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[Vertical development of the jaw in cases of trisomy 21: interaction of form and function]
Insights
Facial development in children with Down syndrome (trisomy 21) shows midface hypoplasia affecting vertical growth. Tongue protrusion impacts incisor alignment but not skeletal vertical development.
Area of Science:
- Orthodontics
- Genetics
- Pediatric Dentistry
Context:
- Facial skeletal development in children with Down syndrome (trisomy 21) is complex.
- Understanding vertical facial growth is crucial for effective orthodontic and surgical interventions.
- The role of parafunctional forces, like tongue protrusion, in trisomy 21 facial morphology requires clarification.
Purpose:
- To analyze the vertical facial development in patients with trisomy 21 from birth to 14 years.
- To investigate the influence of lingual protrusion, a common feature in trisomy 21, on skeletal and dental morphology.
- To compare facial vertical development between individuals with trisomy 21 and a healthy control group.
Summary:
- Lateral tele-X-rays of 1896 patients with trisomy 21 and 1154 controls revealed midface hypoplasia extending to the vertical dimension.
- Reduced caudal development of the maxilla and slight mandibular hypoplasia were observed in the trisomy 21 group.
- Lingual protrusion did not affect vertical skeletal growth but caused bialveolar incisor protrusion; open bites were primarily dento-alveolar.
Impact:
- Provides crucial data on vertical facial growth patterns in trisomy 21, aiding in diagnosis and treatment planning.
- Clarifies that lingual protrusion's primary effect is on dentition, not skeletal structure, guiding orthodontic interventions.
- Highlights the dento-alveolar nature of open bites in trisomy 21, informing targeted treatment strategies.
Abstract:
With reference to lateral tele-X-rays of 1896 patients with trisomy 21 in the period from birth up to the 14th year of life, the vertical development of the face was analysed. 1154 healthy children of the same age serve as control group. Particular attention is paid to the question as to the importance of parafunctional forces which derive from the lingual protrusion typical for trisomy 21. In the context of the statistical analysis, group differences were tested by means of analysis of variance. There were the following results: the hypoplastic development of the midface also involves the vertical dimension. There is a reduced caudal development of the maxilla; the horizontal positioning of the maxilla is only altered slightly in that the maxilla is depressed somewhat less posteriorly; the mandible shows a slightly hypoplastic development, and the mandibular angle is slightly reduced in size; an increased presence of a vertical growth type is not found; the parafunctional force deriving from the lingual protrusion do not have any demonstrable effect on the vertical skeletal development, but bring about a bialveolar protrusion of the incisors; the frontal vertical open bites found in trisomy 21 are mainly dento-alveolar in nature.
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