Dental Management of the Down Syndrome Patient

Daniel Winston Ohio State University Dentistry 623 May 19, 2004

Reproduced with the permission of Daniel E. Jolly, DABSCD, FAAHD, FACD Professor and Director, General Practice Residency The Ohio State University College of Dentistry Columbus, OH 43218-2357

Abstract

Approximately one out of every 800-1,100 births results in an extra chromosome of the twenty-first group called Trisomy 21, or Down syndrome. Affecting over 250,000 people in the U.S. alone, this population has progressed tremendously over recent years to be able to function in the mainstream of society. Inclusive school, work and community settings are now becoming normal practice for persons with Down syndrome. This has resulted in a higher level of functioning for most of these individuals with resulting increases in self-esteem and self-image. The demand for dental care in persons with Down syndrome is increasing with this inclusive trend. Most dental treatment for persons with Down syndrome can take place in a general dental office with relatively minor adaptations. This paper will attempt to summarize the unique systemic, facial and especially oral characteristics associated with Down syndrome that influence the dental care and treatment of this population.

Review of Literature

Systemic Considerations:

The cause of increased susceptibility of Down syndrome individuals to many infections is uncertain. The neutrophils and leukocytes are defective and short lived. There are reports of lymphopenia, and eosinopenia, and in addition, cell mediated immunity is impaired and serum immunoglobin patterns are disturbed. The commonly seen infections in Down syndrome are dermal, mucosal, gastrointestinal and respiratory. An early preventive health program including recall and maintenance visits as often as 3-4 months should be scheduled. Such visits could detect any abnormal findings in the oral cavity. (Scully)

Congenital cardiac anomalies are present in about 40% of Down syndrome infants. In decreasing order of frequencies are the ventricular septal defects, A/V communis, arterial septal defects, and patent ductus arteriosus. All of these cardiac anomalies can be corrected with surgery during infancy and often results in a very good prognosis. The prevalence of a mitral valve prolapse (MVP) may be 5% to 15% higher in Down syndrome individuals than in others. A consultation with a patient's physician is recommended to determine if the MVP requires antibiotic prophylaxis. (Goodman)

It is important that the dental health provider be aware of the incidence of sleep apnea in the Down syndrome population. It has been reported that the incidence of upper airway obstruction may be as high as 31% in children with Down syndrome. The decreased airway size combined with lowered muscle tone predisposes these patients to obstructive sleep apnea. Left untreated, obstructive sleep apnea can further increase developmental delay and lead to pulmonary hypotension and congestive heart failure. Symptoms of obstructive sleep apnea include snoring, restless sleep and unusual sleeping positions. If a patient's family or caregiver reports these symptoms, then referral to a sleep disorders clinic is indicated. Treatment ranges from occlusal repositioning appliances, positive airway pressure and/or surgical correction. Adenotonsillectomy in children with Down syndrome and sleep apnea has been helpful in some cases. (Bloch)

Oral and Facial Anomalies:

The primary skeletal abnormality affecting the orofacial structures in Down syndrome is an underdevelopment or hypoplasia of the midfacial region. The bridge of the nose, bones of the midface and maxilla are relatively smaller in size. In many instances this causes a prognathic Class III occlusal relationship which contributes to an open bite. Absence or reduction in size of the frontal and maxillary sinuses is common.

The incidence of mouth breathing is very high due to a small nasal airway. The tongue may protrude and appear to be too large. True macroglossia is rare, rather a relative macroglossia is found where the tongue is of normal size but the oral cavity is decreased in size due to the underdevelopment of the mid-face. On examination, the palate in a person with Down syndrome appears to be narrow with a high vault. In actuality the vault is of normal height but the sides of the hard palate are abnormally thick. This creates less space in the oral cavity for the tongue, affecting both speech and mastication. Speech pathologists can be of help teaching correct tongue positioning and increasing the tone of the orofacial musculature. In extreme cases, surgical reduction of the tongue may be indicated.

With age, both the tongue and the lips in people with Down syndrome tend to develop cracks and fissures. This is a result of chronic mouth breathing. Fissuring of the tongue can become severe and be a contributing factor in halitosis. Patients should be instructed to brush their tongue when they brush their teeth. Another result of chronic mouth breathing may be a decrease in saliva with a dry mouth. This reduces the natural cleansing that occurs in the oral cavity and may contribute to the development of caries. Irritation at the corners of the mouth ("angular chelitis") may also be a result of mouth breathing.

The eruption of teeth in persons with Down syndrome is usually delayed and may occur in an unusual order. The delay in eruption may be as long as two to three years; and although independence in feeding and the introduction of food is encouraged in the toddler with Down syndrome, the diet may need to be altered because there are not enough teeth to chew some foods. There is an extremely high rate of missing teeth in both the primary and permanent dentitions. Other irregularities such as microdontia and malformed teeth may be seen. However, in an oral cavity with undersized bone structure, microdontia and missing teeth may be more of a blessing than a problem. Severe crowding can occur in persons with Down syndrome who have developed all of their permanent dentition. In these cases, selective extractions under the supervision of an orthodontist may be of benefit.

The roots of the teeth in patients with Down syndrome tend to be small and conical. This is an important factor when considering orthodontic tooth movement and also contributes to early tooth loss in periodontal disease. (Vittek)

Caries and Periodontal Disease:

Historically the incidence of dental decay in persons with Down syndrome has been reported to be extremely low. Recent studies, however, have shown that while the incidence is lower, it is not as rare as once thought and it certainly shouldn't be taken for granted (Barnett). Older studies of caries in persons with Down syndrome used institutionalized populations whose diets were controlled. These groups may not have had the exposure to cariogenic foods at the rate of today's children with Down syndrome who are growing up at home. The incidence is lower, however, and it is theorized that this may be due to delayed eruption of the teeth, increased spacing between teeth or possible differences in the chemical content of the saliva.

Today, Individuals with Down syndrome should be educated in proper oral hygiene, and receive the benefits of topical and systemic fluoride. Occlusal sealants are also recommended. Decay in the primary dentition should be properly treated. With the delay of the permanent teeth and the high number of missing teeth, it is critical to maintain the primary dentition as long as possible.

On the opposite end of the spectrum from caries is the high rate of periodontal disease seen in Down syndrome. Early, severe periodontal disease is often seen with onset in the mid to late teen years. Some studies report an incidence of periodontal disease to be between 90 and 96% of adults with Down syndrome. This is thought to be related to a lowered host immune response due to the compromised immune system in Down syndrome. The amount of plaque and calculus seen on the teeth is not proportionate to the severity of the disease. The teeth most affected are the mandibular incisors and maxillary molars. Good oral hygiene and semi-annual prophylaxis appointments may not be enough to prevent the progression of periodontal disease in these patients. Early, aggressive treatment is needed. These patients may need to be seen as often as every three months for scaling and root planning and may also benefit from the use of chlorhexedine mouth rinse and possibly systemic antibiotic therapy. (Barnett)

Conclusion

Dental care for the patient with Down syndrome can be achieved in the general practitioner's office in most instances with minor adaptations. Although this population has some unique dental care needs, few patients require special facilities in order to receive dental treatment. Adequate dental health care for persons with developmental disabilities is a major unmet health need. Only through further education can we all feel more confident in providing these patients with comprehensive dental care.

Works Cited

Goodman, R., Gorlin R. The Malformed Infant and Child. New York: Oxford University. 1983

Scully, C. Down Syndrome and Dentistry. Dental Update. 1976

Vittek, J., Winik, S. Winik, A., Sioris, C., Tarangelo, A.M., & Chou, M. (1994). Analysis of orthodontic anomalies in mentally retarded developmentally disabled persons. Special Care Dentist, 14

Bloch, K., Witztum, A., Wieser, H.G., Schmid, S. & Russi, E. (1990). Obstructive sleep apnea in a child with trisomy 21. Monatsschr ift Kinderheilkunde, 138

Barnett, M.L., Press, K.P., Friedman, D., & Sonnenburg, E.M. (1986). The prevalence of periodontitis and dental caries in a Down syndrome population. Journal of Periodontology, 57