Are You Sexually Active??? You Should Tell Your Dentist.

Shockingly, recent surveys suggest that fifty percent of sexually active adults in the United States have been infected with two or more of seven genital HPV strains.

Unfortunately for sexually active adults, HPV is readily transmissible. HPV transmission does not necessarily require penetrative acts and thereby can be transmitted via any form of genital contact including vaginal, anal, and oral sex.

Beyond transmission via genital contact, HPV can target almost any basal epithelial cell on your skin. In this way, HPV may be transmitted through a number of less obvious routes. Since HPV can persist in a wide range of temperatures and is resistant to desiccation, nonsexual transmission via fomites can also occur, such as by prolonged exposure to a contaminated object (ie: dirty sheets or clothes). This means HPV can be transmitted through seemingly harmless acts, such as open-mouthed kissing and even shared drinks.

During HPV transmission, HPV’s L1 protein binds to heparan sulfate proteoglycans (HSPGs) found in the lamina densa of the basal lamina (a part of the basement membrane) of the epidermis.

Although not all HPV strains are “dangerous”, at least three of the seven genital strains of HPV have been found to be oncogenic. In the case of cervical cancer, oncogenic HPV substrains 16, 18, and 33 have been found in 99% of cervical cancers worldwide. To make the connection to oral health, genomic DNA of oncogenic HPV (subtypes 16, 18, and 33) has been detected in approximately 26% of all head and neck squamous-cell carcinomas (HNSCC). Although the means by which oncogenic HPV subtypes become associated with the stratified squamous epithelium of the head and neck region is not well understood, emerging research suggests sexual behaviors may influence the transition from the genital region to the head and neck region, due to the efficacy of HPV transmission.

As a subclass of head and neck squamous-cell carcinomas, oral and oropharyngeal cancers also have a frequent association with HPV 16 (one of the oncogenic strains). One case study suggests that a high lifetime number of oral-sex or vaginal-sex partners, engagement in casual sex, early age at first intercourse, and infrequent use of condoms are all associated with HPV-16–positive oropharyngeal cancer. Another case study found that the odds of oral HPV infection increased with the number of oral sex partners or open-mouthed kissing partners, indicating that oral HPV infection is sexually acquired and is transmitted by behaviors as common as open-mouthed kissing.

Since dentists usually only screen for oral cancer in at-risk patients (usually frequent smokers), informing your dentist about your sexual habits will enable them to perform more thorough oral / oropharyngeal cancer screenings, thus possibly saving your life!

Sources: 

1) Workowski K. 2010. Sexually Transmitted Diseases Treatment Guidelines – 2010. Morbidity and Mortality Weekly Report Recommendations and Reports.

2) Burd E. 2003. Human Papillomavirus and cervical cancer. Clinical Microbiology Reviews. 16(1): 1–17.

3) Schiller J, Day P, Kines C. 2010. Understanding of the mechanism of HPV infection. Gynecologic Oncology. 118(1): S12-S17.

4) D’Souza G, Agrawal Y, Halpern J, Bodison S, Gillison M. 2009. Oral sexual behaviors associated with prevalent oral human papillomavirus infection. Journal of Infectious Diseases.  199(9): 1263-1269.

5) D’Souza G, Kreimer A, Viscidi R, Pawlita M, Fakhry C, Koch W, Westra W, Gillison M. 2007. Case–control study of human papillomavirus and oropharyngeal cancer. New England Journal of Medicine. 356(19): 1944-1956.