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The oral cavity (mouth) is the first part of the alimentary tract extending from the oral fissure anteriorly to the oropharyngeal isthmus posteriorly.
It serves as the entry point for food and air and plays a major role in mastication, speech, taste, and swallowing.
The oral cavity is the chamber inside the mouth where food is received, chewed, tasted, mixed with saliva, and prepared for swallowing.
The oral cavity is important because:
Common site of oral cancers
Frequently affected by infections and inflammatory diseases
Closely related to teeth, tongue, salivary glands, and oropharynx
Important for speech and swallowing
Easily accessible for clinical examination
Site of precancerous lesions such as:
Leukoplakia
Erythroplakia
Oral submucous fibrosis
Chewing and grinding of food
Performed by teeth and muscles of mastication
Converts food into a bolus
Initiates voluntary phase of swallowing
Tongue propels food towards pharynx
Modulates sounds produced by larynx
Tongue, lips, palate and teeth are essential articulators
Taste buds mainly present on tongue
Helps identify sweet, salty, sour, bitter and umami sensations
Alternate airway during nasal obstruction
Contributes to airflow passage
Saliva contains:
Lysozyme
Lactoferrin
Immunoglobulin A (IgA)
Provides local immunity
Mucosal barrier protects deeper tissues
The oral cavity is divided into:
Oral Vestibule
Oral Cavity Proper
The oral vestibule is the slit-like space between:
Lips and cheeks externally
Teeth and gingiva internally
| Boundary | Structure |
|---|---|
| Outer | Lips and cheeks |
| Inner | Teeth and gums |
| Superior | Reflection of upper lip |
| Inferior | Reflection of lower lip |
Openings of minor salivary glands
Parotid duct opening opposite upper second molar
Labial frenulum
Buccal frenulum
Space enclosed within dental arches.
| Boundary | Structure |
|---|---|
| Anterior/Lateral | Teeth and gingiva |
| Roof | Hard and soft palate |
| Floor | Tongue and floor of mouth |
| Posterior | Oropharyngeal isthmus |
Through the:
Bounded by:
Soft palate superiorly
Palatoglossal arches laterally
Dorsum of tongue inferiorly
These subsites are recognized by TNM classification and head-neck oncology.
Upper lip
Lower lip
Oral commissures
Includes:
Inner cheek lining
Buccal sulcus
Mucosa opposite alveolar ridges
Most common oral cancer site in India due to tobacco chewing.
Contains:
Tooth sockets
Alveolar processes of maxilla and mandible
Mucosa covering alveolar bone
Surrounds neck of teeth
Small triangular area:
Behind last mandibular molar
Over ascending ramus of mandible
Clinically important because:
Early spread to masticator space
Involvement of mandible common
Bony anterior palate.
Oral tongue includes:
Tip
Lateral borders
Dorsum anterior to sulcus terminalis
Ventral surface
Area beneath tongue.
Boundaries:
Gingiva laterally
Ventral tongue medially
Contains:
Sublingual gland
Wharton duct opening
Junction between:
Skin of lip
Red vermilion mucosa
Important in:
Cleft lip repair
Lip reconstruction
Vertical groove between:
Nose
Upper lip
Embryological fusion line of medial nasal processes.
Angle where upper and lower lips meet.
Connects upper lip to gingiva.
Connects lower lip to gingiva.
Connects tongue to floor of mouth.
Clinical importance:
Ankyloglossia (tongue tie)
Landmark in oral cancer surgery
Gateway for tumour spread
Fibrous band between:
Buccinator
Superior constrictor
Importance:
Landmark for inferior alveolar nerve block
Tonsillectomy orientation
Palatoglossus muscle
Palatopharyngeus muscle
Located between:
Anterior pillar
Posterior pillar
Contains palatine tonsil.
Depressions between:
Base of tongue
Epiglottis
Important during:
Laryngoscopy
Intubation
Anterior two-thirds.
Posterior one-third.
Separates:
Oral cavity
Nasal cavity
Formed mainly by:
Principal muscular diaphragm.
Located above mylohyoid.
Forms bulk of tongue root.
Oral fissure forms external opening.
Contain buccinator muscle.
Communication with oropharynx.
Lips form anterior wall of oral cavity.
Components:
Skin
Vermilion zone
Orbicularis oris muscle
Submucosa
Oral mucosa
Keratinized stratified squamous epithelium
Thin epithelium
Highly vascular
Non-keratinized stratified squamous epithelium
Contains:
Minor salivary glands
From facial artery:
Superior labial artery
Inferior labial artery
Additional:
Infraorbital artery
Mental artery
Through:
Superior labial vein
Inferior labial vein
Drain into:
Facial vein
→ Submandibular nodes
→ Submental nodes
→ Submandibular nodes
Upper lip:
Infraorbital nerve (V2)
Lower lip:
Mental nerve (V3)
Facial nerve (VII)
Muscles of facial expression.
Congenital failure of fusion between:
Maxillary process
Medial nasal process
Unilateral
Bilateral
Complete
Incomplete
Cosmetic deformity
Feeding difficulty
Speech problems
Usually:
Squamous cell carcinoma
Most common site:
Lower lip
Risk Factors:
Tobacco
Smoking
Sun exposure
Chronic irritation
Lymphatic spread:
Submental nodes
Submandibular nodes
Cheeks form lateral walls of oral cavity.
Layers:
Skin
Subcutaneous tissue
Muscles
Buccal fat pad
Buccopharyngeal fascia
Buccal mucosa
Alveolar processes of maxilla
Alveolar processes of mandible
Pterygomandibular raphe
Orbicularis oris
Keeps food between teeth during mastication
Assists blowing and whistling
Buccal branch of facial nerve
Located superficial to buccinator.
Functions:
Facilitates sucking in infants
Provides cheek contour
Surgical reconstructive flap source
Facial artery
Buccal artery (maxillary artery)
Infraorbital artery
Into:
Facial vein
Pterygoid venous plexus
Drain mainly to:
Submandibular nodes
Deep cervical nodes
Long buccal nerve (V3)
Facial nerve (VII)
Supplies buccinator
Due to:
Gutkha
Betel nut
Tobacco chewing
Along occlusal line.
Ulcer
Induration
Trismus
Neck nodes
Chronic progressive premalignant disorder characterized by fibrosis of oral mucosa causing restricted mouth opening.
Areca nut chewing (most important)
Tobacco
Chillies
Nutritional deficiency
Burning sensation
Blanched mucosa
Fibrous bands
Progressive trismus
Potentially malignant disorder with risk of transformation to SCC.
→ Buccal mucosa
→ Squamous cell carcinoma of lower lip
→ Mylohyoid
→ Opposite upper second molar tooth
→ Mental nerve (V3)
→ Infraorbital nerve (V2)
→ Oral Submucous Fibrosis
→ Retromolar trigone
→ Oral cavity and oropharynx
Motor → Facial nerve (VII)
Sensory mucosa → Long buccal nerve (V3)
Divisions of oral cavity (vestibule vs cavity proper)
Boundaries of oral cavity
Oral cavity subsites for oral cancer classification
Faucial isthmus and pillars
Floor of mouth muscles (mylohyoid, geniohyoid, genioglossus)
Blood supply of lips
Lymphatic drainage of lips
Buccinator muscle anatomy
Buccal fat pad anatomy
Retromolar trigone anatomy
Pterygomandibular raphe
Oral cavity surgical landmarks
Cleft lip
Carcinoma lower lip
Buccal carcinoma
Oral submucous fibrosis
Retromolar trigone carcinoma
Tongue tie (ankyloglossia)
Oral cavity examination
Oral leukoplakia
Oral erythroplakia
Lip histology
Buccal mucosa histology
Minor salivary glands
Oral squamous epithelium
Squamous cell carcinoma of lip
Oral submucous fibrosis histopathology
Dysplasia of oral mucosa
Oral SCC histology
Oral mucosa is the moist mucous membrane lining the oral cavity.
It forms a protective barrier and is specialized for mastication, speech, sensation, taste, and immunity.
Oral mucosa is divided into three types:
Subjected to friction and chewing forces.
Locations
Gingiva
Hard palate
Characteristics
Keratinized stratified squamous epithelium
Firmly attached to underlying periosteum
Pale pink in colour
Forms the flexible lining of the oral cavity.
Locations
Lips
Cheeks
Floor of mouth
Soft palate
Ventral surface of tongue
Alveolar mucosa
Characteristics
Non-keratinized epithelium
Soft and elastic
More vascular
Contains taste receptors.
Location
Dorsum of tongue
Characteristics
Contains papillae and taste buds
Stratified squamous epithelium
Basement membrane
Lamina propria
Submucosa (where present)
Present in:
Gingiva
Hard palate
Layers:
Stratum basale
Stratum spinosum
Stratum granulosum
Stratum corneum
Function:
Resists mechanical trauma
Present in:
Buccal mucosa
Floor of mouth
Soft palate
Lips
Layers:
Basal layer
Intermediate layer
Superficial layer
Function:
Flexibility and mobility
Taste buds are barrel-shaped sensory structures.
Components:
Taste receptor cells
Supporting cells
Basal cells
Taste pore
Average lifespan of taste cells:
Approximately 10–14 days
Leukoplakia
Erythroplakia
Oral lichen planus
Oral candidiasis
Oral submucous fibrosis
Squamous cell carcinoma
Lateral border of tongue
Floor of mouth
Soft palate
Retromolar trigone
Gingiva is the part of oral mucosa covering the alveolar processes and surrounding the cervical portion of teeth.
Unattached collar around tooth
Forms gingival sulcus
Normal sulcus depth:
1–3 mm
Firmly attached to periosteum
Resists mastication forces
Triangular gingival tissue between adjacent teeth.
Functions:
Protects interdental spaces
Prevents food impaction
Epithelium:
Keratinized stratified squamous epithelium
Underlying:
Dense fibrous connective tissue
No submucosa in most areas.
From:
Superior alveolar arteries
Inferior alveolar artery
Greater palatine artery
Facial artery branches
Superior alveolar nerves
Greater palatine nerve
Nasopalatine nerve
Inferior alveolar nerve
Lingual nerve
Buccal nerve
Inflammation of gingiva.
Features:
Redness
Swelling
Bleeding
Inflammation involving supporting tissues of teeth.
Results in:
Bone loss
Tooth mobility
Tooth loss
Causes:
Phenytoin
Cyclosporine
Nifedipine
Leukemia
Humans are diphyodont.
Two sets:
Deciduous teeth
Permanent teeth
Also called milk teeth.
Number:
20
Eruption:
6 months to 2½ years
Number:
32
Eruption:
6 years onwards
Third molar:
17–25 years
[
\frac{2;1;0;2}{2;1;0;2}
]
Per quadrant:
2 incisors
1 canine
0 premolars
2 molars
Total = 20
[
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]
Per quadrant:
2 incisors
1 canine
2 premolars
3 molars
Total = 32
Visible part above gingiva.
Junction of crown and root.
Embedded in alveolar bone.
Hardest tissue in body
Derived from ectoderm
Composition:
96% inorganic
Forms bulk of tooth
Produced by odontoblasts
Covers root
Anchors periodontal ligament
Contains:
Blood vessels
Lymphatics
Nerves
Connective tissue
| Tooth | Age |
|---|---|
| Lower central incisor | 6–8 months |
| Upper central incisor | 7–9 months |
| First molar | 12–16 months |
| Canine | 16–20 months |
| Second molar | 20–30 months |
| Tooth | Age |
|---|---|
| First molar | 6 years |
| Central incisor | 6–8 years |
| Lateral incisor | 7–9 years |
| Canine | 9–12 years |
| Premolars | 10–12 years |
| Second molar | 12 years |
| Third molar | 17–25 years |
Superior alveolar arteries
Inferior alveolar artery
Superior alveolar nerves
Inferior alveolar nerve
Definition:
Progressive destruction of tooth by bacterial acids.
Common organisms:
Streptococcus mutans
Lactobacilli
Improper alignment of teeth.
Complications:
Chewing difficulty
Speech problems
TMJ disorders
Develops from floor of primitive pharynx.
| Part | Arch |
|---|---|
| Anterior 2/3 | First arch |
| Posterior 1/3 | Third arch |
| Epiglottic region | Fourth arch |
Tongue is a muscular organ divided into:
Anterior free end.
Anterior two-thirds.
Posterior one-third.
Contains:
Papillae
Taste buds
Smooth and thin.
Contains:
Lingual veins
Frenulum
Midline groove.
V-shaped groove separating oral and pharyngeal parts.
Apex of sulcus terminalis.
Remnant of thyroglossal duct.
Fibrous midline partition.
Lymphoid tissue on posterior one-third.
Spaces between tongue base and epiglottis.
Connects epiglottis to tongue.
Bound lateral margins of valleculae.
Most numerous.
Characteristics:
Keratinized
No taste buds
Mushroom-shaped
Taste buds present
Number:
8–12
Located anterior to sulcus terminalis.
Taste buds abundant.
Located on lateral tongue.
Well developed in children.
Present on:
Fungiform papillae
Circumvallate papillae
Foliate papillae
Not present on:
Filiform papillae
Action:
Protrudes tongue
Most important airway muscle.
Depresses tongue.
Retracts tongue.
Elevates posterior tongue.
Only tongue muscle supplied by vagus nerve.
Superior longitudinal
Inferior longitudinal
Transverse
Vertical
Functions:
Change shape of tongue
Lingual artery
Branches:
Deep lingual artery
Dorsal lingual artery
Sublingual artery
Lingual veins
→ Internal jugular vein
Submental nodes
Submandibular nodes
Deep cervical nodes
Jugulodigastric nodes
Lymphatic drainage crosses midline.
Hence bilateral nodal metastasis is common.
All muscles:
Hypoglossal nerve (XII)
Exception:
Palatoglossus → Vagus nerve (X)
Anterior 2/3:
Lingual nerve (V3)
Posterior 1/3:
Glossopharyngeal nerve (IX)
Epiglottic region:
Internal laryngeal nerve (X)
Anterior 2/3:
Chorda tympani (VII)
Posterior 1/3:
Glossopharyngeal nerve (IX)
Epiglottis:
Vagus nerve (X)
Short lingual frenulum restricting tongue movement.
Tongue deviates toward side of lesion.
Associated with:
Atrophy
Fasciculations
Most common site:
Lateral border of anterior two-thirds
Usually:
Squamous cell carcinoma
Mucous retention cyst in vallecula.
May cause:
Dysphagia
Airway obstruction
Large tongue, vallecular pathology or tongue base masses may obstruct laryngoscopic view.
Area between tongue and mandible.
Located above mylohyoid.
Contains:
Sublingual gland
Wharton duct
Lingual nerve
Located below mylohyoid.
Contains:
Submandibular gland
Between anterior bellies of digastric muscles.
Spaces communicate around posterior border of mylohyoid.
Important pathway for infection spread.
Elevation formed by sublingual gland.
Midline fold attaching tongue to floor.
Rapidly spreading cellulitis involving:
Sublingual space
Submandibular space
Submental space
Common cause:
Dental infection
Airway emergency.
Mucous retention cyst of sublingual gland.
Bluish translucent swelling in floor of mouth.
Can spread into deep neck spaces causing severe complications.
Forms anterior two-thirds of palate.
Separates oral and nasal cavities.
Palatine process of maxilla (75%)
Horizontal plate of palatine bone (25%)
Located near third molar.
Transmits:
Greater palatine nerve
Greater palatine vessels
Located behind central incisors.
Transmits:
Nasopalatine nerve
Sphenopalatine artery branch
Greater palatine artery
Sphenopalatine artery branches
Greater palatine nerve
Nasopalatine nerve
Failure of fusion of palatal shelves.
Features:
Feeding difficulty
Nasal regurgitation
Speech defects
Benign midline bony exostosis.
Usually asymptomatic.
Fibromuscular posterior continuation of hard palate.
Separates nasopharynx from oropharynx during swallowing.
Fibrous framework of soft palate.
Attachment of palatal muscles.
Midline projection from posterior free margin.
Action:
Tenses palate
Opens Eustachian tube
Nerve:
Mandibular nerve (V3)
Action:
Elevates palate
Nerve:
Vagus (pharyngeal plexus)
Shortens uvula.
Narrows oropharyngeal isthmus.
Elevates pharynx during swallowing.
Ascending palatine artery
Lesser palatine artery
Ascending pharyngeal artery
All muscles:
Vagus nerve via pharyngeal plexus
Exception:
Tensor veli palatini → V3
Lesser palatine nerves
Deglutition
Speech resonance
Separation of oral and nasal cavities
Prevention of nasal regurgitation
Eustachian tube function
Causes:
Vagus nerve lesion
Bulbar palsy
Features:
Nasal speech
Nasal regurgitation
Uvula deviates to normal side
Failure of palatal closure during speech.
Features:
Hypernasal speech
Nasal air escape
Articulation defects
The faucial isthmus (or oropharyngeal isthmus) is the opening that connects the oral cavity proper with the oropharynx.
It represents the posterior boundary of the oral cavity.
| Boundary | Structure |
|---|---|
| Superior | Soft palate and uvula |
| Inferior | Dorsum of tongue |
| Lateral | Palatoglossal arches (anterior faucial pillars) |
Formed by:
Palatoglossus muscle
Covered by mucosa
Function:
Narrows the oropharyngeal isthmus during swallowing
Formed by:
Palatopharyngeus muscle
Covered by mucosa
Function:
Elevates pharynx during swallowing
Between anterior and posterior pillars lies:
Contains:
Palatine tonsil
Tonsillar branches of facial artery
Peritonsillar space
Most common pathology involving the faucial region.
Collection of pus in peritonsillar space.
Features:
Severe sore throat
Trismus
Muffled "hot potato" voice
Uvular deviation
May involve:
Faucial pillars
Soft palate
Tonsillar fossa
Faucial anatomy is important during:
Endoscopy
Intubation
Tonsillectomy
Retromolar trigone (RMT) is a small triangular mucosal area situated behind the last mandibular molar.
It is one of the recognized oral cavity subsites in oral cancer staging.
Located over:
Ascending ramus of mandible
Covered by:
Thin mucosa
| Boundary | Structure |
|---|---|
| Anterior | Last mandibular molar |
| Posterior | Ascending ramus |
| Medial | Alveolingual sulcus |
| Lateral | Buccal sulcus |
Maxillary tuberosity
Pterygomandibular raphe
Mandibular periosteum
Temporalis tendon insertion
Buccal mucosa
Tumours spread rapidly to:
Mandible
Masticator space
Oropharynx
Base of tongue
Pterygomandibular space
Usually:
Squamous cell carcinoma
Non-healing ulcer
Pain
Trismus
Referred otalgia
Neck nodes
Small lesions may produce extensive deep spread.
Minor salivary glands are numerous small salivary glands distributed throughout the oral mucosa.
Number:
Approximately 600–1000
Present in:
Lips
Cheeks
Hard palate
Soft palate
Floor of mouth
Tongue
Retromolar region
Absent in:
Gingiva
Anterior hard palate midline
Inside lips.
Inside cheeks.
Hard and soft palate.
Tongue.
Predominantly:
Mucous acini
Some glands contain:
Serous acini
Mixed acini
Drain via small ducts directly into oral cavity.
Maintains oral moisture.
Facilitates speech and swallowing.
Provides:
IgA
Lysozyme
Lactoferrin
Initiates carbohydrate digestion.
Mucous retention cyst due to duct obstruction.
Common palate tumour site.
Examples:
Pleomorphic adenoma
Mucoepidermoid carcinoma
Adenoid cystic carcinoma
Crosses masseter
Pierces buccinator
Opens into oral vestibule
Opposite:
Upper second molar tooth
Visible as:
Parotid papilla
Arises from:
Deep part of submandibular gland
Runs forward in floor of mouth.
At:
Sublingual caruncle
Located on either side of lingual frenulum.
Numerous small ducts.
Open along:
Sublingual fold
May join:
Wharton's duct
or open independently.
Most common in:
Submandibular duct
Reasons:
Long tortuous duct
Thick alkaline saliva
Infection due to duct obstruction.
Results from:
Sublingual gland duct obstruction
Mainly derived from branches of the external carotid artery.
Supplies:
Lips
Cheeks
Soft palate
Branches:
Superior labial artery
Inferior labial artery
Supplies:
Tongue
Floor of mouth
Branches:
Deep lingual
Sublingual
Dorsal lingual
Supplies:
Teeth
Gingiva
Hard palate
Buccal mucosa
Branches:
Inferior alveolar artery
Buccal artery
Greater palatine artery
Infraorbital artery
Supplies:
Soft palate
Oropharyngeal region
Drains:
Lips
Cheeks
Drains:
Tongue
Floor of mouth
Drains:
Deep oral structures
→ Internal jugular vein
Extremely important in oral cancer staging and prognosis.
→ Submandibular nodes
→ Submental nodes
→ Submandibular nodes
→ Submandibular nodes
→ Upper deep cervical nodes
→ Submandibular nodes
→ Submandibular and deep cervical nodes
→ Submental nodes
→ Submandibular nodes
→ Deep cervical nodes
→ Jugulodigastric nodes
Cross-midline lymphatic communication present.
→ Submental nodes
→ Submandibular nodes
→ Deep cervical nodes
→ Retropharyngeal nodes
→ Upper deep cervical nodes
→ Retropharyngeal nodes
→ Jugulodigastric nodes
Jugulodigastric node
(Level II)
May occur directly to deep cervical nodes.
Common in:
Tongue cancer
Floor of mouth cancer
Principal sensory nerve.
Minimal oral cavity contribution.
Supplies:
Upper teeth
Upper gingiva
Hard palate
Upper lip
Branches:
Superior alveolar nerves
Greater palatine nerve
Nasopalatine nerve
Infraorbital nerve
Supplies:
Lower teeth
Lower gingiva
Buccal mucosa
Anterior tongue sensation
Branches:
Inferior alveolar nerve
Lingual nerve
Buccal nerve
Mental nerve
Anterior two-thirds of tongue via:
Chorda tympani
Submandibular gland
Sublingual gland
Provides:
General sensation
Taste
to posterior one-third of tongue.
Supplies:
Soft palate
Epiglottic taste
Palatoglossus muscle
Motor supply to all tongue muscles except:
Palatoglossus
Facial nerve:
Submandibular gland
Sublingual gland
Glossopharyngeal nerve:
Parotid gland
From:
Superior cervical ganglion
Functions:
Vasomotor control
Reduced salivary secretion
These spaces provide pathways for spread of infection.
Between:
Buccinator
Skin of cheek
Contains:
Buccal fat pad
Above mylohyoid.
Contains:
Sublingual gland
Wharton's duct
Lingual nerve
Below mylohyoid.
Contains:
Submandibular gland
Between:
Anterior bellies of digastric muscles
Contains:
Muscles of mastication
Ramus of mandible
Potential space lateral to pharynx.
Communicates with:
Retropharyngeal space
Deep neck spaces
Can spread rapidly between fascial spaces.
Dental infections may spread to:
Buccal space
Sublingual space
Submandibular space
Masticator space
Parapharyngeal space
Particularly in:
Ludwig angina
Parapharyngeal abscess
Forms:
Anterior two-thirds
From:
Lateral lingual swellings
Tuberculum impar
Forms:
Posterior one-third
From:
Hypobranchial eminence
Forms:
Epiglottic region
Derived from:
Intermaxillary segment
Derived from:
Lateral palatine shelves of maxillary processes
Fusion occurs:
7th–12th week
Develop from interaction of:
Forms:
Enamel
Forms:
Dentin
Cementum
Pulp
Dental lamina stage
Bud stage
Cap stage
Bell stage
Apposition
Calcification
Failure of fusion of:
Medial nasal process
Maxillary process
Failure of fusion of:
Palatal shelves
Mildest form of cleft palate.
May indicate submucous cleft palate.
Short lingual frenulum restricting tongue movement.
May affect:
Breastfeeding
Speech articulation
Faucial isthmus connects oral cavity to oropharynx.
Palatine tonsil lies between anterior and posterior faucial pillars.
Retromolar trigone cancers show early deep extension and trismus.
Parotid duct opens opposite upper second molar.
Wharton's duct opens at sublingual caruncle.
Sublingual gland drains through ducts of Rivinus.
Most common site of salivary stone → Submandibular duct.
Tongue lymphatics cross the midline → bilateral nodal metastasis common.
Jugulodigastric node is the most important node in oral malignancy.
Palatoglossus is the only tongue muscle not supplied by hypoglossal nerve.
Ludwig angina involves sublingual, submandibular and submental spaces.
Bifid uvula may be a marker of submucous cleft palate.
Enamel is derived from ectoderm and is the hardest tissue in the human body.
Examination of the oral cavity is an essential component of ENT, dental, oral surgery and head-neck cancer evaluation.
A systematic examination helps identify:
Infections
Ulcers
Premalignant lesions
Malignancies
Congenital anomalies
Salivary gland disorders
Dental diseases
Patient seated comfortably
Adequate illumination
Mouth opened widely
Dentures removed if present
Usually sits facing the patient
Examination performed from right side in right-handed examiner
Uses:
Depress tongue
Visualize oropharynx
Examine tonsils and soft palate
Provides:
Focused illumination
Binocular visualization
Most commonly used in ENT practice.
Uses:
Examination of inaccessible areas
Dental evaluation
Retromolar trigone examination
Uses:
Holding tongue
Examination of lateral tongue border
Assessment of tongue mobility
Essential for:
Oral palpation
Infection control
Examination is performed by:
Inspection should be systematic.
Observe for:
Symmetry
Colour
Swelling
Ulceration
Fissures
Cleft lip
Tumours
Examine:
Labial mucosa
Buccal mucosa
Gingivobuccal sulcus
Look for:
Leukoplakia
Ulcers
OSMF
Buccal carcinoma
Assess:
Number
Alignment
Caries
Missing teeth
Mobility
Colour
Bleeding
Hyperplasia
Recession
Look for:
Papillae
Coating
Ulcers
Tumours
Look for:
Varicosities
Ulcers
Ranula
Most important site for oral SCC.
Inspect for:
Ranula
Swelling
Salivary duct openings
Floor of mouth carcinoma
Look for:
High arch palate
Torus palatinus
Cleft palate
Ulcers
Assess:
Symmetry
Movement during phonation
Palatal palsy
Bifid uvula
Ask patient to say:
“Ahh”
Observe palatal movement.
Assess:
Tonsil size
Inflammation
Exudates
Peritonsillar swelling
Look for:
Congestion
Granules
Growths
Pus
Performed after inspection.
Assesses:
Induration
Nodules
Tumours
Bimanual palpation may be performed.
Detects:
Fibrosis
Masses
Submucosal lesions
Particularly important in oral cancer.
Assesses:
Induration
Depth of invasion
Mobility
Bimanual examination.
One finger:
Inside mouth
Other hand:
Under mandible
Useful for:
Salivary gland lesions
Ranula
Malignancy
Detects:
Bony defects
Torus palatinus
Submucosal lesions
Always performed in oral cavity lesions.
Assess:
Cervical lymph nodes
Size
Mobility
Consistency
A standard sequence should be followed.
Lips
↓
Oral vestibule
↓
Buccal mucosa
↓
Teeth and gingiva
↓
Tongue
↓
Floor of mouth
↓
Hard palate
↓
Soft palate and uvula
↓
Tonsillar region
↓
Posterior pharyngeal wall
↓
Neck examination
Documentation should include:
Exact anatomical location.
Measured in centimeters.
Examples:
Oval
Circular
Irregular
Smooth
Granular
Ulcerated
Well-defined
Ill-defined
Everted
Undermined
Soft
Firm
Hard
Mobile
Fixed
Trismus
Lymphadenopathy
Bleeding
Pain
"Ulceroproliferative growth measuring 3 × 2 cm involving left lateral border of tongue with indurated base and everted margins. Ipsilateral level II cervical lymph node palpable."
Oral cavity infections can spread rapidly through fascial planes.
Dental infections
Tonsillar infections
Salivary gland infections
Oral trauma
↓
↓
↓
↓
Potentially life-threatening.
Classic example of fascial space infection.
Involves:
Sublingual space
Submandibular space
Submental space
May cause:
Airway obstruction
Sepsis
Tumour extends to:
Bone
Tongue muscles
Floor of mouth
Oropharynx
Most common route.
Frequently involved nodes:
Submental
Submandibular
Jugulodigastric
Deep cervical
Seen especially in:
Adenoid cystic carcinoma
Advanced SCC
Usually late.
Common sites:
Lung
Liver
Bone
The oral cavity plays a major role in airway maintenance.
Large tongue causing airway obstruction.
May obstruct laryngoscopic view.
Causes floor of mouth elevation.
May distort anatomy.
Restricts mouth opening.
Common causes:
Oral SCC
OSMF
Deep neck infection
Several oral cavity structures serve as important surgical landmarks.
Important in:
Oral cancer surgery
Mandibular resections
Landmark for:
Inferior alveolar nerve block
Tonsil surgery
At risk during:
Third molar extraction
Floor of mouth surgery
Important during:
Ranula surgery
Sublingual gland surgery
Important landmark for:
Palatal surgery
Regional anesthesia
Important during:
Cleft palate repair
Maxillary procedures
Important during:
Direct laryngoscopy
Endotracheal intubation
| Feature | Oral Vestibule | Oral Cavity Proper |
|---|---|---|
| Definition | Space between lips/cheeks and teeth | Space within dental arches |
| Outer Boundary | Lips and cheeks | Teeth and gingiva |
| Contents | Parotid duct opening, frenula | Tongue, palate, floor of mouth |
| Communication | With oral cavity proper | With oropharynx via faucial isthmus |
| Subsite | Importance |
|---|---|
| Lips | Common SCC site |
| Buccal mucosa | Most common oral cancer site in India |
| Gingiva | Gingival malignancies |
| Alveolus | Dental and tumour involvement |
| Retromolar trigone | Early deep tumour spread |
| Hard palate | Salivary gland tumours |
| Tongue | Most common mobile tongue cancer site |
| Floor of mouth | High-risk oral cancer site |
| Boundary | Structure |
|---|---|
| Roof | Hard and soft palate |
| Floor | Mylohyoid, geniohyoid, tongue |
| Anterior | Lips |
| Lateral | Cheeks |
| Posterior | Faucial isthmus |
| Feature | Hard Palate | Soft Palate |
|---|---|---|
| Composition | Bony | Muscular |
| Position | Anterior 2/3 | Posterior 1/3 |
| Mobility | Fixed | Mobile |
| Function | Separates oral and nasal cavities | Velopharyngeal closure |
| Papilla | Taste Buds | Function |
|---|---|---|
| Filiform | Absent | Mechanical |
| Fungiform | Present | Taste |
| Circumvallate | Numerous | Taste |
| Foliate | Present | Taste |
| Muscle | Action |
|---|---|
| Genioglossus | Protrudes tongue |
| Hyoglossus | Depresses tongue |
| Styloglossus | Retracts tongue |
| Palatoglossus | Elevates posterior tongue |
| Muscle | Action | Nerve Supply |
|---|---|---|
| Tensor veli palatini | Tenses palate | V3 |
| Levator veli palatini | Elevates palate | X |
| Palatoglossus | Narrows isthmus | X |
| Palatopharyngeus | Elevates pharynx | X |
| Musculus uvulae | Elevates uvula | X |
| Region | General Sensation | Taste |
|---|---|---|
| Anterior 2/3 | Lingual nerve (V3) | Chorda tympani (VII) |
| Posterior 1/3 | Glossopharyngeal (IX) | Glossopharyngeal (IX) |
| Epiglottis | Vagus (X) | Vagus (X) |
| Region | Main Artery |
|---|---|
| Lips | Facial artery |
| Tongue | Lingual artery |
| Teeth | Maxillary artery |
| Hard palate | Greater palatine artery |
| Soft palate | Ascending palatine artery |
| Site | Main Nodes |
|---|---|
| Lower lip | Submental |
| Upper lip | Submandibular |
| Buccal mucosa | Submandibular |
| Tongue tip | Submental |
| Tongue posterior 1/3 | Jugulodigastric |
| Floor of mouth | Submental/Submandibular |
| Space | Clinical Importance |
|---|---|
| Buccal | Dental infection |
| Sublingual | Ludwig angina |
| Submandibular | Deep neck infection |
| Submental | Ludwig angina |
| Masticator | Trismus |
| Parapharyngeal | Airway compromise |
| Arch | Derivative |
|---|---|
| First | Anterior 2/3 tongue |
| Third | Posterior 1/3 tongue |
| Fourth | Epiglottic region |
| Structure | Origin |
|---|---|
| Primary palate | Intermaxillary segment |
| Secondary palate | Palatine shelves |
| Part | Origin |
|---|---|
| Anterior 2/3 | First arch |
| Posterior 1/3 | Third arch |
| Epiglottic part | Fourth arch |
| Condition | Defect |
|---|---|
| Cleft lip | Failure of fusion of maxillary and medial nasal processes |
| Cleft palate | Failure of fusion of palatal shelves |
| Bifid uvula | Mild cleft palate |
| Ankyloglossia | Short lingual frenulum |
| Space | Common Source |
|---|---|
| Sublingual | Dental infection |
| Submandibular | Molar infection |
| Parapharyngeal | Tonsillar infection |
| Retropharyngeal | Pharyngeal infection |
| Subsite | Common Tumour |
|---|---|
| Lip | SCC |
| Buccal mucosa | SCC |
| Tongue | SCC |
| Floor of mouth | SCC |
| Retromolar trigone | SCC |
| Primary Site | First Node |
|---|---|
| Lip | Submental/Submandibular |
| Buccal mucosa | Submandibular |
| Tongue | Deep cervical |
| Floor of mouth | Submental/Submandibular |
| Feature | Cleft Lip | Cleft Palate |
|---|---|---|
| Defect | Lip fusion failure | Palatal fusion failure |
| Feeding | Mild difficulty | Severe difficulty |
| Speech | Less affected | Markedly affected |
| Nasal regurgitation | Rare | Common |
| Grade | Description |
|---|---|
| Grade I | Mild |
| Grade II | Moderate |
| Grade III | Severe |
| Grade IV | Complete tongue restriction |
Examination of oral cavity must always be systematic and followed by neck examination.
Lateral border of tongue is the most common site for carcinoma tongue.
Bimanual palpation is essential for floor of mouth lesions.
Parotid duct opens opposite the upper second molar tooth.
Wharton's duct opens at the sublingual caruncle.
Trismus is an important sign of deep space infection and retromolar trigone carcinoma.
Ludwig angina is a surgical emergency because of airway compromise.
Jugulodigastric node is the most important cervical node in oral malignancy.
Retromolar trigone is a strategic area for tumour spread into masticator space.
Vallecula is an important landmark during direct laryngoscopy and intubation.
Tongue lymphatics cross the midline, leading to bilateral nodal metastasis.
Hard palate is supplied mainly by the greater palatine artery.
Genioglossus is the most important muscle maintaining airway patency.
Figures
Oral cavity boundaries
Oral vestibule
Oral cavity proper
Figures
Lips anatomy
Cheek anatomy
Buccinator muscle
Figures
Hard palate
Soft palate
Faucial isthmus
Figures
Tongue gross anatomy
Tongue papillae
Taste buds
Figures
Tongue muscles
Blood supply
Nerve supply
Figures
Valleculae
Glossoepiglottic folds
Lingual tonsil
Figures
Sublingual space
Submandibular space
Submental space
Figures
Fascial spaces
Deep neck space communication
Ludwig angina anatomy
Figures
Tooth anatomy
Dental formula
Tooth eruption chart
Figures
Development of tongue
Development of palate
Cleft deformities
Figures
Oral cavity lymphatic drainage
Cervical lymph node levels
Oral cancer spread pathways
Must know and frequently asked in examinations:
Tongue papillae and taste bud diagram
Nerve supply of tongue
Lymphatic drainage of tongue
Hard palate and soft palate anatomy
Faucial isthmus and tonsillar fossa
Fascial spaces of oral cavity
Ludwig angina spread
Tooth anatomy and eruption chart
Development of palate and cleft palate
Oral cavity lymphatic drainage
Cervical lymph node levels
Oral cancer pathways of spread
Histology Slides
Keratinized oral mucosa
Non-keratinized oral mucosa
Taste buds
Histology Slides
Filiform papilla
Fungiform papilla
Circumvallate papilla
Histology Slides
Enamel
Dentin
Cementum
Histology Slides
Dental pulp
Gingival histology
Periodontal ligament
Histology Slides
Serous acini
Mucous acini
Mixed salivary gland
Clinical Photographs
Normal oral cavity
Oral vestibule
Oral cavity proper
Clinical Photographs
Tongue anatomy
Circumvallate papillae
Lingual frenulum
Clinical Photographs
Normal dentition
Gingiva
Hard palate
Clinical Photographs
Cleft lip
Cleft palate
Bifid uvula
Clinical Photographs
Ankyloglossia
Ranula
Ludwig angina
Clinical Photographs
Carcinoma tongue
Buccal mucosa carcinoma
Floor of mouth carcinoma
Keratinized oral mucosa
Non-keratinized oral mucosa
Taste bud histology
Filiform papilla
Fungiform papilla
Circumvallate papilla
Enamel
Dentin
Cementum
Dental pulp
Serous acini
Mucous acini
Mixed salivary gland
Gingival histology
Periodontal ligament
Normal oral cavity
Circumvallate papillae
Lingual frenulum
Cleft lip
Cleft palate
Bifid uvula
Ankyloglossia
Ranula
Ludwig angina
Carcinoma tongue
Buccal mucosa carcinoma
Floor of mouth carcinoma
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