Anatomy & Physiology
 Orofacial Structures & Velopharyngeal Valve

 1. Nose
 Nasal root - Where the nose begins at the level of the eyes
 Nasal bridge -  Bony structure located between the eyes & corresponds to middle of nasofrontal suture
 Columella -  Cartilage & mucosa that separates the nostrils; runs from nasal tip to lower end of nasal septum
 Alae (singular “ala nasi”)-  Outside curved parts of the nostrils
 Alar rims & alar base

2. Nasal Cavity
 Nasal septum - vomer, perpendicular plate, quadrangular cartilage
 Vomer -  Flat bone positioned perpendicular to the palate; Meets nasal surface of maxilla at midline &
 Forms inferior & posterior portion of nasal septum
 Perpendicular plate of the ethmoid -  Projects down to join vomer; Lies between vomer & quadrangular cartilage
 Quadrangular cartilage - Forms anterior nasal septum: Projects to the columella

3.Nasal Cavity: Surface Structures
 Turbinates -  Bony structures extending from lateral walls of the nose; Covered with mucosa; Superior & middle are part of the ethmoid bone;
 Inferior is part of the sphenoid bone
 Nasal meatuses- Openings or passageways that lie directly under respective turbinates
 Purpose of trubinates is to Create turbulent airflow

4.Upper Lip
 Philtrum -  Indentation that runs from columella to upper lip
 Philtral columns-  Raised lines on either side of the philtrum; Embryological suture lines
 Cupid’s bow -  Shape of the upper lip - rounded with an indentation in the middle
 Tubercle - Prominent point at inferior border of midsection
 White roll & vermilion -  White border tissue surrounding red pigmented portion

5.Oral Cavity
 Tongue -  Dorsum (top) and ventral (lower) surface
 Faucial pillars- Bilateral, paired curtain like structures;  Anterior & posterior
 Palatine tonsils
 Lingual tonsils
 Oropharyngeal isthmus -  Opening from oral cavity to pharynx bordered by velum, faucial pillars and tongue

6.Hard palate: Surface features
 Palatal vault -  Roof of the mouth and floor of the nasal cavity
 Alveolar ridge -  Outer rim of the hard palate; Forms base and bony support for teeth
 Mucoperiosteum -  Tissue covering the hard palate; Mucous membrane (mucosa) - stratified squamous epithelium
 Periosteum - thick, fibrous membrane that covers bone
  Rugae-  Folds, ridges or creases in a structure; Transverse ridges in the mucosa of the hard palate
 Incisive papilla -  Slight elevation of mucosa at anterior end of raphe of the palate
 Median (palatine) raphe-  Line of union between two bilaterally symmetric structures; Midline of the mucosa covering the hard palate
 Runs from incisive papilla to border of hard palate

7.Hard palate: Bones & Suture Lines
 Premaxilla - Triangular-shaped bone that is bordered by incisive suture lines; Dental arch contains central & lateral maxillary incisors
 Incisive foramen -  Hole in the palate to allow blood vessels & nerves to pass through; Located at tip of premaxilla
 Incisive suture lines -  Embryological suture lines that go between the lateral incisors and canines and meet at the incisive foramen
 Palatine processes-  Paired projections of the maxillary bone; Posterior to incisive suture lines; Form anterior 3/4 of maxilla
 Horizontal plates -  Paired horizontal projections of the palatine bones; Form posterior 1/4 of hard palate
                              Joined to palatine processes by transverse palatine suture line (palatomaxillary suture line)
 Posterior nasal spine -  Projection located along the posterior border of the hard palate (horizontal plate) at midline
 Median palatine (intermaxillary) suture line -  Embyological suture line that runes from incisive foramen to posterior nasal spine
                                Separates palatine processes and horizontal plates medially
 Palatine torus (torus palatinus)-  Normal palatal variation consisting of prominent longitudinal ridge on oral surface of hard palate in the area of the median palatine suture line

8. Velum(soft palate): Surface structures
 Oral surface-  Median palatine raphe; Covered by mucous membrane
 Nasal surface -  Ciliated epithelium anterior; Posterior - same epithelial cover as oral surface
 Uvula -  Teardrop-shaped structure hanging from posterior border of velum; Connective, glandular & adipose tissue - highly vascular - no known function

9.Velum: Internal structures
 Anterior portion has tensor tendon (extension of tensor veli palatini), glandular & adipose tissue
 Palatine aponeurosis(velar aponeurosis) -  Anterior part of velum, below nasal surface; Fibrous connective tissue & fibers from tensor tendon
                                                         Attaches to posterior border of hard palate; Provides anchoring point for muscles & adds stiffness
 Medial portion contains 40% of muscle fibers
 Posterior mostly glandular & adipose tissue

10.Pharynx
 Throat area between nasal cavity & esophagus
 Oropharynx - level with mouth
 Nasopharynx - above oral cavity & velum; posterior to nasal cavity
 Hypopharynx - below oral cavity from epiglottis to esophagus
 Adenoids (pharyngeal tonsils)- Posterior pharyngeal wall just behind the velum
 Torus tubarius- Ridge located posterior to pharyngeal opening of eustachian tube; Located slightly above level of velum during phonation

11. Muscles of the Velopharyngeal Mechanism
 Sphenoid & temporal bone provide bony attachment for muscles
 Bilateral projections of sphenoid called the pterygoid processes
 2 thin plates on each process called lateral & medial pterygoid plates
 Inferior tip of medial pterygoid plate is the hamulus
 Levator veli palatini- Main muscle mass of velum - middle portion; Primary muscle for velar elevation; Runs from temporal bone,
                                 enters velum at 45 degree angle,inserts into palatal aponeurosis & median raphe

 Tensor veli palatini -  Originate from scaphoid fossa of sphenoid and membranous portion of eustachian tube
                                  Courses vertically, blends into a tendon which passes around hamulus, bends at a 90 degree angle &
                                   inserts into velum contributing to aponeurosis
                                   Contraction thought to open eustachian tube, stretch palate laterally perhaps providing tension

Levator innervated through pharyngeal plexus - mixture of fibers from CN IX and X
 Tensor innervated by CN V

 Musculus uvulae-  Pair of muscles that are intrinsic to velum; Originate from area of aponeurosis and extend to posterior border of velum
                             Lie side by side along midline; Create a bulge on nasal surface of posterior velum;Provides stiffness;
                             Fill in area of contact between velum and posterior pharyngeal wall; May help extend nasal aspect of velum toward post. wall
                              Innervation from pharyngeal plexus

 Superior pharyngeal constrictor-  Responsible for medial displacement of lateral pharyngeal walls effectively narrowing velopharyngeal port
 Palatoglossus -  Originate from palatal aponeurosis and insert into posterior lateral edges of tongue;
                           Contraction causes lowering of velum & elevation of back of tongue
                            Innervation by pharyngeal plexus as well as CN XII

 Palatopharyngeus -  Originate from palatal aponeurosis & posterior border of hard palate
                                Fibers attach to pharyngeal wall and thyroid cartilage;
                               Function not well understood; May assist in lowering velum, raise larynx & pharyngeal wall
                               May assist in sphincter action of lateral pharyngeal walls; Probably more important for swallowing than velopharyngeal closure for speech

Salpingopharyngeus- Arises from inferior border of torus tubarius, runs vertically under the salpingopharyngeal fold and inserts into lateral pharyngeal wall
 

12 Physiology of the Velopharyngeal Valve
 Coordinated action of velum, lateral & posterior pharyngeal walls function as a valve to close the connection between the nasal & pharyngeal cavities during speech & swallowing
 

  •  Velar movement
  •  Moves in upward & backward direction to contact posterior pharyngeal wall (sometimes lateral walls)
  •  Movement is primarily the result of levator veli palatini contraction
  •  In infants movement is mostly backward because bony attachment for levator is almost level with rest of velum
  •  Velar Movement
  •  Velum bends forming a knuckle (knee action)
  •  Point of bend can be seen on oral surface as  velar dimple located 80% down the length of the velum
  •  Velar eminence - bulge on the nasal surface resulting from contraction of uvular muscle
  •  Velum also elongates or stretches as it elevates: amount of stretch varies according to “need ratio”
  •  For nasal phonemes, velum rapidly lowers or is pulled down through action of palatoglossus muscle & aided by force of gravity & tissue elasticity


    • Pharyngeal Wall Movement

  •  Lateral pharyngeal walls: Move medially; Both walls move but amount of movement may be asymmetrical
  •  Inward movement not seen orally - may seem to bulge out at oral level
  •  Posterior pharyngeal wall-  May move slightly forward
  •  Passavant’s ridge -  Defined area on posterior wall that bulges forward during speech & other closure activities
  •  Occurs inconsistently in some people; Location varies - often below level of closure


    • 13. Variations in Velopharyngeal Closure
     Closure is in a sphincter like motion but Variations occur
     Coronal- posterior movement of velum with some anterior movement of posterior pharyngeal wall
     Circular - contributions from velum, posterior wall and lateral pharyngeal walls
     Sagittal - lateral pharyngeal walls meet at midline behind the velum with minimal velar movement
     Deep oropharynx corresponds to sagittal or circular pattern; flat oropharynx show coronal pattern
     Finkelstein et al (1992) Plastic & Reconstructive Surgery

    14 Physiology of closure varies as a function of the type of activity
     Separate neurological mechanism for closure during nonspeech versus speech activities
     Nonpneumatic - velum raises high, closure is firm and exaggerated, back of tongue assists
     Pneumatic - closure occurs lower in nasopharynx, less exaggerated
     Within the pneumatic category, blowing requires only generalized movements while speech requires rapid precise movements

    15.Variations in velopharyngeal Closure During Connected Speech
     Timing between voice onset and closure must be coordinated
     Closure begins prior to onset of phonation
     Timing is adjusted for the particular oral phoneme that follows
     Velar height and firmness of closure varies with phoneme
     Highest velar height & firmness of closure occur with high pressure consonants especially voiceless
     Higher velar height for high vowels versus low vowels and degree of closure force is greater also
     Increases in speech rate cause decrease in velar height and reduction in firmness of closure
     As speech rate increases, hypernasal quality increases
     Muscular fatigue results in decrease in velar height and reduction in firmness of closure
     Become “whiny” when we are tired

    16.Variations in Velopharyngeal Closure As a Function of Maturation
     Facial bones continue to grow downward & forward in relation to the cranium
     Size of the pharynx changes - volume of nasopharynx increases 80% from infancy to adulthood - most growth in vertical direction
      angle of the wall at junction of naso & oropharynx changes from oblique to right angle
     Velum moves down and slightly forward during growth as it is attached to the hard palate/maxilla
     Velum increases in length, thickness & stretch