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Submental lymph nodes

Submental lymph nodes are a group of small, superficial lymph nodes located in the submental triangle, inferior to the chin (mental protuberance) and between the anterior bellies of the digastric muscles. They lie superficial to the mylohyoid muscle within the subcutaneous tissue of the midline anterior neck. These nodes primarily drain lymph from the central lower lip, anterior floor of mouth, tip of the tongue, and chin, and they ultimately drain into the submandibular lymph nodes. Submental nodes are usually 1–6 mm in size, soft, and non-palpable in healthy individuals but become enlarged in infection, inflammation, or malignancy.

Synonyms

  • Midline submental nodes

  • Anterior cervical lymph nodes

  • Submental cervical lymph nodes

Function

  • Filter lymph from the chin, anterior lower lip, floor of mouth, and tip of tongue

  • Participate in immune defense by trapping pathogens and foreign particles

  • Serve as early indicators of oral, mandibular, or anterior tongue infection or malignancy

  • Drain lymph into submandibular lymph nodes, maintaining midline cervical lymphatic flow

MRI Appearance

T1-weighted images:

  • Normal submental nodes appear as small, oval, hypointense to intermediate signal structures in subcutaneous fat

  • Surrounded by hyperintense fat, providing natural contrast

  • Pathological nodes may show cortical thickening, enlargement, or rounded morphology

T1 Post-Contrast (Gadolinium-enhanced):

  • Normal nodes may demonstrate mild, homogeneous enhancement

  • Enlarged or inflamed nodes show marked homogeneous or heterogeneous enhancement, highlighting the cortex and fatty hilum

  • Useful for detecting early metastatic involvement, abscess, or reactive lymphadenopathy

T2-weighted images:

  • Nodes show intermediate to slightly hyperintense signal, with surrounding fat bright

  • Pathological changes such as edema, inflammation, or infiltration are more conspicuous

  • Fatty hilum, if present, appears slightly hyperintense relative to cortex

STIR (Short Tau Inversion Recovery):

  • Fat suppression highlights node edema or pathology

  • Normal nodes remain low to intermediate signal, while inflamed or metastatic nodes appear bright hyperintense

  • Useful for detecting subtle lymphadenopathy

CT Appearance:

  • Submental nodes appear as small, soft tissue density structures within the subcutaneous fat of the submental triangle

  • Surrounded by air in the oral cavity, which provides hypodense contrast

  • Enlarged or pathological nodes appear as well-defined or irregular soft tissue masses

  • CT is particularly useful for assessing infections, metastatic involvement, or preoperative planning for oral and maxillofacial surgery

MRI images

Submental Lymph Nodes mri axial image -img-00000-00000