Brian, here is the book name, chapter, quotes and links (through OCF I can't copy pdf) to the two items I mentioned in this thread:

"HPV and Head and Neck Cancer. Guest Editor Sara I. Pai, MD, PHD
Otolaryngollogic Clinics of North America.Volume 45. Number 4. August 2012"

Biolgy of Human Papillomavirus Infection and Immune Therapy for HPV-Releated Head and neck cancer. Simon R. best, MD, Kevin J. Nipaerrko, AB, and Sara I. Pai, MD, PHD:

"Most HPV infections are cleared by the immune system within 2 years, defined as an absence of HPV DNA detection on follow-up serial swabs after after detectionof the initial infection. 2 At 12 months, 66% of infections are cleared; this increase to 90% at 24 months. However, in men, HPV-16 has been identified as one of the slowest viral types to be cleared, and takes nearly 2 times longer to be cleared than other high-risk viral types. 2. This is interesting finding because HPV-16 is the viral type that accounts for more than 90% of HPV related oropharyngeal cancers is the United States, and this disease is more prevalent in men than women, suggesting possible gender differences in the ability to mount immunologic responses agianst this viral type."

2. http://www.oralcancerfoundation.org/HPV/pdf/LANCET-HPV-in-men-2011.pdf

Peristant oral HPV infection is a risk factor for the development of HPV-related Oropharyngeal cancers. The prevalence of any HPV type in the oral cavity for both men and women is approximately 6.9%. However, when separated by gender it is signiifigantly higher in men (10%) than in women (3.6%). 5 Oral HPV infection is associated with certain sexual behaviors, with risk increasing with the number of oral sex partners. 6 In healthy individuals, the clearance rate for oral HPV infection at 6 months is approximately 40%. 7

5. http://www.oralcancerfoundation.org/HPV/pdf/Jama-2012.pdf