Tehran University of Medical Sciences Journal of Craniomaxillofacial Research 2345-5489 10 3 2023 12 09 107 113 Ata Garajei Department of Oral and Maxillofacial Surgery, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran; Department of Head and Neck Surgical Oncology and Reconstructive Surgery, The Cancer Institute, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Narges Hajiani Department of Oral and Maxillofacial Surgery, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Azadeh Emami Department of Anesthesiology, Iran University of Medical Sciences, Tehran, Iran. 2023 09 10 2023 11 25 Introduction: Oral Squamous Cell Carcinoma is the 6th most prevalent cancer worldwide. The global increase in frequency and mortality of oral SCC has been shown. There are few studies about the risk factors for oral SCC in Iran. This study is based on finding a possible relationship between oral SCC and some lifestyle factors in the Iranian population. Materials and Methods: This case-control study was conducted at the Iran Cancer Institute in Tehran. The controls were matched to the cases by age and gender and socio-economic status. A number of 204 individuals (102 cases and 102 controls) were interviewed by using a structured questionnaire to obtain data regarding oral hygiene, dietary factors, smoking habits, alcohol consumption and lifestyle risk factors for oral squamous cell carcinoma. Results were analyzed by chisquare and Fisher exact test. P values less than 0.05 were considered significant. Results: The mean age of cases at diagnosis was 60.03 years and 52.9% were male. The analysis showed that poor oral hygiene, low intake of fruits and vegetables (P<0.001), low intake of dairy (P=0.029), alcohol consumption (P=0.015), cigarette smoking (P=0.002) in years and pack per year of smoking (P<0.001) are independent risk factors for oral SCC. Conclusion: The study provided strong evidence that poor oral hygiene, poor dietary factors, smoking habits and alcohol consumption play an etiological role for oral SCC in the Iranian population. Keywords: Risk factors; Oral squamous cell carcinoma. https://jcr.tums.ac.ir/index.php/jcr/article/view/459 https://jcr.tums.ac.ir/index.php/jcr/article/download/459/384