Influence of psychological factors on risk of temporomandibular disorders.

Psychological characteristics potentially may be a cause or consequence of temporomandibular disorder (TMD). We hypothesized that psychological characteristics associated with pain sensitivity would influence risk of first-onset TMD, but the effect could be attributed to variation in the gene encoding catechol-O-methyltransferase (COMT). We undertook a prospective cohort study of healthy female volunteers aged 18-34 yrs. At baseline, participants were genotyped, they completed psychological questionnaires, and underwent quantitative sensory testing to determine pain sensitivity. We followed 171 participants for up to three years, and 8.8% of them were diagnosed with first-onset TMD. Depression, perceived stress, and mood were associated with pain sensitivity and were predictive of 2- to 3-fold increases in risk of TMD (P < 0.05). However, the magnitude of increased TMD risk due to psychological factors remained unchanged after adjustment for the COMT haplotype. Psychological factors linked to pain sensitivity influenced TMD risk independently of the effects of the COMT haplotype on TMD risk.

Immunohistochemical study of the expression of human chorionic gonadotropin-beta in oral squamous cell carcinoma.

BACKGROUND: Human chorionic gonadotropin (hCG) is a glycoprotein hormone comprised of two dissimilar subunits (alpha and beta) and normally is synthesized by trophoblastic tissue. Although hCG expression has been identified in a variety of neoplastic tissues, to the authors' knowledge no investigation has centered on tumors of oral origin. METHODS: Oral squamous cell carcinomas (OSCC) were studied in comparison with oral fibromas for the presence of hCGbeta using the avidin-biotin-peroxidase complex immunohistochemical technique. RESULTS: hCGbeta immunoreactivity was identified in 29 of 45 OSCC (64%). The positively staining cells in each tumor specimen were few (range, 0.5-5%) and were scattered throughout the tumor. When tumors were classified according to grade, it was found that hCGbeta staining was positive in 5 of 15 well differentiated OSCC (33%), in 12 of 15 moderately differentiated OSCC (80%), and in 12 of 15 moderately to poorly differentiated OSCC (80%). hCGbeta immunoreactivity could not be demonstrated in any of the oral fibromas. CONCLUSIONS: The presence of hCGbeta positive tumor cells appears potentially to reflect a malignant behavior of OSCC.