Rett Syndrome and the Dental Office

Rett syndrome is a neurodevelopmental disorder that was first noted in 1954 by an Austrian pediatrician—Andreas Rett, MD—when two young girls with the same distinct hand wringing motion sat with their mothers in the waiting room of his office.¹ After noting that both girls’ clinical and developmental histories were significantly alike, he found six additional girls with similar symptoms in his practice. In a quest to find more patients with the same clinical manifestations, Rett took a film of his affected patients and traveled across Europe looking for more affected children.¹ He published the first paper on Rett syndrome in 1966.² Rett syndrome did not become widely known until 1983 when Hagberg, Aicardi, Dias, and Ramos published a paper detailing the symptoms of 35 affected girls from Sweden, Portugal, and France.³ This prompted the United States to recognize Rett syndrome as a disorder in the early 1980s.⁴

Rett syndrome is caused by a mutation of the X chromosome, 3 occurring in one out of 10,000 female births. Rett syndrome is classified as an autism spectrum disorder but is often confused with cerebral palsy. Girls with Rett syndrome have the same rate of survival up to age 10 as other children but only 70% survive to age 35 years compared with 98% of the general population.⁵

Babies with Rett syndrome often develop normally until approximately 6 months of age, when their neurodevelopmental health begins to deteriorate. Both autism and Rett syndrome are part of a group of conditions known as pervasive developmental disorders (PDD), which are characterized by severe impairment in communication, language, social interaction, play, and behavior.⁶ Some parents notice subtle changes, such as lack of crying and disrupted sleep pattern. Common characteristics of Rett syndrome include irregular breathing with apnea or hyperventilation, bruxism, sleep disturbances, frequent seizures, scoliosis, dystonia, ataxia, and autism.⁷ Psychological features include anxiety and panic, self-injury, reduced eye contact, and lack of interest in play.⁷ As this disorder is somewhat rare, pediatricians may not be well-versed in its symptoms, which may delay a diagnosis.

THE GENETIC COMPONENT

More than 80% of girls with Rett syndrome have a specific gene mutation (MECP2). Boys with the underlying characteristics of Rett syndrome do not survive past childbirth, although, boys with Klinefelter’s syndrome may also present with this disorder. A genetic link is possible due to multiple diagnoses of children with Rett syndrome in the same family unit. Research suggests that mutations are largely passed on by the father owing to problems with spermatogenesis. Thus, the rare occurrence of the mutation in boys is likely due to fathers not passing on an X chromosome to their sons.⁵

CLINICAL MANIFESTATIONS

Today, there are four known stages of Rett syndrome (see Table 1).⁸ Stage one (stagnation stage) occurs between 6 months and 18 months. Developmental delays and personality changes begin to occur along with some diminished interest in play time. Delays in postural control and balance are also noted.⁹

Stage two (deterioration stage) involves children who are 1 year old to 3 years old. A loss of hand coordination and cognitive skills, and difficulty with speech are noted. The most distinctive symptom of cognitive decline—hand wringing—begins at this point. Children begin to show autistic characteristics, to hold their breath for long periods of time, and to hyperventilate. In some instances, seizures may begin at this stage. Affected children often become uncoordinated with normal movements.
Stage three (plateau stage) is usually discovered at preschool age. Children begin having “blue spells,” where they hold their breath until their visage takes on a bluish appearance. They have some difficulty performing “normal” tasks such as walking or standing still. Seizures are most common at this stage and children experience severe mental retardation at this point.

Stage four (motor deterioration) occurs anywhere between 5 years and 25+ years of age. These children develop scoliosis and have some motor activity decline, which leaves many wheelchair bound. Sometimes, muscles begin to lose elasticity and extremities become mottled. Some vasomotor disturbances occur. Bowel disruption occurs in this stage.

A common thread with Rett syndrome patients is the constant hand wringing and cupping. Affected children will grip and twist their hands continuously as well as cup their hands and force them together. This movement mimics a clapping motion. Children with Rett syndrome experience moments of fear throughout the day and night. They have specific nighttime problems such as laughing, screaming, seizures, teeth grinding, sleep walking, sleep talking, and night terrors.⁶ They may have repetitive tongue and mouth movements, which can affect their dental health. Also, they may feel a social isolation by peers and may be plagued with hyperactive personality traits. Some children hit themselves with their hands and can cause trauma and infection to the affected areas.

The majority of children with Rett syndrome lose expressive language. During this period, children will have deterioration of visual processing, memory, and expressive language function. Children will often lose all ability to communicate verbally and with expressive gestures, other than eye movement or facilitated communication boards.¹⁰

Children with Rett syndrome may have gastric problems that result in acid reflux and regurgitation. A decreased tolerance for certain textures of food, such as crunchy or chewy, is also noted. They also have a tendency to have thiamin, vitamin D, calcium, and iron vitamin deficiencies due to decreased food intake. Some swallowing difficulty may present and an inability to self feed may result.

Involvement of the autonomic nervous system in Rett syndrome is suggested by the frequent clinical observation of small, cold, and/or blue or red hands and feet; facial flushing; dilated pupils during periods of agitation; abnormal sweating; and rarely, reports of urinary retention.¹¹ Dystonia, which is a neurological movement disorder, creates muscle contractions causing twisting and postural issues. This is sometimes linked to hand dominance in family traits.

DENTAL EFFECTS

Issues seen most often in children with Rett syndrome are tongue protrusion, open bite, sucking or biting habits, palatal shelving, and mouth breathing. They have the same dental problems as healthy children, although some are more common in children who have this disorder.

One of the most typical problems in children with Rett syndrome is bruxism. Because of the uncontrolled movements in their bodies, teeth grinding is often a reflex they cannot control. In extreme cases, splints can be made, but are often worn through within a short period of time. Drooling can be caused by apraxia and, most commonly, inappropriate swallowing of saliva. Xerostomia can occur due to medications the children are prescribed. Phenytoin, used to control epilepsy can create a greater risk for caries and gingival hyperplasia. Epilepsy also creates dental issues when teeth are knocked out or fractured after falling from a seizure. Gastroesophageal reflux is another common characteristic seen in children with Rett syndrome. Because of their prolonged exposure to gastric acid, tooth erosion can cause a number of other problems. Jaw issues can be present due to the selfinflicted injuries. Self-abusive behavior, such as hitting the mouth and face, hair pulling, and biting of fingers or hands, is seen on occasion, especially when the child is agitated.⁷

TREATING THE PATIENT WITH RETT SYNDROME IN THE DENTAL OFFICE

A visit to the dental office can be intimidating for any child, although children with disabilities such as Rett syndrome can experience a higher level of anxiety. This anxiety can create stress for for the child, the parent, and the clinician. Parents and clinicians both need to understand that children with Rett syndrome need special care. A good beginning to a positive relationship with the dental office is to have the child spend some time in the dental chair surrounded by familiar faces. Make the first appointment short and nonthreatening. This may make it easier for subsequent appointments.¹¹

Specific techniques that can help calm an anxious child are music, massage, and calm, soft voices. Loud noises should be kept to a minimum. Sudden movements may be seen as threatening, so slow movements as well as working expeditiously are imperative. The “tell-show-do” method works well for keeping children with Rett syndrome calm and comfortable.¹¹

Children who are too hyperactive or anxious to sit in the dental chair may need a sedative before the appointment. The child’s primary care physician should always be contacted before a sedative is prescribed. More importantly, the child’s dental team should be aware of the current literature concerning anesthesia risks as well as medication dosing in patients with Rett syndrome. Sedatives are not always efficacious in children.

In some cases when a patient with Rett syndrome is too fragile, the use of oral sedatives is contraindicated. If the patient needs substantial dental care, the patient should be treated in a surgery center or hospital setting under general anesthesia. This allows the dental team to provide detailed, comprehensive care more easily.¹¹

Instruments and lights can often initiate a negative reaction in children with Rett syndrome. Initially, try to keep them out of the child’s view. Getting into the mouth is usually the most difficult challenge. Most children with Rett syndrome will clench down, making it difficult to even visualize inside the oral cavity. If the child opens, it is typically for short segments of time. In certain cases, a mouth prop may be helpful in gaining access into the oral cavity. In addition to commercial mouth props, clinicians can also use wooden spoon handles, bound tongue depressors, toothbrush handles, and even rubber door stops. The clinician should not use fingers to prop the mouth open because the child may bite down, causing an inadvertent injury. Also, the “hand over mouth” technique and the use of papoose boards are not recommended as their level of success is questionable and they are somewhat controversial.⁷

During the clinical examination, clinicians may note some bruising and self-injury on children with Rett syndrome. The size, shape, and consistency of the affected areas should be noted in the treatment record to provide documentation for the dental office. If clinicians notice dental erosion or any other injury in the head and neck region, they must inform the parent or caregiver so they are informed of the dental condition. These notations are important because obtaining a thorough dental history for patients who have Rett syndrome is difficult since the patients cannot communicate these items to the clinician or caregiver. Taking radiographs is virtually impossible due to their inability to cooperate.

Children with Rett syndrome may be prone to gingivitis and periodontal diseases. Providing special instructions to caregivers about maintaining dental care at home is integral to the child’s oral health. When brushing the child’s teeth, very small amounts of liquids along with a small bristled brush are the best strategies. The easiest way to clean the child’s teeth is to have him or her lie down and then the caregiver stands behind the child to brush. Short, quick time frames to brush while counting aloud is a good strategy. Praise and rewards should be offered when the child allows the provision of oral health care.

Some professionals and parents who have children with Rett syndrome suggest using electric toothbrushes. The prescription of fluoride drops or tablets to strengthen the child’s enamel structure may also be helpful. This is important due to the clenching and grinding that can occur in these patients as well as the potential excessive acidity due to gastric reflux or vomiting.

THERAPIES FOR PATIENTS WITH RETT SYNDROME

Unfortunately, there is no cure for Rett syndrome nor are there any treatments that mitigate the symptoms over the long term. However, strategies are available to help children maintain as much function as possible. Special education programs, behavior modification, and drug therapy may help improve adaptive skills such as self-expression, self-feeding, and achievement of various motor skills.⁴

Advances are being made in pharmacological therapies that can aid in decreasing seizures, sleep problems, and improving eye coordination and sleep patterns. Music therapy, hydrotherapy, and instrumental interventions for reducing symptoms have also been somewhat successful.⁷

Music therapy only temporarily helps to disrupt the movements of the body and hands. Hydrotherapy is also a short-term intervention, but the warm water does help relax the muscles and decrease tension. Occupational therapy is used to promote and increase purposeful use of the hands in daily life activities.⁷ Computers are also being utilized with speech and touch screen capabilities so children with Rett syndrome can have the ability to communicate and express their needs to the caregiver.

CONCLUSION

Patients with Rett syndrome face many challenges in their day-to-day lives. As there are significant oral implications to this disorder, the ability for these patients to seek professional dental care is paramount. The dental professional must be prepared and understand the implications of Rett syndrome in order to provide effective oral health care for this patient population.

REFERENCES

1. History of Rett Syndrome. International Rett Syndrome Foundation. Available at: www.rettsyndrome.org/index.php?option=com_content&task=view&id=12&Itemid=375. Accessed April 25, 2009.
2. Rett A. [On a unusual brain atrophy syndrome in hyperammonemia in childhood]. Wien Med Wochenschr. 1966;116:723-726. German.
3. Hagberg B, Aicardi J, Dias K, Ramos O. A progressive syndrome of autism, dementia, ataxia, and loss of purposeful hand use in girls: Rett’s syndrome: report of 35 cases. Ann Neurol. 1983;14:471-479.
4. Armstrong DD. Neuropathology of Rett syndrome. J Child Neurol. 2005;20:747-753.
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7. Pizzamiglio MR, Piccardi L, Zotti A, et al. Sensory-motor rehabilitation in Rett syndrome. Focus on Autism and Other Developmental Disabilities. 2008;23:49-62.
8. Witt Engerström I. Age-related occurrence of signs and symptoms in the Rett syndrome. Brain Dev. 1992;14(Suppl):S11-20.
9. Lavas J, Slotte A, Jochym-Nygren M, Van Doorn J, Witt Engerström I. Communication and eating proficiency in 125 females with Rett syndrome: The Swedish Rett Center Survey. Disabil Rehabil. 2006;28:1267-1279.
10. Marco EJ, Skuse DH. Autism-lessons from the X chromosome. SCAN. 2006;1:183-193.
11. Friedlander AH, Yagiela JA, Paterno VI, Mahler ME. The neuropathology, medical management and dental implications of autism. J Am Dent Assoc. 2006; 37:1517-1527.

From Dimensions of Dental Hygiene. May 2009; 7(5): 38-41.