Altered Levels of Salivary 8-oxo-7-hydrodeoxyguanosine in Breast Cancer

Oxidative stress has been implicated in the pathogenesis of breast cancer (BC). To determine whether BC is associated with altered salivary redox homeostasis, we performed a case-control study assessing the relationship between BC and 8-oxo-7-hydrodeoxyguanosine (8-oxodG), a marker for oxidative damage to DNA. Enzyme-linked immunosorbent assay for 8-oxodG was used on whole, unstimulated saliva of 134 BC patients and 226 healthy controls. Associations of the redox data were assessed by analysis of variance and logistic regression analysis. Our results revealed that there were 1) significantly lower mean levels of salivary 8-oxodG in BC patients versus controls ( P = 0.0005), 2) significantly lower levels among participants who did not receive radiotherapy and/or chemotherapy as compared with controls ( P < 0.0001), 3) significantly lower levels among BC patients who did not receive these treatments than among those who did ( P < 0.02), 4) and no significant differences in mean 8-oxodG levels among BC patients positive or negative for estrogen receptor, progesterone receptor, and human epidermal growth factor receptor 2 ( P ≥ 0.08). Our results suggest that BC is associated with decreased levels of oxidatively modified DNA in saliva. Knowledge Transfer Statement: The results of our current case-control study indicate that the molecular biomarker of oxidative stress 8-oxo-7-hydrodeoxyguanosine, measured from saliva, is associated with breast cancer. Our findings may provide the basis for future studies on molecular biomarkers of oxidative stress and breast cancer using saliva as an accessible and noninvasive tissue.

Human temporomandibular joint and myofascial pain biochemical profiles: a case-control study

Neurobiological mechanisms of human musculoskeletal pain are poorly understood. This case-control study tested the hypothesis that biomarkers within temporomandibular muscle and joint disorders (TMJD) subjects' masseter muscles or temporomandibular joint (TMJ) synovial fluid correlate with plasma biomarker concentrations. Fifty subjects were recruited and categorized into TMJD cases (n=23) and pain-free controls (n=27) at the University of Minnesota School of Dentistry. Prior to specimen collection, pain intensity and pressure pain threshold masseter muscles and the TMJs were assessed. We collected venous blood; biopsied masseter muscle; and sampled TMJ synovial fluid on the subjects' side of maximum pain intensity. We assayed these tissues for the presence of nerve growth factor (NGF), bradykinin (BK), leukotreine B(4) (LTB(4) ) and prostaglandin E(2) (PGE(2) ), F(2) -isoprostane (F(2) I) and substance P (SP). The data was analyzed using Spearman Correlation Coefficients. We found that only plasma concentrations of bradykinin statistically correlated with synovial fluid concentrations (ρ=-0·48, P=0·005), but no association was found between pain intensities. The data suggests that biomarkers used to assess TMJD need to be acquired in a site-specific manner. We also discovered that F(2) I concentrations were associated with muscle pain intensity and muscle pressure pain threshold (PTT) (β=0·4, 95%CI: 0·03-0·8) and joint PPT (β=0·4, 95%CI: 0·07-0·8) suggesting that muscle oxidative stress is involved in myofascial pain and that F(2) -I may be a biomarker for myofascial pain.

Evidence of oxidative stress in temporomandibular disorders: a pilot study

Oxidative stress is involved in the pathogenesis of many conditions and is caused by free radicals in concentrations that overwhelm the natural scavenging mechanisms and cause pain and inflammation. This investigation sought to determine whether pain from temporomandibular disorders was associated with increased oxidative stress as measured by biomarkers in saliva and serum. Both salivary and serum levels of the oxidative stress biomarkers including 8-hydroxydeoxyguanosine, malondialdehyde and total antioxidant status were compared in patients with mild and severe TMJD pain and with healthy controls. These biomarkers were determined spectrophotometrically in saliva and serum from 10 high TMJD pain patients, 10 low TMJD pain patients, and 10 healthy control subjects from National Institute of Dental Research's TMJ Implant Registry and Repository. Linear and logistic regression analyses were used to evaluate the association between each biomarker and TMJD pain. The mean levels of log 8-hydroxydeoxyguanosine (saliva P < 0·0001, serum P = 0·0008), malondialdehyde (saliva P = 0·002, serum P = 0·004) and total antioxidant status (saliva P = 0·005; serum P = 0·001) achieved statistically significant differences between groups. In linear regression analysis, both salivary and serum levels of each biomarker were associated with TMJD pain. In a multivariable analysis, again, both salivary levels and serum levels were also different between groups. Salivary levels of oxidative stress ratios of 8-hydroxydeoxyguanosine, malondialdehyde and total antioxidant status were significantly different between patients with TMJD pain and controls and was comparable to that in serum. These biomarkers hold promise as a potential diagnostic and therapeutic strategy.

Clinical decision on pit and fissure sealing according to the occlusal morphology. A descriptive study

BACKGROUND

The objective of this descriptive study was to evaluate the clinical decision on sealing pits and fissures according to the occlusal morphology in patients with low individual caries risk (ICR).

MATERIALS AND METHODS

A total of 222 dentists, 86 affiliated to the French Society of Paediatric Odontology (SFOP) and 136 general practice dentists (GPs), answered the same questionnaire with illustrations of 4 occlusal surfaces of permanent molars: they indicated firstly if these were at risk and secondly the corresponding decision regarding sealing. This questionnaire assessed the decision on widening pits and fissures before sealing and the type of sealant material used. Multivariate logistic regression analyses were performed to identify the factors associated with the clinical decision to widen pits and fissures.

RESULTS

Sealing of at-risk teeth was indicated by 89% of dentists, whereas sealing of not at-risk occlusal surfaces was recommended by 46%. SFOP dentists were more prone to recommend pit and fissures sealants. The multivariate analyses demonstrated that only the type of material was associated with the clinical decision to widen pits and fissures. Forty eight percent of dentists choose the same material in all clinical situations.

CONCLUSION

The wide variations in sealant use and placement technique implies there is no apparent consensus among GP and SFOP dentists. Although the criteria are similar in numerous scientific societies, not all dentists are acting upon these recommendations.

Manual toothbrush wear and consequences on plaque removal

OBJECTIVE

The aim of this study was to determine the mean time interval before needing to discard different types of manual toothbrushes based on wear, and on the impact of progressive wear on plaque removal efficacy.

METHODOLOGY

Two cross-over randomized clinical trials involving the same 12 volunteers tested four toothbrushes of different designs. In Study 1, the brushes were the Butler 211 (BTB) and Fluocaril Sensia (FSTB). In Study 2, the brushes were Elmex InterX (ETB) and Elgydium Interactive (ELTB). In both trials, the volunteers randomly used one of the two toothbrushes for two minutes twice a day during the first week, and the other brush during the following week, and continued this alternating routine for two months. An image acquisition system and the Visilog 5.2 image analysis program were used to calculate the wear index (WI) after one and two months of use for each toothbrush. The OHI-S plaque index (PI) was recorded after one and three minutes of tooth brushing at one and two months. The Friedman or Kruskal-Wallis test was used to compare data.

RESULTS

Except for the ELTB, the wear of the toothbrushes was greater during the first month of brushing than during the second. The total WI was FSTB 35.46 (range = 62.11), ELTB 30.14 (range = 67.92), ETB 48.77 (range = 123.87), and BTB 98.20 (range = 134.75). The differences were significant at p = 0.008. The post one-minute PI scores significantly increased with wear, except in the case of ELTB (p = 0.244). When comparing all toothbrushes' PI at the one and three-minute tooth brushing times, there were significant differences at one month among them at p < 0.0001.

CONCLUSION

The amount of wear depended on the toothbrush design. It was greater for rectangular tooth brushing areas or when bristles had smaller diameters and different heights. With two-month-old toothbrushes, plaque removal was better when there was less measurable wear.

Heterogeneity of temporomandibular disorders: cluster and case-control analyses

Cluster analysis has been applied to the classification of temporomandibular disorders (TMD). The factors most often used in these classification systems are psychological and psychosocial. The aim of this study is to classify individuals diagnosed with TMD, by using cluster analysis based on their clinical condition and the global severity of the disease. In this study, one investigator selected the patients at the dental clinics located at the Jewish General and Montreal General hospitals, Montreal, Canada, from September 1994 to December 1997. The study population included 162 outpatients. The results of this study indicated the existence of four TMD subgroups: three TMD pain groups with localized or generalized disorder related to different levels of interferences in their life and a non-pain, but disabled group. External validation of the cluster solution support the replication of the four groups and allow for further interpretation of the patients' profiles. Clenching-grinding and depression were related to the groups presenting generalized TMD. Orthodontic treatment and female sex, however, were the factors associated with a more localized condition. This classification system may provide a better understanding of the TMD subgroups and clues for the treatment and prognosis of TMD patients.

A case-control study of temporomandibular disorders: symptomatic disc displacement

This case-control study was designed to investigate the risk factors for disc displacement (DD) without myofascial pain (MFP). The study population included 59 cases with DD without MFP, selected in two hospital dental clinics, and 100 concurrent controls selected in one of these clinics. The association with DD was evaluated for bruxism, head-neck trauma, orthodontic treatment, and sociodemographic characteristics by using unconditional logistic regression. In the multivariate analysis, excluding psychological factors, an association was found between DD and clenching-grinding (OR=3.57; 95% CI: 1.27-9.98). This association persisted when anxiety (OR=3.07; 95% CI: 1.08-8.70) or depression (OR=4.02; 95% CI: 1.43-11.31) was included in the model. A positive association was noted between orthodontic treatment and DD (OR=3.10; 95% CI: 1.06-9.65). The effect between orthodontic treatment and DD remained and increased with the inclusion of anxiety (OR=3.65; 95% CI: 1.15-11.61) or depression (OR=3.20; 95% CI: 1.06-9.65). A high level of anxiety (OR=2.40; 95% CI: 1.01-5.73), was positively related to DD. We concluded that clenching combined with grinding, and orthodontic treatment are factors related to DD. The interpretation of these associations, however, requires caution because of the inclusion of prevalent cases.

Relationship between dental factors and risk of upper aerodigestive tract cancer

We examined the relationship between dental health variables and risk of upper aerodigestive tract (UADT) cancers in a case-control study in Southern Brazil. The study population included 717 cases of cancers of the mouth, pharynx, and larynx and 1434 controls matched on age, gender, period of admission and study site. The association with dental factors was investigated by conditional logistic regression using extensive adjustment for a priori and empirical confounders, including tobacco and alcohol consumption, diet and sociodemographic variables. Lifetime use of dentures was not associated with risk of any UADT cancer, but history of oral sores secondary to ill-fitting dentures was associated with cancers of the mouth (odds ratio [OR] = 2.3, 95% confidence interval [CI] 1.2-4.6) and of the pharynx (OR = 2.7, 95% CI 1.1-6.2) among those using dentures. The association for mouth cancers was restricted primarily to an increased risk of tongue neoplasms (OR = 9.1, 95% CI 1.9-43.4). Less than daily tooth brushing frequency was also associated with risk of cancer of the tongue (OR = 2.1, 95% CI 1.0-4.3) and of other parts of the mouth (OR = 2.4, 95% CI 1.0-5.4). Having broken teeth was not significantly associated with risk of UADT cancer of any site. We conclude that poor oral hygiene due to infrequent tooth brushing and sores caused by dentures are risk factors for cancer of the mouth and that these associations are unlikely to be due to insufficient control of confounding.