Lymph Drainage & Fascial Spaces

Where dental structures drain (primary nodes)

Nodes	Drain
Submental	Mandibular incisors and their gingiva, tip of the tongue, floor of mouth anteriorly, chin, middle of the lower lip
Submandibular	Most other teeth and gingiva, cheeks, upper lip, lateral lower lip, anterior hard palate, body of the tongue; also receive submental drainage
Superior deep cervical (incl. jugulodigastric)	Maxillary third molars (often), posterior hard palate, soft palate, base of the tongue, tonsils

All head and neck lymph ends in the deep cervical chain and then the thoracic duct (left) or right lymphatic duct.
Infected nodes: tender, soft, mobile. Malignant nodes: hard, painless, fixed (matted).

Source	Rule	Space
Mandibular incisors	Apex below the mentalis attachment	Submental
Mandibular premolars and first molar	Apex above the mylohyoid line	Sublingual
Mandibular second and third molars	Apex below the mylohyoid line	Submandibular
Mandibular molars (buccal)	Apex below the buccinator attachment	Buccal space (above it: vestibular abscess)
Maxillary molars (buccal)	Apex above the buccinator attachment	Buccal space (below it: vestibular abscess)
Maxillary canine	Apex above the levator anguli oris	Canine (infraorbital) space; danger of cavernous sinus spread
Maxillary third molar	Posterior and superior spread	Infratemporal space
Mandibular third molar	Posterior spread	Masticator spaces (pterygomandibular, submasseteric) → trismus; then lateral pharyngeal

Ludwig angina: bilateral cellulitis of the submandibular, sublingual and submental spaces, usually from mandibular molars; raised tongue, drooling, brawny neck swelling, airway compromise. Airway first, then drainage and antibiotics.
Lateral pharyngeal → retropharyngeal → danger space (between the alar and prevertebral fascia) → posterior mediastinum.
The pterygomandibular space is where the IANB is deposited; a contaminated needle can seed infection there.

Sending second and third molar infections to the sublingual space: their apices are below the mylohyoid line, so they go submandibular.
Draining the mandibular incisors to the submandibular nodes: they drain to the submental nodes first.
Treating Ludwig angina as a simple abscess: it is a spreading cellulitis and an airway emergency.
Calling a hard, fixed, painless node 'reactive'.

Pick an answer to see right away whether it is correct and why.

A periapical abscess on a mandibular second molar perforates the lingual plate. Which space is most likely involved?
Primary lymph drainage of the mandibular central incisors is to the:
Which tooth's infection carries the greatest risk of spreading to the cavernous sinus through the canine space?
Ludwig angina involves which spaces?
A palpable node is hard, painless and fixed. This is most suggestive of:

0 of 5 answered

Answer key: 1 A · 2 B · 3 C · 4 B · 5 C

Dental School Map · Original study material, written and checked by our team; always confirm clinical decisions against current guidelines.