s10 - Congenital palatal defects Flashcards
What is the definition of maxillofacial prosthetics?
The branch of prosthodontics concerned with restoring/replacing missing or damaged oral and facial structures due to surgery, trauma, or congenital defects.
What structures can maxillofacial prosthetics restore?
Teeth, oral tissues, and facial structures (e.g., ears, nose, eyes).
What are the primary causes of maxillofacial defects?
Surgery, trauma, congenital malformations, or developmental defects.
How does maxillofacial prosthetics differ from general prosthodontics?
It focuses on extra-oral and complex intra-oral rehabilitation (e.g., obturators, facial prostheses).
What is the goal of maxillofacial prosthetic treatment?
To restore function (speech, swallowing), aesthetics, and psychosocial well-being.
What are the three main types of maxillofacial defects?
Congenital, acquired, and developmental.
Give two examples of congenital maxillofacial defects.
Cleft lip/palate, microtia (missing ear).
What causes acquired maxillofacial defects?
Surgery (e.g., tumor resection), trauma, or pathology (e.g., osteoradionecrosis).
Name two developmental maxillofacial defects.
Prognathism, retrognathism, macro/micrognathia.
Why are congenital defects often more challenging to treat than acquired defects?
They involve growth abnormalities and may require multidisciplinary care from birth.
How are maxillofacial prostheses classified by location?
Intra-oral, extra-oral, combined, or cranial/facial.
What is the purpose of an intra-oral obturator?
To close a palatal defect (congenital or acquired) and improve speech/swallowing.
Name three types of intra-oral stents and their uses.
Antihaemorrhagic (bleeding control), radium carriers (radiation therapy), mouth protectors.
What is the function of a splint in maxillofacial prosthetics?
To stabilize jaw fractures by holding bone fragments in place during healing.
When is a resection appliance used?
To correct mandibular closure paths after partial jaw resection.
What are extra-oral prostheses? Examples?
Prostheses replacing facial structures (e.g., ocular, nasal, auricular prostheses).
What is a radium shield prosthesis?
A protective device to shield tissues from radiation therapy.
What are combined intra-oral/extra-oral prostheses used for?
Cases with loss of maxilla/mandible and adjacent facial structures.
What is a cranial onlay/inlay prosthesis?
A prosthesis to replace lost cranial bone (e.g., after skull injury).
What are intra-mandibular implants?
Implants placed within mandibular bone to support prostheses.
Who are the key members of a maxillofacial rehabilitation team?
Plastic surgeon, prosthodontist, speech therapist, orthodontist, psychologist, social worker, dental technician.
What is the role of the plastic surgeon in cleft care?
Surgical repair of lip/palate deformities and reconstructive procedures.
When is a prosthodontist essential in maxillofacial cases?
When surgical reconstruction isn’t possible (e.g., large defects, unoperated clefts).
How does a speech therapist contribute to cleft palate management?
Corrects compensatory speech patterns post-surgery/prosthetic placement.
Why is an orthodontist involved in cleft care?
To manage malocclusion and align maxillary segments before/after surgery.
What role does a psychologist play in treatment?
Helps patients cope with psychosocial challenges (e.g., self-esteem, social integration).
How does a social worker support cleft patients/families?
Provides education, resources, and guidance on long-term care and community support.
Define cleft lip and palate embryologically.
Failure of fusion between embryonic processes (premaxillary, lateral maxillary, palatine).
What is the incidence rate of cleft lip/palate?
~1 in 800 live births.
Which gender is more commonly affected by clefts?
Males (2:1 ratio).
What does Veau Class I cleft involve?
Soft palate only.
Describe Veau Class III cleft.
Unilateral cleft of hard/soft palate extending through alveolar ridge and lip.
What is a bilateral complete cleft (Veau IV)?
Cleft affecting both sides of hard/soft palate, alveolus, and lip.
How does a submucous cleft present clinically?
Intact mucosa with underlying muscle separation (often diagnosed late due to speech issues).
What is the “prolabium” in bilateral cleft lip?
The central lip segment attached to the nasal septum.
What is the primary function of the palato-pharyngeal sphincter?
To separate nasopharynx from oropharynx during speech/swallowing.
Which muscle is most critical for velar elevation?
Levator veli palatini.
What is the Ridge of Passavant?
A muscular bulge on the posterior pharyngeal wall aiding velopharyngeal closure.
How does the relaxed position of the velum differ from its elevated position?
Relaxed: Velum hangs down (nasal breathing); Elevated: Curves upward (speech/swallowing).
What compensates for inadequate velar length during closure?
Pharyngeal wall movement (medial/lateral) and Ridge of Passavant.
Define palato-pharyngeal insufficiency (PPI).
Structural inadequacy (e.g., short palate) preventing closure.
What causes palato-pharyngeal incompetence (PPI)?
Neuromuscular dysfunction (e.g., stroke, cerebral palsy) despite normal anatomy.
How does PPI differ from PPI?
PPI: Anatomic defect; PPI: Functional impairment.
What prosthetic device treats PPI?
Palatal lift prosthesis.
Why is nasal breathing impossible with a meatal obturator?
It blocks the posterior nasal choanae.
Name 3 hereditary factors linked to cleft formation.
Family history, genetic syndromes (e.g., Van der Woude), chromosomal abnormalities.
How can maternal infections contribute to clefts?
Viruses like rubella disrupt embryonic process fusion during first trimester.
Which vitamin deficiencies increase cleft risk?
Vitamin A, riboflavin (B2), and folic acid.
What chemical exposures may cause clefts?
Teratogens (alcohol, phenytoin), hypoxia, hypervitaminosis A.
How does radiation exposure lead to clefts?
Pelvic/therapeutic radiation in pregnancy damages developing facial processes.
What hormonal factors influence cleft formation?
Cortisone therapy, maternal diabetes, thyroid disorders.
Why is stress a risk factor?
High cortisol levels in 1st trimester may impair embryonic fusion.
Why do cleft palate infants struggle with feeding?
Inability to generate negative pressure for sucking.
How does food regurgitation occur in unrepaired clefts?
Nasopharynx remains open during swallowing.
What masticatory problems arise from clefts?
Malocclusion, missing teeth, and alveolar defects.
List 3 psychosocial impacts of clefts.
Low self-esteem, social stigma, depression/anxiety.
What causes hypernasal speech in cleft patients?
Air escapes through nasal cavity due to inadequate palato-pharyngeal closure.
Why is hearing loss common in cleft patients?
Eustachian tube dysfunction leads to chronic otitis media.
Name the 7 steps of speech production.
Respiration → phonation → palato-pharyngeal closure → resonance → articulation → neurologic integration → audition.
How do vocal cords modify speech?
Vibrate to produce laryngeal sound waves (phonation).
Which sounds require nasal resonance?
/m/, /n/, /ŋ/ (e.g., “sing”).
What is the role of the tongue in articulation?
Shapes sounds by changing position (e.g., /t/, /d/, /l/).
How does CNS damage affect speech?
Disrupts motor control of speech organs (dysarthria) or language processing (aphasia).
Why is hearing critical for speech development?
Allows self-monitoring and sound imitation.
What is the purpose of a feeding plate?
To seal the cleft during bottle-feeding in infants.
Why are squeezable bottles used for cleft infants?
To compensate for inability to suck by gravity-assisted flow.
When is lip repair typically performed?
6–12 weeks postpartum.
Why delay hard palate closure until 12–18 months?
To allow maxillary growth and reduce scarring-induced midface hypoplasia.
What is a pharyngeal flap surgery?
A tissue graft from pharynx to palate to improve closure.
When is prosthetic treatment preferred over surgery?
In unoperated adults, failed surgeries, or poor surgical candidates.
Describe a fixed pharyngeal obturator.
A prosthesis with palatal + pharyngeal sections to augment velopharyngeal closure.
How is the pharyngeal bulb positioned clinically?
At the level of Passavant’s ridge during phonation (“ah”).
What is the advantage of a meatal obturator?
Reduces leverage compared to horizontal pharyngeal extensions.
Why might a palatal lift prosthesis fail?
If the patient has inadequate neuromuscular control.
What is the key difference between speech aid and feeding appliances?
Speech aids target velopharyngeal closure; feeding appliances focus on nutrition.
