W12 Fascia and spaces Flashcards
Define fascia
It is connective tissue layer that surrounds muscles, bones, organs, nerves, blood vessels and other structures.
Fascia has superficial, middle and deep layers which divide, unite, blend and fuse to form various compartments
Define space
Spaces between the fascia.
Potential spaces created between the layers of fascia, due to the sheet like nature of fascia. Contain loose CT, some spaces in the head are created by boundries of other structures, not necessarily fascia. Spaces that communicate with one another.
Define superficial fasciae of the head and neck
Superficial is found just deep to and attached to the skin. It separates skin from deeper structures, permitting the skin to move independently from those deeper structures.
Fascia varies in thickness. Vessels and nerves of the skin travel in the superficial fascia.
Encloses the muscles of facial expression, superficial cervical fascia of the need contains the platysma muscle.
Define deep fasciae of the head and neck
Forms sheath around deeper structures such as bones, muscles, vessels and nerve
What are the (3) names of deep fascia of the head?
- Temporal fascia
- Masseteric-parotid fascia
- Pterygoid fascia
What are the (6) names of deep fascia of the neck (cervical fascia)?
- Investing layer
- Pretracheal fascia (muscular and visceral portions)
- Carotid sheath - surrounds carotid arteries, internal jugular vein and the vagus nerve.
- Prevertebral fascia
- Buccopharyngeal fascia
- Alar fascia
Name the (6) layers of the head and neck and there fuctions.
Investing layer: Outter most layer, surround the neck like a collar.
Prevertebral fascia: lies in front of the prevertebral muscles, provides fixed basis for phayrnx and larynx, esophagus, carotid sheath, can glide your neck movements and swallow.
Pretracheal fascia: lies deep to the infrahyoid muscles, encloses the thyroid, esophagus, trachea, providing a lubricated surface for the up and down gliding of the trachea during swallowing and neck movements. Blends laterally with carotid sheath.
Carotid sheath: Felt work of the aerolar tissue that surrounds the carotid arteries, both common and internal, surrounding the internal jugular vein and vagus nerve. Thin over the internal jugular veins, because it allows the vein to dilate during ↑ blood flow.
Define the Temporal space
Located between temporal fascia and temporalis muscle
Define the Infratemporal space
Occupies the infratemporal fossa. Bound by ramus, lateral pterygoid plate and maxillary tuberosity. No boundary inferiory and posteriorly, where the infratemporal space is continuous with the cervical fascial space, the parapharyngeal space
EXAM Define the Sublingual and Submandibular tissue space
Sublingual is medial to the mandible and superior to mylohyoid muscle.
Submandibular is inferior to mylohyoid muscle, reaching inferiorly to the hyoid bone
Define the Submental tissue space
Located in the midline between the mandibular symphysis and hyoid bone.
Floor of this space: superficial cervical fascia
Define the Submassetric space
Located between the masseter muscle and external surface of ramus.
This space communicates with the temporal and infratemporal spaces.
Define the Pterygomandibular space
*
IAV: Inferior Alveolar Vein
IAA: Inferior Alveolar artery
IAN: Inferior Alveolar Nerve Trigeminal, V3
SML: Sphenoid Mandibular Ligament
MP:
R: Ramus
L: Lingual
TT: Tendon of Temporalis
SCM: Superior constrictor muscle
PMR: PterygoMandibular Raphe
B: Buccinator muscle
Located between the medial pterygoid muscle and medial surface of the ramus.
INSERTIONS FOR IAN BLOCK
EXAM What are the Pterygomandibular space-borders
Superior border: lower head of lateral pterygoid muscle.
Inferior border: medial pterygoid m. attachment to the medial surface of ramus of mandible.
Lateral: medial surface of ramus
Medial border: medial pterygoid m.
Posterior border: parotid gland
Anterior border: oral mucosa and posterior part of buccinator m./pterygomandibular raphe
What is the danger space?
Retropharyngeal space located between the Alar space and Prevertebral space.
Define the retropharyngeal space
Immediately posterior to the pharynx. Infection in this space may pass behind the carotid sheath, or inferiorly into the upper part pf the thorax.
Define the Parapharyngeal/lateral pharyngeal space
Lateral to the pharynx, medial to medial pterygoid muscles.
Continuous with buccal and infratemportal spaces anteriorly and retropharyngeal space posteriorly.
How do dental infections spread?
Infections can spread:
- Via facial spaces - cellulitis, risk of deep infections spreading into the neck and mediastium,
- Into bone osteomyelitis
- Via the cardiovascular system to the heart, infective endocarditis
- Via venous system into the veins of cranial cavity, specifically the cavernous sinuses cavernous sinuses thrombosis (blood clotting).
- Into the paranasal sinuses secondary sinusitis
- Via Lymphatic system Lymphadenopathy (lymphadenitis)
What does the spread of dental infection cause?
Periodontal space infections may cause gingival or soft tissue or mucosal swelling, whereas infections at the apices cause swelling in either buccal or palatal direction.
Abcess in vestibual spaces: an infection may break through bone around the involved teeth and spread/travel into tissue spaces/fascial spaces.
Infection will follow the path of least resistance.
Muscle attachment serve as barrier to the spread of infection via fascial spaces
What is Cellulitis?
When an infection has entered the fascial space, the loose CT of this space undergoes diffuse inflammation, with severe inflamation of dermal and subcutaneous layers of the skin.
E:O swelling
Clinically: pain, tenderness, redness, diffuse oedema, psyphagia, restricted eye opening, dyspnoea.
What is Ludwig’s Angina?
Bilateral infection of the submandibular and sublingual spaces in addition to the submental space. It is a life threatening condition
