Inverse association between toothbrushing and upper aerodigestive tract cancer risk in a Japanese population.
BACKGROUND
Oral hygiene is attracting increasing attention as a potential risk factor for cancers. To investigate the association between toothbrushing frequency and upper aerodigestive tract (UADT) cancer, the authors conducted a large-scale case-control study.


METHODS
A total of 856 UADT cancer case participants and 2696 age- and sex-matched control subjects without cancer were included. Edentulous or participants with unknown frequency of toothbrushing or number of remaining teeth were excluded. Associations were assessed by odds ratios and 95% confidence intervals in logistic regression models with adjustment for potential confounders.


RESULTS
Compared with toothbrushing once per day, the adjusted odds ratio for brushing twice or more was 0.82 (95% confidence interval: 0.68, 0.99) whereas that for not brushing was 1.79 (0.79, 4.05). This association was observed especially in subjects who had a history of heavy smoking or drinking.


CONCLUSIONS
The authors suggest that toothbrushing could have a protective effect for UADT cancer.
Division of Epidemiology and Prevention, Aichi Cancer Center Research Institute.
Fumihito
F
Sato
Isao
I
Oze
Daisuke
D
Kawakita
Noriyuki
N
Yamamoto
Hidemi
H
Ito
Satoyo
S
Hosono
Takeshi
T
Suzuki
Takakazu
T
Kawase
Hiroki
H
Furue
Miki
M
Watanabe
Shunzo
S
Hatooka
Yasushi
Y
Yatabe
Yasuhisa
Y
Hasegawa
Masayuki
M
Shinoda
Minoru
M
Ueda
Kazuo
K
Tajima
Hideo
H
Tanaka
Keitaro
K
Matsuo
D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D000428:Alcohol Drinking / Q000009:adverse effects / Q000453:epidemiology; D002294:Carcinoma, Squamous Cell / Q000453:epidemiology* / Q000473:pathology; D016022:Case-Control Studies; D015331:Cohort Studies; D016001:Confidence Intervals; D004938:Esophageal Neoplasms / Q000453:epidemiology / Q000473:pathology; D005260:Female; D006258:Head and Neck Neoplasms / Q000453:epidemiology* / Q000473:pathology; D006801:Humans; D007012:Hypopharyngeal Neoplasms / Q000453:epidemiology / Q000473:pathology; D015994:Incidence; D007564:Japan / Q000453:epidemiology; D007822:Laryngeal Neoplasms / Q000453:epidemiology / Q000473:pathology; D016015:Logistic Models; D008297:Male; D008875:Middle Aged; D009062:Mouth Neoplasms / Q000453:epidemiology / Q000473:pathology; D016017:Odds Ratio; D009910:Oral Hygiene; D012016:Reference Values; D018570:Risk Assessment; D017678:Sex Distribution; D012907:Smoking / Q000009:adverse effects / Q000453:epidemiology; D014099:Toothbrushing / Q000706:statistics & numerical data*