BackgroundWe aimed to define the indications for sentinel lymph node biopsy (SLNB), the third option for cervical treatment in oral cancer with negative cervical lymph nodes.MethodsThe greatest depth of invasion (DOI) and long diameter (LD) of the primary site were used as exposures. SLN metastasis was considered the outcome.ResultsIn three trials conducted between 2009 and 2016, 158 patients were eligible and reassigned to this study group. The scatterplot based on the respective values of DOI and LD would eventually be divided into three sections. In cases of sections T1, T2, and T3, the proportions of SLN metastasis positivity were 21.3%, 35.3%, and 51.2%, respectively. In certain cases of T1 with 2 mm < DOI ≤ 5 mm and 8 mm < LD ≤ 20 mm, the proportion of SLN metastasis positivity was 40.9%.ConclusionsSLNB‐navigated or assisted neck dissection can be added as an effective procedure for N0 neck control.