Oral Cavity Anatomy and Terminology

Introduction to Oral Cavity

• Initial shock of looking at someone's mouth is normal and something you'll get used to.
• Proper infection control is crucial; use hand coverings, hair coverings, and masks.

Course Expectations

• The book goes into extensive detail, but the course will focus on essential knowledge.
• Core concepts of four classes are condensed into a ten-week course.

Anatomy of the Oral Cavity

• Lips: Anterior border of the oral cavity.

• Palate: Roof of the mouth divided into two sections:

  • Hard Palate: Pale white color, tissue tightly attached to bone.
  • Soft Palate: Redder color, no bone above, can move.
  • Uvula: Appendage hanging down.

• Pillars/Arches: Formed by muscles that aid in swallowing and speaking.

  • Examples: pterygomandibular fold (pterygoid bone to mandible), palatoglossal (palate to tongue), palatopharyngeal (palate to pharynx).

• Tonsils: Often located between these folds; sometimes called adenomas.

Oral Cavity as a Dual System

• Beginning of both the digestive and respiratory systems.
• Unique for multitasking but can lead to aspiration (food/liquids entering the trachea/lungs).
• Aspiration can cause life-threatening lung infections/pneumonia, especially in elderly individuals.
• Respiratory system includes the nose and nasal cavity.

Vestibule of the Oral Cavity

• Area between the lips/cheeks and the teeth.
• Site for smokeless tobacco use, increasing the risk of oral cancer.
• Intraoral exams check for keratosis (thickening of mucosal lining).
• Maxillary vestibule (upper), Mandibular vestibule (lower).

Key Terms

• Frenum: Tissue attachments from the alveolar mucosa to the inner lip.

  • Maxillary frenum, Mandibular frenum. Large frenums can cause tissue recession.
  • Lingual frenum can cause a "tongue-tie" (ankyloglossia), affecting speech and swallowing.

• Frenectomy: Surgical correction of problematic frenums.

External Features of Lips

• Vermilion Zone: Transition zone between the lip and regular skin tone.

• Philtrum: Indentation above the center line of the nose; common exam question.

• Lateral Commissure: Angle of the mouth.

  • Problems here can cause angular cheilitis (inflammation), due to yeast infection, vitamin deficiency, or ill-fitting dentures.

Borders of the Vestibule

• Lip or cheek and the teeth.

• Alveolar Mucosa: Soft tissue or gum around the teeth.

• Mucogingival Junction.

Gingiva (Gums)

• Normal gingiva is pink; darker skin may have pigmentation.

• Melanoma concerns; pigmentation needs to be checked.

• Diastema: Space between teeth, commonly between the top front teeth (8 and 9).

  • A pulling frenum can create one.
  • Can be fixed with braces

Tooth Movement and Recession

• Pressure on teeth (from braces, frenum, lip, or tongue) can cause movement and gingival recession (gingiva moving away from teeth).

• Recession can be:

  • Normal (anatomical, aging).
  • Caused by periodontal disease (gum disease), which is the primary cause and leads to bone dissolution and tooth loosening.

Lingual Frenum

• Large lingual frenum can cause "tongue-tie", also known as ankyloglossia, which can be corrected by a frenectomy.

Terminology: Directions in the Mouth

• Lingual: Inside of the arch.

• Outside:

  • Buccal (posterior).
  • Facial or Labial (anterior).

• Note: Recession is a problem as the root isn't covered with enamel, causing sensitivity.

Mandibular vs. Maxillary

• Mandibular: Bottom arch, identified by lack of palate and visible tongue.

• Maxillary: Upper arch.

Bone Growth Abnormalities

• Mandibular Tori: Bony outcroppings on the mandible (lingual tori).
• Palatal Torus: Bony outcroppings on the palate.
  -Usually not a problem until dentures are needed, then they must be removed

Palate and Tooth Anatomy

• The ridges in the anterior part of the hard palate are called Rugae

• Terminology about teeth

  • Big teeth are called Molars.

  • A term-molar is equivalent to wisdom tooth

  • Next two teeth are Pre-Molars

  • Then there is a canine, that is long root.

  • Anterior Teeth, the main types are incisors.

  • Projections of soft tissue, called Incisive Papilla, that goes up between the central inscissors.