Association of CXCL12 gene promoter methylation with periodontitis in patients with diabetes mellitus type 2

ObjectivesCXCL12 is widely expressed, constitutive chemokine involved in tissue repair and regeneration, while the extent of its expression is important in various chronic inflammatory conditions. Involvement of DNA methylation in CXCL12 gene suppression (CXCL12) has been shown in malignancy and some autoimmune diseases. The aim of this study was to investigate whether the alterations in DNA methylation of CXCL12 are also involved in progression of periodontitis in combination with diabetes, as these chronic inflammatory conditions are strongly interrelated.DesignStudy included 72 subjects divided in three groups: healthy control (C, n = 21), periodontitis (P, n = 29) and diabetes/periodontitis group (D/P, n = 22). DNA extracted from epithelial cells obtained by sterile cotton swabs from buccal mucosa was subjected to methylation specific polymerase chain reaction (MSP) to obtain DNA methylation pattern of CXCL12 promoter.ResultsCXCL12 promoter was predominantly unmethylated in all groups. However, increase in the frequency of the methylated form and increase in percent of methylation of CXCL12 promoter in periodontitis and diabetes/periodontitis group compared to control group were found, although without statistical significance. However, statistically significant increase in Tm of MSP products in diabetes/periodontitis group was observed. Correlation analysis revealed statistically significant relationship between the extent of DNA methylation of the CXCL12 promoter and periodontal parameters, as well as between DNA methylation of CXCL12 and glycosylated hemoglobin.ConclusionPresented results suggest that chronic inflammation contributes to the change of CXCL12 DNA methylation in buccal cells and that DNA methylation profile of CXCL12 promoter plays important role in development and progression of periodontal disease.     

Influence of smoking on methylation and hydroxymethylation levels in global DNA and specific sites of KRT14, KRT19, MIR-9-3 and MIR-137 genes of oral mucosa

ObjectiveThe aim of this study was to investigate the influence of smoking on the methylation and hydroxymethylation status of global DNA and specific sites of KRT14, KRT19, miR-9-3 and miR-137 genes in the healthy oral mucosa.MethodsSamples of oral epithelial cells were collected using mouthwash from a population of former and current smokers and those who had never smoked. Genomic DNA was extracted, and global DNA methylation and hydroxymethylation was performed using an ELISA-based technique; DNA methylation at specific sites was performed using Methylation-Specific PCR (MSP) (KRT14, miR-9-3 and miR-137) or Methylation-Sensitive Restriction Enzymes (MSRE) (KRT19). K14 and K19 protein expression was analysed by immunohistochemistry.ResultsHigher levels of global DNA methylation were found in current smokers with over 15 years of consumption (p = 0.04), but no differences were found in relation to global DNA hydroxymethylation. No differences in global DNA methylation and hydroxymethylation levels were found in relation to age or gender. Global DNA methylation was higher than the hydroxymethylation level (p < 0.001) but they were not correlated in the oral mucosa. For specific sites, miR-9-3 hypomethylation was detected in current smokers (p < 0.001). Additional analysis showed no difference in the methylation status when age, gender, period of consumption or amount of cigarettes were considered for any of the studied genes. K19 expression was higher in current smokers in comparison to former smokers and those who had never smoked (p < 0.05).ConclusionWe concluded that smoking habits were capable of inducing changes in global DNA methylation, miR-9-3 methylation status and K19 expression.     

Promoter methylation of MGMT in oral carcinoma: A population-based study and meta-analysis

IntroductionThe relevance of DNA methylation of O⁶-methylguanine-DNA methyltransferase (MGMT) in relation to several cancers and other disorders has been extensively explored in several cancer types.AimsTo ascertain the significance of DNA methylation of MGMT promoter in oral squamous cell carcinoma (OSCC), we undertook a study to a) analyse the methylation patterns of MGMT gene promoter in afflicted and normal population of coastal Karnataka, b) determine the expression status of MGMT in oral cancer cell lines (CAL-27 and SCC-4) and its relationship to DNA methylation and c) performed a meta-analysis of the published data.MethodsBisulfite sequencing of MGMT promoter region was performed on non-malignant/malignant oral samples, and oral cancer cell lines, followed by gene expression studies. Further, using a systematic search, 1024 publications were retrieved from PubMed, Scopus, Google Scholar and Web of Science and 23 relevant articles were reviewed.ResultsSignificant association of MGMT promoter methylation with OSCC (p < 0.0001) was observed in the case-control study. The studies chosen for meta-analysis showed predictive significance of MGMT gene promoter. Overall, we obtained a statistically significant (p < 0.0001) association for both sensitivity and specificity of MGMT DNA promoter methylation in oral cancer cases without publication bias. Gene expression was significantly elevated in both oral cancer cell lines (p < 0.03) after treatment with a demethylating agent (5-Aza-2′-deoxycytidine).ConclusionDNA promoter hypermethylation and gene expression of MGMT may associate with recursive mutagenesis and is a promising biomarker for OSCC prediction. Studies suggest further validation in large distinct cohorts to facilitate translation to clinics.     

Evaluation of DNA methylation in matched oral swab and tissue specimens from Chinese patients with oral squamous cell carcinoma

The DNA methylation statuses of the paired box 1 (PAX1) and zinc finger protein 582 (ZNF582) genes have shown promise in the detection of oral squamous cell carcinoma (OSCC). The aim of this study was to investigate the ability of PAX1 and ZNF582 methylation to distinguish OSCC and the adjacent normal tissue among cancer patients. This study included 67 patients with OSCC. The methylation levels of these two genes were analysed in tissue specimens (lesion site and adjacent normal site) and in oral swabs (lesion site and contralateral normal site). Levels of DNA methylation were higher at lesion sites than at the corresponding normal sites. According to receiver operating characteristics curve analysis, the area under the curve for PAX1 and ZNF582 methylation ranged from 0.73 to 0.82. No significant difference was observed between tissue specimens and oral swabs (PAX1, P =  0.41; ZNF582, P = 0.28). For the oral swab, PAX1 methylation was more pronounced in bone invasion (Z = 1.988, P =  0.047), and ZNF582 methylation was more pronounced in early-stage (Z = 2.354, P =  0.02) and well-differentiated tumours (Z = 3.731, P =  0.0002). Hypermethylated PAX1 and ZNF582 are effective biomarkers to distinguish lesion sites and corresponding normal sites in tissue specimens and oral swabs from OSCC patients.     

The effect of rheumatoid arthritis and functional loading on the structure of the mandibular condyle in a transgenic mouse model: An FTIR study

ObjectiveThe objective of the present study was to investigate the effect of rheumatoid arthritis and functional loading through diet modification on the biochemical properties of the mandibular condyle in a transgenic mouse model and compare with healthy littermates.DesignTwenty three, 4-week old hybrid male mice were used. Eleven were of transgenic line hTNF 197 (Tg 197 – with rheumatoid arthritis – RA) and 12 healthy littermates, both from mixed background CBAxC57BL/6. Four groups of mice were formed. Group 1 [n = 5, RA-hard] included transgenic mice and received ordinary (hard) diet; group 2 [n = 6, RA-soft] included transgenic line and received soft diet; group 3 [n = 6, control-hard] were healthy littermates receiving ordinary (hard) diet and group 4 [n = 6, control-soft] were healthy littermates with soft diet. Experimental period was 28 days. Following sacrifice, the mandibular condyles were subjected to micro-attenuated reflection Fourier transform infrared spectroscopy (micro-ATR FTIR) to reveal collagen/proteoglycan conformation of the condylar cartilage, while resin-embedded and metallographically polished specimens were evaluated through reflection FTIR microscopy to identify mineralization status of the corresponding condylar bone.ResultsThe multivariable analysis revealed significantly lower a-helix to amide I percentage area ratio for the transgenic animals after adjusting for diet (β = −4.29, 95% CIs: −8.52, −0.06; p = 0.04). Mineral phase indices did not differ significantly between RA and control groups regardless the type of diet.ConclusionsInternal derangement of the anatomical structure with denaturation in the collagen structural components of the mandibular condyles of the RA animals was found, while no association with functional loading through diet modification was recorded.     

The nocturnal use of complete dentures and sleep stability in edentulous elders

ObjectiveTo evaluate the stability of sleep quality and the impact of nocturnal use of complete dentures on sleep quality in an elderly edentulous population over a one-year period.Materials and methodsWritten informed consent was obtained from 172 edentulous elders who agreed to enrol in a longitudinal cohort study. A total of 153 participants completed the follow-up after one year. Perceived quality of sleep and daytime sleepiness were measured using the Pittsburgh Sleep Quality Index (PSQI, score 0–21) and the Epworth Sleepiness Scale (ESS, score 0–24) at baseline (T₀) and at follow-up (T₁). Data on oral health related quality of life, type of mandibular dentures (conventional versus implant-retained mandibular overdenture), nocturnal wear of the dentures and socio-demographic status were obtained by means of the OHIP-20 questionnaire, a clinical examination form and a socio-demographic questionnaire.ResultsNo statistically significant differences were detected in the global PSQI mean scores and EES mean scores from baseline (PSQI 4.77 ± 3.32; EES 5.35 ± 3.72) to the follow-up assessment (PSQ1 5.04 ± 3.50; EES 5.53 ± 4.34). Edentate elders wearing prostheses at night had poorer daytime sleepiness scores than those who removed their prostheses at night (p = 0.003 unadjusted model; p = 0.058 adjusted for age, gender, type of prosthesis and the OHIP-20 total score).ConclusionResults of this study suggest that wearing complete dentures while sleeping has little effect on sleep quality or daytime sleepiness.     

Measurement of root surface area of permanent teeth with root variations in a Chinese population—A micro-CT analysis

ObjectivesThis study investigated the influence of root variations on the root surface area (RSA) by using micro-CT scans.DesignA total of 228 extracted permanent teeth (2-rooted and single-rooted maxillary first premolars, mandibular first premolars with non-Tomes’ and Tomes’ roots, 2-rooted and 3-rooted mandibular first molars, and 2-rooted and C-shaped mandibular second molars) were collected in a Chinese population and scanned using a micro-CT. In Mimics 15.01, 3D tooth models were generated, and the net and percent remaining RSA at various simulated attachment levels were measured. The data corresponding to attachment level were fitted to a linear function.ResultsThe mean total RSA for different root forms decreased in the following order: 3-rooted > 2-rooted > C-shaped > single-rooted. However, the differences were statistically significant (p < 0.01) only for 2-rooted vs. single-rooted maxillary first premolars, and 2-rooted vs. C-shaped mandibular second molars. Linear functions can perfectly fit in relating the attachment level to the net and percent remaining RSA.ConclusionMicro-CT combined with Mimics software offers simple and precise technique for quantitative analysis of the RSA. Root variations may affect the total amount and vertical distribution of the net RSA. However, the degree of influence varies with the tooth type.     

Mechanical and hypoxia stress can cause chondrocytes apoptosis through over-activation of endoplasmic reticulum stress

ObjectiveTo examine the role of mechanical force and hypoxia on chondrocytes apoptosis and osteoarthritis (OA)-liked pathological change on mandibular cartilage through over-activation of endoplasmic reticulum stress (ERS).MethodsWe used two in vitro models to examine the effect of mechanical force and hypoxia on chondrocytes apoptosis separately. The mandibular condylar chondrocytes were obtained from three-week-old male Sprague–Dawley rats. Flexcell 5000T apparatus was used to produce mechanical forces (12%, 0.5 Hz, 24 h vs 20%, 0.5 Hz, 24 h) on chondrocytes. For hypoxia experiment, the concentration of O₂ was down regulated to 5% or 1%. Cell apoptosis rates were quantified by annexin V and propidium iodide (PI) double staining and FACS analysis. Quantitative real-time PCR and western blot were performed to evaluate the activation of ERS and cellular hypoxia. Then we used a mechanical stress loading rat model to verify the involvement of ERS in OA-liked mandibular cartilage pathological change. Histological changes in mandibular condylar cartilage were assessed via hematoxylin & eosin (HE) staining. Immunohistochemistry of GRP78, GRP94, HIF-1α, and HIF-2α were performed to evaluate activation of the ERS and existence of hypoxia. Apoptotic cells were detected by the TUNEL method.ResultsTunicamycin, 20% mechanical forces and hypoxia (1% O₂) all significantly increased chondrocytes apoptosis rates and expression of ERS markers (GRP78, GRP94 and Caspase 12). However, 12% mechanical forces can only increase the apoptotic sensitivity of chondrocytes. Mechanical stress resulted in OA-liked pathological change on rat mandibular condylar cartilage which included thinning cartilage and bone erosion. The number of apoptotic cells increased. ERS and hypoxia markers expressions were also enhanced. Salubrinal, an ERS inhibitor, can reverse these effects in vitro and in vivo through the down-regulation of ERS markers and hypoxia markers.ConclusionWe confirmed that mechanical stress and local hypoxia both contributed to the chondrocytes apoptosis. Mechanical stress can cause OA-like pathological change in rat mandibular condylar cartilage via ERS activation and hypoxia existed in the meantime. Both mechanical forces and hypoxia can induce ERS and cause chondrocytes apoptosis only if the stimulate was in higher level. Salubrinal can protect chondrocytes from apoptosis, and relieve OA-liked pathological change on mandibular condylar cartilage under mechanical stress stimulation.     

Measurement of root surface area of permanent teeth in a Chinese population

ObjectivesThe aim of this study was to investigate the relation between the remaining area of periodontal attachment and the attachment levels for each type of permanent teeth in a Chinese population by using micro-computed tomography (micro-CT) scans.DesignA total of 440 extracted permanent teeth (including each tooth type except for the third molars) were collected from a Chinese population and scanned using a micro-CT. The CT data were input into Mimics 15.01 to generate 3D tooth models. To simulate various attachment levels, the roots were virtually cut at 0, 2, 4, 6, 8, and 10 mm from the cemonto-enamel junction (CEJ). The net and percent remaining root surface area (RSA) were measured and calculated, and the data corresponding to attachment level were fitted to a linear function.ResultsA Linear function can perfectly fit in relating the simulated attachment level to the net and percent remaining RSA (R² > 0.99, and p < 0.001 for each tooth type). For net remaining RSA, the slope of the linear function was steepest for maxillary first molars (b₁ = −39.32) and least steep for mandibular central incisor (b₁ = −13.08); whereas for the percentage of remaining RSA, the slopes (b₁) were relatively within a narrow range, from −7.40 (maxillary canine) to −9.64 (maxillary first molars).ConclusionMicro-CT offers simple and precise technique for quantitative analysis of the RSA. The total amount and vertical distribution of the RSA varied by tooth type. Linear formulas can perfectly describe the relation between the attachment level and the net and percent remaining RSA.     

Hydrogen peroxide induces cell proliferation and apoptosis in pulp of rats after dental bleaching in vivo: Effects of the dental bleaching in pulp

ObjectiveThis study provides an in vivo evaluation of the inflammatory response, levels of cell proliferation and apoptosis, and the presence of necrosis after dental bleaching with two concentrations of hydrogen peroxide (H₂O₂).DesignWistar rats were divided into Control (placebo gel), BLUE (20% H₂O₂, 1 × 50 min), and MAXX (35% H₂O₂, 3 × 15 min) groups. At 2 and 30 days, the rats were killed (n = 10). The jaws were processed for histology analysis and PCNA and Caspase-3-cleaved immunohistochemistry, and data were submitted to the Mann-Whitney or ANOVA test (P < 0.05).ResultsAt 2 days, the MAXX group showed necrosis and the BLUE group revealed moderate inflammation on the occlusal third of the crown (P < 0.05). At 30 days, tertiary dentin had formed and there was an absence of inflammation. The level of cell proliferation was higher in the middle third of the BLUE group (P < 0.05), and cervical of MAXX at 2 days (P < 0.05), decreasing at 30 days. The apoptosis was present at 2 days, particularly in the cervical third of the crown in the bleached groups (P < 0.05), with a decrease only at 30 days in the BLUE group (P < 0.05).ConclusionsThe concentration of H₂O₂ influences effects on the pulp tissue, where a higher concentration of H₂O₂ can cause necrosis in the pulp and a prolonged effect within the apoptotic process; lower concentrations of H₂O₂ provide moderate inflammation, cell proliferation and apoptosis with a reduction of these processes over time.     

Osteochondral angiogenesis in rat mandibular condyles with osteoarthritis-like changes

ObjectiveTo investigate angiogenesis at the osteochondral junction and changes in expression of pro- and anti-angiogenic factors in rat mandibular condyles with osteoarthritis-like changes.MethodsIn order to evoke osteoarthritis-like lesions in mandibular condyles, disordered occlusion was created experimentally in rats. Osteochondral vascularity was assessed histologically at 20 and 24 weeks. Protein and mRNA levels of pro-angiogenic factors including vascular endothelial growth factor (VEGF), connective tissue growth factor (CTGF) and matrix metalloproteases 9 (MMP9), and anti-angiogenic factor chondromodulin-I (CHM-I) were investigated by means of immunohistochemical staining and real-time PCR.ResultsOsteochondral angiogenesis was demonstrated as increased numbers of vascular channels terminating in the calcified cartilage and non-calcified cartilage in 20- and 24-week experimental groups compared with controls (all P < 0.05). In the experimental groups, VEGF, CTGF and MMP9 were highly expressed in the tissues adjacent to the osteochondral junction. However, CHM-I was more expressed in the superior but not deep hypertrophic chondrocytes. Compared to their age-matched controls, the protein levels of VEGF and CTGF were higher in 20-week experimental group, and the protein and mRNA levels of CTGF, MMP-9, and CHM-I increased in the 24-week experimental group (all P < 0.05).ConclusionIn the present rat model, osteochondral angiogenesis was observed in mandibular condyles with osteoarthritis-like changes, accompanied with local upregulation of VEGF, CTGF and MMP9. Although the increase in CHM-I may moderate pro-angiogenic factors effects in the superior cartilage, the deficiency of deep hypertrophic chondrocytes to express CHM-I may permit vascular invasion into condylar cartilage.     

Influence of mandibular residual ridge resorption on objective masticatory measures of lingualized and fully bilateral balanced denture articulation

PurposeTo assess the influence of mandibular residual ridge resorption (RRR) on objective masticatory measures of two occlusal schemes: lingualized occlusion (LO) and fully bilateral balanced articulation (FBBA).MethodsThe enrolled patients (n = 22) were randomly allocated one set of complete dentures with either LO or FBBA. Maximum occlusal force, masticatory performance (by the MPI), and mandibular movements were measured at 3- and 6-month follow-ups. Mandibular RRR was assessed as the sum of the mandibular bone height at the midline, first premolar region, and least vertical height region, and from the mental foramen to the alveolar crest, measured on panoramic radiographs; the treatment groups were subclassified into severe or moderate RRR subgroups by the value of the sum of individual measurements.ResultsSignificant differences were observed in the between-subgroup comparisons (Kruskal–Wallis test) of the MPI (3 months, p = 0.01; 6 months, p = 0.04) and linear deviation from intercuspal position (anterior–posterior: 6 months, p = 0.01; inferior–superior: 3 months, p = 0.008; 6 months, p = 0.02). The patients with severe RRR in the FBBA group showed a significant decrease in the MPI and increase in linear inferior deviation from intercuspal position at 3 months (post hoc comparison) as well as a significant increase in the linear posterior and inferior deviation from intercuspal position at 6 months.ConclusionsLO is the preferable occlusal scheme for patients with severe RRR. (This trial has been registered at http://clinicaltrials.gov/ct2/show/NCT00959530.)     

Evaluation of effects of activator treatment on mandibular growth by analyzing components of condylar growth and mandibular rotation

PurposeThe objective of this study is to clarify the effects of activator treatment on mandibular growth in relation to condylar growth and total rotation of the mandible, and to investigate the relationships between the treatment responses and pretreatment facial morphology.Materials and methodsThirty Japanese girls with Class II division 1 malocclusion treated with activator were examined. Mean age at the start of treatment was 9.6 ± 1.6 years. Mean treatment duration was 19 ± 4 months. Lateral cephalograms obtained before and after treatment were used to analyze skeletal changes during treatment. Regional superimposition analysis was performed to evaluate activator effects by decomposing the mandibular growth into condylar growth and mandibular total rotation.ResultsThe changes in intermaxillary relationships were significantly correlated with vertical condylar growth and mandibular total rotation (P < 0.05 and P < 0.01). The changes in the forward displacement of the mandible were significantly correlated with sagittal condylar growth and mandibular total rotation (P < 0.05 and P < 0.01). Vertical condylar growth and mandibular total rotation were significantly correlated with pretreatment mandibular morphology (P < 0.05 and P < 0.01).ConclusionBoth the sagittal condylar growth and counterclockwise mandibular total rotation attributed to activator treatment contribute to forward displacement of the mandible. The activator effects are expected greater in patients with flat mandibular plane, small gonial angle, backwardly inclined mandibular ramus and long posterior facial height.     

Hypermethylation of Death-Associated Protein Kinase (DAPK1) and its association with oral carcinogenesis - An experimental and meta-analysis study

ObjectivesThe value of abnormal DNA methylation of DAPK1 promoter and its association with various cancers have been suggested in the literature. To establish the significance of DNA methylation of DAPK1 promoter in oral squamous cell carcinoma (OSCC), we a) performed a case-control study, b) evaluated published data for its utility in the diagnosis and prognosis of OSCC and c) identified the association of DAPK1 gene expression with promoter DNA methylation status.DesignBisulfite gene sequencing of DAPK1 promoter region was performed on non-malignant and malignant oral samples. Further, using a systematic search, 330 publications were retrieved from PubMed, Scopus, and Google Scholar and 11 relevant articles were identified.ResultsSignificant association of DAPK1 promoter methylation with OSCC (p < 0.0001) was observed in the case-control study. The studies chosen for meta-analysis showed prognostic and predictive significance of DAPK1 gene promoter, despite defined inconsistencies in few studies. Overall, we obtained a statistically significant (p-value < 0.001) association for both sensitivity and specificity of DAPK1 DNA promoter methylation in oral cancer cases, without publication bias.ConclusionDNA hypermethylation of DAPK1 gene promoter is a promising biomarker for OSCC prediction/prognostics and suggests further validation in large distinct cohorts to facilitate translation to clinics.     

Repair genes expression profile of MLH1, MSH2 and ATM in the normal oral mucosa of chronic smokers

ObjectiveThe aim of this study was to evaluate the effect of chronic smoking on the expression profile of the repair genes MLH1, MSH2 and ATM in the normal oral mucosa of chronic smokers and never smokers.Materials and methodsThe sample consisted of thirty exfoliative cytology smears per group obtained from Smokers and Never Smokers. Total RNA was extracted and expression of the MLH1, MSH2 and ATM genes were evaluated by quantitative real-time and immunocytochemistry. The gene and protein expression data were correlated to the clinical data. Gene expression was analyzed statistically using the Student t-test and Pearson’s correlation coefficient, with p < 0.05.ResultsMLH1, MSH2 and ATM genes were downregulated in the smoking group compared to the control with significant values for MLH1 (p = 0.006), MSH2 (p = 0.0001) and ATM (p = 0.0001). Immunocytochemical staining for anti-MLH1, anti-MSH2 and anti-ATM was negative in Never Smokers; in Smokers it was rarely positive. No significant correlation was observed among the expression of MLH1, MSH2, ATM and age, number of cigarettes consumed per day, time of smoking during life, smoking history or levels of CO in expired air.ConclusionThe expression of genes and proteins related to DNA repair mechanism MLH1, MSH2 and ATM in the normal oral mucosa of chronic smokers was reduced.     

Cell migration,viability and tissue reaction of calcium hypochlorite based-solutions irrigants: An in vitro and in vivo study

ObjectiveThis study aimed to analyze in vitro cytotoxicity to cultured 3T3 fibroblasts and in vivo inflammatory reaction in rats by calcium hypochlorite (Ca(OCl)₂) solutions compared with sodium hypochlorite (NaOCl) solutions.DesignCultured 3T3 fibroblasts were exposed to different concentrations of (Ca(OCl)₂) and NaOCl solutions, and a scratch assay was performed. The viability rate was analyzed with trypan blue assay. Both solutions of 1% and 2.5% concentrations were injected into the subcutaneous tissue of 18 male Wistar rats aged 18 weeks. The inflammatory tissue reaction was evaluated at 2 h, 24 h, and 14 days after the injections. The samples were qualitatively analyzed using a light microscope. Statistical analysis was performed with ANOVA and Tukey post hoc tests for in vitro assays and Kruskal–Wallis and Dunn post hoc tests for in vivo assays (α = 0.05).ResultsIn the scratch assay, Ca(OCl)₂ showed no significant difference compared with the control group (culture medium) at 24 h (p < 0.05). Solutions of 0.0075% and 0.005% NaOCl and Ca(OCl)₂ concentrations presented similar results compared with those in the positive control group (hydrogen peroxide) (p > 0.05) in the trypan blue assay. In the in vivo assay, 1% Ca(OCl)₂ group showed a significant decrease in neutrophils at 2 h and 24 h (p = 0.041) and 2 h and 14 days (p = 0.017). There was no statistically significant difference for lymphocyte/plasmocyte and macrophage counts among the different concentration groups.ConclusionsCa(OCl)₂ showed favorable results of viability and induced a low-level inflammatory response. Ca(OCl)₂ presented acceptable cytotoxicity and biocompatibility as an irrigant solution.     

Treatment of mandibular angle fractures – Linea obliqua plate versus grid plate

ObjectivesTo compare treatment outcomes, handling and long term results between two osseo-fixation systems for mandibular angle fractures – the external oblique ridge (external oblique) plate and the grid plate.Material and methodsSixty patients with mandibular angle fracture were analyzed regarding their operative treatment: 30 patients were treated with an external oblique plate and compared to 30 patients treated with a grid plate on the vestibular cortex.The follow up period was at least 1 year for both groups and the following complications were noted: infection, abnormality in fracture healing, nonunion, pain, hypoaesthesia and dysocclusion.ResultsThe overall average operation time (from intubation to extubation) was 102.1 min (±44.1 min). Single sided fractures treated with the grid plate needed in average 81.07 min (±37.9 min) of operation time while single sided fractures treated with the external oblique plate needed 89.3 min (±42.2 min). In multiple mandibular fractures, no significant change in the operation time between either plating system was found (118.8 ± 35.2 min).After the follow up period fracture healing was considered clinically complete in all patients, but complications occurred significantly more often in the external oblique group (13.3%; N = 8) than in the grid plate group (0%; N = 0).ConclusionIsolated mandibular angle fractures can be more effectively treated using grid plates than using other osteosynthesis techniques. It is an easy to use alternative to conventional miniplate systems with good clinical outcome and fewer complications. An angulated burr and screwdriver has to be used to put on the plate laterally.     

Short-term condylar and glenoid fossa changes in infants with Pierre Robin sequence undergoing mandibular distraction osteogenesis

The purpose was to evaluate short-term changes in condylar and glenoid fossa morphology in infants with Pierre Robin sequence (PRS) undergoing early (age <4 months) mandibular distraction osteogenesis (MDO) for the management of severe airway obstruction. Computed tomography data from infants with PRS who had MDO were compared to those of age-matched control infants without facial skeletal dysmorphology. Surface/volume, linear, and angular measurements of the condyle and glenoid fossa were obtained and compared between infants with PRS and controls. Eleven infants with PRS met the inclusion criteria. There were five female and six male subjects with a mean age at the time of MDO of 41 ± 32 days. Prior to MDO, PRS mandibles had a smaller condylar articulating surface area and volume than age-matched control mandibles, with a more laterally positioned condylar axis (P ≤ 0.05). Following MDO, there were significant increases in condylar articulating surface area and volume, approaching those of normal controls, with further lateral translation of the condylar axis (P ≤ 0.05). Condyle and glenoid fossa morphology is largely normalized following early MDO in infants with PRS. The condylar axis translates laterally as a result of MDO; this change is not observed with mandibular growth in infants without PRS.