A Practical Approach to Special Care in Dentistry. Группа авторов

2.3 Down Syndrome

      Section I: Clinical Scenario and Dental Considerations

      Clinical Scenario

      A 48‐year‐old patient attends the dental clinic complaining that his removable upper partial denture is unstable and ‘does not work when eating’. The patient has been given several dentures in recent years but none of them has been successful

      Medical History

       Down syndrome

       Atrial septal defect corrected in childhood

       Recurrent respiratory infections

       Mild hearing loss

       Gastroesophageal reflux

       Chronic anaemia

       Hyperuricaemia

      Medications

       Budesonide

       Theophylline

       Allopurinol

       Lansoprazole

       Iron and folic acid

      Dental History

       Regular dental attender

       Previous dental treatment with local anaesthesia tolerated on numerous occasions without the need for pharmacological adjuncts (calculus removal, extraction, fillings, endodontics, non‐surgical periodontal treatment and prosthetic rehabilitation)

       Three years ago, the patient underwent excision of a maxillary odontogenic cyst (5 × 2.5 cm) under general anaesthesia

       The patient brushes his teeth independently twice a day using a fluoride toothpaste (without supervision)

      Social History

       Parents deceased; lives with one of his sisters

       Independent for activities of daily life

       Attends a centre where he participates in cognitive stimulation and craft workshops

      Oral Examination

       Very co‐operative

       Lip fissures

       Fissured tongue

       Fair oral hygiene

       Microdontia

       Dental spacing

       Missing maxillary teeth: #14, #15, #16, #17, #21, #22, #23, #24, #25 and #26

       The remaining maxillary teeth have significant gingival recession with cervical exposure and grade 1–2 mobility

       Missing mandibular teeth: #32, #35, #42 and #45 (possibly due to agenesis, based on the findings of previous radiographs)

       Irregular alveolar bone crest in the upper left quadrant, with a considerable bone defect as sequela of the cystectomy (intact mucous coating with a normal appearance) (Figure 2.3.1a)

       Unstable upper partial denture (Figure 2.3.1b)

      Radiological Examination

       Orthopantomogram and cone beam computed tomography (Figure 2.3.2) undertaken

       No radiological evidence of recurrence of the odontogenic cyst, but there is loss of bone mineral density

       The only available bone volume for the direct insertion of dental implants identified in positions corresponding to teeth #14 and #26Figure 2.3.1 (a) Irregular palate, with erythema of the denture bearing mucosa (clinically suggestive of candidiasis). (b) Unstable upper partial denture.

      Structured Learning

      1 What are lip fissures and what causes them?Lip fissures are a frequent finding in patients with Down syndrome (>25%), especially among men, with a peak prevalence in the third decade, and occur preferentially in the lower lipTheir aetiology is unknown (embryological defects, mandibular prognathism and lip eversion have been implicated)In most patients, the lesions coexist with angular cheilitis and are colonised by Candida albicans

      2 What factors are considered important in assessing the risks of managing this patient?SocialFavourable family environmentHearing impairmentComplications can arise due to other comorbidities associated with Down syndrome (e.g. premature ageing and cognitive impairment)MedicalRespiratory dysfunctionFatigue/reduced tolerance for treatment in relation to anaemiaCorrected atrial septal defect is not associated with risk when delivering dental interventionDentalMultiple failed attempts at providing removable partial denturesOral hygiene could be improvedMultiple missing teeth but low caries rate; chronic periodontal disease likely cause of tooth lossPrognosis of the remaining teeth guardedImplication for success of osseointegrated dental implantsGastroesophageal reflux‐related risk of dental erosionAnaemia‐related oral side‐effects (pale mucosa, glossitis, oral ulceration)

      3 What factors determine the prognosis of the dental implants in this patient (Figure 2.3.3)?The available bone volume is limitedOsteopeniaSusceptibility to infections (potential defects in neutrophil chemotaxis due to Down syndrome)Sub‐optimal oral hygiene and a history of periodontal disease can favour the onset of peri‐implantitis. Ongoing oral hygiene/periodontal support provided due to variable complianceObserved higher failure rate: in patients with Down syndrome, 1 in every 5 dental implants fails

      4 If considering the use of dental premedication/sedation to place dental implants, what additional factors should be taken into account?Benzodiazepines should not be prescribed for patients with severe respiratory dysfunction or hypotonia (musculoskeletal effect of Down syndrome)Theophylline reverses the sedative effect of benzodiazepines

      5 Is administering antibiotic prophylaxis before a surgical procedure such as implant insertion justified?The corrected atrial septal defect does not justify the prescription of antibiotic prophylaxis for the prevention of bacterial endocarditisHowever, the immunological defects observed in Down syndrome may constitute an indication for administering antibiotics prior to the surgical procedure and for maintaining them in the postoperative periodFigure 2.3.2 Cone beam computed tomography showing a bone defect in the upper left quadrant.Figure 2.3.3 (a–d) Prosthodontic rehabilitation with a new upper dental prosthesis supported on the remaining teeth and 2 osseointegrated implants.

      6 What antibiotics should be avoided for this patient?The toxicity of theophylline increases with macrolide antibiotics and quinolones

      General Dental Considerations

      Oral Findings

       Orofacial muscle hypotonia

       Poor labial seal/open mouth posture (may lead to xerostomia)Figure 2.3.4