Moderate gingivitis is present in at least 75% of the population. Although the strongest contributor to oral health is oral hygiene, there is a range of susceptibility caused by immune function and differences in plaque microflora. Pregnancy, oral contraceptive use, smoking, and diabetes are all associated with increased susceptibility to gum disease.¹

Oral sex has been associated with oral sores in some populations,² and can cause ulceration in the oral cavity.³ It may also spread infection from the oral cavity to the genital tract or vice versa, altering oral and genital microflora.⁴ The purpose of this study was to examine the association between sexual behaviour and self reported gum disease.

From 1999 to 2001, the Feminine Hygiene Study interviewed 411 African-American women seeking routine gynaecological care at two New York hospitals about their hygiene habits and health behaviours. Sexual practices were assessed, including “Within the last 3 months, how often have you received oral sex in which your partner’s mouth or tongue was touching your vulva/vagina?” and “Within the last 3 months, how often have you given oral sex in which you put your mouth or tongue on his penis and then followed by vaginal intercourse?” An average weekly frequency of giving oral sex was created by multiplying frequency of intercourse times a reported frequency of oral sex (1 for always, 0.75 for often, 0.5 for half the time, and 0.25 for occasionally). In addition, women were asked if they had been diagnosed with gum disease, if their gums bled when they brushed their teeth, and if they had bad breath.

Crude bivariate associations were estimated. Age, marital status, income, education, parity, sex partners, smoking, alcohol use, douching, and hormonal contraceptive use were examined as potential confounders. Variables that changed the beta coefficient of the main exposure by more than 10% were included in the full logistic model.

Approximately 5% of women often or always had bleeding gums when brushing their teeth; often or always had bad breath; or had been told they had gum disease. After controlling for potential confounders, giving oral sex was associated with gum problems (table 1). The odds ratio for gum bleeding, perhaps the best of our indicator variables of gum disease, was 3.5 (95% confidence interval 1.0 to 12.4). Those who reported giving oral sex most frequently had substantially raised risk of bleeding gums, while those who reported giving oral sex occasionally had somewhat higher risk.

To our knowledge, this is the first study to examine the association between oral sex and gum disease. We found that giving oral sex was significantly associated with gum problems. Although causality has yet to be established, it is plausible that giving oral sex may increase the risk of oral disease, either through introduction of microbes or mechanical trauma to the oral cavity. As would be expected if oral sex were directly leading to gum problems, the association was the strongest for women who performed oral sex on their partners, and virtually absent for those who only received oral sex. If the association were equally linked with giving and receiving oral sex, it would be more likely to be the result of confounding by social habits.

There are limitations to the observed data. The number of subjects with oral problems was small, the oral problems were self reported, and we did not collect information on oral hygiene practices. Although we controlled statistically for socioeconomic status and a number of other risk factors, residual confounding by oral hygiene may still have influenced the result. Secondly, we asked about giving oral sex followed by vaginal intercourse rather than simply giving oral sex. The question was worded in order to assess possible transmission of bacteria to the vagina. Although this might misclassify some women who gave oral sex without vaginal intercourse, the prevalence of reported oral sex in our study was similar to other studies,⁵ and it is difficult to imagine why women who had oral sex alone would have different oral health. Because of the increased prevalence of oral sex in the general population,⁴ the current interest in periodontal disease as a risk factor for chronic disease,⁶ and the high prevalence of gingivitis and periodontitis generally, more studies on this issue are warranted.

Contributors

EWH analysed the data and wrote the paper; JZ contributed to the design and data management of the study; MCH contributed to the design and the conduct of the study; all authors assisted with conceiving this analysis and reviewing drafts of the paper.