IV' Special Populations

1
IV. Special Populations

• Cleft Palate and Other Cranial Facial Anomalies

2
A. Clefts of the Lip and Palate

• Cleft lip and palate is the fourth most common
  birth defect and the most common congenital
  defect of the face.
• The prevalence of clefts is usually quoted as 1
  in every 750 live births (Cleft Palate
  Foundation, 1999), although this varies with
  racial background.
• This estimate does not include the prevalence of
  bifid uvula, submucous cleft palate, or
  congenital palatal incompetence.

3
A. Clefts of the Lip and Palate

• In addition, there are about 300 recognized
  syndromes that include cleft palate as one of the
  features of the syndrome.
• When the cleft palate occurs as part of a
  syndrome, there are usually other associated
  craniofacial malformations (Jones, 1988 Rollnick
  Pruzansky, 1981 Shprintzen, Schwartz,
  Daniller, Hoch, 1985).

4
A. Clefts of the Lip and Palate

• In addition to infants with cleft lip and palate,
  there are infants who are born with other types
  of congenital craniofacial anomalies, which can
  also affect communication abilities.

5
What is a cleft?

• A cleft is an abnormal opening or fissure in an
  anatomical structure that is normally closed.
• A cleft lip is the result of failure of parts of
  the lip to come together early in the life of a
  fetus.
• Cleft palate occurs when the parts of the hard
  palate do not fuse normally during fetal
  development, leaving a large opening between the
  oral cavity and the nasal cavity.

6
What is a cleft?

• Clefts can vary in length and in width, depending
  on the degree of fusion of the individual parts.
  It is important to note that, with cleft lip and
  palate, the structures are all there, but the
  structures have not fused together normally.
• In addition, the structures may be hypoplastic,
  or underdeveloped, in their formation.

7
Congenital Malformation

• A cleft of the lip and/or palate is a congenital
  malformation that occurs in utero during the
  first trimester of pregnancy.
• A cleft is due to a disruption in embryological
  development of the midface and oral cavity.
• Clefts typically follow the normal embryological
  fusion lines.

8
Congenital Malformation

• They are often associated with malformations of
  the nose, eyes, and other facial structures.
• Most clefts are caused by a combination of
  genetic and environmental factors.
• When other congenital anomalies occur along with
  the cleft lip and palate, they usually have a
  genetic etiology and are part of a multiple
  malformation syndrome (Jones, 1988).

9
Congenital Malformation

• A cleft lip presents with more serious cosmetic
  concerns than cleft palate, but a cleft palate
  presents with more serious speech problems.
• Individuals born with both cleft lip and cleft
  palate are at risk for problems with aesthetics,
  feeding, speech, resonance, and hearing.

10
Embryological Development of the Lip and Palate

• Embryological development of the face and palate
  is dependent on the formation of neural crest
  cells in the embryo.
• These cells migrate at different rates to form
  the structures of the skull and face.
• If migration of the neural crest cells fails to
  take place or if the migration is delayed, this
  can affect the formation of facial structures and
  can cause clefts or other craniofacial anomalies.

11
Embryological Development of the Lip and Palate

• Embryological development of the lip and alveolus
  begins around 6 to 7 weeks of gestation and
  starts at the incisive foramen (C).
• The development of the lip and alveolus proceeds
  in an anterior direction to first form the
  alveolus through the fusion of the bilateral
  incisive suture lines.

12
Embryological Development of the Lip and Palate

• Closure then proceeds to form the base of the
  anterior nose and finally the upper lip.
• The median and two lateral lip segments are then
  fused, forming the philtral lines and completing
  the formation of the upper lip.

13
Embryological Development of the Lip and Palate

• Embryological development of the palate starts
  around 8 to 9 weeks of gestation.
• Prior to palate formation, the tongue is high and
  in the area of the nasal cavity.
• The palatal shelves are vertical and positioned
  on each side of the tongue.

14
Embryological Development of the Lip and Palate

• Around the seventh or eighth week, the tongue
  begins to gradually drop down.
• When this occurs, the palatal shelves move slowly
  from a vertical to a horizontal position and
  fuse, first with the premaxilla at the incisive
  foramen and then with each other.

15
Embryological Development of the Lip and Palate

• The process of fusion proceeds between the
  palatal shelves, moving in a posterior direction
  from the incisive foramen along the median
  palatine suture line.
• This completes the formation of the hard palate.

16
Embryological Development of the Lip and Palate

• The vomer, forming a portion of the nasal septum,
  moves downward and fuses with the superior
  surface of the hard palate, thus completing the
  separation of the nasal cavity.
• Once the hard palate is formed, the velum and
  finally the uvula are formed.
• This process is usually complete by 12 weeks of
  gestation.

17
Causes of Clefts

• Since embryological development goes from the
  incisive foramen out, anything that disrupts that
  process of fusion will cause a cleft from that
  point all the way to the periphery (lip or
  uvula).
• When the cleft is complete, it follows the
  embryological fusion line all the way through to
  the incisive foramen.
• Clefts can occur due to disruptions or delays in
  cell migration or palatal shelf movement.

18
Causes of Clefts

• There are four basic causes of clefts and related
  craniofacial anomalies.
• These include chromosomal disorders and genetic
  disorders, which are both endogenous (internal)
  factors.
• In addition, clefts can be caused by
  environmental teratogens or by mechanical factors
  in utero.
• These are both considered exogenous (external)
  factors.

19
Causes of Clefts

• Environmental teratogens are substances that can
  cause congenital malformations.
• Teratogens that have been associated with cleft
  lip/palate include cigarette smoke, phenytoin
  (Dilantin), thalidomide and valium.
• Certain viruses, including rubella, can also
  cause clefts and other malformations.
• Even maternal nutritional deficiencies have been
  implicated in causing malformations.

20
Causes of Clefts

• In particular, folic acid has been found to be
  important for normal embryonic and fetal
  development.
• Maternal folic acid deficiency has been
  associated with decreases in embryonic cell
  proliferation, and thus congenital malformations
  such as clefting.

21
Gender Differences

• There is evidence to show that there are
  differences between males and females in the
  timing of embryological fusion and also in the
  types of clefts typically presented.
• Cleft lip, with or without cleft palate, occurs
  about twice as often in males than in females and
  is usually more severe in males.

22
Gender Differences

• On the other hand, cleft palate occurs about
  twice as frequently in females than in males
  (Jensen, Kreiborg, Dahl, Fogh-Andersen, 1988
  Oka, 1979 Warkany 1971).
• Although the reason for these differences between
  males and females is not clearly understood, it
  has been speculated that it could be related to
  differences in the timing of the development of
  the lip and palate in the embryo.

23
Gender Differences

• Burdi and Silvey (1969) found that, in the male
  human embryo, the horizontal positioning and
  subsequent closure of the secondary palate is
  more advanced and occurs earlier than in the
  female embryo.
• Because the palatal shelves are open longer in
  the female, there is a greater period of time
  during which there is susceptibility to
  environmental teratogens.

24
Mechanical Interference

• Mechanical interference can also affect embryonic
  development and cause clefts.
• In the case of Pierre Robin sequence, crowding in
  utero can cause the head to be down and the
  mandible to be retracted, thus restricting oral
  cavity space.

25
Mechanical Interference

• This prevents the tongue from dropping down into
  the oral cavity.
• Because of the interference of the tongue when
  the palate is formed, the result is a wide,
  bell-shaped cleft palate.

26
Multifactorial Inheritance

• Although various causes of clefts have been
  identified, the etiology of clefting in a single
  individual is complex and may involve a
  combination of factors.
• Several genes can contribute to clefting.
• These genes may lead to agenetic predisposition
  for the cleft, but may not cause expression of
  the cleft unless combined with certain
  environmental factors.

27
Multifactorial Inheritance

• In fact, in most cases the cause of the cleft is
  not due to just one factor but instead, is due to
  the interaction of several factors, which is
  called multifactorial inheritance.

28
Cleft Lip/Palate Classification

• Because there are different types of clefts with
  different combinations, naming and classification
  of clefts can be a challenge.
• The system that has gained the most universal
  acceptance was the one proposed by Kernahan and
  Stark (1958) who recommended that clefts be
  classified based on embryological development.

29
Cleft Lip/Palate Classification

• The two basic categories are clefts of the
  primary palate and clefts of the secondary palate
  with the incisive foramen as the dividing point
  between the two.
• The primary palate includes the structures that
  are anterior to the incisive foramen.
• These are the structures that fuse around 7 weeks
  of gestation and include the alveolus and also
  the lip.

30
Cleft Lip/Palate Classification

• A cleft of the primary palate can be unilateral
  or bilateral, following the philtral and incisive
  suture lines.
• It can also be complete (through the entire lip
  and alveolus) or incomplete (as a notch in the
  upper lip).

31
Cleft Lip/Palate Classification

• The secondary palate includes the structures that
  are posterior to the incisive foramen.
• These are the structures that fuse around 9 weeks
  of gestation and include the hard palate
  (excluding the premaxilla) and the velum.

32
Cleft Lip/Palate Classification

• A cleft of the secondary palate can be
  incomplete, such as a bifid uvula or cleft of the
  velum only.

33
Cleft Lip/Palate Classification

• A complete cleft of the secondary palate includes
  the entire velum and hard palate to the incisive
  foramen.

34
Cleft Lip/Palate Classification

• Clefts of both the primary and secondary palate
  are common.
• When there is a combination, each section
  (primary palate and secondary palate) can be
  unilateral, bilateral, complete, or incomplete.

35
Types of Cleft Lip

• There are various types of cleft lip and various
  degrees of severity
• An incomplete cleft lip can be as minor as a
  small, subcutaneous notch in the vermillion with
  no involvement of the alveolar ridge or palate.

36
Types of Cleft Lip

• In more severe cases, the cleft lip can extend
  through the vermillion and course up through the
  philtral lines to the nostril sill, causing a
  distortion of the nose.

37
Types of Cleft Lip

• When the term complete cleft lip is used, it
  may refer to a complete cleft of the primary
  palate.
• In this case, it implies involvement of not only
  the entire lip through the nostril sill, but also
  the alveolus all the way to the are of the
  incisive foramen.

38
Types of Cleft Lip

• In addition to incomplete or complete, a cleft
  lip can be unilateral or bilateral.
• If the cleft is unilateral, it most often occurs
  on the left side (McWilliams, Morris, Shelton,
  1990).

39
Types of Cleft Lip

• A bilateral cleft of the lip results in the
  complete separation of the tissue that would
  normally form the philtrum.
• The philtral tissue segment that is isolated due
  to the bilateral cleft is called the prolabium.

40
Types of Cleft Lip

• When a bilateral cleft courses through the lip
  and through both incisive suture lines in the
  alveolus to the incisive foramen, it separates
  the triangular-shaped premaxilla bone.
• Therefore, when there is a complete bilateral
  cleft of the lip and alveolus, both the prolabium
  and the premaxilla are separated.

41
Types of Cleft Lip

• In many cases, these structures are positioned in
  an extremely anterior position at birth so that
  they appear to extend from the tip of the nose.

42
Effects of Cleft Lip on Structure and Function

• Because a complete cleft of the lip and alveolus
  courses through the nostril sill, the nose can be
  adversely affected.
• The nose may appear to be very wide and flattened
  due to the separation of the orbicularis oris
  muscle.
• This muscle is not only divided, it is misaligned
  and curves upward along the edges of the
  vermillion.

43
Effects of Cleft Lip on Structure and Function

• The wide space within the cleft can further
  distort the nose by spreading the nasal ala.
• In fact, the wider the cleft, the more distorted
  the nasal features will be.
• The formation of the columella may also be
  adversely affected by the cleft lip.
• The columella is usually abnormally short.

44
Effects of Cleft Lip on Structure and Function

• If the cleft is unilateral, the columella will be
  shortest on the cleft side and it will be
  positioned obliquely, with its base deviated
  toward the non-cleft side.

45
Effects of Cleft Lip on Structure and Function

• When the cleft is bilateral and complete, the
  columella may be so short that it is virtually
  nonexistent, giving the appearance that the
  prolabium and premaxilla are attached to the tip
  of the nose.

46
Effects of Cleft Lip on Structure and Function

• Upper airway obstruction is common in individuals
  with a history of cleft lip and palate.
• As a result, mouth breathing is noted more
  frequently in the population with cleft than with
  non-cleft.
• The causes of upper airway obstruction are
  thought to be a combination of developmental
  defects of the nasal cavity and the surgical
  correction of the cleft.

47
Effects of Cleft Lip on Structure and Function

• Clefts of the lip and palate often result in
  nasal cavity deformities that tend to reduce the
  size of the nasal airway.
• The airway is smallest in individuals with
  unilateral cleft lip and palate and is largest in
  those with bilateral clefts.
• Although the nose continues to grow with age, it
  remains 30 smaller than the non-cleft nose.

48
Effects of Cleft Lip on Structure and Function

• The lip repair can also cause nasal obstruction
  if it results in stenosis of the nasal vestibule.
• In fact, surgical correction of labial, nasal,
  palatal and pharyngeal structures have the
  potential to compromise breathing further.

49
Effects of Cleft Lip on Structure and Function

• A complete cleft of the lip may result in
  occlusal abnormalities as the dentition is
  developed.
• This can cause specific articulation errors,
  particularly on anterior speech sounds.
• The production of anterior sounds is often
  affected by dental interference of tongue tip
  movement of or crowding in the anterior portion
  of the oral cavity.

50
Types of Cleft Palate

• As with cleft lip, a cleft palate can be either
  incomplete or complete and can occur with various
  degrees of severity.
• An incomplete cleft palate can be as slight as a
  bifid uvula or the cleft can extend farther into
  the velum.
• A complete cleft palate goes through the uvula
  and the velum, and then follows the median
  palatine suture line through the hard palate, all
  the way to the incisive foramen.

51
Types of Cleft Palate

• The vomer bone, which is the bottom part of the
  nasal septum, is usually attached to the larger
  of the two palatal segments in a unilateral
  cleft, and is not attached to either segment in a
  bilateral cleft.

52
Types of Cleft Palate

• A cleft of the palate can occur with or without a
  cleft lip.
• Isolated cleft palate is more frequently
  associated with a syndrome and thus with other
  anomalies.

53
Types of Cleft Palate

• Some patients will demonstrate a palatal fistula,
  or hole in the palate, even after the palate is
  repaired.
• Although this may look like partial cleft, it is
  actually due to a partial dehiscence, or
  breakdown, of the cleft repair.
• The fistula can be located anywhere in the hard
  palate or velum, but will always be located along
  the embryological or surgical suture lines.

54
Effects of Cleft Palate on Structure and Function

• With cleft palate, there are additional
  abnormalities of the anatomy other than the
  obvious.
• If the cleft goes entirely through the velum, the
  velar aponeurosis is conspicuously absent and the
  orientation of the muscles is necessarily altered.

55
Effects of Cleft Palate on Structure and Function

• Although the muscle origins are normal, the
  muscle insertions are abnormal due to the open
  cleft.
• As a result, the levator veli palatini muscles do
  not interdigitate in the midline.

56
Effects of Cleft Palate on Structure and Function

• Instead, this paired muscle and the
  palatopharyngeus muscles are inserted onto the
  posterior border of the cleft hard palate,
  rendering them essentially nonfunctional.

57
Effects of Cleft Palate on Structure and Function

• As a result, rather than being amuscular, the
  anterior one third of the velum contains the
  muscle fibers of the levator veli palatini and
  the palatopharyngeal muscles.
• This configuration of muscles has been referred
  to as the cleft muscle of Veau.
• One goal of cleft palate surgery is to correct
  the orientation of the muscles in order to
  achieve normal function.

58
Effects of Cleft Palate on Structure and Function

• Despite surgical attempts to normalize the muscle
  orientation, individuals with a repaired cleft
  have great variability in the insertion point of
  the muscles and in the muscle mass (Moon Kuehn,
  1997).
• Therefore, the function of the muscles following
  surgery can be difficult to predict.

59
Effects of Cleft Palate on Structure and Function

• In addition, the velum may be abnormally short
  due to the absent aponeurosis and hypoplasia of
  the levator veli palatini muscles (Dickson,
  1972).
• Due to the risk of poor velar movement or a short
  velum, about 20 to 30 of individuals with a
  history of cleft palate are likely to have
  velopharyngeal dysfunction (Bardach, 1995).

60
Effects of Cleft Palate on Structure and Function

• Velopharyngeal dysfunction is the primary cause
  of defective speech and resonance in children
  with a history of cleft.
• Individuals with a history of cleft palate are at
  high risk for otitis media and associated
  conductive hearing loss.

61
Effects of Cleft Palate on Structure and Function

• This is due to malfunction of the eustachian tube
  (Bluestone, Beery, Cantekin, Paradise, 1975
  Doyle, Cantekin, Bluestone, 1980 Paradise,
  Bluestone, Felder, 1969).
• If the tensor veli palatini muscle does not
  function normally, as is common when there is a
  history of cleft palate, this results in poor
  ventilation of the middle ear.

62
Effects of Cleft Palate on Structure and Function

• This can lead to bacterial infection,
  inflammation, and the accumulation of fluids.
• The build-up of fluids impairs the conduction of
  sound through the ossicles, resulting in a
  conductive hearing loss.
• If this fluid build-up and inflammation become
  chronic, permanent damage of the middle ear,
  surrounding structures and hearing can results.

63
Effects of Cleft Palate on Structure and Function

• The nasal cavity space can also be compromised by
  developmental defects secondary to cleft lip and
  palate.
• Cleft palate alone can include abnormalities of
  both the cartilaginous and bony septum, causing a
  nasal septal deviation that can alter nasal
  cavity size.
• The nasopharyngeal anatomy may also be altered in
  individuals with a history of cleft palate.

64
Effects of Cleft Palate on Structure and Function

• These differences include a reduction of the
  nasopharyngeal airway due to a decrease in depth
  of the nasopharyngeal bony framework and the
  posterior displacement of the maxilla.
• Both reduced nasal cavity size and reduced
  nasopharyngeal depth can explain the high
  incidence of upper airway obstruction and mouth
  breathing in the cleft palate population.

65
Submucous Cleft Palate

• A submucous deft palate is a congenital defect
  that affects the underlying structures of the
  palate, while the structures on the oral surface
  are intact.
• This defect can involve the muscles of the velum
  and can also involve the bony structure of the
  hard palate.
• Like an overt cleft palate, a submucous cleft
  often occurs as part of a generalized syndrome of
  multiple malformations (Lewin, Croft,
  Shprintzen, 1980).

66
Submucous Cleft Palate

• The diagnosis of submucous cleft palate is
  usually made by identification of one or more of
  the classic stigmata through an intraoral
  examination.
• Submucous cleft palate has a triad of
  characteristics, which include bifid uvula, zona
  pellucida, and a notch in the posterior border of
  the hard palate.

67
Classic Stigmata

• One characteristic of a submucous cleft palate
  that can be seen through an intraoral examination
  is a bifid uvula.
• Instead of a single pedicle, a bifid uvula has
  two tags due to a cleft down the middle.
• The uvula may have two distinct pendulous
  structures or it may appear as one structure with
  a line down the middle.

68
Classic Stigmata

• In other cases, the uvula may merely have an
  indentation in the inferior border.
• At times, a bifurcation is not easily
  appreciated, but the uvula will appear to be
  hypoplastic (small and underdeveloped).

69
Classic Stigmata

• A bifid uvula can be an isolated anomaly, but it
  is frequently associated with a submucous cleft
  that extends into the velum.
• As a result, individuals with bifid uvula may
  have velopharyngeal insufficiency with
  hypernasal speech (Shprintzen et al., 1985).

70
Classic Stigmata

• In addition to a bifid uvula, an inspection of
  the velum may reveal a zona pellucida.
• This is a bluish area in the middle of the velum
  and is the result of thin mucosa with a lack of
  the normal underlying muscle mass.

71
Classic Stigmata

• The velum may also appear to be in the shape of
  an inverted V at rest, but especially with
  phonation.
• This shape is due to the diastasis (separation)
  of the paired levator veli palatini muscle with
  abnormal insertion of these muscles in the
  posterior border of the hard palate rather than
  in the midline of the velum.

72
Classic Stigmata

• With phonation, this abnormal muscle insertion
  makes the velum appear to tent up toward the
  hard palate.
• At times, it is difficult to see evidence of
  submucous cleft on the oral surface of the velum.
• In fact, a submucous cleft may be present, even
  when an intraoral examination shows an intact
  uvula and velum.

73
Palpation for Submucous Cleft

• Palpation of the palate may reveal an abnormality
  that can not be appreciated through visual
  inspection alone.
• Using a gloved finger, the examiner feels along
  the posterior border of the hard palate at the
  midline.
• If there is an appreciable notch in the posterior
  border of the hard palate, this is indicative of
  a submucous cleft palate.
• The notch can be small and very narrow, so it is
  often helpful to use the little fifth finger to
  feel it.

74
Occult Submucous Cleft

• A occult submucous cleft is a defect in the velum
  that is not apparent on the oral surface.
• It can only be appreciated by viewing the nasal
  surface of the velum through nasopharyngoscopy.
• The diagnosis of occult submucous cleft is only
  pursued if the patient has velopharyngeal
  dysfunction of unknown etiology.

75
Occult Submucous Cleft

• With the help of nasopharyngoscopy it is possible
  to identify the velar abnormalities that commonly
  occur on the nasal surface only.
• Most individuals with occult submucous cleft have
  the same abnormalities as those with an overt
  submucous cleft.
• The musculus uvulae muscles are either absent or
  deficient and there is abnormal insertion of the
  muscles into the hard palate.

76
Effect of Submucous Cleft on Function

• The effect of a submucous cleft on function
  depends greatly on the type and extent of the
  defect.
• Abnormalities in the morphology of the velum can
  particularly affect velopharyngeal function and,
  therefore, speech.
• These abnormalities can also cause nasal
  regurgitation with swallowing, especially during
  the first year.

77
Effect of Submucous Cleft on Function

• With submucous cleft palate, there is an
  increased risk for middle-ear disease with
  conductive hearing loss due to abnormalities of
  the tensor veli palatini muscle, which can cause
  eustachian tube malfunction.
• Although individuals with a submucous cleft are
  at risk for dysfunction of the velopharyngeal
  valve, many people with this abnormality have
  normal speech, normal middle-ear function, and no
  history of nasal regurgitation with swallowing.

78
Effect of Submucous Cleft on Function

• McWilliams (1991) studied a group of 130 patients
  with submucous cleft, and found that 44 remained
  asymptomatic into adulthood.
• Therefore, the observation of a submucous cleft
  in the presence of normal speech should not be of
  concern.
• It is important, however, that the patient and
  the family be counseled regarding this
  abnormality for several reasons.

79
Effect of Submucous Cleft on Function

• The family should be informed that a full
  adenoidectomy with a submucous cleft is usually
  contraindicated due to the risk that this will
  cause velopharyngeal dysfunction (Shprintzen et
  al., 1985).
• In addition, the family should be counseled
  regarding the genetic risk for additional
  offspring with cleft palate or associated
  syndromes.

80
Prevalence of Submucous Cleft

• In epidemiology, the term incidence refers to the
  number of new cases of a disease or disorder in a
  given population.
• On the other hand, the term prevalence refers to
  a measure of existing cases of a disorder in a
  given population.
• Therefore, the term prevalence is used to refer
  to the number of cases of submucous cleft in the
  general population.

81
Prevalence of Submucous Cleft

• Several studies have attempt to determine the
  prevalence of submucous cleft in the general
  population.
• In a large sample of over 10,000 Denver schools
  children, the prevalence of a complete submucous
  cleft was found to be 0.08 (Stewart, Otet,
  Legace, 1972 Weatherly-White, Sakura, Brenner,
  Steward Ott, 1972).
• In a study of almost 10,000 Yugoslavian children,
  the prevalence of submucous cleft was found to be
  0.05 (Bagatin, 1985).

82
Prevalence of Submucous Cleft

• Gosain, Conley, Marks, and Larson (1996)
  summarize the results of several surveys in the
  literature and stated that the prevalence of the
  classic stigmata of submucous cleft palate among
  the general population is between 0.02 and
  0.08.
• The prevalence of submucous cleft palate in
  individuals with clefts of the primary palate has
  been found to be significantly greater than the
  prevalence of submucous cleft palate found in the
  general population.

83
Prevalence of Submucous Cleft

• Kono, Young, and Holtmann (1981) found submucous
  cleft palate in 13 of 71 patients with clefts of
  the primary palate.
• Because of this increased prevalence, it is
  important for individuals with cleft lip to be
  thoroughly examined for submucous cleft.
• Early detection of submucous cleft associated
  with cleft lip is important for the prevention of
  middle-ear problems and for the proper management
  of velopharyngeal dysfunction if it develops.

84
Prevalence of Submucous Cleft

• Individuals with submucous cleft palate are at
  high risk for velopharyngeal dysfunction
  resulting in hypernasality.
• The occurrence of velopharyngeal dysfunction in
  individuals with submucous cleft has been studied
  with various results.
• Generally, 1/4 to 1/2 of individuals with
  submucous cleft will have associated
  velopharyngeal dysfunction.
• It is important to recognize, though, that most
  individuals with a submucous cleft will have
  normal speech (Shprintzen et al., 1985 Stewart
  et al., 1972).

85
Prevalence of Submucous Cleft

• Although a submucous cleft may be noticed at
  birth or soon after, especially if there are
  early feeding problems, an occult submucous cleft
  is usually not discovered until the child begins
  to speak and has evidence of hypernasality.
• In some cases, the defect is not noted for years
  or is never discovered, especially if it is
  asymptomatic and not causing any problems with
  speech.
• Therefore, the prevalence of occult submucous
  cleft is not known.

86
Treatment of Submucous Cleft

• The literature and most professionals do not
  support the prophylactic surgical correction of
  the physical stigmata of submucous cleft palate,
  because many individuals with a sub-mucous cleft
  have normal speech, swallowing, and middle-ear
  function.
• Instead, surgical correction is indicated only if
  there is evidence of velopharyngeal dysfunction
  that is affecting speech (Chen, Wu, Noordhoff,
  1994 Garcia Velasco et al., 1988 Gosain et al.,
  1996).

87
Treatment of Submucous Cleft

• It is important to wait until speech has fully
  developed before considering surgical correction
  so that speech and velopharyngeal function can be
  adequately evaluated.
• For optimal speech results, however, it is best
  to surgically correct the defect as soon as a
  velopharyngeal dysfunction has been diagnosed
  (Abyholm, 1976).

88
Treatment of Submucous Cleft

• When surgical correction is necessary and the
  child is still very young, a palatoplasty is
  often done to improve the orientation of the
  muscles for better function.
• If this is not effective, if the individual is
  older, or if there is significant velopharyngeal
  dysfunction, a common procedure for correction is
  the pharyngeal flap, either alone or in
  combination with a palatoplasty (Porterfield,
  Mohler, Sandel, 1976).