Adults have four teeth, the larger pair is situated apically, with the smaller pair positioned posterior to a short diastema. The apical teeth project obliquely forward well beyond upper lip.The smaller posterior teeth are concealed by the closed mouth.
The teeth erupt around the onset of sexual maturity in both sexes.
The larger apical teeth are triangular and laterally compressed. The greatest traverse diameter of an apical tooth exceeds 28 mm, which is wider than those of Mesoplodon. The posterior teeth are peg-like.