Pierre Robin syndrome is a condition characterized by three components: cleft palate, mandibular micrognathia or retrognathia, and glossoptosis. It is caused by the mechanical theory where cleft palate prevents palatal shelf fusion and mandibular hypoplasia constrains growth, leading to tongue displacement. Achondroplasia is caused by mutations affecting endochondral ossification, leading to disproportionate short stature and limb shortening, large head size, and restricted joint motion. Both conditions are diagnosed based on clinical features and imaging findings, and require multidisciplinary care.
Vip Call Girls Anna Salai Chennai 👉 8250192130 ❣️💯 Top Class Girls Available
Pierre Robin Sequence and Achondroplasia Oral Pathology Findings
1. dr vaISHNAVI
Department of Oral Pathology
& Microbiology
SRM Dental College,
Ramapuram, Chennai, India
PIERRE ROBIN SYNDROME &
ACHONDROPLASIA
2.
3. PIERRE ROBIN SYNDROME
Pierre robin sequence/Anomalad
Pierre robin malformation
Robin sequence/ complex
It has three essential components
1. Cleft palate
2. Mandibular Micrognathia (smaller-than-normal
mandible) or Retrognathia (retruded mandible)
3. Glossoptosis (lower and posterior displacement of
tongue airway obstruction)
4.
5. Pierre Robin is a sequence, not a syndrome!
Sequence = a series of sequential developmental
malformations produced by a single cause
Syndrome = a group of signs and symptoms that
occur together and that underlie a particular
abnormality or condition
10. Mechanical theory
Most accepted
cleft palate
Prevents fusion of palatal shelves
failure of tongue to descend
(tongue remains high in the oral
cavity)
Constraint of mandibular growth in
utero (mandibular hypoplasia 7th to
11th week of gestation)
13. Oligohydramnios could play a role
Absence of amniotic fluid deformation of chin
subsequent impaction of tongue between the palatal
shelves
Retruded mandible results in the following:
Posterior displacement of tongue
Lack of support of tongue musculature
Airway obstruction
Respiratory difficulty especially when child is in
supine position (from birth) can cause asphyxiation
Palatal cleft is U – shaped and wider than isolated
cleft palate
14. Other theories:
Neurological Maturation Theory :
Delay in neurological maturation delay in
hypoglossal nerve conduction
Explains spontaneous correction of mandibular
hypoplasia with age in most cases
The rhomboencephalic dysneurulation theory :
Major and regulatory organization of
rhomboencephalus (hindbrain) is related
15. CLINICAL FEATURES:
1 in 8500
Palate : U-Shaped/V-Shaped
Mandible :
Hypoplasia
Micrognathia
Small body
Obtuse gonial angle
Posteriorly located condyle
Resolves and child attains normal profile by 5-6 years
Tongue:
Glossoptosis
Macroglossia, ankyloglossia (rare)
Severe respiratory distress and feeding difficulty in newborn
16. OTHER ASSOCIATED ANOMALIES
Otitis media (inflammatory diseases of the middle ear)
Hearing loss
Nasal deformities
Dental and philtral malformation
Anomalies of musculoskeletal system:
Syndactyly (some or all of the fingers or toes wholly or partly
united)
Dysplastic phalanges
Polydactyly
Clinodactyly (curvature )
Hyperextensive joints
Oligodactyly in hands
CNS defects:
language delay
Epilepsy
Neurodevelopmental delay
Hydrocephalus (accumulation of CSF within the brain.)
17. DIAGNOSIS:
Mainly based on the clinical assessment and radiographic findings of
micrognathia
Shortly after birth due to characteristic facies :
Small lower jaw (micrognathia)
A tongue which tends to ball up at the back of the mouth and fall
back towards the throat (glossoptosis)
Horseshoe-shaped cleft palate
Breathing difficulties
Feeding difficulties
Genetic testing is important to determine if it is isolated or associated
with another syndrome.
18. Treatment and Prognosis
Multidisciplinary approach
Depends on the airway compromise and extent of
feeding difficulty
Surgical intervention
21. ETIOLOGY
Also known as Chondrodystrophia fetalis
Non-lethal form of chondrodysplasia
Transmitted as Autosomal Dominant Trait with
complete penetrance
De-Novo mutations (80% cases)
Mutations in gene for FGFR3 results in
decreased endochondral ossification inhibited
proliferation of chondrocytes in growth plate
cartilage decreased cartilage matrix production
22. Try to remember:
• The bones of the extremities and those parts of the axial skeleton that bear
weight (e.g., vertebrae) develop by endochondral ossification.
• The flat bones of the skull and face, the mandible, and the clavicle develop
by intamembranous ossification.
25. CLINICAL FEATURES
1 in 15000-40000 births
Short stature
Rhizomelic shortening of the arms
and legs
A disproportionately long trunk
Trident hands
Midfacial hypoplasia
Prominent forehead frontal bossing
Thoracolumbar protuberance
True megalencephaly (A growth
development disorder in which the
brain is abnormally large)
Characteristic limitation of joint
motion
28. The body phenotype is shown in individuals of different ages: Left to right –
infancy, early childhood, childhood and adulthood. In all, note the rhizomelic
shortening of the limbs, which are disproportionately short compared with
the trunk. In the infant and young child macrocephaly is evident
29. Oral Manifestations:
Maxilla is retruded due to restriction of growth of
base of skull
Relative mandibular prognathism
Malocclusion
Might have congenitally missing teeth/ shape
disturbances
30.
31. RADIOGRAPHIC FEATURES:
Skull, spine and extremeties
Lateral skull radiograph : midface hypoplasia, enlarged calvaria,
frontal prominence, shortening of base of skull
Size of foramen magnum is diminished
Long bones are shorter than normal they have thickening/mild
clubbing at ends
Epiphyses appear normal, but may close early/late
Bones at the base of the skull fuse prematurely
Maxilla – retruded
Malocclusion between the jaws
32. Intraoral views showing anterior reversed jet, posterior cross bite, Class III
dental malocclusion, crowding at the mandibular anterior region, and dental
caries
33. Histologic features:
Failure of endochondral ossification:
Loss of chondrocyte proliferation
Fibrous tissue is present in the zone of provisional
calcification, but bone trabeculae present are
irregular
Orderly longitudinal growth of bone is disturbed
stunted growth
Intramembranous and periosteal ossifications
undisturbed so normal clavicles and skull and
width of long bones normal
34. DIAGNOSIS
Preconception: affected parent/family member ,
genetic counselling
Prenatal : routine ultrasound, DNA test
Post natal : clinical findings, skeletal survey,
radiographs
35. Treatment and Prognosis
No treatment
May be delay in motor milestones but speech is
normal
Treatment for Frequent middle ear infections and
Dental crowding
Life expectancy – as that of a normal person