OCMM - Paired Bones Flashcards
What are the 5 bony articulations of the parietal bone?
Occiput Frontal bone Sphenoid Temporal Opposite parietal
The ____ is the old mastoid fontanelle
The _____ is the old sphenoid fontanelle
Asterion
Pterion
The ____ bone is the only bone that contacts all 4 fontanelles
Parietal
Which part of the parietal bone provides attachment point of temporal fascia?
Upper temporal ridge
Which part of the parietal bone is the origin of the temporalis m?
Lower temporal ridge
Which part of of the parietal bone is filled by temporalis m?
Temporalis fossae
Describe the inner surface of the parietal bone
Contains sagittal sulcus (along sagittal suture in which sagittal sinus runs)
Groove of middle meningeal a. (Ant. and post)
There are bevel changes along coronal and lambdoidal articulations
Along lateral part is groove for transverse sinus which carries marginal insertion of tentorium cerebelli
There is a bevel change midway along the sagittal and lambdoidal sutures which creates a hinge for AP axis of motion (coronal plane). What motion occurs in the following parts of the paired bones with SBS flexion:
Inferior borders
Superior borders
Pterion, asterion, and squamous sutures
Sagittal sutures
Inferior borders move laterally
Superior borders move medially and inferiorly
Pterion, asterion, and squamous sutures move laterally
Sagittal suture moves slightly inferiorly
[this is external rotation; cranium widens laterally]
Signs and symptoms of parietal bone SD
Cranial synostosis (premature closure of sutures)
Head pain — pain along a suture
Middle meningeal a. trauma or giant cell arteritis
Head, face, or tooth pain patterns — temporal SD (TrP)
[OSCE says HA, alteration of seizure threshold, localized pain]
Parietal bone SD may manifest as head pain via pain along a suture. What sutures are often involved?
OM and asterion = often involved in tension headaches
Pterion = often involved in temporal headaches
Parietosquamous
Most common form of synostosis
Sagittal synostosis, accounting for about 50% of all cases
Premature fusion of the sagittal suture restricts the transverse growth of the skull
Form of synostosis most commonly mistaken for posterior positional deformational plagiocephaly
Lambdoid synostosis
When unilateral, results in flattening of the back of the head on affected side as well as compensatory growth of mastoid process on the same side (ipsilateral mastoid bulge) — leads to characteristic ‘tilt’ in cranial base
The ear on the effected side is often deviated back and toward the fused suture
2 parts of temporal bone
Squamous portion — contains zygomatic process (affected in facial injury)
Petrous portion — contains otovestibular organ, eustachian tube exit is between sphenoid and temporal bones, border of foramen lacerum (with sphenoid) = greater superficial petrosal n. and lacrimation via pterygopalatine ganglion, attachment for tentorium, encloses internal carotid a., lateral part of jugular foramen, styloid process
What is unique about the temporal bone of a newborn skull?
Lacks a mastoid process
The mastoid process provides attachment for what muscles?
Splenius
Digastric
Longissimus capitis
SCM
Internal rotation of the temporals may result in ____ pitched tinnitus
High
[Internal rotation places pressure on eustachian tubes leading to high pitched tinnitus; External rotation —> low roaring sound or low pitched tinnitus]
Temporal bone motion is driven by the ______ through ____ articulation
Occiput; OM
Describe external rotation of the temporal bone
Squamous portion moves laterally while mastoid process moves medially
Signs and symptoms of temporal bone SD
TMJ pain
Head pain (OM/asterion, pterion, parietosquamous), neck pain d/t SCM or other muscle SD
Dizziness, ear infections, swallowing and chewing (stylohyoid, stylomandibular/TMJ, and styloglossus), tinnitus and eustachian tube dysfunction, bell’s palsy (CN VII)
[OSCE says OM, mastoiditis, tinnitus, hearing loss, dizziness, migraines, Bell’s, neuralgia; dysfunction can be caused by trauma, whiplash, chronic neck tension, dental extraction]
A 23 y/o male presents to the outpatient clinic with right sided head pain and ringing in his right ear 1 week after getting hit with a foul softball on top right side of the head. He was seen in the ER and dx with a grade 1 concussion after x-rays and PE found no neuro defects or fractures. The tinnitus started a day after his injury. MSK findings include:
Right mastoid process medial
Tenderness at point of injury
Right squamous area laterally prominent
What is the most likely temporal SD?
A. External rotation B. Internal rotation C. Flexion D. Extension E. Superior vertical strain
A. External rotation
Frontal bone articulations
Parietals Sphenoid Ethmoid Lacrimals Maxillae Nasals Zygoma
Describe external rotation of the frontal bone
Moves with hingelike motion as if still 2 bones (unfused metopic suture)
During SBS flexion (paired bone external rotation), lateral sides move anterior/lateral and slightly inferior, glabella moves posteriorly
What cranial bone is responsible for moving the frontal bone during external rotation?
Sphenoid
Signs and symptoms of frontal bone SD
Head pain d/t pain along suture (coronal in tension headaches, pterion in temporal headaches), head pain d/t diminished PRM and CSF flow d/t increased dural tension at cribriform plate
Sinusitis (allergic or infectious), visual problems, anosmia (frontal influences cribriform plate), frontalis m. TrP/TP
[OSCE says HA, visual or smell disturbance (anosmia d/t ethmoid association), restriction can limit falx and all attachments; can get “wedged” from trauma]
Condition characterised by fusion of both coronal sutures leading to head shape called bracycephaly. Causes restriction of growth of anterior fossa resulting in a shorter and wider than normal skull. Compensatory vertical growth also occurs, called turricephaly
Bicoronal synostosis
Often seen in pts wtih associated syndromes like Crouzon, Apert, Saethre-Chotzen, Muenke and Pfeiffer
What type of synostosis leads to head shape called anterior plagiocephaly?
Unicoronal synostosis — d/t premature fusion of a single coronal suture —> restricted anterior growth of the skull as well as cranial base
Causes deformities of the face, ear, nose, and forehead; affected forehead is flat with contralateral side more forward. Affected side ear also more forward. Face has characteristic C-shaped deformity (base of nose drawn toward affected side and tip of nose pointing away)
Axis and plane of motion associated with frontal bone
Dual AP axis in coronal plane
Superior/inferior axis in horizontal plane
[metopic suture has “hinge-like” property. Additionally, d/t location, inferior aspect travels more laterally and medially during flexion/extension (AP axis)]
Axis of temporal bone motion
Oblique axis from jugular surface to petrous apex — no exact plane (possibly modified coronal plane)
Axes of motion and plane associated with parietal bones
2 AP axes (one through each bone) — coronal plane
A low, sloping forehead (“toboggan slide forehead”) may indicate what type of frontal bone SD?
External rotation
[a high bulging/prominent forehead aka Ski jump forehead would indicate internal rotation SD]
Objective of Rocking the Temporals tx
To release or relieve CN IX, X, XI entrapment/dysfunction, eustachian tube compression, jugular vein compression, restricted temporal/occipital articulation, or tinnitus
Describe Rocking the Temporals tx
Encourage free directions of motion first (indirect) - usually started with flexion cycle:
-To encourage internal rotation: thumb and index finger move superomedially while 4th and 5th digits move inferolaterally
-To encourage external rotation, thumb and index finger move inferolaterally, whilst 4th and 5th ride along with superomedial motion
Simultaneous ER/IR motions are encouraged in a back and forth motion until bones achieve asynchronous motion…then just monitor for physiologic motion to return; if physiologic synchronous motion does not return, gently begin to resist the motions to induce a stillpoint
Objective of CV4 tx
Stimulate the body’s inherent capacity to deal with whatever cranial dysfunction is present
[Physician is attempting to resist the PRM that is being monitored through the CRI; success relies on inherent forces. Physician monitors several cycles of CRI motion then permits exhalation motion at the bone being palpated (occipital squama), then gently resists flexion until cessation of CSF fluctuation is palpated = still point. Held here for 15 seconds to a few minutes until CRI returns]
Points of contact in CV4 tx
Lateral angles of occiput medial to occipitomastoid suture
[thenar eminences are inferior to the superior nuchal line and MEDIAL to the patient’s OM sutures]
Describe tx with CV4 technique
Note the movement of the occiput; gently encourage extension (hands move toward you) while discouraging flexion; wait for motion to reach “still point”; carefully remove hands and let pts head rest on table
Objective of temporal pull tx
Balances tentorium cerebelli and/or temporal bones
[also disengages the petrojugular; may help release petrosphenoid; BLT for occipitomastoid]
Describe temporal pull tx
Assess motion of temporal bones prior to technique; use pincer grip on pinnae as close to temporal bones as possible
Apply traction laterally, posteriorly, and superiorly along a vector that parallels the petrous ridge of the temporals
Encourage inhalation phase and take up slack maintaining tension at “feathers edge” of restrictive barrier until release is felt
Reassess
Opposing joint useful for directing the tide to the parietal eminence
Petrobasilar or sphenosquamous pivot
Opposing joint useful for directing the tide to the lateral vertex
Petrojugular
Opposing joint useful for directing the tide to the frontal eminence
OM or sphenopetrous
Opposing joint useful for directing the tide to the pterion
Parietomastoid
Opposing joint useful for directing the tide to the asterion
Pterion
