What is a syndrome?
the collection of signs and symptoms that are observed in, and characteristic of, a single condition.
What is a sequence?
In medicine, a sequence is a series of ordered consequences due to a single cause.
It differs from a syndrome in that seriality is more predictable: if A causes B, and B causes C, and C causes D, then D would not be seen if C is not seen. However, in less formal contexts, the term "syndrome" is sometimes used instead of sequence.
oligohydramnios sequence (also known as Potter sequence)
Pierre Robin sequenc
What is a malformation?
A structural defect in the body due to abnormal embryonic or fetal development. There are many types of malformations. For example,cleft lip and cleft palate.
What is a deformation?
It is caused by mechanical stress on a normal structure, usually by oligohydramnios (too little amniotic fluid).
What does congenital mean?
a condition existing at birth and often before birth, or that develops during the first month of life (neonatal disease), regardless of causation. Of these diseases, those characterized by structural deformities are termed "congenital anomalies" and involve defects in or damage to a developing fetus.
What does acquired mean?
An acquired disorder is a medical condition which develops post-fetally; in contrast with a congenital disorder, which is present at birth. A congenital disorder may be antecedent to an acquired disorder (such as Eisenmenger's syndrome).
What's the aetiology of congenital diseases?
• Genetic factors are the most common cause of congenital malformations
• Chromosomal abnormalities including gross numerical and structural defects are common
• A teratogenic agent is a chemical, infectious agent, physical condition, or deficiency that, on fetal exposure, can alter fetal morphology or subsequent function
What are the different groups of teratogens?
-Drugs and Environmental Chemicals
-Maternal & Metabolic Imbalance
What is fetal alcohol syndrome?
Fetal alcohol syndrome is caused by consumption of alcohol during pregnancy and is the leading cause of intellectual disability in the western world.
What's the relevance of congenital diseases to dentistry?
• Depends on the syndrome.
• Depends on how severely the patient is affected.
• Difficulties with diet – increased risk of caries, difficult to make changes to diet
• Problems with home care – pt may be reluctant to allow brushing, find it difficult to brush.
• Oral care may be neglected.
• Pt. may be unable to co-operate with a dental exam.
• Pt. may be unable to communicate if they are in pain.
• Small mouth, restricted opening
• Hypodontia/microdontia/supernumerary teeth
• Delayed eruption
• May need to be treated under sedation/GA
• Difficulties accessing dental treatment – accessing the dental surgery or transferring to the dental chair
What are the problems caused by congenital diseases?
Failure to thrive, due to feeding problems.
Multiple hospital admissions and surgeries
Increased risk of caries due to chronic health problems.
Psycho-social problems due to appearance.
Associated intellectual disabilities.
Need to be managed by multi-disciplinary teams – paediatrician, plastic surgeons, ENT surgeons, maxillofacial surgeons, speech and language therapist, occupational therapist, paediatric dentist, orthodontist.
Give examples of chromosomal syndromes?
• Trisomy 21 (Down syndrome)
• Klinefelter Syndrome
What is Trisomy 21 (Down Syndrome)
-A meiotic non-disjunction resulting in an extra copy of chromosome 21.
-1 in 700 children born with it, more common if mother over 35 years old.
What are the traits of those with Trisomy 21?
Low set, rounded ears
Flattened nasal bridge
Congenital heart defects
Single transverse palmar crease
Brushfield spots (iris)
What are the dental aspects of Down Syndrome?
Delayed eruption of both primary and permanent dentitions.
35-55% microdontia, clinical crowns are short, conical, small, roots complete.
Enamel hypocalcificiation and hypoplasia common.
DS patients 50% more likely to have congenitally missing teeth, taurodonts are frequent finding.
1/3 more caries resistant than their non-DS siblings.
Gingivitis develops earlier and more rapidly and extensively in persons with DS, perhaps because of an abnormality in host defenses. Patients with DS have altered microbiological composition of subgingival plaque, including increased Actinomycesand Hemophilus strains.
V-shaped palate, incomplete development of the midface complex, soft palate insufficiency.
Hypotonic O. Oris, Masseter, Zygomatic, Temporalis Muscles
Absent incisors make articulation difficult
High incidence of laryngeal-tracheal stenosis, also upper airway obstruction and sleep apnea common
Scalloped, fissured tongue with bifid uvula, cleft lip/palate, enlarged tonsils/adenoids
What is Klinefelter Syndrome?
• ‘XXY Syndrome’ • 1 in 750 live male births • Hypogonadism • Infertility • Tall • Female characteristics
What are the congenital syndromes affecting bone?
• Osteogenesis Imperfecta
• Cleidocranial Dysplasia
• Marfan Syndrome
• McCune Albright Syndrome
• Craniosynostosis Syndromes:
-Apert Syndrome -Crouzon Syndrome
What is osteogenesis imperfecta?
• Abnormality in type 1 collagen synthesis with resulting areas of reduced bone density and tendency to fracture
• Other features:
-Deafness (distortion of the ossicles)
-Thin translucent skin
-Joint hypermobility with lax ligaments
-Heart valve defects
-Associated with dentinogenesis imperfecta (type 1)
• Types 1 to 4 exist
What is achondroplasia?
• A hereditary AD condition or acquired via sporadic defects (advanced paternal age)
• 1 in 25,000
• Failure of normal endochondral ossification at
• Normal appositional bone growth with normal spine length giving appearance of lumbar lordosis and a relatively large head
• Retrusive mid third of face (defective growth at base of skull)
What is osteopetrosis?
• A defect in osteoclast activity due to defective carbonic anhydrase
• Excessive formation and density of bone
• Susceptibility to fracture
• Delayed dental eruption
• Difficult extractions
• Haematological abnormalities
What is Cleidocranial Dysplasia?
• A defect largely affecting the skull, jaws and clavicles:
▫ Partial or complete absence of clavicles
▫ Underdeveloped maxilla: narrow, high-arched palate resulting in retained primary teeth, delayed eruption of secondary dentition, increased risk of supernumary teeth
▫ Skull sutures/fontanelles remain open: prominent frontal, parietal and occipital bones, depressed nasal bridge, hypoplastic mid third of face
What is Marfan Syndrome?
• An autosomal dominant connective tissue disease
• Major criteria (diagnositic if >2):
▫ Lens dislocation
▫ Aortic dilation or dissection
▫ Dural ectasia
▫ Skeletal features (arachnodactyly, armspan>height, pectus deformity, pes planus)
• Minor criteria:
▫ High arched palate
▫ Mitral valve prolapse
▫ Joint hypermobility
What is McCune-Albright Syndrome?
• Polyostotic Fibrous Dysplasia
• Café-au-lait pigmentation
• Precocious puberty
• Associated endocrinopathies (hyperactivity)
What is Apert syndrome?
A type of Craniosynostosis Syndrome.
A gene defect causing some of the bony sutures of the skull to close too early.
▫ Severe under-development of the mid-face
▫ Prominent or bulging eyes
▫ Ridging along cranial sutues
▫ Hearing loss and recurrent ear infections
▫ Fusion/webbing of fingers and toes
▫ Short height and limb abnormalities
What is Crouzon Syndrome?
A type of Craniosyntosis Syndrome.
▫ Cranial synostosis (short broad head)
▫ Dental effects:
Narrow high-arched palate
Crowding of teeth
What are Hamartoneoplastic Syndromes?
• Cowden Syndrome
• Gardner Syndrome
• Gorlin Goltz Syndrome
• Sturge Weber Syndrome
• Multiple Endocrine Neoplasia (MEN)
• Peutz Jeghers Syndrome
• Tuberous Sclerosis
What is Cowden Syndrome?
• Multiple hamartomas, namely facial trichilemmomas, acral and palmoplantar keratosis and oral papillomatosis. Other mucocutaneous lesions may include fibromas, lipomas, skin tags and haemangiomas
• Increased risk of malignant neoplasms, especially cancers of the endometrium, thyroid and breast
• Cystic lesions of bones and the genitourinary tract
• Reduced IQ, macrocephaly and development of Lhermitte-Duclos Disease (cerebellar gangliocytoma)
What is Gardner Syndrome?
▫ Multiple polyps of the colon, each with high malignant potential
▫ Benign bone osteomas
▫ Epidermal cysts
▫ Dermoid tumours, fibromas, neurofibromas