OCMM midline Bones Flashcards
cranial base is composed of the unpaired bones:
sphenoid and occiput
unpaired facial bones
ethmoid, mandible, vomer and frontal
paired bones of the cranial vault
parietal, tmeporal, squamous temporal and frontal
facial paired bones
inferior nasal concha, lacrimal, maxilla, nasal, palatine, zygoma
motion of midline bones
usually rotate about a trasverse axis in an anterior/posterior direct
even when it is labeled a flexion/extension
motion of paired bones
usually move about an AP axis in a alteral motion (coronal plane)
external rotation or internal rotation
motion of the SBS in flexion
sphenodi rotates about a transverse axis so that the wings move anteriorly
SBS movfes superior
occiput rotates along a transverse axis and moves posterior and inferior
four components of the ethmoid
cribiform plate
perpendicular plate
two lateral masses
describe flexion of the ethmoid
perpendicular plate is roatated by the sphenoid about its transverse axis
swings he crista galli SUPERIORLY AND POSTERIORLY
effects of external rotation of the maxillae on the ethmoid
lateral masses expand inferiorly
describe extension of the ethmoid
crista galli moves inferior and anterior along its transverse axis
effects of internal rotation on the ethmoid
lateral masses compress inferiorly
what drives the vomer
sphenoid
vomer in flexion
wide flat palate
depresses the hard palate, flattening the roof of the mouth
vomer in extension
narrow tall palate
ascends to allow premaxillae to externally rotate
when the SBS is in flexion, the
ethmoide will mvoe in the same direction as the _____
vomer will move in the same direction as the _____
ethmoid and occiput
vomer and sphenoid
vowels move together, consonants move together
in flexion, what happens to the palatine bones
follows the maxillae into external rotation and
PALATE FLATTENS
in extension, what happens to the palatine bones
follows the maxillae into internal rotation and PALATE RISES
number of axes in SBS vertical strain
2
horizontal and left-right
how do you name a vertical strain?
by the directi onof the basisphenoid
sphenoid is in flexion, vertical strain
superior vertical strain
bones rotate anteriorly
sphenoid is in extension, vertical strain
inferior vertical strain
bones rotate posteriorly
superior vertical strain
sphenoid is flexed with rotation around its transverse axis and basisphenoid superior; bilateral anterior quadrants are in external rotation
occiput is EXTENDED with rotation around its transverse axis; bilateral posterior quadrants are in internal rotation
inferior vertical strain
sphenoid extended, basisphenoid inferior, bilateral atnerior quandrants in IR
occiput flexed, bilateral posterior quadrants are in ER
sphenoid and occiput rotate in opposite directions around an AP axis
SBS: torsion
how to name an SBS torsion
superior sphenoid on the greater wing side
1st fingers move away from the practitioner, pinky fingers move toward the practitioner
superior vertical strain
1st fingers move toward the practitioner, pinky fingers move away from
inferior vertical strain
how many axes are in an SBS torsion
one saggital axis - AP axis
right greater wing of the sphenoid is superior compared to the left
right SBS torsion
left greater wing of the sphenod is superior when compared to the right
left SBS torsion
evidence of rotation along an AP axis would be palpated as
a high greater wing
right hand moves superior. left hand moves inferior
RIGHT SBS TORSION
left hand moves superior
right hand moves inferior
LEFT SBS TORSION
how many axes in an SBS lateral strain?
two VERTICAL axes - superior and inferior
how do you name an SBS lateral strain
by the direction of the translation of the basisphenoid
parallelogram head describes
an sbs lateral strain
index finger pads move left and pinky pads move to the right
SBS right lateral strain
index finger pads move right and pinky pads move left
SBS left lateral strain
how many axes in SBS sidebending rotation
one sagittal axis (AP)
two vertical axes (superior-inferior)
how do you name a sidebending rotation dysfunction
designated by the convex or flexed side
side of the lower greater wing and occiput is in relative flexion and high side is in relative extension
SBS sidebending rotation
one side feels fuller - 1st finger and pinky move away from each other and opposite side shrinks
sidebending rotation palpatory findings
right side fullness, right index and pinky move away, left fingers approximate
right SBS sidebending rotation
left side fullness, left index and pinky move away, right fingers approximate
left SBS sidebending rotation
a somatic dysfunction of the cranium in which the basisphenoid and the basilar portion of the occiput have been approximated that motion is moderately impaired, seriously lacking or almost completely lost
induced by trauma or compressive forces
sphenobasilar compression
how to test for compression
lift the lateral angles of the frontal bone anteriorly with thumbs while stabilizing the lateral angles of the occiput posteriorly with the hands
in SBS extension, which way does the sacrum move
nutation
base moves anteriorly
apex moves posteriorly
in SBS flexion, which way does the sacrum move
counternutation
base moves posteriorly
apex moves anteriorly
