During ultrasound examinations in patients with dysphagia, deficiencies in the mylohyoid muscle with herniation of the sublingual gland were found, which may be mistaken as soft tissue tumors. Between the years 2001 and 2003, 205 half-heads used in dissection courses were examined to determine the location and contents of these gaps. In 25 of these cadaveric specimens, the hiatus (of variable size) appeared as small fissures between the divided fibers of the mylohyoid. In 18 cases (72%), the sublingual gland slipped through these deficiencies and occurred in the front part of the submandibular triangle. From the inferior surface of the muscle, the submental artery also coursed through the separated muscle fibers. The herniations of 7 specimens (28%) were found without any contents, neither with gland perforation nor with a submental artery. The following study points out the spatial relation of the salivary glands to the floor of the mouth and the clinical significance, and some factors referred to the development of herniations are discussed.