Lymph Vessels of the Hard Palate
This section includes the gingivae on the lingual side of the maxillary (incisor, premolar, and molar) teeth.
The lymph vessels of the hard palate mostly drain to the mandibular lymph nodes, and only a small number of lymph vessels, those from the part of the hard palate adjacent to the soft palate, drain to the medial retropharyngeal lymph node.
The lymph vessels from the rostral and middle thirds of the hard palate (from the maxillary incisors to the 4th molar) pass outwards through the spaces between the teeth, joining the lymph vessels from the gingivae on the labial side of the maxillary incisors and the buccal side of the maxillary premolar and molar teeth (see lymph vessels of the gingivae), accompanying them to the mandibular lymph nodes. The lymph vessels form extensive networks in and under the mucosal membrane of the hard palate; one consequence of this is that the median plane is crossed very often, so that when one half of the hard palate is injected, the dye almost always drains to the lymph nodes on the contralateral side. The individual lymph vessels can run for long distances under the mucous membrane, resulting in them passing through the cheek muscles at all points (up to the M. masseter) (Figure 13: 6, 7). In the more closely examined cases, the lymph vessels of the rostral third of the hard palate drained into the dorsal and ventral groups of the mandibular lymph nodes (Figure 13: 2, 2’, 2’’), whereas the lymph vessels of the middle third only drained to the dorsal mandibular lymph node (Figure 13: 2).
From the caudal third of the hard palate, some of the lymph vessels may also drain to the mandibular lymph nodes, though most drain to the medial retropharyngeal lymph node. The lymph vessels draining to the mandibular lymph node (Figure 14: 1’) run laterally around the last molar, and, at this location, join the corresponding gingival lymph vessels (see lymph vessels of the gingivae), emerging with them from under the M. masseter and descending to the dorsal mandibular lymph node. The lymph vessels draining to the medial retropharyngeal lymph node (Figure 14: 1) originate from the caudal-most part of the hard palate (that is, the part of the hard palate adjacent to the soft palate); these vessels run over both surfaces of the M. pterygoideus and join the corresponding lymph vessels of the soft palate and tonsil (see lymph vessels of the soft palate and tonsil).
