Bechara Y. Ghorayeb, MD
OTOLARYNGOLOGY - HEAD & NECK SURGERY
Memorial Hermann Professional Building
1140 Business Center Drive, Suite 560
Houston, Texas 77043
For appointments, call: 713 464 2614
Jaw cysts are broadly defined as an epithelial-lined space within bone.
They are classified as being either nonodontogenic (fissural), such as nasopalatine duct cysts, median palatal cysts, globulomaxillary cysts, and nasolabial cysts; or, odontogenic, such as apical cysts, dentigerous cysts, primordial cysts, odontogenic keratocysts, and residual cysts.
Odontogenic and nonodontogenic cysts are distinguished based on the ontogeny of the epithelium rests from which the cysts are thought to derive, with odontogenic jaw cysts arising from tooth development epithelium, and nonodontogenic jaw cysts arising from epithelium trapped during the fusion of upper jaw bones during embryonic development at sites of fissures.
Nonodontogenic jaw cysts may be further differentiated from one another based on anatomic location: nasopalatine duct cyst (incisural canal), medial palatal cyst (midline of hard palate), globulomaxillary cyst (between premaxilla and maxilla) and nasolabial cysts (along side of nose). Of note, some authors have stopped distinguishing nasopalatine duct cysts from medial palatal cysts, arguing that medial palatal cysts are merely more posterior manifestations of a nasopalatine duct cyst.
The Hard Palate
(The Palatal Process of the Maxilla)
The hard palate is much thicker in front than behind, and forms a considerable part of the floor of the nostril and roof of the mouth.
On the palatal surface of the palatal process, a delicate linear suture may sometimes be seen extending from the anterior palatine fossa to the interval between the lateral incisor and the canine tooth. This marks the intermaxillary or incisive bone, which is commonly called premaxilla. It includes the whole thickness of the alveolus, the corresponding part of the floor of the nose, and the anterior nasal spine, and contains the sockets of the incisor teeth.
The inferior surface of the hard palate is concave, rough and uneven, and forms part of the roof of the mouth. This surface is perforated by numerous foramina for the passage of nutrient vessels, channeled at the back of its alveolar border by a longitudinal groove, sometimes a canal, for the transmission of the posterior palatine vessels, and the anterior and external palatine nerves from the second division of the trigeminal.
Where the left and right superior maxillary bones are articulated together, a large orifice may be seen in the midline, immediately behind the incisor teeth. This is the anterior palatine canal or incisive fossa.
On examining the bottom of this fossa, four canals are seen: two branch off laterally to the right and left nasal fossae, and two, one in front and one behind, lie in the midline.
The two lateral canals are named foramina of Stenson. They transmit the terminal branch of the descending or posterior palatine arteries, which ascend from the mouth to the nasal fossae.
The two canals in the midline are termed foramina of Scarpa. They transmit the nasopalatine nerves, the left passing through the anterior canal and the right passing through the posterior.
The superior surface of the hard palate is concave from side to side, smooth and forms part of the floor of the nose. The upper orifices of the foramina of Stenson are visible, however, the foramina of Scarpa are located in the intermaxillary suture and, therefore, are not visible unless the two maxillary bones are placed in apposition.
Adapted from :
Descriptive and Surgical
By Henry Gray
A revised American From The Fifteenth English Edition
Bounty Books. New York pp. 86-87, 1977