Anatomy and Location
The greater palatine canal is a downward continuation of the pterygopalatine fossa (fossa pterygopalatina).
Its walls are formed by the articulation of two bones:
- Maxilla (maxilla): features the greater palatine groove (sulcus palatinus major) on its nasal surface (facies nasalis).
- Palatine bone (os palatinum): the opposing groove on the perpendicular plate of the palatine bone.
Together, these grooves form a bony canal that opens into the oral cavity via the greater palatine foramen (foramen palatinum majus) and lesser palatine foramina (foramina palatina minora).
Contents of the Greater Palatine Canal
The canal transmits neurovascular structures traveling from the pterygopalatine fossa to the oral and nasal cavities:
- Descending palatine artery (a. palatina descendens) — a branch of the third (pterygopalatine) part of the maxillary artery. Within the canal, it branches into the lesser palatine arteries (aa. palatinae minores), supplying the soft palate and palatine tonsil, and the greater palatine artery (a. palatina major), which courses along the hard palate.
- Palatine nerves (nn. palatini) — branches arising from the pterygopalatine ganglion, divided into three groups including the greater palatine nerve (n. palatinus major) and lesser palatine nerves (nn. palatini minores).
- Posterior inferior lateral nasal branches (rami nasales posteriores inferiores laterales) — branches of the pterygopalatine ganglion that enter the canalis palatinus major before exiting through minor foramina into the nasal cavity.
Blood Supply and Innervation Territories
Structures passing through the greater palatine canal supply and innervate the following regions:
- Hard palate: The greater palatine nerve supplies the mucosa of the posterior and middle hard palate up to the canine tooth, mucous glands, and gingival mucosa on the palatal side. The greater palatine artery runs anteriorly along the hard palate, anastomosing with the sphenopalatine (posterior septal) and superior labial arteries.
- Soft palate: The lesser palatine arteries supply the soft palate and tonsil. The greater palatine nerve partially innervates the soft palate mucosa.
- Nasal cavity: The posterior inferior lateral nasal branches innervate the mucosa of the inferior nasal concha, inferior and middle meatuses, and maxillary sinus.
Topography and Communications
The greater palatine canal is a key communication pathway of the pterygopalatine fossa, linking it directly to the oral cavity.
The greater palatine artery forms anastomoses with the posterior septal and superior labial arteries.