The Role of the Mylohyoid Line in the Spread of Mandibular Odontogenic Deep Neck Infection

Introduction: Although mandibular odontogenic deep neck infections are occasionally fatal, the transmission pathway has not been elucidated.
Materials and Methods: This multicenter retrospective study was comprised of the patients of both sexes who were over 18 years of age and who had mandibular odontogenic deep neck abscesses. The patients' characteristics, laboratory tests, and radiographic findings were analyzed.
Results: One hundred eighteen patients with mandibular odontogenic deep neck abscesses were included. Bone resorption superior to the mylohyoid line and the related abscess formation in submandibular space or submental space were both significantly associated with the presence of sublingual space abscess. In addition, the type of causative tooth was not a risk factor for abscess formation in both the sublingual space and “submandibular or submental” space.
Conclusions: When an odontogenic lesion is located superior to the mylohyoid line, the abscess tends to initially form in the sublingual space and subsequently spread to the submandibular or submental space. Since any mandibular tooth can lead to abscess formation in these regions, oral and maxillofacial surgeons should carefully assess the anatomical position of the lesion and accurately identify the causative tooth.