Tehran University of Medical Sciences Journal of Craniomaxillofacial Research 2345-5489 9 4 2023 07 25 170 175 EN Abbas Karimi Department of Oral and Maxillofacial Surgery, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran. Ata Garajei Department of Oral and Maxillofacial Surgery, School of Dentistry, Tehran University of Medical Sciences, Tehran, Iran AND Department of Head and Neck Surgical Oncology and Reconstructive Surgery, The Cancer Institute, School of Medicine, Tehran University of Medical Sciences, Tehran, Iran. Hesam Nazari Department of Oral and Maxillofacial Surgery, School of Dentistry, Kermanshah University of Medical Sciences, Kermanshah, Iran. Azadeh Emami Department of Anesthesiology, Iran University of Medical Sciences, Tehran, Iran. 2023 04 07 2023 06 19 Background: Microscopically, oral Squamous Cell Carcinoma (SCC) spreads more than the gross tumor. Thus it is recommended to resect the tumor with a proper safe margin. The aim of this study was to evaluate the correspondence between clinical and histopathological margins in oral SCC. Materials and Methods: Samples were collected from patients diagnosed with oral SCC and referred to Iran Cancer Institute in 2015. All margins of tumors were determined by a marker and then the tumors were resected with 1cm safe margin. The superior, inferior, left and right borders were marked and examined microscopically. The lowest distance between tumor cells and border of resected tissue was considered as pathological margin. The cases with pathological margin less or more than 5 millimeters were classified as close and free margin groups, respectively. Results: Forty-four specimens (20 females and 24 males), definitely diagnosed as SCC, were examined. The mean age was 61 years old. 19 cases (43.2%) were in the mandible; 23 cases (52.3%) in the tongue and 2 cases (4.5%) in the maxilla. 16 cases (38.4%) were free margin and 28 cases (63.6%) were close margin and the mean pathological margin was 3.52mm. Conclusion: For some cases, especially SCCs of the mandible, 1-centimeter margin is not adequate to achieve free margins, thus evaluating tumor location, size and stage for more resection seems worthwhile and advisable and can decrease the risk of relapse after resection. Keywords: Squamous cell carcinoma; Clinical margin; Histopathological margin. https://jcr.tums.ac.ir/index.php/jcr/article/view/433 https://jcr.tums.ac.ir/index.php/jcr/article/download/433/365