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.pdfPeristant 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