodontitis group (110.23 ± 9.20 pg/30 s, 1284.46 ± 86.32 pg/30 s) were significantly higher than those in the chronic periodontitis group (423.65 ± 35.24 pg/30 s, 82.64 ± 9.12 pg/30 s), the gingivitis group (52.10 ± 7.15 pg/30 s, 824.24 ± 44.68 pg/30 s) and the periodontally healthy group (36.44 ± 8.86 pg/30 s, 628.26 ± 34.61 pg/30 s). Conclusion: CCL28, IL‐8, IL‐1β and TNF‐α may play key roles in the host response to inflammation in periodontal diseases. As the severity of periodontal diseases increases, destruction of periodontal tissues also increases. Inflammation is one among many factors that trigger periodontal tissue destruction. Identification of the mediators that influence the development and progression of inflammation in periodontal diseases may be very important in understanding the prognoses of periodontal diseases.     

CXC亚家族趋化因子配体10-受体3/CC亚家族趋化因子配体17-受体4轴在口腔扁平苔藓发病机制中的交互作用

目的 探讨CXC亚家族趋化因子配体10(CXCL10)-CXC亚家族趋化因子受体3(CXCR3)、CC亚家族趋化因子配体17(CCL17)-CC亚家族趋化因子受体4(CCR4)两轴间在口腔扁平苔藓(OLP)发病机制中的交互关系.方法 收集OLP患者(非糜烂、糜烂型)和健康对照者外周血,分离T细胞并鉴定纯度,分为空白(不...     

Th1/Th17/Th22 immune response and their association with joint pain,imagenological bone loss,RANKL expression and osteoclast activity in temporomandibular joint osteoarthritis: A preliminary report

It is well accepted that the presence of cytokines belonging to the Th1/Th17/Th22 axis of immuno‐inflammatory response in the joint environment, such as IL‐1β, IL‐17 and IL‐22, respectively, are associated with pathogenesis of several synovial joint degenerative disorders. During temporomandibular joint osteoarthritis (TMJ‐OA), IL‐1β and IL‐17 have been implicated in the inflammation and resorption of sub‐chondral bone; however, the role of Th22 response in the TMJ‐OA pathophysiology has not been established. This study aimed to compare the expression of Th1/Th17/Th22‐type cytokines, chemokines and chemokine receptors in synovial fluid samples obtained from TMJ‐OA or disk displacement with reduction (DDWR) patients. In addition, it aimed to associate these levels with joint pain, imagenological signs of bone degeneration, RANKL production, osteoclastogenesis and osteoclast‐induced bone resorption. Higher levels of IL‐1β, IL‐17 and IL‐22 were expressed in TMJ‐OA compared with DDWR subjects, and these increased levels significantly correlated with RANKL expression, joint pain and articular bone degeneration. Higher levels of CCR5, CCR6 and CCR7, as well as their respective ligands CCL5 and CCL20, responsible for recruitment of IL‐1β, IL‐17 and IL‐22‐producing cells, were over‐expressed in TMJ‐OA compared with DDWR subjects. Osteoclastogenesis and osteoclast‐induced bone resorption were significantly greater in presence of synovial fluid from TMJ‐OA compared with DDWR subjects. These data demonstrate that cytokines, CCLs and CCRs associated with the Th1/Th17/Th22 axis of immuno‐inflammatory response are involved in TMJ‐OA pathogenesis. These findings suggest that IL‐22 is involved in the RANKL expression in TMJ‐OA, which in turn induces differentiation of osteoclasts and subsequent resorption of sub‐chondral bone.     

Toll‐Like Receptor 2 Knockdown Modulates Interleukin (IL)‐6 and IL‐8 but not Stromal Derived Factor‐1 (SDF‐1/CXCL12) in Human Periodontal Ligament and Gingival Fibroblasts

Background: Fibroblasts are now seen as active components of the immune response because these cells express Toll‐like receptors (TLRs), recognize pathogen‐associated molecular patterns, and mediate the production of cytokines and chemokines during inflammation. The innate host response to lipopolysaccharide (LPS) from Porphyromonas gingivalis is unusual inasmuch as different studies have reported that it can be an agonist for Toll‐like receptor 2 (TLR2) and an antagonist or agonist for Toll‐like receptor 4 (TLR4). This study investigates and compares whether signaling through TLR2 or TLR4 could affect the secretion of interleukin (IL)‐6, IL‐8, and stromal derived factor‐1 (SDF‐1/CXCL12) in both human gingival fibroblasts (HGF) and human periodontal ligament fibroblasts (HPDLF). Methods: After small interfering RNA‐mediated silencing of TLR2 and TLR4, HGF and HPDLF from the same donors were stimulated with P. gingivalis LPS or with two synthetic ligands of TLR2, Pam2CSK4 and Pam3CSK4, for 6 hours. IL‐6, IL‐8, and CXCL12 mRNA expression and protein secretion were evaluated by quantitative polymerase chain reaction and enzyme‐linked immunosorbent assay, respectively. Results: TLR2 mRNA expression was upregulated in HGF but not in HPDLF by all the stimuli applied. Knockdown of TLR2 decreased IL‐6 and IL‐8 in response to P. gingivalis LPS, or Pam2CSK4 and Pam3CSK4, in a similar manner in both fibroblasts subpopulations. Conversely, CXCL12 remained unchanged by TLR2 or TLR4 silencing. Conclusion: These results suggest that signaling through TLR2 by gingival and periodontal ligament fibroblasts can control the secretion of IL‐6 and IL‐8, which contribute to periodontal pathogenesis, but do not interfere with CXCL12 levels, an important chemokine in the repair process.     

Distinct Th1, Th2 and Treg cytokines balance in chronic periapical granulomas and radicular cysts

J Oral Pathol Med (2010) 39 : 250–256 Background: Periapical lesions are a host response that involves immune reaction to prevent dissemination of bacteria from an infected root canal. The purpose of this study was to evaluate the levels of nitric oxide (NO), IL‐4, TGF‐β, tumor necrosis factor‐α (TNF‐α), and interferon‐γ (IFN‐γ) in chronic periapical lesions and to determine their possible association with clinical and radiographic parameters. Methods: Seventeen human radicular cysts and 30 periapical granulomas were used in this study. Cytokines and NO were assessed by enzyme‐linked immunosorbent assay and by the Griess reaction respectively confirmed by immunohistochemical. Results: TNF‐α and IFN‐γ were detected in 10% of granulomas and in 41.2% and 70% of radicular cysts. IL‐4 was reactive in 24% of cysts, and TGF‐β was positive in all samples. Patients with tenderness showed significantly higher levels of IFN‐γ and IL‐4 (P < 0.05). Swelling was associated with high levels of TNF‐α, IFN‐γ, and IL‐4 (P < 0.05). Lesions presenting bone resorption were associated with high levels of NO (P < 0.05). Conclusions: Periapical granulomas display a regulatory environment characterized by high TGF‐β and low inflammatory cytokine levels, while radicular cysts has mist Th1 and Th2 inflammatory reaction with the presence of IFN‐γ, TNF‐α, and IL‐4.     

Blocking Proinflammatory Cytokine Release Modulates Peripheral Blood Mononuclear Cell Response to Porphyromonas gingivalis

Background: Chronic periodontitis (CP) is an inflammatory disease in which cytokines play a major role in the progression of disease. Anti‐inflammatory cytokines (interleukin 4 [IL‐4] and IL‐10) were reported to be absent or reduced in diseased periodontal tissues, suggesting an imbalance between the proinflammatory and anti‐inflammatory mediators. This study tests the hypothesis that there is cellular crosstalk mediated by proinflammatory and anti‐inflammatory cytokines and that blocking proinflammatory cytokine (tumor necrosis factor‐α [TNF‐α] and IL‐1) production will enhance anti‐inflammatory cytokine (IL‐4 and IL‐10) production from peripheral blood mononuclear cells (PBMCs) in response to Porphyromonas gingivalis. Methods: PBMCs were isolated from individuals diagnosed with CP or healthy individuals and cultured for 24 hours. Concanavalin A (ConA) was used as an activator of lymphocyte function. Live and heat‐killed P. gingivalis or lipopolysaccharide from P. gingivalis were used as the bacterial stimulants. TNF‐α and IL‐1 production was neutralized by specific antibodies against TNF‐α and IL‐1α or IL‐β. Culture supernatants were evaluated by enzyme‐linked immunosorbent assay for TNF‐α, IL‐1β, IL‐4, and IL‐10 production. Results: Live P. gingivalis did not result in any significant IL‐10 or IL‐4 release, whereas heat‐killed P. gingivalis led to a significant increase in IL‐10 levels compared with unstimulated or live P. gingivalis–stimulated cells from both healthy individuals or those with CP. Overall, PBMCs from patients with CP produced significantly lower IL‐10 in response to ConA and P. gingivalis, suggesting chronic suppression of the anti‐inflammatory cytokine production. Blocking the proinflammatory cytokine response did not result in any substantial change in IL‐10 or IL‐4 response to live P. gingivalis. Blocking the proinflammatory cytokine response restored IL‐10 production by cells from CP in response to P. gingivalis lipopolysaccharide. Conclusions: These findings suggest that PBMCs from patients with CP have suppressed anti‐inflammatory cytokine production that can, in part, be restored by neutralizing proinflammatory cytokines. Monocytes are an important source of IL‐10 production, and monocyte‐derived IL‐10 might play a regulatory role in the pathogenesis of CP.     

Tumor Necrosis Factor‐α Inhibits Transforming Growth Factor‐β–Stimulated Myofibroblastic Differentiation and Extracellular Matrix Production in Human Gingival Fibroblasts

Background: Fibroblasts play a critical role during wound healing and chronic inflammation through the synthesis and assembly of extracellular matrix (ECM) molecules. These responses may be modulated by soluble cytokines and growth factors present in tissues. In the present study, we evaluate whether transforming growth factor‐β1 (TGF‐β1) and tumor necrosis factor‐α (TNF‐α) modulate myofibroblastic differentiation and the production of ECM components. Methods: Primary cultures of human gingival fibroblasts (HGFs) were stimulated with recombinant TGF‐β1 and TNF‐α. Protein levels of α‐smooth muscle actin (α‐SMA), type I collagen, heat shock protein‐47 (HSP‐47), fibronectin (FN), ED‐A‐FN, and periostin and activation of the Smad pathway were evaluated through Western blot analysis. α‐SMA and actin fibers were identified by immunofluorescence. TGF‐β1, TNF‐α, and α‐SMA were identified by immunohistochemistry in biopsies of inflamed human gingival tissues. TGF‐β1 activity was evaluated using a plasminogen activator inhibitor‐1 (PAI‐1) reporter transfected in HGFs. Results: TGF‐β1 stimulated the differentiation of myofibroblasts as evidenced by strong expression of α‐SMA and ED‐A‐FN. Moreover, TGF‐β1 induced the production of type I collagen, HSP‐47, FN, and periostin. Costimulation with TNF‐α and TGF‐β1 significantly reduced the expression of all the above‐mentioned proteins. TNF‐α also inhibited the activation of the Smad2/3 pathway and the activity of the PAI‐1 reporter. Conclusions: TNF‐α inhibits several cell responses induced by TGF‐β1, including the differentiation of myofibroblasts, the activation of the Smad signaling pathway, and the production of key molecules involved in tissue repair, such as type I collagen, FN, and periostin. The interaction between cytokines may explain the delayed tissue repair observed in chronic inflammation of gingival tissues.     

DNA from Porphyromonas gingivalis and Tannerella forsythia induce cytokine production in human monocytic cell lines

Toll‐like receptor 9 (TLR9) expression is increased in periodontally diseased tissues compared with healthy sites indicating a possible role of TLR9 and its ligand, bacterial DNA (bDNA), in periodontal disease pathology. Here, we determine the immunostimulatory effects of periodontal bDNA in human monocytic cells (THP‐1). THP‐1 cells were stimulated with DNA of two putative periodontal pathogens: Porphyromonas gingivalis and Tannerella forsythia. The role of TLR9 in periodontal bDNA‐initiated cytokine production was determined either by blocking TLR9 signaling in THP‐1 cells with chloroquine or by measuring IL‐8 production and nuclear factor‐κB (NF‐κB) activation in HEK293 cells stably transfected with human TLR9. Cytokine production (IL‐1β, IL‐6, and TNF‐α) was increased significantly in bDNA‐stimulated cells compared with controls. Chloroquine treatment of THP‐1 cells decreased cytokine production, suggesting that TLR9‐mediated signaling pathways are operant in the recognition of DNA from periodontal pathogens. Compared with native HEK293 cells, TLR9‐transfected cells demonstrated significantly increased IL‐8 production (P < 0.001) and NF‐κB activation in response to bDNA, further confirming the role of TLR9 in periodontal bDNA recognition. The results of PCR arrays demonstrated upregulation of proinflammatory cytokine and NF‐κB genes in response to periodontal bDNA in THP‐1 cells, suggesting that cytokine induction is through NF‐κB activation. Hence, immune responses triggered by periodontal bacterial nucleic acids may contribute to periodontal disease pathology by inducing proinflammatory cytokine production through the TLR9 signaling pathway.     

Group of serum inflammatory markers and periodontitis-metabolic syndrome coexistence in Koreans

Background: Recent epidemiologic studies have shown that individuals with periodontitis have a significantly increased risk of metabolic syndrome (MetS). Chronic infection and subsequent production of systemic inflammatory markers may be associated with this increased risk. The aim of present study is to determine whether the presence of periodontitis and MetS is associated with a group or an individual of C‐reactive protein (CRP), interleukin (IL)‐1β, IL‐6, IL‐8, tumor necrosis factor‐α (TNF‐α), and homocysteine (HCY) in the serum of a Korean population. Methods: Medical and periodontal parameters, including CRP, IL‐1β, IL‐6, IL‐8, TNF‐α, and HCY, were evaluated in 118 individuals (73 healthy; 20 with periodontitis only; 13 with MetS only; and 12 with both). The community periodontal index was used to assess periodontitis. Age, sex, monthly household income, smoking, and drinking were evaluated as confounders. Analysis of covariance, linear regression analysis, and factor analysis were applied. Results: The group of serologic cytokines was synergistically associated with the periodontitis–MetS coexistence. TNF‐α and IL‐6 were two representing serologic cytokines in the group. Conclusions: Our results suggest that a group of systemic biologic markers represented by TNF‐α and IL‐6 might mediate the association between MetS and periodontitis adjusted for various confounders. Additional evidence is needed to generalize our results more widely.     

Saliva and Serum Levels of B‐Cell Activating Factors and Tumor Necrosis Factor‐α in Patients With Periodontitis

Background: B‐lymphocytes play a central and critical role in the adaptive immune response against invading pathogens. This study evaluates saliva and serum levels of APRIL (a proliferation‐inducing ligand), B‐cell activating factor (BAFF), tumor necrosis factor‐α (TNF‐α), interleukin (IL)‐6, and IL‐10 in patients with chronic periodontitis (CP) or aggressive periodontitis (AgP) and periodontally healthy individuals. Methods: Twenty‐five patients with AgP, 20 patients with CP, and 20 periodontally healthy individuals were included. Smoking status was recorded, and all individuals were divided into non‐smokers and smokers. Saliva and serum samples were collected before clinical periodontal measurements. APRIL, BAFF, TNF‐α, IL‐6, and IL‐10 levels in serum and saliva samples were determined by enzyme‐linked immunosorbent assay. Statistical analysis was performed using multivariate analysis of variance and bivariate correlation. Results: Serum and saliva levels of TNF‐α, APRIL, BAFF, IL‐6, and IL‐10 were similar in CP and AgP groups. Serum levels of TNF‐α, APRIL, and BAFF and saliva levels of BAFF were significantly higher in periodontitis groups than healthy controls (P <0.05). Non‐smokers with CP or AgP had lower levels of saliva TNF‐α and APRIL and serum APRIL and IL‐6 than smokers with CP or AgP (P <0.05). Saliva APRIL and serum TNF‐α and IL‐6 levels were significantly higher in healthy smokers than healthy non‐smokers (P <0.05). Clinical periodontal parameters correlated positively with TNF‐family cytokines and negatively with IL‐10 (P <0.05). Conclusions: Within the limits of this study, it may be suggested that elevated salivary and serum TNF‐α, APRIL, and BAFF in patients with periodontitis may contribute to the dominance of B cells in periodontitis lesions. Moreover, higher levels in healthy smokers than non‐smoking counterparts may play a role in detrimental effects of smoking on periodontal tissues.     

Functional TLRs and NODs in human gingival fibroblasts

Since human gingival fibroblasts are the major cells in periodontal tissues, we hypothesized that gingival fibroblasts are endowed with receptors for bacterial components, which induce innate immune responses against invading bacteria. We found clear mRNA expression of Toll-like receptors (TLR)1, TLR2, TLR3, TLR4, TLR5, TLR6, TLR7, TLR8, TLR9, MD-2, MyD88, NOD1, and NOD2 in gingival fibroblasts. Gingival fibroblasts constitutively expressed these molecules. Upon stimulation with chemically synthesized ligands mimicking microbial products for these receptors, the production of pro-inflammatory cytokines, such as interleukin (IL)-6, IL-8, and monocyte chemoattractant protein-1, was markedly up-regulated. Furthermore, the production of pro-inflammatory cytokines induced by TLR and NOD ligands was significantly inhibited by an RNA interference assay targeted to NF-kappaB. These findings indicate that these innate immunity-related molecules in gingival fibroblasts are functional receptors involved in inflammatory reactions in periodontal tissues, which might be responsible for periodontal pathogenesis.     

Role of helper T cells in the humoral immune responses against 53‐kDa outer membrane protein from Porphyromonas gingivalis

Outer membrane protein with a 53‐kDa molecular weight (Ag53) isolated from Porphyromonas gingivalis evokes strong humoral immune responses in many periodontitis patients. To examine the effects of cytokines produced by Ag53‐specific Th cells on the IgG production against Ag53, we established Ag53‐specific Th‐cell lines from patients with early onset periodontitis and from healthy volunteers. We then developed a mixed lymphocyte culture system between Ag53‐specific Th cells and auto‐ or allo‐derived T‐cell‐depleted leukocytes produced from the subjects whose HLA class II haplotypes were completely matched. Interferon‐γ production was observed in all Th cell lines from patients and healthy subjects. As for Th2 type cytokines, interleukin (IL)‐4, IL‐5, IL‐6 and IL‐10 production varied greatly in Th cells regardless of the periodontal condition of the donor. Only Th cell lines with a high Th2/Th1 ratio induced Ag53‐specific IgG production when cocultured with T‐cell‐depleted leukocytes. Thus, the difference in Th2/Th1 balance may regulate the Ag53‐specific IgG production.     

Cytokines differentially regulate CXCL10 production by interferon-gamma-stimulated or tumor necrosis factor-alpha-stimulated human gingival fibroblasts

Background and Objective: CXC chemokine 10 (CXCL10) activates CXC chemokine receptor 3 (CXCR3) and attracts activated T‐helper 1 cells. In this study we examined the effects of cytokines on CXCL10 production by human gingival fibroblasts. Material and Methods: Human gingival fibroblasts were exposed to pro‐inflammatory cytokines (interleukin‐1β, tumor necrosis factor‐α), a T‐helper 1 cytokine (interferon‐γ), T‐helper 2 cytokines (interleukin‐4, interleukin‐13), T‐helper 17 cytokines (interleukin‐17A, interleukin‐22) and regulatory T‐cell cytokines (interleukin‐10, transforming growth factor‐β1) for 24 h. CXCL10 production by human gingival fibroblasts was examined by enzyme‐linked immunosorbent assay. Results: Human gingival fibroblasts produced CXCL10 protein upon stimulation with interleukin‐1β, tumor necrosis factor‐α and interferon‐γ. Treatment of human gingival fibroblasts with interferon‐γ in combination with tumor necrosis factor‐α or interleukin‐1β resulted in a synergistic production of CXCL10. However, interleukin‐4 and interleukin‐13 inhibited CXCL10 production by interferon‐γ‐stimulated or tumor necrosis factor‐α‐stimulated‐human gingival fibroblasts. On the other hand, interleukin‐17A and interleukin‐22 enhanced CXCL10 production by human gingival fibroblasts treated with interferon‐γ and inhibited CXCL10 production by tumor necrosis factor‐α‐stimulated human gingival fibroblasts. Furthermore, the anti‐inflammatory cytokine, interleukin‐10, inhibited CXCL10 production by both interferon‐γ‐ and tumor necrosis factor‐α‐stimulated human gingival fibroblasts, but transforming growth factor‐β1 enhanced interferon‐γ‐mediated CXCL10 production by human gingival fibroblasts. Conclusion: These results mean that the balance of cytokines in periodontally diseased tissue may be essential for the control of CXCL10 production by human gingival fibroblasts, and the production of CXCL10 might be important for the regulation of T‐helper 1 cell infiltration in periodontally diseased tissue.     

Orthodontic Force Increases Interleukin‐1β and Tumor Necrosis Factor‐α Expression and Alveolar Bone Loss in Periodontitis

Background: The present study aims to evaluate the effects of orthodontic movement (OM) on the periodontal tissues of rats with ligature‐induced periodontal disease. Methods: Eighty‐eight rats were divided into four groups: 1) negative control (sham operated); 2) periodontal disease; 3) OM; and 4) periodontal disease followed by OM (OMP). Rats were sacrificed 3 hours or 1, 3, or 7 days after OM commencement. Bone volume fraction (BVF) and bone mineral density (BMD) were assessed in hemimaxillae by microcomputed tomography analysis. Expression of the proinflammatory cytokines interleukin (IL)‐1β and tumor necrosis factor (TNF)‐α were evaluated in gingival samples by quantitative polymerase chain reaction and enzyme‐linked immunosorbent assay, and in the furcation region by immunohistochemistry analysis (IHC). Results: The OMP group had lower BVF and BMD levels compared to the other groups at day 7 (P <0.05). Maximum messenger ribonucleic acid expression of both cytokines was observed in the OMP group at day 1 (P <0.05). In the same period, all proteins were expressed in high levels for all test groups compared to the control group. The number of cells positive for IL‐1β and TNF‐α by IHC was highest in the OMP group at day 1, with progressive reduction thereafter. Conclusion: The results suggest that OM acts synergistically with periodontal disease in periodontal breakdown through upregulation of proinflammatory cytokines.