The submandibular space lies between the mylohyoid muscle and anterior layer of the deep cervical fascia, just deep to the platysma muscle, and includes the lingual and inferior surfaces of the mandible below the mylohyoid muscle attachment. (Modified from Flint PW, Haughey BH, Lund VJ, et al, eds. Cummings Otolaryngology: Head and Neck Surgery. 5th ed. Philadelphia: Elsevier;