Oral cavity & oropharynx



Topic Completed: 1 January 2013

Minor changes: 14 January 2021

Copyright: 2002-2021, PathologyOutlines.com, Inc.

PubMed Search: Normal anatomy[TIAB] oral cavity

Charu Thakral, M.D.
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Cite this page: Thakral C. Anatomy. PathologyOutlines.com website. https://www.pathologyoutlines.com/topic/oralcavitynormalanatomy.html. Accessed December 8th, 2021.
Definition / general
  • Oral cavity extends anteriorly from vermilion junction of lips to junction of hard and soft palate above and to line of circumvallate papillae on dorsal tongue below; communicates freely with oropharynx posteriorly
  • Oral cavity contains buccal mucosa, maxillary and mandibular arches, retromolar trigone, anterior 2/3 of tongue, floor of mouth and hard palate
  • Dorsal tongue: villous, normally exposed surface; contains papillae and specialized taste receptors
  • Ventral tongue: nonvillous, undersurface
  • Anterior 2/3 of tongue (oral tongue): freely mobile portion of tongue that extends anteriorly from line of circumvallate papillae to undersurface of tongue at junction of floor of mouth; composed of skeletal muscle, includes 4 areas: tip, lateral borders, dorsum and undersurface (nonvillous ventral surface of tongue)
  • Base of tongue (posterior 1/3 of tongue): bound anteriorly by circumvallate papillae, laterally by glossotonsillar sulci and posteriorly by epiglottis
  • Buccal mucosa: all of membrane lining inner surface of cheeks and lips from line of contact of opposing lips to line of attachment of mucosa of alveolar ridge (upper and lower) and pterygomandibular raphe; contains ostia of main duct of parotid gland (Stenson duct)
  • Floor of mouth: semilunar space of myelohyoid and hyoglossus muscles, extending from inner surface of lower alveolar ridge to undersurface of tongue; posterior boundary is base of anterior pillar of tonsil; divided into two sides by frenulum of tongue, contains ostia of submaxillary and sublingual salivary glands
  • Gingiva: mucosa in area of teeth and palate; extends from labial sulcus and buccal sulcus to a cuff of tissue around each tooth
  • Hard palate: forms roof of oral cavity; semilunar surface between upper alveolar ridge and mucous membrane covering palatine process of maxillary palatine bones; extends from inner surface of superior alveolar ridge to posterior edge of palatine bone
  • Lip: begins at junction of vermilion border (mucocutaneous junction) with skin, includes only vermilion surface or that portion of lip that comes into contact with opposing lip; upper and lower lip are joined at commissures of mouth; external surface is skin and mucous membrane; internally contains orbicularis oris muscle, blood vessels, nerves, areolar tissue, fat and small labial glands; inner surface of lip is connected to gum in midline by frenulum, a mucous membrane fold
  • Lower alveolar ridge: mucosa overlying alveolar process of mandible which extends from line of attachment of mucosa in lower gingivobuccal sulcus to line of free mucosa of floor of mouth; posteriorly extends to ascending ramus of mandible
  • Retromolar gingiva (retromolar trigone): mucosa overlying ascending ramus of mandible from level of posterior surface of last molar tooth to apex superiorly, adjacent to tuberosity of maxilla
  • Tonsillar area: anterior and posterior tonsillar pillars and tonsillar fossa
  • Upper alveolar ridge: mucosa overlying alveolar process of maxilla which extends from line of attachment of mucosa in upper gingivobuccal sulcus to junction of hard palate; posterior margin is upper end of pterygopalatine arch
  • Vermillion border: mucocutaneous junction of lip
Juxtaoral organ of Chievitz
  • Not actually a congenital anomaly but normal occurring neuroepithelial structure called organ of Chievitz, Chievitz paraparotid organ, juxtaoral organ or epithelial nests
  • Reported in 56% of adult autopsies without oral mucosal lesions
  • Within intraoral sensory nerve
  • May undergo nodular hyperplasia
  • Located bilaterally in buccotemporal fascia on medial surface of mandible, near angle
  • Rare examples of proliferative / hamartomatous masses of juxtaoral organ reported
  • May be interpreted as squamous cell carcinoma, mucoepidermoid carcinoma or metastasis especially during frozen sections (Am J Surg Pathol 1979;3:147)

Microscopic (histologic) description
  • Multilobulated nests of squamous-like epithelium without keratin formation, occasionally with lumen lined by cuboidal cells
  • Associated with small nerves and resembling perineural invasion

Case reports

Images hosted on other servers:

Sagittal section

Tongue surface

Tongue and oral cavity

Undersurface of tongue

Coronal section of tongue

Diagrams / tables

Contributed by Katherine Hulme, M.B.Ch.B.
Oropharynx (frontal view)

Oropharynx (frontal view)

Oropharynx (lateral view)

Oropharynx (lateral view)

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