Abstract
Progressive muscular dystrophy is a muscular disease characterized by progressive atrophy and weakness of the skeletal muscles.
Several authors have described the effects of this disease on the occlusion of the patient. Some of the oral manifestations which they observed included open bite, macroglosia and expanded dental arches.
We encountered the case of a 5 year 4 month-old boy first diagnosed as having progressive muscular dystrophy at the age of 3, and we have followed up it for about 5 years. We measured the arch width on dental casts taken every 6 months.
The results are summarized as follows.
1) At the first oral examination the patient did not show any functional disorders of the body. Also the value of his maxillary arch width was within th e range of the standard deviation but the mandibular dental arch width was greater than the average value in children of the same age.
2) The increase in the mandibular arch width had started earlier than in the maxillary. With the progress of the functional disorders, the arch width in creased markedly in the maxilla.
3) The increase in the arch width was greater in the maxilla than in the mandibule after 8 years and 6 months of age.
4) The increase in the distance between deciduous canines was within the standard deviation in both maxilla and mandibule.
5) The rate of increase of the arch width was the greatest between the permanent first molars, and followed by the distance between the deciduous seco nd molars and the deciduous canines.
