Are flossing and obesity linked?

The mouth is indeed connected to the rest of the body, but how oral health behaviors affect the rest of the body is a tricky question. Spurious or false connections can be made, depending on the research question asked. Reporting the frequency of flossing and the incidence of obesity can confound actual relationships. Researchers in Boston reported the findings for obesity and flossing frequency in a group of 1,483 individuals who scheduled periodontal examinations. Of this group, 37% reported daily flossing and 21% were classified as obese. Fewer obese people reported daily flossing than those classified as normal or overweight. Does this mean flossing prevents obesity?

It is possible that good general health awareness – eating well and exercising – surely has more impact on obesity than oral habits. This may also fit for oral habits and oral disease – better eating habits may prevent dental disease more than oral habits. Jumping to conclusions is dangerous when comparing oral habits and systemic conditions.

The editors of the Journal of Clinical Periodontology added a note, suggesting that the terminology “systemic disease” be replaced with “other disease” to break down the barrier between the oral cavity and the rest of the body. For example: “There is observational evidence that periodontal disease may be associated with other diseases, but that the causal associations between periodontal disease and other diseases has not been established.”

Clinical Implications: When reading research, ask yourself, does it make sense? Does one thing actually cause the other? Researchers must ask the right question, at the right time, in order to discover relevant information.

Hujoel, P., Cunha-Cruz, J., Kressin, N.: Spurious Associations in Oral Epidemiological Research: The Case of Dental Flossing and Obesity. J Clin Perio 33: 520-523, 2006.

Neaton, J., Mugglin, A.: From Observational Studies to Randomized Trials: Asking the Right Question at the Right Time. J Clin Perio 33: 517-519, 2006.

Dominant hand makes no difference in probing accuracy

Periodontal probing is an essential part of data gathering to determine periodontal health. Several factors influence the accuracy of periodontal probing: probe design and handling, condition of the periodontal tissues, access to the areas being probed, and the experience of the clinician. Many aspects of periodontal probing have been investigated, such as probing force, probe placement, probe angulation, manual dexterity, and accuracy of probe readings. This is the first study to evaluate the effect of right or left-handedness on periodontal probing.

Researchers in the Department of Periodontics at Indiana University compared probings done by five right-handed and five left-handed examiners on a total of eight patients. Before the study began, examiners underwent calibration training until measurements agreed with the calibrator within 1 mm at over 50% of sites and within 2 mm at over 90% of sites. Each of the examiners, but no more than two per day examined each patient, with a week between visits. Probing was done with a manual UNC probe. One probe was assigned to each patient and all examiners used that probe for their measurements: six sites per tooth. Interestingly, all examiners were positioned on the right side of the patient.

Although the left-handed examiners tended to have shallower readings in some areas, there was no statistical difference between the right-handed and left-handed examiners. Probing depths ranged from 1 mm to 9 mm with the full-mouth average being 2.5 mm. Approximately 15% of sites measured 4 mm or deeper and 1.5% of sites were 6 mm or deeper. A total of 1,278 sites were evaluated.

No differences were found between right and left-handedness at individual sites, or for the percentage of sites 4 mm or more or sites 6 mm or more. A previous study by Owens found deeper probing depths on the right side of the mouth, compared to the left side. This study confirmed those finding, with deeper reading on the right compared to the left.

Clinical Implications: Probing depths should be consistent between dentists and hygienists without regard for right or left-handedness. If calibrated, clinicians should measure within a millimeter of one another.

Khan, S., Blanchard, S., Dowsett, S., Eckert, G., Kowolik, M.: Periodontal Assessment by Right- and Left-Handed Examiners: Is There a Difference? J Perio 77: 1099-1103, 2006.

Snuff not associated with bone loss

Cigarette smoke contains many toxins thought to be responsible for increasing periodontal disease in smokers. Smokeless tobacco use includes many forms of tobacco, mainly chewing tobacco (loose leaf, plug, or twist) and snuff (moist or dry). Because of the differences, comparisons are difficult when various forms of tobacco are included in a study.

Researchers in Stockholm, Sweden evaluated moist snuff use among employees in the submarine service of the Swedish Armed Forces. A total of 84 men between 26 and 54 years of age were evaluated. Current snuff users numbered 25, former snuff users 21, and never users 38. In Sweden, snuff is used by 20% of men and 3% of women. Smoking is found in 17% of men and 18% of women.

Bitewing radiographs were evaluated to determine bone loss. No significant differences were found between current, former and never users of snuff. Swedish moist snuff is routinely placed in the maxillary anterior region and mucosal lesions have been observed there. Based on findings of this study, the effects of moist snuff do not extend beyond the site of placement.

An American study published last year reported bone loss associated with smokeless tobacco use; however, when those with a history of smoking were removed from the data, bone loss was not associated with smokeless tobacco use. Two studies published in 1998 and one in 2005 were unable to show a connection between moist snuff and oral cancer or head/neck cancer.

Clinical Implications: There are many reasons to council patients to stop using Swedish moist snuff; however, periodontal bone loss is not one of them.

Bergström, J., Keilani, H., Lundholm, C., Radeståd, U.: Smokeless Tobacco (Snuff) Use and Periodontal Bone Loss. J Clin Perio 33: 549-554, 2006.

Tongue scraping reduces bad breath

Researchers in Brazil compared flossing and tongue scraping to determine the impact on oral malodor. Volunteers were dental students between 19 and 22 years of age with excellent oral health. Four test groups were assigned and the cross-over study design allowed each student to participate in each of the four groups: brushing only; brushing and flossing; brushing, flossing and tongue scraping; and brushing and tongue scraping. Each test cycle was seven days, followed by a seven-day washout period. At the beginning and end of each test cycle, mouth odor was measured in two ways: organoleptic (using an odor judge) and with a sulfide monitor.

A screen with a disposable tube separated the trained odor judge and each subject. Subjects were asked to close their mouths around the tube for 60 seconds, breathe through their nose and not swallow. The tube with mouth air led right to the odor judge’s nose. Readings were recorded immediately. There was a positive correlation between organoleptic and sulphur readings for baseline and seven-day readings.

Baseline scores were the same for all groups. Higher malodor scores were measured following brushing alone and brushing and flossing. The lowest odor scores were recorded for both tongue cleaning groups. The use of dental floss did not significantly reduce oral malodor. The tongue provides a large surface area for bacterial biofilm to accumulate and produce volatile sulphur compounds.

Clinical Implications: Those concerned about bad breath should be instructed to clean their tongues daily using a tongue scraper.

Faveri, M., Hayacibara, M., Pupio, G., Cury, J., Tsuzui, C., Hayacibara, R.: A Cross-Over Study on the Effects of Various Therapeutic Approaches to Morning Breath Odour. J Clin Perio 33: 555-560, 2006.