6Dahi BL, Carlsson GE, Ekfeldt A. Occlusal wear of teeth and restorative materials. A review of classification, etiology, mechanisms of wear, and some aspects of restorative procedures [ J ].Acta Odontol Seand, 1993,51:299-311.
7Murti PR , Bhonsle RB,Gupta PC, et al. Etiology of oral submucous fibrosis with special reference to the role of areca nut chewing[ J ]. J Oral Pathol Med, 1995,24 : 145-152.
8Lee CH, Ko AM, Warnakulasuriya S, et al. Inter- country prevalences and practices of betel-quid use in south, southeast and eastern Asia regions and associated oral preneoplastic disorders: an intema-tional collaborative study by Asian betel-quid con- sortium of south and east Asia[J]. Int J Cancer, 2011, 129(7):1741-1751.
9Gupta PC. Survey of sociodemographic characte- ristics of tobacco use among 99 598 individuals in Bombay, India using handheld computers[J]. Tob Control, 1996, 5(2):114-120.
10Ko YC, Chiang TA, Chang S J, et al. Prevalence of betel quid chewing habit in Taiwan and related sociodemographic factors[J]. J Oral Pathol Med, 1992, 21(6):261-264.
