A Practical Approach to Special Care in Dentistry

Duchenne muscular dystrophy is the most common amongst children and is characterised by:Inheritance (linked to the X chromosome)Onset in the first years of childhoodInvolvement of all muscles (generalised muscle weakness)Muscle pseudohypertrophy (enlargement)Pelvic girdle muscle impairmentDifficulty standing up (Gowers sign)Severe lumbar lordosis and peculiar gait (‘duck‐like’)Confined to wheelchair before pubertyCardiomyopathyRespiratory impairmentIn some cases, intellectual impairment may be presentDeath in the first years of the adult stage

The initial diagnosis is based on clinical findings (e.g. generalised muscle weakness) Table 1.3.2 Classification and characteristics of muscular dystrophy.TypeSex Age at onsetMuscles involvedAssociated complicationsLife expectancyDuchenne muscular dystrophyMales3–5 yearsAllCardiomyopathy Intellectual disabilityDie at the end of adolescenceBecker muscular dystrophyMales10–20 yearsAllCardiomyopathy (uncommon)NormalEmery–Dreifuss muscular dystrophyMales<10 yearsAllCardiomyopathy (severe)Die at 30–50 yearsLimb‐girdle muscular dystrophyBoth sexes15–20 yearsPelvic girdle and shouldersCardiomyopathyVariableFacioscapulohumeral muscular dystrophyBoth sexes15–20 yearsFace and shouldersCardiomyopathy (uncommon)NormalMyotonic muscular dystrophy – types 1 and 2Both sexes20–30 yearsAllCardiomyopathy Cutaneous dystrophy Ocular disorders Intellectual disabilityDie at 30–50 years (earlier for type 1)Congenital muscular dystrophyBoth sexesBirthAllRespiratory distress Intellectual disabilityVariableOculopharyngeal muscular dystrophyBoth sexes40–50 yearsUpper eyelids, pharynx, tongueVision problems Dysphagia CardiomyopathyNormalDistal muscular dystrophyBoth sexes40–60 yearsDistalRespiratory distress (in advanced phases)Normal

Blood tests: serum levels of creatine phosphokinase (CPK), aspartate transaminase (AST) and lactate dehydrogenase (LDH)

Electromyography

Muscle biopsy (histopathological and immunological analysis of the muscle) ( Figure 1.3.5)

In some types of muscular dystrophy, genetic analysis may be of value Figure 1.3.5 Diagnostic muscle biopsy showing random variation in fibre size, increase in fibrosis and degeneration of muscle fibres (Masson trichrome staining, ×20).

Physical therapy

Occasionally orthopaedic surgery to help correct the shortening of muscles or to improve scoliosis ( Figure 1.3.6) Figure 1.3.6 Orthopaedic surgery to improve scoliosis.

Additionally, cardiac surgery and/or surgery to repair cataracts may be required

Corticosteroids, cardioprotective agents, antidepressants, ventilation with positive non‐invasive pressure

Although there is no known cure, there has been notable progress in correcting the underlying genetic mutations

The prognosis for muscular dystrophy depends on the type and severity of symptoms

However, most individuals do lose the ability to walk and eventually require a wheelchair

Life expectancy is reduced if there is pulmonary dysfunction and/or cardiac involvement

In most cases, the patients die at the end of adolescence or at the start of adulthood, as the consequence of pneumonia or cardiopulmonary failure

There are major differences between countries in terms of the prevalence of muscular dystrophy. For example, the rate of Duchenne muscular dystrophy in South Africa is estimated at 1 case/100 000 males compared with approximately 17 cases/100 000 males in Sweden

The survival of individuals with some varieties of muscular dystrophy has increased significantly in countries with access to corticotherapy, cardiac medical treatment and mechanical ventilation

1 Balasubramaniam, R., Sollecito, T.P., and Stoopler, E.T. (2008). Oral health considerations in muscular dystrophies. Spec. Care Dentist. 28: 243–253.

2 Flanigan, K.M. (2014). Duchenne and Becker muscular dystrophies. Neurol. Clin. 32: 671–688.

3 Goiato, M.C. (2016). Duchenne muscular dystrophy and the stomatognathic system. Dev. Med. Child Neurol. 58: 650.

4 Mielnik‐Błaszczak, M. and Małgorzata, B. (2007). Duchenne muscular dystrophy – a dental healthcare program. Spec. Care Dentist. 27: 23–25.

5 Morinushi, T. and Mastumoto, S. (1986). Oral findings and a proposal for a dental health care program for patients with Duchenne type muscular dystrophy. Spec. Care Dentist. 6: 117–119.

6 Symons, A.L., Townsend, G.C., and Hughes, T.E. (2002). Dental characteristics of patients with Duchenne muscular dystrophy. ASDC J. Dent. Child. 69: 277–283.

7 Waldrop, M.A. and Flanigan, K.M. (2019). Update in Duchenne and Becker muscular dystrophy. Curr. Opin. Neurol. 32: 722–727.

A 13‐year‐old male presents to the dental clinic with his mother. She is concerned about her son's teeth, stating that ‘they are discoloured, and keep falling out’. Other dentists have been unable to examine her son and have refused to provide care.

Attention deficit and hyperactivity disorder (ADHD) diagnosed at the age of 5 years old

Self‐harm predominantly associated with stress

Mild learning disability

Dental anxiety

Methylphenidate

Managed to have a single amalgam filling placed in a deciduous tooth when he was 9 years old

Last dental visit was 18 months ago when repair of a fractured incisal tip was attempted; the tooth is asymptomatic at present

Mother reports this was a traumatic experience for her son as the dental nurse held her son down to allow the dentist to examine the tooth

Dentists have since declined to provide care as the patient has refused to co‐operate with examination and treatment

Now an irregular attender

Only brushes his teeth once a day or when he remembers and refuses help

Lives with parents

Youngest of five siblings

Only member of the family with a learning disability and ADHD

Attends a special education school

Poor dietary habits, snacks frequently on biscuits and sweets, consumes fizzy drinks daily

(performed within 2 desensitisation visits)

Generalised plaque, calculus, gingival inflammation and spontaneous bleeding

Enamel demineralisation at gingival margins most pronounced on the buccal aspect of the upper teeth

Fractured incisal tip of tooth #21 – simple without pulp exposure, no mobility ( Figure 2.1.1)

Caries: #54, #53, #65, #75, #84 and #85 ( Figures 2.1.2and 2.1.3)

Stained fissures: #16 and #26

Maxillary canine bulge can be palpated buccally on both sides

Patient required acclimatisation appointments to enable bite‐wing radiographs ( Figure 2.1.4)

Hence #54 and #65 present in clinical images but missing in the radiographic images as they had exfoliated naturally by the time the images were taken

Patient did not accept orthopantomogram, hence further evaluation not possible

1 What factors may be impacting on this patient's poor oral health and increased caries risk?Compliance issues in daily lifeLack of perceived needCognitive difficulties due to learning disabilityMotor problems due to hyperactivity Figure 2.1.1 Dentition: generalised plaque, calculus and gingival inflammation, fracture of the incisal tip of tooth # 21. Figure 2.1.2 Maxilla: caries in teeth #54, #53, #65, stained fissures in #16 and #26.Poor oral health habits and dietIrregular dental check‐ups due to dental anxiety and lack of accessOral dryness due to methylphenidateChanges in oral health behaviour during adolescence