Craniofacial conditions, including cleft lip and palate, are congenital structural anomalies caused by atypical embryological development. Craniofacial differences are a result of interruption in embryologic growth between the 4th and 10th week of the developing embryo or fetus (Peterson-Falzone, Hardin-Jones, & Karnell, 2010).
Clefts are described based on the structures involved (lip, alveolus, hard palate, soft palate), laterality (unilateral left, unilateral right, or bilateral), and severity (width and extent of structures involved). Clefts can be isolated (cleft lip only or cleft palate only), or they can occur in combination. They can be unilateral or bilateral, and they can be complete or incomplete.
Figure 1 contains images of the most common types of cleft affecting the palate, along with a labeled image of intact structures. The primary palate is the triangular area of the hard palate anterior to the incisive foramen and includes a portion of the alveolar ridge. The secondary palate consists of the remaining hard palate and all of the soft palate.
[Figure 1]
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Figure 1: Representation of the most common types of cleft affecting the palate. (a) Unilateral cleft lip with alveolar involvement; (b) bilateral cleft lip with alveolar involvement; (c) unilateral cleft lip associated with cleft palate; (d) bilateral cleft lip and palate; (e) cleft palate only (© Copyright Brito, Meira, Kobayashi, & Passos-Bueno, 2012).
Palatal clefts can be overt or submucous. An overt palatal cleft is visibly open and can be observed on intraoral inspection. In a submucous cleft palate (SMCP), oral mucosa is intact, but the underlying velar musculature has failed to attach at midline. The cleft is not visibly open and often is not obvious on intraoral inspection. There are three signs of an SMCP: (a) zona pellucida—a blue discoloration due to levator veli palatini muscle diastasis (i.e., separation in the midline); (b) a bifid uvula; and (c) a palpable bony notch at the edge of the hard palate.
Another type of SMCP, referred to as an occult (hidden) submucous cleft palate (OSMCP) has no visual oral manifestations and can be diagnosed only by direct observation during surgery or by magnetic resonance imaging (MRI). Nasendoscopy may demonstrate a concave or flattened nasal surface of the palate, indicating possible diastasis and/or absence of the musculus uvulae muscle.
Cleft lip and cleft palate can be associated with a large number of craniofacial and genetic sequences or syndromes, some of which are rare. Some examples include the following:
- 22q11.2 deletion syndrome (a.k.a. velocardiofacial syndrome [VCFS] and DiGeorge sequence)
- Stickler syndrome
- Pierre Robin sequence
- Van der Woude syndrome
- Treacher-Collins syndrome
- Craniofacial microsomia (spectrum of disorders, including Goldenhar syndrome)
- Neonatal Abstinence Syndrome (NAS), which includes Fetal Alcohol Spectrum Disorder (FASD)
Signs and symptoms
The signs and symptoms associated with clefting depend on a variety of factors, including type and severity and whether both lip and palate are involved. Individuals with cleft lip and palate may experience difficulties in one or more of the areas listed below.
Resonance and Airflow: Normal velopharyngeal (VP) closure separates the nasal and oral cavities and allows for speech to be produced with a balance between oral and nasal resonance. VP closure allows for (a) oral resonance of vowels, liquids, and glides and (b) the buildup of intraoral pressure and facilitation of orally directed airflow required for production of the oral pressure consonants (stops, fricatives, and affricates). With normal resonance balance, nasal consonants /m/, /n/, and \"ng\" have nasal energy enhancement.
Velopharyngeal dysfunction (VPD; also referred to as velopharyngeal inadequacy [VPI]) may result from palatal clefting or from other noncleft causes such as mechanical interference (e.g., large tonsils), neurogenic etiologies, or velopharyngeal mislearning (see Classification of Velopharyngeal Dysfunction [PDF] [Peterson-Falzone, Trost-Cardamone, Karnell, & Hardin-Jones, 2006; Trost-Cardamone, 1989]).
During speech production, VPD can cause hypernasality (a resonance disorder), nasal air emission, or both. Hypernasality and nasal air emission that result from an anatomical or physiological inability to close the VP port are considered obligatory (see \"obligatory errors\" in the Articulation subsection below).
Hypernasality is an acoustic phenomenon that occurs when there is excessive resonance in the nasal cavity during production of vowels and vocalic consonants (i.e., the liquids and glides), due to coupling of the oral and nasal cavities. Hypernasality may increase in connected speech due to increased demands on the VP mechanism.
Nasal air emission is an aerodynamic phenomenon resulting in audible or inaudible release of air from the nasal cavity during production of oral pressure consonants (i.e., the stops, fricatives, and affricates). It can be heard as nasal turbulence (nasal rustle), especially if the VP gap is small. Nasal air emission can also be caused by airflow through a palatal fistula into the nasal cavities.
(See e.g., Kummer, 2011, 2014a; Trost-Cardamone, 2013; Zajac & Vallino, 2017a.)
Articulation
The resulting impact of VPD on articulation can be described as \"cleft palate speech\" or \"cleft-type speech\" and may include obligatory errors and/or compensatory (learned) errors.
Feeding and Swallowing
Feeding problems can vary considerably in infants with clefting, depending on the type and severity of the cleft. In most cases, infants with clefts who are otherwise typically developing have normal pharyngeal swallowing function; once the milk reaches the oropharynx, the swallow is initiated with normal airway protection (Miller & Kummer, 2014; Shprintzen & Bardach, 1995).
Babies with cleft lip only typically have little feeding difficulty. Once the nipple is positioned in the baby's mouth, he or she can usually achieve sufficient compression of the nipple against the intact palate.
Babies with cleft palate—with or without cleft lip—may have more significant feeding difficulty. They are unable to separate the nasal cavity from the oral cavity and therefore cannot create the negative pressure necessary for sucking. In addition, they may have difficulty compressing the nipple to express milk because the palatal surface is not intact.
Potential problems associated with feeding difficulties include
- fatigue due to excessive energy expended during feeding;
- poor weight gain due to inadequate nutritional intake;
- excessive air intake; and
- nasal regurgitation (Dailey, 2013; Miller & Kummer, 2014; Peterson-Falzone et al., 2016; Zajac & Vallino, 2017a).
Infants with cleft palate and other craniofacial anomalies associated with genetic syndromes or sequences may have more significant feeding and swallowing difficulties (Cooper-Brown et al., 2008; Dailey, 2013). For example, children with Pierre Robin sequence are at increased risk for airway obstruction, dysphagia, and aspiration due to micrognathia and glossoptosis, which position the tongue toward or even against the posterior pharyngeal wall (Monasterio et al., 2004; Nassar, Marques, Trindale, & Bettiol, 2006; Shprintzen & Singer, 1992). In infants with 22q11.2 deletion syndrome, laryngeal, neurologic, or cardiac abnormalities may exacerbate feeding difficulties (e.g., Cuneo, 2001; Golding-Kushner & Shprintzen, 2011) and may contribute to fatigue (Cuneo, 2001).
Infants with cleft lip and palate who are preterm may have feeding and swallowing problems, which, in addition to those problems associated with clefting, place these infants at high risk for aspiration and poor nutritional intake.
More significant feeding and swallowing difficulties seen in these populations may be signaled by the following:
- Inability to establish suck–swallow–breathe sequence
- Arching of back or refusal of nipple
- Coughing
- Choking and gagging
- Increased respiration rate
- Oxygen desaturation
- For more information, see ASHA's Practice Portal page, Pediatric Dysphagia.
- Dental/Orthodontic
- Dental deviations and malocclusion can affect articulatory placement.
- Dental deviations include the following:
- Congenitally missing teeth
- Malrotated teeth
- Ectopic teeth (abnormally located)
- Supernumary or duplicated teeth
- Malocclusions include the following:
- Overjet/overbite, often associated with Class II malocclusion (upper teeth protrude beyond lower teeth)
- Underjet/underbite, often associated with anterior crossbite or Class III malocclusion (lower teeth protrude beyond upper teeth)
- Open bite (teeth do not fully occlude)
- Lateral (buccal) crossbite (lower teeth buccal to upper teeth)
Hearing
Children with cleft palate with or without cleft lip may be at high risk for middle ear effusions and associated conductive hearing loss because of eustachian tube malfunction (Flynn, Möller, Jönsson, & Lohmander, 2009). The prevalence of middle ear fluid in children with unrepaired cleft palate has been estimated at more than 90% (Paradise, Bluestone, & Felder, 1969; Stool & Randall, 1967). Middle ear fluid is also seen in children with isolated cleft lip, although the prevalence is lower than in children with cleft palate (Deedler et al., 2011; Ruegg et al., 2015; Vallino, Zuker, & Napoli, 2008).
Other potential causes of conductive hearing loss include anomalies of the outer ear (e.g., stenotic or narrow external auditory canal) and anomalies of the middle ear (e.g., malformation of the ossicles; Zajac & Vallino, 2017b).
Fluctuating and long-standing conductive hearing loss is the primary concern for children with cleft palate. However, sensorineural hearing loss (e.g., due to inner ear anomalies), or mixed hearing loss may also be present, especially in children with syndromes (e.g., Stickler syndrome; Nowak, 1998; Zajac & Vallino, 2017b).
See ASHA's Practice Portal pages, Permanent Childhood Hearing Loss and Hearing Loss Beyond Early Childhood, for more detailed information about hearing loss. Will link to Practice Portal page on otitis media, currently under development.
Causes
There is no one cause of cleft lip and palate. However, most cases are thought to result from multifactorial inheritance—an interaction between the person's genes (genetic predisposition) and specific environmental factors (see, e.g., Beaty et al., 2011). Clefting can also be caused by chromosomal differences in individuals born with genetic syndromes.
Risk factors that increase the likelihood of cleft lip and palate include the following:
- Strong family history of cleft lip and palate (e.g., Grosen et al., 2010; Natsume, Kawai, Ogi, & Yoshida, 2000; Sivertsen et al., 2008).
- Race—cleft lip and palate are more common in Asians and Native Americans than in African Americans (see Incidence and Prevalence section).
- Sex—males are more likely to have cleft lip with or without cleft palate; females are more likely to have cleft palate without cleft lip (see Incidence and Prevalence section).
- Exposure to certain environmental substances, such as tobacco and alcohol, prescription drugs, and illegal drugs (e.g., Arpino et al., 2000; DeRoo, Wilcox, Drevon, & Lie, 2008; Källén, 2003; Li et al., 2010; Little, Cardy, & Munger, 2004; van Gelder, Reefhuis, Caton, & Werler, 2009).
Treatment
The primary components of treatment are surgical repair and behavioral intervention (i.e., speech therapy).
The goal of surgery is to repair affected structures to establish adequate VP function, facilitate orofacial growth, and improve appearance.
The goal of speech therapy is to establish normal articulation behaviors and feeding/swallowing function.
Treatment may also include early feeding intervention, dental care and orthodontics, audiologic care and monitoring of hearing status, and psychological services.
Information taken from ASHA.org