The philtrum is a vertical groove on the skin superior to the midline of the upper lip, extending inferiorly from the nasal septum.
The tubercle of the upper lip is a thicker area at the midline of the upper lip, inferior to the philtrum.
The labial commissure is where the upper and lower lips meet at each corner of the mouth.
Displacement or thinning of the philtrum is easily noticed, making it important for lip reconstruction.
The health of the labial commissure tissue is important for overall patient health.
The nasolabial sulcus is a groove running upward between each labial commissure and ala of the nose, commonly called "smile lines" or "laugh lines."
The labiomental groove is a horizontal groove separating the lower lip from the chin in the mental region.
It should be midway between the apex of the nose and chin and level with the angle of the mandible.
It can deepen with age.
Intraoral examination involves bidigitally palpating the lips and visually inspecting them systematically.
Oral Cavity
The oral cavity is the inside of the mouth, containing the jaws deep to the lips.
The maxilla is the bony upper jaw underlying the upper lip.
The mandible is the bony lower jaw underlying the lower lip.
The angle of the mandible is the sharp bend of the lower jaw inferior to the ear's lobule.
Borders of the oral cavity:
Anterior: Lips
Posterior: Throat or pharynx
Lateral: Cheeks
Superior: Roof of the mouth or palate
Inferior: Floor of the mouth
Orientational Terms
Facial: Structures closest to the facial surface.
Labial: Facial structures closer to the lips.
Buccal: Facial structures closer to the inner cheek.
Lingual: Structures closest to the tongue.
Palatal: Lingual structures closer to the palate.
Oral Mucosa
The oral cavity is lined by a mucous membrane or oral mucosa.
The labial mucosa is a pink and thick lining of the inner parts of the lips, continuous with the buccal mucosa.
The buccal mucosa, which lines the inner cheek, may vary in coloration depending on skin pigmentation.
It covers the buccal fat pad.
Parotid papilla: A small elevation of tissue on the inner buccal mucosa, opposite the maxillary second molar, protecting the ductal opening of the parotid salivary gland.
Maxillary tuberosity: A tissue-covered elevation on the maxilla posterior to the most distal maxillary molar.
Retromolar pad: A dense pad of tissue on the mandible posterior to the most distal mandibular molar.
Intraoral Examination Techniques
Labial mucosa examination: Gently pull the lips away from the teeth to visually inspect and bidigitally palpate the inner lips.
Buccal mucosa examination: Gently pull the buccal mucosa away from the teeth to visually inspect and bidigitally palpate the inner cheek using circular compression.
Vestibules
Maxillary and mandibular vestibules: Horseshoe-shaped spaces in the oral cavity between the lips and cheeks (anteriorly and laterally) and the teeth and soft tissue (medially and posteriorly).
Vestibular fornix: Deep within each vestibule, where the labial or buccal mucosa meets the alveolar mucosa at the mucobuccal fold.
Labial frenum (frena): Folds of tissue at the midline between the labial mucosa and the alveolar mucosa on both the maxilla and mandible.
Alveolar Process and Teeth
Alveolar process/bone: Bony extension of the maxilla and mandible containing each tooth socket or alveolus (alveoli).
Maxillary teeth: Teeth of the maxilla.
Mandibular teeth: Teeth of the mandible.
Maxillary anterior teeth overlap the mandibular anterior teeth; maxillary buccal cusps overlap the mandibular buccal cusps posteriorly.
Dental arches in adults have permanent teeth: incisors, canines, premolars, and molars.
Gingiva
Gingiva (or gingivae): Gums surrounding the maxillary and mandibular teeth, composed of firm pink oral mucosa.
Attached gingiva: Gingiva tightly adhering to the bone around the roots of the teeth, possibly with localized pigmentation.
Mucogingival junction: Scallop-shaped line of demarcation between the attached gingiva and the alveolar mucosa.
Marginal gingiva (free gingiva): Nonattached gingiva at the gingival margin of each tooth.
Gingival sulcus: Space faced by the inner surface of the marginal gingiva.
Interdental gingiva: Gingival tissue between adjacent teeth adjoining attached gingiva; each extension is an interdental papilla.
Examination: Retract buccal and labial mucosa to inspect and palpate the vestibular area and gingival tissue using circular compression, including the maxillary tuberosity and retromolar pad.
Palate
Palate: Roof of the mouth with two parts: hard palate and soft palate.
Hard Palate
Bony whiter anterior arched part.
Incisive papilla: Small bulge of tissue at the most anterior part of the hard palate, lingual to the anterior teeth.
Palatine rugae: Firm irregular ridges of tissue directly posterior to the incisive papilla.
Soft Palate
Yellower, looser, and softer posterior part; approximately 15% of the total palatal surface.
Connected to the hard palate but can be separately elevated and depressed by muscles.
Uvula of the palate: Midline muscular structure hanging as an extension from the posterior margin of the soft palate.
Median palatine raphe: Midline ridge of tissue running from the incisive papilla to the uvula.
Pterygomandibular fold: Vertical fold of tissue extending from the junction of the hard and soft palates to the medial side of the mandibular ramus, posterior to the most distal mandibular molar and the retromolar pad.
Stretches when the patient opens the mouth wider.
Covers a deeper tendinous band separating the cheek from the throat (or pharynx).
Examination: Tilt the head back, extend the tongue to visually inspect the soft palate and throat (pharynx), using a mouth mirror to intensify the light source.
Gently place the mouth mirror on the middle of the top surface of the tongue and ask the patient to say "ah" to observe the soft palate, uvula, and visible parts of the throat.
Compress the hard palate with the first or second finger, avoiding circular compression, and avoid palpating the nearby soft palate to prevent initiating the gag reflex.
Tongue
The tongue is a prominent feature of the oral region.
Parts of the Tongue
Posterior one-third: Pharyngeal part or base of the tongue.
Attaches to the floor of the mouth.
Located within the oral part of the throat or pharynx.
Anterior two-thirds: Oral part or body of the tongue.
Located within the oral cavity.
Separation: Important due to differences in innervation, structure, and embryonic development.
Dorsal Surface: Top surface of the tongue
Median Lingual Sulcus: Midline depression corresponding to a midline tendinous band deep within the tongue.
dividing septum creates a surgical bloodless plane of dissection.
Apex: Tip of the tongue.
Sulcus Terminalis: V-shaped groove farther posteriorly on the dorsal surface; separates the base from the body of the tongue.
Foramen Cecum: Small pitlike depression where the sulcus terminalis points toward the throat or pharynx.
Lingual Tonsil: Irregular mass of lymphoid tissue on each side of the dorsal surface of the tongue base.
Ventral Surface: Underside of the tongue.
Deep Lingual Veins: Visibly large blue blood vessel branches close to the surface on each side.
Plica Fimbriata (plicae fimbriatae): Fold(s) with fringelike projections lateral to the deep lingual veins on each side.
Specialized Mucosa: Certain surfaces of the tongue have elevated small structures, the lingual papillae, some of which are associated with taste buds.
Lingual Papillae
Foliate Lingual Papillae: Vertical ridges on the side or lateral surface of the tongue, containing taste buds; more prominent in children.
Filiform Lingual Papillae: Slender threadlike lingual papillae on the dorsal surface, giving it a velvety texture.
Fungiform Lingual Papillae: Red mushroom-shaped dots found in lesser numbers than filiform on the body of the dorsal surface; contain taste buds.
Circumvallate Lingual Papillae: Approximately 10 to 14 large mushroom-shaped lingual papillae lining up along the anterior side of the sulcus terminalis on the body; have taste buds at their bases.
Examination: Extend the tongue, wrap gauze around its body (anterior two-thirds) to obtain a firm grasp, and visually inspect and digitally palpate the dorsal surface of the body of the tongue.
Turn the tongue slightly to visually inspect its base (posterior one-third) and bidigitally palpate its lateral borders.
Floor of the Mouth
The floor of the mouth is a mucosal covered space that extends from the lingual surface of the mandibular alveolar process inferiorly to the ventral surface of the tongue.
Posteriorly, it extends to the beginning of the throat (at the anterior tonsillar pillar).
The left and right sides meet at the lingual frenum along the anterior midline.
Lingual frenum: An anterior midline fold of tissue between the ventral surface of the tongue and the floor of the mouth.
Underlying muscles provide support for the floor of the mouth.
Sublingual fold: A ridge of tissue on each side of the floor of the mouth, arranged in a V-shaped configuration from the lingual frenum to the base of the tongue.
Associated with the underlying sublingual salivary gland and contain openings of the sublingual duct.
Sublingual caruncle: A small papilla at the anterior end of each sublingual fold and the base of the lingual frenum, containing the duct openings from both the submandibular and sublingual salivary glands.
Examination:
While the patient lifts the tongue to the palate, visually inspect the mucosa of the floor of the mouth using a mouth mirror to intensify the light source and check the lingual frenum at the midline.
Dry each sublingual caruncle with gauze to observe salivary flow from the ducts.
Bimanually palpate the sublingual area by placing an index finger intraorally and the fingertips of the opposite hand extraorally under the chin, compressing the tissue between the fingers.
Pharynx
The oral cavity provides the entrance into the throat or pharynx.
Pharynx: A muscular tube that serves both the respiratory and digestive systems.
Parts of the Pharynx:
Nasopharynx
Oropharynx
Laryngopharynx
*Not visible during an intraoral examination.
Nasopharynx: Superior to the level of the soft palate and continuous with the nasal cavity.
Oropharynx: Between the soft palate and the opening of the larynx.
Parts of the nasopharynx and oropharynx are visible during an intraoral examination when examining the palate.
Special diagnostic tools are needed to examine more extensive parts of the nasopharynx, laryngopharynx, or oropharynx.
Epiglottis: A flap of cartilage behind the base of the tongue and in front of the oropharynx.
At rest, it is upright, allowing air to pass through the larynx and into the rest of the respiratory system.
During swallowing, it folds back to cover the entrance to the larynx, preventing food and liquid from entering the trachea and lungs.
Fauces (faucial isthmus): Opening from the oral region into the oropharynx.
Anterior faucial pillar and posterior faucial pillar: Folds of tissue created by the underlying muscles, forming the fauces laterally on each side.
Palatine tonsils: Tonsillar tissue located between each of these pillars.