11th Class Flashcards
- Incidence
- 1:700-800 live births
- Higher incidence with maternal age >35
- Etiology
- Genetic disorder –trisomy 21
- Autosomal (not dominant nor recessive)
- Diagnosis
- Prenatal –Screening during pregnancy
Down syndrome
The prevalence of down syndrome is greater with maternal age greater than _____ yrs
> 35 yrs
Down syndrome is an autosomal disorder that is a trisomy ___
Trisomy 21
- Physical features
- Mental and developmental delays
- Short stature, stalky build
- Upward slant to the eye
- Small head, short neck
- Flattened nose
- Poor muscle tone
- Xerosis (dry skin)
- Broad short hands with single crease
- Cardiovascular problems (heart defects)
Down syndrome
•Craniofacial features
• Flattened facial features.
• cranial base is flattened, therefore shorter in AP length, therefore less forward movement of Mx
during growth
• Class III relative due to deficient maxillary growth.
• Brachycephalic (flattened occipital bone)
• Small head, Short neck
• Protruding tongue
• Macroglossia (relative to small mouth)
• Upward slanting eyes (Mongoloid eyes)
Down syndrome
•Skeletal features •A-P •Sagittal area of endocranium smaller •Smaller midface, cranial base, frontal bone, paranasal sinus •Ethmoid bone is retruded •Maxilla hypoplastic, Md normal (Class III) •Cranial base is flatter and shorter •so must be considered for ceph analysis –Lowered position of sella •Vertical •High MPA Transverse -High MPA
Down syndrome
- Dental features
- Macroglossia and/or tongue thrusting.
- Low rate of caries.
- High saliva flow, interproximal spaces between teeth
- chronic mouth breathing
- Dysplastic enamel
- Delayed eruption of both primary and permanent teeth
- Anterior open bite
- Crossbite (anterior and posterior)
- Hypodontia
- Microdontia
- Generalized spacing
- High prevalence of periodontal disease
- High prevalence of class III malocclusion
Down syndrome
- Orthodontic considerations
- OSA
- Periodontal problems
- Generalized spacing caused by
- Hypodontia
- Microdontia
- Macroglossia and tongue thrusting
- Due to heart defects, require prophylactic antibiotics
Down syndrome
•Autosomal dominant disorder •Affects development of bones and teeth Incidence •1:200,000 •Males=Females Etiology •Haploinsufficiencey of CBFA-1 (RUNX2) transcription factor
Cleidocranial dysplasia
Characteristics- Face•Brachycephalic •Frontal and parietal bossing •Depressed nasal bridge •Midface hypoplasia •Mandibular prognathism •Class III •Vertical maxillary deficiency
Cleidocranial dysplasia
Characteristics- Dental• High palatal vault • Cleft palate • Delayed exfoliation of primary teeth • Delayed eruption of permanent teeth • Impacted supernumerary teeth • Crowding • Dentigerous cysts • Multiple crown and root abnormalities Normal Eruption is Impeded by: • Multiple supernumerary teeth • Deficient resorption of primary teeth and bone • Heavy fibrous gingiva
Cleidocranial dysplasia
Other Physical Characteristics•Sloping/absent shoulders due to severe hypoplasia or absence of clavicles •Ability to bring shoulders together •Short stature •Short limbs (especially upper limbs) •Narrow thorax •Tapered fingers, broad thumbs •Frequent sinus and ear infections •Flat feet
Cleidocranial dysplasia
Treatment
•Orthodontics and Orthognathic surgery
•Timely extraction of deciduous teeth
•Exposure of unerupted/impacted permanent teeth and forced eruption
Cleidocranial dysplasia
•Rare group of closely related conditions affecting development/function of
teeth, hair, nails, sweat glands, skin and eyes
•Over 150 different syndromes identified
Incidence
•1:17000 newborns affected
•Primarily affects males
Etiology
•X chromosomal recessive disorder
•Multiple interactions between genetic and epigenetic factors
Ectodermal Dysplasia
Physical Characteristics•Thin skin with decreased pigmentation • Sparse, thin hair •Hypoplastic sweat glands •Impairment or loss of hearing or vision •Sensitivity to light •Respiratory problems •Lack of breast development •Frequent infections due to immune deficiencies
Ectodermal dysplasia
