Explanation
One of the typical abnormalities of anatomical structure that causes pediatric dysphagia is cleft lip and palate. Because a cleft affects the lip, alveolar ridge, and soft and hard palates, and poor occlusion occurs as a complication of palatoplasty performed at 12-18 months of age, patients tend to have diverse problems in feeding and swallow function from immediately after they were born and even into adulthood. This is a serious concern for their parents. Medical professionals and caregivers must be fully aware of the characteristic problems in eating and swallow functions associated with cleft palate.
In this module, we look at understanding (1) the problems in eating (masticating) and swallowing in children with cleft lip and palate and (2) the necessary concepts to help address such problems.
Explanation
Cleft lip and palate is a congenital disorder, the incidence of which varies widely among different ethnic groups. A review of more than 60 studies on the occurrence of cleft lip and palate among different ethnic groups showed the rate of 1 per 297-1170 births in Japan1. However, in the clinical setting, the general belief is roughly 1 in 500-750 births, with slightly higher frequencies in Asian ethic groups and indigenous peoples of the Americas.
Explanation
There are several ways that cleft palate is classified. Based on eating and swallow functions, we can classify cases as syndromic cleft when there are other associated conditions, and nonsyndromic cleft when there are no associated conditions. Patients with syndromic cleft have problems with other body parts, such as the neuromuscular system, cardiocirculatory system, respiratory system, and digestive system, so treatment solely addressing the cleft lip and palate does not address the dysphagia. Instead, a multidisciplinary approach is needed.
There are 2 types of dysphagia associated with cleft lip and palate. One includes problems in nursing (breast feeding) occurring immediately after birth, and the other includes problems in mastication due to the influence of palatoplasty on jaw development. The severity of dysphagia varies widely depending on the type of the cleft.
Explanation
Problems in breast feeding immediately after birth in patients with a cleft of the soft palate and those with cleft lip and palate (excluding Robin sequence) occur because the nipple moves away into the cleft, resulting in impaired transmission of the tongue pressure to the nipple, and because negative pressure is not created around the nipple, resulting in insufficient suction and compression for sucking milk. If the nipple continuously stays in the cleft, an ulcer develops on the nasal mucosa, and milk intake may decrease because of pain from the ulcer.
Explanation
According to specialists2, patients with Robin sequence have all 3 of the following features: (1) micrognathia, (2) glossoptosis, and (3) cleft palate: these features complicate dysphagia more in children with Robin sequence than in children with cleft lip and palate.
Explanation
Among the various possible causes of micrognathia that is the major characteristic of Robin sequence, physical causes such as restricted movement of the fetus in utero is often mentioned3. The fetus can't move around in the uterus in a normal way due to maternal factors (eg, an extremely small uterus and low amniotic fluid) and/or fetal factors (eg, hypotonia and neuromuscular disorders). This means that the head of the fetus is continuously in contact with the chest, resulting in mandibular hypoplasia. The tongue is displaced downward toward the pharynx due to the micrognathia and occupies the space between the left and right palatal shelves, preventing their fusion. For this reason, the cleft, often U-shaped, involves the hard and soft palate, or the soft palate in Robin sequence.
Micrognathia and respiratory disturbance worsen the problems associated with Robin sequence. More precisely, difficulties in exerting pressure on the nipple due to the micrognathia and respiratory disturbance due to glossoptosis result in incoordination of movements for nipple compression and sucking with respiratory movements.
Explanation
Today, we generally address these problems mainly through the usage of devices. We can use a bottle nipple and/or a plate (eg, milk feeding plate, Hotz plate) specially designed for babies with cleft palate. These nipples are commercially available. The common feature of these nipples is that the part contacting the cleft is thicker, so the nipple won't move into the cleft.
The dental resin plate is prepared using a maxillary impression. The plate covers the cleft, preventing the nipple from moving into the cleft. So, the standard bottle nipple for feeding can be used in combination with the plate. A plate to which a feeding tube is attached is used sometimes. Before surgery, which is usually performed in babies weighing 5,000 g (roughly age 3 months), we can use a plate (eg, Hotz plate) that aims to facilitate growth of the ipsilateral and contralateral alveolar ridges to form an alveolar arch with normal morphology. Because such plates reduce the size of the cleft, better surgical outcomes are also expected.
In addition to the use of devices, it is important to give mothers instructions on feeding. General instructions include: (1) holding the infant in a slightly upright position, not in a supine position; (2) using flexible milk bottles; and (3) using nipples that makes good contact with the infant's tongue and one side of the palate.
Explanation
Gastrostomy or nasogastric tube placement is often performed by doctors with little experience in the treatment of cleft palate because they wrongly expect pharyngeal dysphagia due to the cleft. However, if children are nonsyndromic and have no problems with the neuromuscular function responsible for swallowing and respiration, stopping oral feeding may: 1) inhibit the development of the opression-sucking-swallowing movements for milk intake; 2) interfere with the development of motor function of the tongue; 3) cause pharyngeal discomfort, resulting in markedly increased salivation; and 4) increase the pharyngeal sensory threshold over the long term, leading to saliva aspiration. Non-oral modes of feeding should be used with caution.
Explanation
Once children acquire the necessary skills, milk feeding goes smoothly, particularly after cleft lip surgery. Special nipples that were previously believed to be essential in this stage are not actually required, and infants can be fed using a conventional spoon4.
Explanation
Problems in milk feeding in Robin sequence occur because of respiratory disorders caused by the abnormal position of the tongue due to micrognathia. So, we need to provide interventions for micrognathia and respiratory disorders.
The delay in jaw growth often resolves with general physical growth when Robin sequence is not complicated by other syndromes, but not when there are other genetic factors involved or it manifests as a symptom of complicating syndromes.
Mandibular distraction osteogenesis has been performed for micrognathia in recent years5,6. However, given that the dental germ is within the operative field in some cases, we need to decide whether micrognathia should be treated by distraction osteogenesis or another approach after carefully comparing their long-term benefits.
Explanation
In Robin sequence, respiratory obstruction occurs because: (1) the soft palate is stuck between the downwardly displaced tongue and the posterior wall of the pharynx; (2) the pharynx is narrowed because both sides of the pharyngeal wall protrude inwardly; (3) the pharynx itself is contracted3. Glossopexy (suturing of the apex of the tongue onto the lower labial mucosa) has been used for a long time but is effective only in cases of (1). Multiple approaches are often used for cases of (2) and (3), with common approaches including control of posture, placement of a nasopharyngeal airway, and placement of a tracheal cannula.
Explanation
When invasive intervention is necessary (eg, a nasopharyngeal airway or tracheal cannula is placed), we usually use a non-oral route of feeding.
However, if we use a non-oral mode of feeding immediately after birth, this will hinder development of the movements needed for milk intake and eating function, and consequently respiratory, eating, and swallowing problems become persistent and difficult to address. When oral care is inadequate in children with tubing, these problems become more complex because plaque-contaminated saliva enters the larynx and can cause pneumonia.
When a non-oral mode of feeding is selected for children who are receiving intervention for their respiratory problems, they need to learn eating functions that are usually acquired through the normal developmental process. Perioral massage and oral care are essential. In such cases we need to plan training aimed at oral eating, which will in turn facilitate the development of oral function. Oral cleaning before and after training is essential to prevent aspiration pneumonia in such cases.
Explanation
Palatoplasty is performed when patients are 12-18 months old. Its primary purpose is facilitating the acquisition of normal speech-language function by restoring soft palate movement between the nasal and oral cavities. Mucoperiosteal palatal pushback is widely used today, but elevation of the mucoperiosteal flap leaves a part of the vomer and hard palate exposed, which results in impaired maxillary in the long term. The surgery prevents maxilla and mandibular growth if performed too early; it interferes with articulation if performed too late. So, to balance these effects, it is thought that the surgery should be scheduled for just before children start talking (12-18 months old).
Explanation
After palatoplasty, narrowing of the dental arch and pseudo mandibular protrusion occur due to impaired jaw growth, and these lead to masticatory disturbance from the mixed dentition period onward. Orthodontic treatment and surgical orthodontic treatment are required for masticatory disturbance after palatoplasty. In Japan, these treatments are covered by insurance, and patients with cleft palate are eligible for support from the healthcare and welfare system (ie, the system of medical payment for services and support for persons with disability). So, medical professionals should provide guardians with information about these systems.
Explanation
The efficiency of nasopharyngeal closure, as a part of speech-language activity, decreases at around 10 years of age due to the atrophy of the adenoids, and this may result in insufficient pharyngeal negative pressure being created during swallowing. However, there are fundamental differences in the innervation involved in nasopharyngeal closure in the production of speech sounds (a variation of respiratory activity) and in nasopharyngeal closure in eating for nutrient intake. Also, the epiglottis does not close the trachea during the production of speech sounds, so impairment in nasopharyngeal closure during speech does not indicate impairment in nasopharyngeal closure during swallowing.
Although some textbooks state that nasopharyngeal closure during the production of speech sounds serves as an indicator of nasopharyngeal closure during swallowing, this is not physiologically supported.
In patients with cleft palate, in general, nasopharyngeal closure is incomplete during the production of speech sounds and nose blowing, but it is complete and creates sufficient pharyngeal negative pressure during swallowing. So, dysphagia does not develop solely due to cleft palate after growth stops.
References
- Vanderas AP: Incidence of cleft lip, cleft palate, and cleft lip and palate among races: a review. Cleft Palate Journal, 25:171-173, 1988.
- Gorlin RJ, Cohen MM Jr, Levin LS: Syndromes of the head and neck. Oxford Unversity Press, New York, 1990, 700-704.
- Shprintzen RJ: The implication of the diagnosis of Robin sequence. Cleft Palate-Craniofacial Journal, 29:205-209, 1992.
- Peterson-Falzone S., et al.: Dental management of Cleft Lip and Palate. Cleft Palate Speech, Peterson-Falzone S., Hardin-Jones M, Karnell M , Mopsby, St Louis, 2001, 131-132.
- Denny A, Amm C: New technique for airway correction in neonates with severe Pierre Robin sequence. Journal of Pediatrics. 147(1): 97-101, 2005.
- Burstein FD, Williams JK: Mandibular distraction osteogenesis in Pierre Robin sequence: application of a new internal single-stage resorbable device. Plastic Reconstructive Surgery, 115(1): 61-69, 2005.
