GUIDE
Head and Neck: Oral Region
Oral Cavity
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Divided into two regions
Oral vestibule
Narrow space between teeth and gingival and lips and cheeks
Size controlled by orbicularis oris, buccinator, risorius, and muscles controlling lips
Contains frenula (singular: frenulum)-midline mucosal folds from upper and lower lips to the gums
Oral cavity proper
Boundaries
Anteriorly: lips
Posteriorly: oropharyngeal isthmus to oropharynx
Roof: hard palate anteriorly and soft palate posteriorly
Floor: mucosa beneath the tongue
Space occupied by tongue
Anatomical features of the lips
Contain
Orbicularis oris muscle, and fibers of levator labii superioris, depressor anguli oris, zygomaticus major and risorius muscles
Superior and inferior labial arteries and veins
a. From infraorbital and facial vessels superiorly
b. From facial and mental vessels inferiorly
Branches of infraorbital nerves (cranial nerve [CN] V 2 ) superiorly
Branches of mental nerves (CN V 3 ) inferiorly
Vermilion border: transition zone (border) of lip
Nasolabial grooves from nose to just lateral of angle of mouth separated lips from cheek
Philtrum: depression from nasal septum to vermilion border of upper lip
Labiomental groove separates lower lip from chin
Labial frenula: midline mucosal folds with a free edge that extend from upper and lower lips to the gums
Anatomical features of the cheeks
Lateral walls of oral cavity
Form zygomatic prominences over zygomatic bones
Principal muscle is buccinator
Buccal fat pad external to buccinator
Supplied by buccal branches of maxillary artery
Innervated by buccal branches of mandibular nerve (CN V 3 )
Gingivae
Composed of fibrous tissue covered by mucous membrane
Firmly attached to alveolar processes of mandible and maxilla and necks of teethTongue