THERAPEUTIC APPROACH

3.1. Behaviour management
Cognitive problems lead to difficulties in behaviour management, particularly in the medical or dental setting. Primitive defence reactions to the unknown may prevent quality treatment. As for all populations with intellectual deficiency, behaviour management techniques rely on the construction of a relationship of trust between the patient and the clinician. Time needs to be taken to explain, in simple terms or gestures, the act the practitioner wishes to undertake. “Tell, show, do” is still very much the method of choice. Control should not be removed from the patient and under no circumstances should pain control be neglected or underestimated, even when pain is not manifested³⁵ The use of physical constraint is strongly discouraged as it can only lead to further opposition and increase fear and defence reactions. Other techniques, such as conscious sedation, are essential for those patients whose fear or lack of comprehension prevents co-operation. Only on rare occasions, or when there is an accumulation of untreated disease, should it be necessary to undertake treatment under general anaesthesia.

Experience of pain-free successful treatment in the normal setting has been shown to reduce dental anxiety in the Down syndrome population, whereas anxiety levels remain the same before and after treatment under general anaesthesia¹⁴². General anaesthesia is thus to be used as a last resort rather than as first line management.
Autistic patients may be amenable to simple treatment (scaling, small restorations) using a conditioning approach if they are accustomed to the dentist and the surroundings and if they are not in pain. Otherwise, more extensive treatment usually needs to be undertaken under general anaesthesia, with preventive follow-up. These patients are rarely able to cope with orthodontic treatment, and treatment goals may need to be reduced to the prevention of pain and infection.

3.1. Oral health management
The mainstay of treatment for this group is prevention. It is essential that good dietary and oral hygiene practices are established from the very beginning and that the parents are counselled from the earliest age. Parents should be warned of the dangers of nursing caries and shown how to brush their child’s teeth correctly. They should be aware that even as the child grows in autonomy he or she may not be able to brush his/her teeth effectively due to reduced motor precision. Brushing will need to be supervised for longer than for other children and this supervision may extend into adulthood in some cases. Toothbrushing needs to be part of an established routine from a young age because late introduction of oral hygiene measure can lead to opposition and because early oral stimulation can help neuromuscular development, regression of the gag reflex and the introduction of solid foods. Collaboration with a physiotherapist or occupational therapist may be necessary for the person with Down syndrome to acquire the praxis required for effective toothbrushing. Fluoride toothpaste should be encouraged, dose related with age. Local application of a sustained-release delivery system of chlorhexidine has also been reported useful in the control of bacterial plaque in children with Down syndrome¹⁴³. Other carers should also be educated in dental prevention, particularly those working with both adults and children in homes or institutions¹⁴⁴. The importance of oral hygiene must be stressed if destructive periodontal disease is to be avoided and sweet foods should not be used as an award system for favourable behaviour.
Regular dental examination is essential if problems are to be intercepted early, and in order to acclimatise the patient to the dental environment. The dentist should recognise early signs of facial dysmorphology and be able to intervene at the appropriate point in the child’s development. Early functional orthopaedic treatment is generally well accepted and veryfavourable. Regular professional scaling is required from an early age in order to prevent the advance of aggressive periodontal disease (up to four times a year is often necessary). When routine treatment is required, the complexity of the work undertaken will depend upon the co-operation of the patient but the dentist should aim to give the same quality of care as for the general population. Caries must be treated, even in the very young and, at any age, missing teeth should be replaced by prosthetic treatment. Orthodontic treatment can often be carried out conventionally although greater attention may be required to maintain a high standard of oral hygiene. The easy option of ‘supervised neglect’ is no more excusable for this group of patients than for the population as a whole, although it has unfortunately been demonstrated that persons with Down syndrome continue to receive less treatment than their peers¹⁴⁵.

3.3. Multidisciplinary approach
For the prevention of major oral health problems, be they due to periodontal disease, caries or malocclusion, it is essential that all those concerned in the person’s well being be involved. Initially parental guidance is required but with age oral healthcare becomes the responsibility of the young adult him or herself, or of the appropriate care team. The paediatrician or family physician needs to be able to advise on feeding techniques and nursing caries. Often a nutritionist may also be involved. Pre-speech therapy may be required for oral stimulation and to aid in the introduction of solid foods and lingual motricity. The physiotherapist will also help with orofacial stimulation and in the acquisition of the movements needed for oral self-care. The cardiologist must advise on the risks of endocarditis related to oral infection. The educational and occupational therapy team can help to establish a regular oral hygiene routine. The dentist must maintain communication with all concerned in order that potential problems are addressed beforethey become serious. He or she must be prepared to refer the patient to the appropriate professional if further intervention is required, for example to the functional orthodontist.

3.4. Orthodontics and orthopaedics
The knowledge of the development of orofacial structures in this syndrome is the reason for early intervention. Neuromuscular stimulation provided by orofacial therapy helps to avoid secondary pathology of the jaws. The use of palatal plates, as explained below, could be considered as an early stage of myofunctional orthodontic treatment. According to each individual’s treatment, these stimulators can also be added or combined to ordinary myofunctional appliances. Becker et al¹⁴⁶suggested that orofacial discrepancy can be corrected during puberty by functional orthodontic therapy although these techniques need a degree of co-operation from the child and a certain familiarisation with the dental environment. The aim of early orthopaedic intervention is to guide skeletal growth using muscular stimulation, thus avoiding midfacial and palatal deficiency and severe malocclusion. The tongue is encouraged to take up a higher, more posterior position, using a lingual envelope for example, and closure of the lips is sought, possibly using lip bumpers or equivalent appliances. It is hoped that normal oral function can be encouraged by structural guidance. The number of different techniques used to fulfil these aims is great, but in all cases the earlier intervention is started the more effective treatment will be (treatment may be started in some cases before the age of 12 months). This is explained by the concept of a “critical period” after which acquisition of a particular behaviour is more difficult¹⁴⁷.
For the older child, the only contraindication for the use of fixed appliances is that of patient non-compliance. However, special consideration should be paid to early onset of periodontal disease and the ability to achieve acceptable control of bacterial plaque⁴.

Castillo-Morales and palatal plates. It was said that in early 1970’s, Dr. Castillo Morales had observed how children with a cleft palate searched the cleft with the tongue as if it had a vacuum effect. Based on that observation, he designed an intraoral device for hypotonic patients to stimulate the tongue into reaching a more physiological position^{61, 148} . The use of orofacial regulation therapy spread among European dentists mainly because of those reports that highlighted positive effects of the use of palatal plates. However, this appliance was meant to be integrated with a full therapy plan, which includes physiotherapy, speech therapy and manual exercises to stimulate the orofacial musculature. According to its mentor, the plate is not a treatment method in itself but a resource to sustain the results obtained by physical therapy⁶¹.
Basically, the device consists of a resin plate, like the base of a full denture, with an oval or round vacuum stimulator near the post-dam of the palate. The tongue inevitably rises to establish contact with the stimulator and a physiological tongue position is thus achieved. In the vestibular region in front of the upper incisors, acrylic bumpers are added to the plate to pull the upper lip downwards. ANIMATION Different means for retention are used depending on the age of the patient and the presence of teeth in the upper arch¹⁴⁸. VIDEO
These techniques have been widely used in the Down syndrome population, and successful results have been reported in many articles¹⁷,⁶³,⁶⁴,⁶⁹,^149-153, although no significant differences have been found by other authors¹⁵⁴. The subject for debate remains the study design and the necessity for long term follow up. Such a study was presented by Carlstedt et al^{155, 156} during the IADH Congress in Madrid/2000. With regard to the study design, the ethical aspects of the use of a control group, the impact of spontaneous correction of tongue protrusion that occurs around 5 years of age, the choice of outcome variables, the criteria for inclusion, the methods of assessment and the characteristics of the survey group all need to be clarified.
Leaving aside research matters, the use of palatal plates has been suggested for patients with Down syndrome with a hypotonic and protruding tongue, hypotonic upper lip and/or impaired oral motor functions, in order to improve muscular tone and to increase intraoral pressure by means of the regulation of the buccinator mechanism^{64, 69} . It is advisable not to use the plates during tooth eruption, the verticalisation process, obstruction of the upper airways or chronic nasal insufficiency. Children with true macroglossia are not suitable for such devices⁶¹.

3.5. Prosthetics and implants
Prosthetic treatment, if required, can usually be carried out as for the general population. Specific problems that may be encountered are lack of oral hygiene and a hypersensitive gag reflex. The dentist may be intimidated by marked dysmorphology, particularly in the older Down syndrome population who has not benefited from early orthopaedic intervention. The discrepancy between the upper and lower maxilla can be great but successful prosthetic treatment is still possible, and may help to correct the occlusion to a great extent.
Crown and bridge work is entirely feasible to replace missing teeth, if oral hygiene can be maintained. This type of restoration is particularly indicated following trauma to the incisor region. Such treatment cannot, however, improve the occlusal relationship and treatment aims will be purely aesthetic.
As tooth loss is often caused by advancing periodontal disease, an intermediate partial denture, to which teeth can be added, may be an appropriate treatment choice in this population. The intermediate denture has the advantage of possible gradual integration of the prosthesis into the routine of the patient, even if initially the dental relationship is not ideal. In other cases, previous chaotic tooth loss may mean that a partial denture is unstable and that rapid progression to complete dentures is favourable, particularly when there is a large discrepancy between the alveolar arches. Registering jaw relationships may be difficult but mandibular resorption following tooth loss favours the establishment of a stable occlusion as it tends to be vestibular. The anterior position and hypotonicity of the tongue are an aid to the retention of the lower denture and the mucosal seal is good¹⁵⁷. As mandibular movement is freed and a stable rest position is provided, function is improved. Patience and encouragement may be required for the patient to wear the finished prosthesis initially, particularly if the vertical dimension is greatly increased, but with the collaboration of the parents or care team these prostheses are usually well accepted.
The provision of dentures in the young patient following multiple extractions due to nursing caries is particularly important for this population. The acquisition of speech and full masticatory function is difficult for these children normally, but if the teeth are missing during this critical period of development these functions may never be recovered. Alveolar stimulation is also required to encourage eruption of the permanent teeth and to stimulate growth of the maxillae.
Another indication for prosthetic treatment may be in the provision of bite raising appliances or onlays to establish a stable occlusal relationship in cases of severe dysmorphology. For those adults for whom conventional orthodontic treatment is not an option, appliances that restore vertical dimension, establish a uniform contact on closure and enable free jaw movements may improve function and comfort⁸¹.
Osseointegrated implants may be a possibility in certain patients with Down syndrome but care should be taken in case selection. The patient must be able to understand and co-operate with the surgical stages of treatment and be able to maintain meticulous oral hygiene. The impact of the immunological deficiencies that play so great a role in the development of periodontal disease have not, to our knowledge, been evaluated with regard to implants and further research is therefore required in this field before the practice can be fully endorsed.

3.6. Surgical procedures
Different surgical procedures have been proposed to improve aesthetics and function^158-160 in the population with Down syndrome. Glossectomy, tonsillectomy and plastic surgery are widely practised in the United States of America but serious evaluation has yet to be undertaken^161-162. Glossectomy seems particularly radical as the appearance of a large tongue in Down syndrome has been shown to be due to hypotonicity and anterior positioning, and not to true macroglossia⁶⁹. Not only is function rarely improved but also language development and psychological stability may be compromised^{163, 164} Ethical questions are also raised as to the imposition of aesthetic norms on the intellectually disabled population.