Table 2.

Summary of studies to define human buccal cell changes associated with smokeless tobacco and similar-use substances

No.First author (year) (ref.)Tobacco used or chewing behaviorBuccal cell change*,Remarks
1Goral (1999) (64)Moist snuffYesSignificant buccal cell alterations were recorded in a study of buccal cells of smokeless tobacco users.
Chewing tobaccoYes
Dip tobaccoYes
2Ramaesh (1999) (65)Smoked tobaccoYesThe effect of tobacco use on buccal mucosa was assessed by cytomorphometry of buccal cells. A significant increase was discovered for cells in all habit groups. There was a significant reduction in the cell diameter of the chewing group and the combined habit group compared with the control nonuser group.
Betel chewers with tobaccoYes
Smoke and chewYes
Nontobacco usersNo
3Ozkul (1997) (66)Chewed maras powderYesThere was no difference in the micronuclei of buccal cells of subjects who smoked or chewed smokeless tobacco (maras powder). Buccal cells of both groups showed a higher frequency of micronuclei than nonusers (nonsmokers, nonchewers).
Smokers, no marasNo
Nonsmokers, no marasYes
4Roberts (1997) (67)SnuffYesComparative cytology of the oral cavity was conducted to define the effects of snuff users. The regular use of snuff caused an increase in the incidence of buccal cell micronuclei, loss of cell cohesion, and hyperkeratosis.
5Desai (1996) (68)Betel nutYesThe exfoliated oral mucosal cells had significantly higher numbers of micronuclei compared with those of healthy normal subjects having no chewing or smoking habit.
Pan masalaYes
6Ghose (1995) (69)Tobacco smokers with Pika habitYesIn India, tobacco smokers with Pika habit showed higher frequency of micronuclei of buccal cells than tobacco chewers with Dungia habit.
Tobacco chewers with Dungia habitYes
7Kayal (1993) (70)Areca nutYesAll groups studied (see listing) had a significantly higher frequency of micronuclei of buccal cells than nonusers from different parts of India. Patients with oral leukoplakia had a high incidence of micronucleated cells in spite of the fact they had stopped chewing months before collection of the oral mucosa cells.
Tobacco with limeYes
Dry snuffYes
8Stich (1992) (71)Reverse cigar smokersYesAn elevated frequency of micronuclei of buccal cells was documented for reverse cigar smokers and Khaini-tobacco chewers; no increase was observed for gudakhu users.
Khaini-tobacco chewersYes
Gudakhu usersNo
9Das (1992) (72)GudakhuYesThe incidence of micronuclei was increased in users, and the increased incidence was correlated with the period of use. There were no significant differences between men and women.
10Dave (1992) (73)Areca nutYesA clinical study in India showed statistically significant increases in the frequencies of micronuclei among of chewers compared with controls.
11Adhvaryu (1991) (74)MavaYesWhen compared with healthy controls, a clinical study showed a significant increase in micronuclei of buccal cells for all three groups studied (chewers free of oral disease, chewers with oral submucous fibrosis, and chewers with oral cancer).
12Dave (1991) (75)Pan masalaYesBuccal cells collected from the site where the pan masala was placed showed a statistically significant (P < 0.001) increase in micronuclei of buccal cells compared with nonconsuming controls.
Pan masala with tobaccoYes
13Nair (1991) (76)Betel quid with tobaccoYesSignificantly elevated micronuclei frequencies of buccal cells were observed in the exposed groups compared with the control group. No correlation was seen among age, duration, and frequency of habits.
Tobacco with limeYes
14Tolbert (1991) (77)SnuffYesA study was conducted of subjects who use snuff at levels known to be associated with a significant increase in cancer risk. The prevalence of micronuclei was elevated in the snuff users compared with the nonusers (prevalence ratio = 2.4) and, to a lesser extent, at the contact site compared with a distal buccal site in the snuff users (prevalence ratios = 2-13).
15Livingston (1990) (78)Smokeless tobaccoYesCytologic and cytogenetic studies were done to assess the prevalence of somatic cell genetic damage in 48 young adults (college students) equally divided into users and nonusers of smokeless tobacco. The frequency of micronuclei of buccal cells was significantly higher in users than nonusers (P = <0.01).
16Stich (1988) (79)Betel quid with tobaccoYesRemission of oral leukoplakias and micronuclei in tobacco/betel quid chewers treated with β-carotene and with β-carotene plus vitamin A. Remission and inhibition of new oral leukoplakias and reduction of micronuclei of mucosal cells occurred in the groups receiving β-carotene and β-carotene plus vitamin A during the continuous presence of carcinogens derived from tobacco and areca nut.
17Stich (1985a) (80)SnuffYesA pilot β-carotene intervention trial with inuits using smokeless tobacco. β-Carotene seemed to be an efficient inhibitor of micronuclei formation in buccal cells of snuff users who do not suffer from any vitamin A deficiency and who had normal levels of retinol.
18Stich (1985b) (81)Areca nutYesDefined the frequency of micronuclei of buccal cells from areca nut and/or tobacco users. When compared with subjects who used areca nut only, all others (see listing to left) showed a significant increase in micronuclei frequency. Authors review critical buccal cell assay variables and statistical methodologies to be used in future large-scale screening programs.
Areca nut + lime + betel leafYes
Areca nut + lime + betel leaf + tobaccoYes
Tobacco + lime + ash + oilYes
Tobacco + limeYes
19Stich (1984a) (82)Betel (areca) nut/tobacco chewersYesThe frequency of exfoliated cells with micronuclei in buccal mucosa swabs was used to estimate the protective effect of vitamin A, β-carotene, and canthaxanthin on the buccal mucosa of betel (areca) nut/tobacco chewers. The betel (areca) nut/tobacco chewers served as their own controls. Following a 9-week ingestion of vitamin A and β-carotene the frequency of micronuclei-positive cells decreased significantly.
20Stich (1984b) (83)Betel nut and tobaccoYesReduction with vitamin A and β-carotene administration of proportion of micronuclei in Asian betel nut and tobacco chewers.
21Stich (1983) (84)Betel nut (“pan”)YesThe frequency of micronuclei of buccal cells was significantly elevated in all examined betel quid chewers. The betel nut/tobacco mixture of a “pan” seems to be more genotoxic than the chewing of raw betel nut alone. Khaini tobacco only produced less micronuclei in cells than the betel nut with or without tobacco.
Betel nut and tobaccoYes
Khaini tobacco onlyYes
22Stich (1982a) (85)Betel quidYesElevated frequency of micronuclei in buccal cells of individuals at high risk for oral cancer-betel quid chewers. The micronuclei frequency was lower among individuals chewing a raw betel nut, betel leaf, and lime mixture compared with those using quids with tobacco, betel nut, lime, or betel leaf.
23Stich (1982b) (86)Betel quidYesThe frequency of micronuclei of buccal cells in all three groups of chewers compared with a group of nonchewing subjects.
Khaini (tobacco and lime)Yes
Raw betel nutYes
  • * For all reports, buccal cell changes were evaluated using the micronuclei assay.

  • Statistically significant association identified between buccal cell changes and chewing: positive (yes) or negative (no) association.