TP53 and lip and oral cavity carcinoma: Codon 72 polymorphism and a heterozygous mutation at codon 172 were observed in TP53 gene of OSCC patients. Tissue samples which showed codon 72 polymorphism, matched salivary DNA sequence. Similarly, tissue samples which showed codon 172 polymorphism, matched salivary DNA sequence The ORR approach has the potential to be used in clinical settings as an alternative to invasive tissue biopsy to detect genetic alterations in assumed biomarkers in oral cancer.