Association of radiographic and clinical findings in patients with temporomandibular joints osseous alteration

Objectives

To characterize the relationship between radiographic and clinical characteristics of patients with temporomandibular joint (TMJ) osseous changes.

Materials and methods

TMJ cone beam computed tomography (CBCT) images of 73 patients (142 joints) with changes in osseous component of TMJ were included in this study. Based on both clinical and radiographic findings, each TMJ was diagnosed as either non-degenerative joint disease (non-DJD) or degenerative joint disease (DJD) according to the Diagnostic Criteria for Temporomandibular Disorders (DC/TMD) criteria. The DJD group was further classified into two subgroups of osteoarthritis and osteoarthrosis. The data were analyzed using t test and Pearson’s correlation. Level of statistical significance was set at 0.05.

Results

Statistically significant relationships were found between TMJ crepitation sound and 4 radiographic characteristics of DJD. DJD group demonstrated statistically significant higher CBCT bone change score (BCS) and age. In contrast, there was no significant difference of BCS between osteoarthrosis and osteoarthritis groups within the DJD group.

Conclusions

Crepitation sounds and osseous changes in TMJ radiograph are confirmed to be important diagnostic criteria for TMJ DJD. However, degree of TMJ osseous changes does not correlate significantly with clinical pain symptom.

Clinical relevance

For TMJ DJD diagnosis, dentists should consider both clinical examination for TMJ crepitation and radiographic assessment for TMJ bony changes.

     

p53 mutations and aflatoxin B1 exposure in hepatocellular carcinoma patients from thailand

The prevalence and type of mutations in the p53 tumoursuppressor gene have been determined in 15 hepatocellular carcinomas (HCC) originating from Thailand. Direct sequencing of exons 5-8 revealed 2 mutations, an AGG to AGT (Arg → Ser) transversion at codon 249, and an ATC → AAC (lle → Asn) transversion at codon 254. Samples from the Thai patients were analyzed for the presence of aflatoxin-liver DNA and aflatoxinserum albumin adducts, and all but one were found negative. All the patients were genotyped for glutathione-S-transferase (GST) μ, an enzyme possibly involved in the detoxification of AFB₁, and 12 out of 15 had the null genotype. In general, the level of aflatoxin-albumin adducts in sera and the prevalence of p53 mutation at codon 249 in HCC were lower than in other areas at high risk of HCC, including southern China and parts of Africa.     

Duck hepatitis B virus infection, aflatoxin B1 and liver cancer in domestic Chinese ducks.

The oncogenicity of Duck hepatitis B virus (DHBV) is unclear since hepatocellular carcinomas (HCCs) have been reported only in domestic ducks in Qidong, an area of China where hepatitis B virus (HBV) and aflatoxin B1 (AFB1) are risk factors for liver cancer in man. In order to better define the association between DHBV infection, AFB1 and HCC we analysed a series of 16 duck liver samples collected from local farms in Qidong. HCC was found in eight and cirrhosis in one of these samples. Furthermore bile duct proliferation, characteristic of AFB1 exposure in ducks and other animal species, was found in these ducks. Integration of DHBV DNA into cellular DNA was observed in only one out of four DHBV positive HCCs, indicating that viral integration is not prerequisite for tumour development. In four remaining HCCs the polymerase chain reaction (PCR) failed to show any DHBV DNA suggesting that liver tumours do occur in polymerase chain reaction (PCR) failed to show any DHBV DNA suggesting that liver tumours do occur in these ducks in the absence of DHBV infection. In addition, AFB1-DNA adducts were detected by hplc-immunoassay in one such DHBV-negative tumour. In summary we demonstrate that risk factors other than DHBV, including AFB1 exposure, may be important in duck liver carcinogenesis in Qidong.     

Carcinogenicity of an oxidation product of p-phenylenediamine

para-Phenylenediamine (p-PD), a widely used aromatic amine inthe preparation of commercial oxidative-type hair dyes, hasbeen previously demonstrated to have neither mutagenic activityto Salmonella typhimurium nor carcinogenic activity in ratsand mice. In this study, the mutagenicity of p-PD after an oxidationby hydrogen peroxide towards S. typhimurium TA98 and its carcinogenkityin Wistar rats were examined both by topical application tothe shaved skin and by s.c. injection. Hie oxidation productwas found to be strongly muta-genic to the bacterial testerstrain in the presence of rat liver S-9 fraction. Interestingly,in female rats, both topical application and s.c. injectionfor 18 months of oxidized p-PD could induce a statisticallysignificant incidence of mammary gland tumors (>50%, P <0.05). In addition, uterine tumors and soft tissue tumors ofboth malignant and benign types were also significantly induced(43% and 57%, P < 0.05) hi the s.c. injection group. On theother hand, tumors of mammary gland and soft tissue were notobserved in male rats under similar experimental conditions.However, tumors of other organs including liver, kidney, adrenalgland, thyroid gland, urinary bladder and lung were occasionallyobserved in male rats of both groups and might be related tothe p-PD treatment.