Region Jnkpings ln Odontologiska Institutionen

A questionnaire survey on tooth agenesis in patients with hypohidrotic ectodermal dysplasia in the Nordic countries

Bergendal B, National Oral Disability Centre, Koch G, Dertment of Paediatric Dentistry, The Institute for Postgraduate Dental Education, Jönköping, Sweden

As preparatory work for the seventh consensus conference at the Institute for Postgraduate Dental Education in Jönköping, Sweden an inventory of patients with a tentative diagnosis of Hypohidrotic Ectodermal Dysplasia (Christ-Siemens-Touraine syndrome, EDA) was made. EDA is the most common of the ectodermal dysplasia syndromes and is characterized by hypoplasia of hair, teeth, sweat glands, salivary glands and symptoms from other organs of ectodermal origin. EDA is a rare disorder with an estimated incidence of 1 in 100.000 births.


The aim of the study was to invent EDA patients known at specialist clinics in dentistry in the Nordic countries and assess tooth agenesis in this group of individuals.

Material and methods

Specialists in orthodontics, paediatric dentistry and prosthodontics in the Nordic countries were asked to report age, gender and number of tooth agenesis in patients with a tentative diagnosis of EDA syndrome.


Reports on 179 patients were collected and their age ranged from 2 to 73 years. The majority of the patients were children and young adults; only 24 individuals (13 %) were 25 years and older. Seventy per cent of the reported patients were male (125 men and 54 women). In 167 patients radiographic examination was performed which constituted the basis for diagnosis of agenesis of teeth. The number of tooth agenesis varied from 0 to 28 with a mean of 15.3. Seven patients had anodontia in both jaws. Tooth agenesis was seen in all types of teeth. The teeth least frequently affected were the upper central incisors followed by the upper first molars.


It was concluded that this inventory reveals a substantial underdiagnosis of EDA syndrome especially in adults and that diagnostic criteria need to be established for this diagnosis.

The result of the consensus conference has been published:

Bergendal B, Koch G, Kurol J, Wänndahl G 1998: Consensus Conference on Ectodermal Dysplasia with special reference to

Uppdaterad: 2013-04-03
Anna Thofelt, Avdelningen för odontologisk radiologi Jönköping, Folktandvården