Disorders of growth and development in children Flashcards
Growth
Complex biological phenomenon that starts at conception and is regulated by nutritional, hormonal and genetic factors
When is growth fastest
Conception to infancy
Distinct phases of somatic growth in children
Infancy
Childhood
Puberty
Growth pattern in infancy
Rapid foetal growth
In infancy deceleration of the foetal growth rate
-determinant: nutrition
Growth pattern in childhood
Slow deceleration except mid childhood adrenal spurt
-determinant: growth hormone
Growth pattern in puberty
Pubertal growth spurt
-determinant: sex steroids and growth hormone
WHO child growth standards
For measuring growth in children, checking they’re healthy
Measuring growth
Growth charts -height -weight BMI (proxy for body fat) Bone age
Difference in BMI children vs adults
adults: (weight/height)^2
- cut-offs 18-25
children: calculated against age and gender
- use for pxs that need sedation or GA
BMI
Mass (kg)/ (height(m))^2 Proxy for body fat <18.5 underweight =18.5 to 25 optimal weight >25 overweight >30 obese >40 morbidly obese
BMI for general anaesthetic
High BMI (overweight), more chance of complications -sleep achnea, taking more drugs to get them to sleep
The concept of bone age
The use of standardised X-rays
Estimate the maturity of each epiphyseal centre of the left hand wrist to derive a score
The age at which the score is on 50th centile is the bone age of the individual
Bone age standard system
Tanner & Whitehouse
-quantify how much growth has occurred and how much is to come
Common causes of short stature of failure to thrive
Nutritional
-under nutrition
-malabsorption: intestinal infection, CF, Crohns, Coeliac
Constitutional
-individual and familial short stature
Intra-uterine growth retardation
-damage by alcohol, drugs
-genetic e.g. Down’s Syndrome
Systemic disease
-heart, lung, renal, haematological, diabetes mellitus
-endocrine e.g. hypothyroid, hypopituitary
Iatrogenic
-steroid excess
Inherited
-achondroplasia, hypophosphatasia, Noonan’s syndrome
Terminology
Environmental defect Chromosomal disorder Single gene defect Polygenic disorder (multifactorial)
Environmental factors
Drugs/ chemicals -Thalidomide, Epanutin, Warfarin, Alcohol, Fluoride (teeth) Radiation Infection e.g. zika Metabolic defects e.g. if mother has diabetes Hyperthermia Vascular Amniotic bands
Amniotic band disruption
Congenital disorder caused by entrapment of fetal parts by part of amniotic band (usually a limb or digits) in fibrous amniotic bands while in utero
Birth defects - more terminology
Single/ isolated defect Multiple defects -associations -sequences -field complexes -syndromes
Single system defect
Common and often multifactorial
e. g. abnormal or failed completion of embryonic process
- e.g. cleft lip
- e.g. spina bifida (incomplete closure of neural tubes)
Associations
Combinations which are associated statistically but underlying mechanism not clear e.g. VATER, CHARGE
VACTERL
Vetebral anomalies Anal atresia Cardiac defect Tracheo- Esophageal atresia Radial and Renal anomalies Limb abnormality
Potter’s sequence
- Includes oligohydramnios*
- squashed facies
- joint contractures
- bowed limbs
- lung hypoplasia
Pierre-Robin sequence
Early mandibular hypoplasia –> glossoptosis –> failed palatal closure
Sequences
Potter’s sequence
Pierre-Robin sequence
Field complexes
Insult to localised part of an embryo resulting in abnormalities in adjacent structures of disparate embryonic origin
-e.g. stapedial artery interruption in rodents –> hemifacial microsomia
Syndrome -Trisomy 21 dental symptoms
Down’s Syndrome
- large, fissured tongue
- periodontal disease
- hypodontia
- microdontia
- enamel defects
- class 3 malocclusion due to maxillary retrognathia
Pierre Robin sequence management implications
breathing difficulties feeding difficulties cleft palate speech therapy dental care possible learning disability
Trisomy 21 non-dental symptoms
Learning delay Cardiac Defects (70%) Relatively short neck, unstable atlanto-axial joint Short stature Increased risk of Leukaemia Hypotonia Hypothyroidism Epilepsy, Alzheimers
Williams syndrome
Deletion of genes Ch 7 Fault in calcium metabolism leading to xs calcium Failure to thrive in infancy Highly verbal and overly sociable Characteristic facial appearance “Elfin” Short stature Delayed growth Variable learning delay & behavioural problems Heart defects Susceptible to loud noise Renal calculi -angel like faces
General disorders of growth and development
Osteogenesis imperfecta Down’s syndrome X-linked Vitamin D resistant rickets Cleidocranial dysostosis Achondroplasia Gigantism Acromegaly
Dental disorders of growth and development
Dentinogenesis imperfecta
Amelogenesis imperfecta
Dentinogenesis imperfecta
AD Inherited disorder of dentine
Can be associated with OI
Three types
Three types of dentinogenesis imperfecta
1) Mutation in Type I collagen. Associated with OI, Chromosome 7 and 17
2) Mutation in Dentine Sialophosphoprotein I Gene, Chromosome 4
3) Brandywine Isolate, Maryland Chromosome 4
Background of DI
Shield’s 1973 classification based solely on clinical phenotype
Human mutations of DSPP gene –> Shield’s DI types II and III and DD type II
Genetics show these are a severity variation of the same pathology, i.e. a single entity with variability of expression
i.e. DD type II mild form of DI and DI type III severe form of DI
Defect in non-collagenous dentine matrix proteins (DSP, DPP and DGP)
Dental features of DI
Amber, grey to purplish discolouration
Pulpal obliteration
Relatively bulbous crowns, short narrow roots
Enamel may be lost following tooth eruption, exposing soft dentine which wears rapidly
Normal mantle dentine
Affects primary > permanent
Bisphosphonates
- osteonecrosis concern
- given to pxs with osteogenesis imperfecta
Osteogenesis imperfecta
Bone fragility Multiple fractures Unstable vertebral column Blue sclera Progressive hearing loss Bisphosphonates- risk of osteonecrosis Dentinal changes
X-linked Vitamin-D resistant rickets
Aka Hypophosphatemic rickets Rachitic changes in long bones Failure of distal tubular phosphate reabsorption Short stature Bowing of legs ↓Serum phosphate, ↑Alkaline phosphatase Large pulp chambers and elongated pulp horns Abscesses in the absence of caries
X-linked Vitamin-D resistant rickets dental symptoms
Large pulp chambers and elongated pulp horns
Abscesses in the absence of caries
Achondroplasia
Sporadic mutation in 75% and AD
Defect in FGFR3 gene
Shortened arms and legs. Upper arms & thighs > than forearms and lower legs
Large head size, frontal bossing
Flattened nasal bridge
Crowding due to small jaws especially maxilla
Achondroplasia dental symptoms
Crowding due to small jaws especially maxilla
Cleidocranial dystosis
AD (autosomal dominant) Defective development of intramembraneous ossification Short in stature Delayed closure of sutures Absent clavicles
Cleidocranial dystosis dental features
Frontal and parietal bossing Hypoplastic maxilla and zygoma Multiple unerupted teeth Multiple supernumeraries Failure of eruption -can be pulled down with gold chains -overdentures
Gigantism
Overproduction of pituitary growth hormone Usually due to adenoma Before fusion of the epiphyses -results in gigantism of whole skeleton After fusion -results in acromegaly
Acromegaly
Continued growth at mandibular condyle Gross prognathism Macroglossia Spacing of dentition Thickening of facial soft tissues Overgrowth of hands and feet
Radicular dentine dysplasia
Radicular pathology; aetiology unknown
DI with IO (syndromic)
Collagenous proteins affected
