Department of Education, University of Karlstad
Department of Pedodontics, University of Umeå
Reprinted with permission of the publisher
Phonum 4, 9-12, Department of Phonetics, University of Umeå, Sweden
An evaluation of the effects of early oral motor and sensory intervention including palatal plate therapy in children with Down syndrome indicates positive effects at the age of 18 months. The final evaluation will be carried out when the children are 8 years old.
Children with Down syndrome have an unbalanced genetic disposition which affects many aspects of the development of the child. Usually, health and cognitive problems are focused. Less attention has been paid to the oral motor problems, although social inclusion calls for the individual to be able to talk, to use his facial expressions and to eat and drink in an accepted way.
The findings in the present project (Notes 1 and 2) show that children with Down syndrome have severe oral deficiencies when compared to children with normal development, i.e. in oral morphology, dentition, occlusion, biting, chewing and swallowing during eating and drinking, oral sensory function, deliberate movements of the tongue or the lips, articulation and facial expressions. The reasons for these problems are complex and multifactorial including neuromotor and -sensory disorders e.g. the generalised hypotonia. The morphological deviations are obvious, i.e. the hypoplastic midface including the maxilla and the high and narrow palatal vault. The interaction between the oral structures and the capacity of the child to use the oral motor system is, however, far from obvious.
The aim of this paper is to present some effects of an early intervention programme including use of palatal plates in children with Down syndrome.
The E-group consists of 42 children with Down syndrome, trisomy 21, 24 boys and 18 girls. Starting at the age of 6 months at the latest, the children have participated in a stimulation programme, including language intervention and oral motor- and sensory stimulation. Palatal plate therapy was part of the stimulation programme.
At the age of 18 ± 3 months the children were videotaped during play and interaction with one of the parents and a test leader. The evaluation was done in two steps. During the session a first rough observation was made, which subsequently was supplemented by a more detailed analysis of the videotapes. The results of these analyses were compared to identical analyses of two control groups of children of the same age, 32 children with normal development and 31 children with Down syndrome not using palatal plates.
The palatal plates are removable acrylic devices, individually made on a replica of the maxilla of each child. The plates are to be used for 15- 30 minutes 2-3 times daily under the supervision of a grown up.
The aim of palatal plate 1 is to stimulate a normalised position of the tongue and the lips at rest. To achieve this, the plate has a bowl-shaped elevation at the borderline between the hard palate and the velum with the aim to stimulate the back of the tongue to retract the tongue body. Facing the inside of the upper lip several minor plastic knobs are placed with the aim to stimulate lip closure. Palatal plate 1 was used by all children in the E-group for a period of 4.5 ± 1.6 months.
Palatal plate 2 is designed to stimulate closure of the lips, retraction and lateral movements of the tongue. In addition to the stimulation areas seen in plate 1, this plate has a thin stainless steel wire with a movable ball placed on the alveolar ridge in the region behind the future front teeth. Palatal plate 2 was used by 41 children for a period of 3.5 ± 1.6 months.
Palatal plate 3 is designed to stimulate lip closure, retraction of the tongue and concave tongue formation. In stead of the arch wire with the movable ball in plate 2, plate 3 has several plastic knobs on both sides of the alveolar ridges to stimulate the margins of the tongue and hence the concave formation of the tongue. Plate 3 was used by 35 of the 42 children for 3.1 ± 1.4 months.
During periods of tooth eruption, the palatal plate was replaced by an oral screen with the aim to stimulate lip closure. The oral screen was used by 17 children.
When comparing the three groups of 18 ± 3 months-old children, the results cluster into three groups. The children with normal development performed the tests on a more mature level than the children with Down syndrome. The children with Down syndrome in the control group performed on a more immature level than the children in the E-group. They were less active, appeared to be less conscious and to have an inferior control of motor performance than the children with Down syndrome in the E- group.
None of the children was successful in non vocal imitations of tongue and lip movements. The results possible to watch, e.g. to stretch the tongue out and just keep it that way or to stretch it out and raise it, to lower the tongue or to move it to the left or the right corner obtained more correct answers than tests performed within the mouth, e.g. to follow the buccal or the lingual/palatal surfaces of the mandibular and the maxillary front teeth. The tests that require a simple command, e.g. to move the tongue to the left or the right corner of the mouth, obtained more correct answers than the tests that required repeated movements, e.g. to move the tongue from the left to the right corner several times. The tests that required symmetrical movements, e.g. symmetrical spreading of the lips, obtained more positive answers than tests that required asymmetrical movements, e.g. elevating the left or the right corner of the mouth.
The vast majority of the observed test parameters could not be answered at all or in a very deviant way. However, the children in the E-group scored more in accordance with the children with normal development than with he control children with Down syndrome. The proportion of imitations that met the criterion of correct answer was the same in the two groups (10% of the test items - to be compared to 1% in the Down syndrome control group). The percentage of missing answers was even lower than in the group of children with normal development as 9% of the answers met the criterion of approximately correct answer. All but nine children in the E-group and one child with normal development scored at least one correct answer. This is to be compared to the control children with Down syndrome; only three children in this group scored at least one correct answer.
The children with Down syndrome kept very silent compared to the children with normal development during the test sessions. They produced a narrower range of sound qualities as well - an average of 4 different sound qualities each, compared to an average of 9 different sound qualities each among the children with normal development. Some of them used spoken words but most of them did not. All children with normal development but two had started to talk. One child used most of the Swedish phonemes.
Due to the limited extent of speech, it was not possible to evaluate speech development. However, the control children with Down syndrome were less consistent in their use of the upper and the lower articulators than the children in the E-group. The variability in the articulation patterns was also more extensive. Although they produced a wider range of sound qualities, the sounds produced by the children in the E-group, and above all the patterns of upper and lower articulators, were more appropriate according to spoken Swedish. Thus, the children in the E-group have better motor prerequisites for articulation.
The parents answered a questionnaire about the oral function of their children. Their opinion of the behavior of their children differed between the E- and the control group. The children in the E-group were said to be more sensitive to tactile stimulation in the mouth, to have an improved mobility of the tongue, to swallow liquids and solid foods in a more mature way and to breathe through the nose more often than the children in the control group.
The use of palatal plate 1 was judged as uncomplicated or rather uncomplicated by the parents of 97% of the children and as unsatisfactory by the parents of 1 child. Of the 42 plates, 4 were totally and 10 partly remade during the period of use, 6 plates had to be used with an adhesive to stay put. The problems noted are mainly lack of retention in the end of the period either because the child had outgrown the plate or because the child had learnt how to remove it. One parent was afraid that the child should swallow the plate. 4 plates did not stimulate as they should, 3 children choked from the plate to begin with and in one child erupting teeth interfered with the plate. One child was often infected and could not use the plate during those periods.
The use of plate 2 was judged as uncomplicated or rather uncomplicated by 75% of the parents and as unsatisfactory by 25%. Of the 41 plates, 8 were totally and 14 partly remade during the period of use, 11 plates had to be used with an adhesive. The problems noted are mainly lack of retention due to eruption of teeth or due to the design of the plate with an arch wire that constituted a convenient grip for the tongue or finger of the child. One child did not want to use the plate and 3 children were frequently infected or otherwise ill and could therefore not use the plate.
The use of plate 3 was judged uncomplicated or rather uncomplicated by 63% of the parents and not satisfactory by 37%. Of these plates, 3 were totally and 7 partially remade. Adhesive was used for 9 plates. Tooth eruption and connected problems with retention was the prevailing problems for this plate.
The use of the oral screen was judged successful by the parents of 9 children, 8 children did not co-operate with the oral screen.