Oral Cavity

• Lips


  Mobile, musculofibrous folds surrounding the mouth, covered externally by skin and internally by mucous membrane
• Labial Frenula (Frenulum)


  • Free edge folds of mucous membrane in the midline extending from the vestibular gingiva to the mucosa of the upper and lower lip
  • Frenulum in the upper lip is larger than the frenulum in the lower lip
  • Some small lateral occurrence of frenulum (in the premolar regions): mandibular buccal frenulum
• Speaker: 'Superior labial frenulum is called a lip tie when it is interfering with breastfeeding'
• Oral Cavity Boundaries

  1. Superior Boundary: Anteriorly - hard palate, Posteriorly - soft palate

  2. Inferior Boundary: Comprised of suprahyoid muscles and tongue

  3. Anterior Boundary: Bounded by the lips and associated musculature

  4. Lateral Wall (Cheek): Comprised of the buccinator muscle and associated mucosa in the region
• Lips Functions

  • Controls entry and exit from the mouth and respiratory tract
  • Grasping food
  • Sucking liquids
  • Keeping food out of the vestibule
  • Forming speech
  • Osculation (Kissing)
• Superior labial frenulum is called a lip tie when it interferes with breastfeeding
• Frenulectomy


  Oral surgery procedure that treats lip-tie or tongue-tie
• Blood supply & innervation of lips

  1. From the facial artery

  2. Superior labial artery supplies the upper lip

  3. Inferior labial artery supplies the lower lip

  4. The superior and inferior labial artery anastomoses together with the lips to form an arterial ring
• 1. year-old female with excessively large superior labial frenulum may have a space between the central incisors caused by the frenulum
• Space between the central incisors (especially of pediatric patients) caused by excessively large frenulum
• Frenulectomy is an oral surgery procedure that treats lip-tie or tongue-tie
• Blood supply & innervation of cheeks

  Buccal branches of facial nerve innervate the skin of the cheek and buccal mucosa
• Blood supply & innervation of cheeks

  1. Blood Supply: Buccal branches of maxillary artery

  2. Innervation: Buccal branches of facial nerve
• Stanford superior labial frenulum classification


  • Type 1: The insertion of the frenulum is near the mucogingival junction
  • Type 2: The insertion of the frenulum is along the mid, attached to the gingiva
  • Type 3: The insertion of the frenulum is along the inferior margin at the alveolar papilla and can continue in the posterior surface
• If kids have parted incisors, one thing to check is their labial frenulum
• 20 deciduous teeth are temporary and found in children
• Delayed eruption of permanent anterior teeth in a 13-year-old Caucasian male due to supernumerary teeth
• Vascular & nerve supply of the teeth

  1. Arteries supplying maxillary and mandibular teeth

  2. Veins accompanying the arteries supplying maxillary and mandibular teeth

  3. Nerves from dental plexuses supplying maxillary and mandibular teeth
• Inferior surface of the palate is covered with oral mucosa made up of stratified squamous non-keratinized epithelium
• Palate has regions: hard palate and soft palate
• Structure of tooth

  1. Crown erupts from the gingiva

  2. Neck is between the crown and the root

  3. Roots are fixed in the tooth socket surrounded by connective tissue (cementum)

  4. Most of the tooth is composed of dentin covered by enamel

  5. Pulp cavity contains connective tissue, blood vessels, and nerves

  6. Root canal/pulp canal transmits nerves and vessels to and from the pulp cavity

  7. Apical foramen is where the nerves and vessels pass through/exits
• 32 permanent teeth are normally found in adults
• Functions of teeth

  • Incise (cut), reduce, and mix food material with saliva during mastication (chewing)
  • Participate in articulation (distinct connected speech)
• Palate forms the arch roof of the mouth, the floor of the nasal cavity, and separates the oral cavity from the nasal cavity
• Supernumerary teeth may require multiple extractions in certain patient cases
• Tooth sockets, interalveolar septa, & interradicular septa

  1. Tooth sockets are located in the alveolar processes of the maxilla and mandible

  2. Interalveolar septa separate adjacent sockets

  3. Interradicular septa within the socket separate the socket of teeth with more than one root
• Superior surface of the palate is covered with respiratory mucosa/epithelium
• Types of teeth

  • Incisors have thin cutting edges
  • Canines have single prominent cone
  • Premolars have 2 cusps
  • Molars have 3 or more molar cusps
• Cleft palate, with or without cleft lip, occurs in approximately 1 of 2500 births
• Palatine Aponeurosis


  • Strengthens the aponeurotic part of the soft palate, which attaches to the posterior edge of the hard palate
  • Thick anteriorly and thin posteriorly
  • Blends with the muscular part
  • Has a curved free edge/margin where the uvula hangs
• Hard Palate


  • Covered with oral mucosa
  • Made up of stratified squamous non-keratinized epithelium
• Embryological basis of cleft palate: failure of fusion of the lateral palatine processes with the nasal septum and/or with the posterior margin of the median palatine process
• Arches of the soft palate

  • The soft palate is continuous with the wall of the pharynx laterally
  • The palatoglossal arch & palatopharyngeal arches join the soft palate to the tongue and pharynx
• Nasopalatine block

  1. A nerve block of the nasopalatine nerves facilitated by injecting into the incisive fossa in the hard palate

  2. The anesthetized tissues: Palatal mucosa, Lingual gingivae, Alveolar bone of the six anterior maxillary teeth, Hard palate, Nasal septum
• Soft Palate

  • Movable posterior third of the palate
  • Suspended from the posterior border of the hard palate
  • Without bony skeleton
• Each tonsil is bounded by the palatoglossal and palatopharyngeal arches, as well as the tongue
• Levator veli palatini


  • Origin: Cartilaginous part or pharyngotympanic tube, Petrous part of the temporal bone
  • Insertion: Palatine aponeurosis
  • Action: Elevates soft palate
  • Vascular supply: Ascending palatine artery, Greater palatine artery
  • Innervation: Pharyngeal branch of vagus nerve
• Structures in the palate

  • Palatine glands
  • Transverse palatine folds (Rugae)
  • Palatine raphe
• Tensor veli palatini

  • Origin: Scaphoid fossa of medial pterygoid plate, Spine of sphenoid bone, Pharyngotympanic tube
  • Insertion: Palatine aponeurosis
  • Action: Tenses soft palate, Opens the mouth of the eustachian tube
  • Vascular supply: Ascending palatine artery, Greater palatine artery
  • Innervation: Medial pterygoid branch of CNV3
• Palatoglossus

  • Origin: Palatine aponeurosis
  • Insertion: Lateral side of tongue
  • Action: Elevates posterior part of the tongue, Draws the soft palate onto the tongue
  • Vascular supply: Ascending palatine artery, Ascending pharyngeal artery
  • Innervation: Pharyngeal branch of the vagus nerve