(Test #1) Paired Bones of the Cranial Vault

Question 1

Review of Cranial Motion in Mid-line Bones

Answer 1

• Rotate around TRANSVERSE AXIS
• FLEXION paired with INHALATION
• EXTENSION paired with EXHALATION

Paired boned of the Cranial Vault and the Temporals:
- Frontalis, Parietals, and Temporalis

Paired Bones of the Face:
- Maxilla, Palatines, and Zygomae

Question 2

Parietal Bone

Answer 2

• The parietal bone is the only bone that contacts ALL 4 fontanelles!!!!

Question 3

Parietal Outer Surface

Answer 3

• UPPER Temporal Ridge
– Attachment of the Temporal FASCIA

• LOWER Temporal Ridge
– Origin of the TEMPORALS MUSCLE

• Temporalis FOSSA
– Filled by the TEMPORALS MUSCLE

Question 4

Parietal: Inner Surface

Answer 4

• Sagittal Sulcus: a groove along the sagittal suture in which the SAGGITAL SINUS RUNS!!!!
• Groove of the MIDDLE MENINGEAL ARTERY (anterior & posterior)

• Lateral part of the groove for the TRANSVERSE SINUS
– Carries the marginal insertion of the tentorium cerebelli

Question 5

Parietals Axis of Motion

Answer 5

• Bevel change midway along sagittal and lambdoidal sutures creates a HINGE for the AP AXIS OF MOTION (coronal plane).

Question 6

Signs and Symptoms of Parietal bone (SD)

Answer 6

1) Cranial synostosis: premature closure of the sutures
– Coronal, sagittal, lambdoidal…

2) Head Pain: Pain along a suture
– OM & asternion:
• Often involved in TENSION HEADACHES

– Pterion:
• Often involved in TEMPORAL HEADACHES

– Parietosquamous

3) Middle Meningeal Artery
– Trauma
– Giant Cell Arteritis: diagnosed by contrast-enhanced, high-resolution MRI

4) Head, Face and Tooth pain – temporal muscle SD (TrP)

Question 7

Cranial Synostosis

Answer 7

• SAGITTAL SYNOSTOSIS is the most common form
  of synostosis, accounting for about 50% of all cases with a prevalence of 1 in 2000 live births
• LAMBDOID SYNOSTOSIS is the form of synostosis most commonly mistaken for posterior positional deformational plagiocephaly and must be closely evaluated.

Question 8

Temporal Bone

Answer 8

1) SQUAMOUS PORTION CONTAINS:
• Zygomatic process
– facial injury affects temporal bone

2) PETROUS PORTION CONTAINS:
• Otovestibular organ

• Eustachian tube exit is between the sphenoid and the temporal bones

• Border of foramen Lacerum (with sphenoid)
– Greater superficial petrosal nerve
– Lacrimation via the ptergopalatine ganglion

• Attachment of the tentorium
• Encloses the internal carotid artery
• Lateral part of the jugular foramen
• Styloid process

** Axis is just INFERIOR to the Petrous RIDGE!!!!!

*** Has the motion of a Wobbly Wheel!!!!

Question 9

Newborn Skull

Answer 9

• Lacks a MASTOID PROCESS

Question 10

Eustachian Tube

Answer 10

• Eustachian tube exits the petrous portion and becomes the medial wall of the middle ear (the sphenoid is the lateral wall)
• INTERNAL rotation of the temporals will place pressure on the Eustachian tube = HIGH- PITCHED TINNITUS
• EXTERNAL rotation will often produce a low roaring sound or LOW PITCHED TINNITUS

Question 11

Signs and Symptoms of Frontal Bone SD

Answer 11

1) HEAD PAIN: Pain along a suture
– Coronal: Often involved in tension headaches
– Pterion: • Often involved in temporal

2) HEAD PAIN: from diminished primary respiration and CSF flow due to increased dural tension at the cribriform plate
3) Sinusitis (allergic or infectious)
4) Visual problems (double vision)
5) Anosmia – frontal influences cribriform plate

6) Frontalis Muscle TrP/TP
headaches

Question 12

Bicoronal Synostosis

Answer 12

• Fusion of BOTH Coronal sutures leads to a head shape called “bracycephaly.”
• This causes restriction of growth of the anterior fossa resulting in a shorter and wider than normal skull.
• Compensatory vertical growth also occurs, which is called TURRICEPHALY.
• Bicoronal synostosis is often seen in patients with associated syndromes such as Crouzon, Apert, Saethre-Chotzen, Muenke and Pfeiffer syndromes. These patients can also have additional sutures that are prematurely closed.

Question 13

Unicoronal Synostosis

Answer 13

• Premature fusion of a SINGEL CORONAL SUTURE leads to a head shape called anterior plagiocephaly.
• This results in restricted anterior growth of the skull, involving the top of the skull as well as the cranial base.
• This causes deformities of the face, ear, nose and forehead.
• The affected forehead is FLAT with the CONTRALATERAL SIDE MORE FORWARD.
• The AFFECTED SIDE EAR is also MORE FORWARD.
• The face always has a characteristic “C-shaped” deformity or “facial twist”.
• This is characterized by the base of the NOSE drawn towards the AFFECTED SIDE and the tip of the nose pointing away.
• The associated facial deformity is the key method of differentiating anterior plagiocephy from positional/deformational plagiocephaly, which is not the result of synostosis.