20 - Oral cavity Flashcards
What are the borders of the oral cavity?
Roof - hard and soft palate
Floor - tongue, floor of mouth
Lateral walls - cheeks
Anterior - oral fissure, lips
Posterior - oropharyngeal isthmus
What is the oral vestibule?
Area between teeth and cheeks
What is the oral cavity proper?
Area from the teeth to the oropharyngeal isthmus
Describe the lips.
- mobile musculo-fibrous folds
- lined externally by skin and internally by oral mucosa
- orbicularis oris is the main muscular contribution
What is the philtrum?
Depression in the midline above the upper lip
What is the blood supply of the lips?
Labial arteries are branches of the facial artery, which anastomose together to form an arterial ring
What is the sensory innervation of the lips?
Upper - CN V2 (infraorbital)
Lower - CN V3 (mental)
What is the lymphatic drainage of the lips?
- submandibular nodes
- except for lower middle lip which drains to the submental nodes
Describe the cheeks.
- lateral moveable walls of oral cavity
- continuous anteriorly with lips
- composed of muscle and fascia, lined externally with skin and internally with oral mucosa
What is the main muscular component of the cheeks?
Buccinator
Where is the buccal fat pad located?
Superficial to buccinator
What is the blood supply of the cheeks?
Maxillary artery
What is the sensory innervation of the cheeks?
Buccal branches of CN V3
What is the motor innervation of the cheeks?
Buccal branch of CN VII
What are key features of the oral vestibule?
- labial frenulum (connects gingiva to lips) in midline
- buccal frenulum laterally
- papilla of parotid duct (near maxillary 2nd molar)
What forms the floor of the mouth?
- muscular diaphragm by paired mylohyoid muscles
- mylohyoid muscles attach from the mylohyoid line on mandible to body of hyoid and into each other, forming the raphe in the midline
- paired geniohyoid muscles sit superior to the mylohyoid raphe
What separates the anterior 2/3 and posterior 1/3 of the tongue?
Terminal sulcus and valate papilllae