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Ch.26 Skull Osteology Part II
Paranasal or Sphenoid Sinuses (pair)
4 pairs of cavities in the bones around nasal cavity Behind maxillae
project down from body of Sphenoid, just behind Maxillae. Med. & Lat. Pter. plates.
largest, most troublesome of paranasal sinuses. Form thin wall of bone btw roots of maxillary posterior teeth & sinus spaces themselves.
anterior nasal spine
Small projection of maxillae at the bottom of the nasal aperture. Lower end, front nasal cavity. (landmark often used in ortho. xrays)
some anter. teeth n premolars cause these bulges.
behind Maxillae 3rd molars. Posterior bulge of bone. Blood vessels, nerves enter bone to supply posterior teeth n part of maxill. sinus, much growth of maxil. takes place.
Insufficient growth of Maxillary Tuberosity
inadequate room for wisdom teeth to erupt & Maxil. may be shorter than should be. Mandible looks more forward, cause Class III occlusion.
Hiatus or Ostium of maxillary sinus
opening into nasal cavity, varies in size. Medial view of Maxillae.
runs down from inner corner of eye. Tears flow into nose=runny nose when crying!
tip of chin area
slightly narrowed area just beneath condyle of mandible, which articulates with temporal bone to make TMJ
Coronoid or Mandibular Notch
Depression in Ramus, in front of condyle.
Bony projection at upper anterior ramus of mandible; point of attachment for temporal muscle. Just anterior to Cor. Notch.
External Oblique Line
anterior border of ramus ends here. Shows up as radiopacity on posterior periapical or pantographic radiographs.
midway up ramus, nerves and blood vessels for lower teeth & lip enter mandible
Just in front of the foramen, running forward & down. Attachment for Myloh. muscle
Sublingual & Submandibular fossae
2 depressions in bone, toward anterior part of Myloh. line-one above, one below the line. Glands lie in these depressions.
Behind Mandible 3rd molars. (denture construction, landmarks)
External Oblique Line
Lateral margin of R. Triangle
Internal Oblique Line
Medial margin of R. Triangle
Superior & Inferior Genial Tubercles or Mental Spines
2 small, grouped projections at midline, one above, one below. Attachments for muscles that aid in tongue movement & swallowing - Genioglossus, Geniohyoid.
"little tongue" Projection of bone partially covers opening of mandibular foramen.
just below Genial projections at inferior border of mandible. Pts of attachment for anterior digastric muscle.
Lingula is pt of attachment. Location & size may affect success of anesthetic injections in area.
How many bones form the skull?
How are the bones subdivided?
Which bones form the hard palate?
Palatal process of maxilla, Palatal process of palatine bone
Another name for each:
Where is largest paranasal sinus?
Name area behind Maxillary 3rd molars
Divisions of Mandible?
Body, Alveolar process, Ramus
Where is Sphenoid Sinus?
Paranasal sinuses, within the body, just behind Maxillae.
What bones make up rim of orbit?
Frontal, Maxillae, Zygomatic
Ethmoid (upper) + Vomer (lower)