Down's syndrome is associated with all of the following except:

Skeletal finding is an underdeveloped mid-face, creating a prognathic occlusal relationship.  Oral findings include mouth breathing, open bite, appearance of macroglossia, fissured lips and tongue, angular cheilitis, delayed eruption times, missing and malformed teeth, oligodontia, small roots, microdontia, crowding, and a low level of caries.  Children with Down syndrome experience a high incidence of rapid, destructive periodontal disease, which may be related to local factors such as tooth morphology, bruxism, malocclusion, and poor oral hygiene.  Pediatric Dentistry / Shobha Tandon - 2nd Ed