General symptoms
There are four sub-groups of DM1 depending on age at onset – congenital, childhood, classical and mild. In general, the earlier the symptoms occur, the more severe the clinical symptoms of the disease will be. DM1 is a neuromuscular disease with muscle weakness, muscle wasting and myotonia (delayed muscle relaxation) as cardinal symptoms. Multiple systems can be affected such as the heart, smooth muscle, brain, endocrine regulation and skin. Most individuals with congenital and childhood DM1 have learning disability and the frequency of neuropsychiatric disorders is higher than in the general population. The disease has a slowly progressive course.
Orofacial/odontological symptoms
Sucking difficulties and breathing problems are common in newborns. Weak orofacial muscles may lead to impaired facial expression, open mouth posture and difficulties with eating, speech and saliva control. The muscular wasting may affect facial growth and cause malocclusion. Some have problems with the temporomandibular joints and impaired jaw opening capacity. There is also an increased risk for caries and gingivitis in individuals with dry mouth and impaired self oral clearance. An increased sensitivity for general anaesthesia drugs has been reported.
