Theme 4 - Dental anomalies Flashcards
Why may teeth be impacted (aetiology)?
Local causes:
- Lack of space: overcrowding e.g. small arch or supernumary teeth
- Prematures/delayed loss of primary teeth
- Greater density of overlying bone e.g. osteopetrosis
- Fibrosis of overlying mucous membrane
- Pathology: cysts, odontomes, tumours
Postnatal systemic causes (interfere with growth of child):
- Anaemia
- Congenitas syphilis
- Endocrone dysfunction
- Malnutrition
- Irradiation
-TB
Prenatal systemic causes:
- Cleft lip and palate (often lateral incisors as lie in suture of maxilla)
- Cleidocranial dysplasia
- Garners syndrome
What syndromes are known for causing supernumary teeth?
Cleidocranial dysplasia (absent or hyperplastic clavicles too)
Gardners syndrome
What is the prevalence of impaction from most likely tooth to least?
8’s - upper 3 - upper 1 - lower 4 - lower 5 - supernumary
What are the complications associated with impaction?
- Pericoronitis (mandibular 3rd molars)
- Food trap
- Resorption (when unerupted and in close proximity to other teeth)
- Cystic change around follicle of crown
- Mandibular fracture
What signs would make you suspect a tooth is impacted?
- Retention of primary teeth
- Tooth missing
- Swelling
- Mobility of adjacent tooth
- Tilting of adjacent tooth
- Loss of vitality of adjacent tooth
- Periocoronitis
What is the most to least likely angle of impaction of mandibular 3rd molars?
Vertical - mesial angled - distal angled - horizontal
What features on a DPT would make you suspect there is communication of a mandibular 3rd molar with the IAN?
- Darkening of the root
- Diversion of the canal
- Interruption of the cortical outline
- Narrowing of the canal
- Deflected roots
- Narrowing of the rooth
- Dark bifid root
When would a CBCT be appropriate when extracting mandibular 3rd molars?
- If high risk IAN signs on plain film
- Unusual root morpholoy
- Superimpositions in unerupted teeth
- Decision to perform surgical removal has been made
What is the
a) Coated vicryl suture
b) Coated vicry raptide suture
intended for closing?
a) General ST approximation and ligation, including opthalmic. NOT CVS or neuro tissue
b) superficial ST approximation and mucosa for short-term wound support (7-10 days)
For managing impacted/unerupted teeth, what is
a) Open exposure
b) Closed exposure
a) Through keratinized tissue, by tissue sacrifice (maintain gingival margins, small circular palatal mucosa removed and bone chiseled) or apically repositioned flap followed by a coverplate and co-pack (ZoE) for 2 weeks to prevent re-epithelialisation. If very superficial punch biopsy and pt keeps brushing tooth to prevent mucosa growth
b) Through non-keratinized tissue, mucoperiosteal flap raised, bone removed to expose crown only, etch prime bond (only using aspirator as 3in1 surgical emphysema) chain/wire ligature/brackets/magnets applied, ST closure. For when buccal tooth sits high in buccal sulcus.
Must be brought through keratinised tissue in order for PDL to form correctly
What is a transplant in the management of impacted teeth?
What are its complications?
Expose donor tooth (open apex tooth), carefully extract, reposition in surgically prepared socket, splinted for 2-4 weeks, antibiotic prophylaxis. Transplanted teeth can be moved orthodontically
Complications = root resorption and ankylosis, require RCT
When may a coronectomy be carried out? How is it done?
High risk lower 3rd molars. Expose amelo-cemental junction, fissure bur to section crown, avoid disturbing exposed pulp, primary closure of STs
For hypodontia:
a) M or F
b) Permanent or primary
c) Genes affected?
d) Pattern?
e) Other clinical findings
a) Females more
b) Permanent more
c) homeobox genes MSX1 and PAX9
d) 8s then upper 2s then lower 5s
e) often present teeth are microdont, opposing teeth overerupt, primary teeth important for retaining bone
For hyperdontia with supernumary teeth:
a) M or F
b) Permanent or primary
c) Types
a) Female more
b) Permanent more
c) Abnormal form (conical), Mesiodens (midline), Paramolar (another tooth to the side), Distomolar (extra tooth behind a molar)
For hyperdontia with supplemental teeth:
a) Shape
b) Pattern
a) Normal form
b) Upper 2s then lower 5s then upper 5s
What syndromes is hypodontia linked to?
- Hypohidrotic ectodermal dysplasia
- Cleft lip and palate
- Crouzon syndrome
- Ellis-van Creveld syndrome
- Orofacial digital syndrome
- Down syndrome
What syndromes is hyperdontia linked to?
- Garner syndrome
- Orofacial digital syndrome
- Cleft lip and palate
- Cleidocranial dysplasia
For hypohidrotic ectodermal dysplasia, what are the:
a) General features
b) Dental anomalies
c) Genetics
a) Smooth dry skin, sparse hair, protruded earts, absence of sweat glands, nail abnormalities, reduced lower face height
b) Ano/hypodontia, delayed eruption, deformed teeth, conical crowns
c) X-linked recessive (rare in F)
For cleidocranial dysplasia, what are the:
a) General features
b) Dental anomalies
c) Genetics
a) Absent or hypoplastic clavicles, fontanelled and sutures persist, helmet like skull, hypertolerism
b) High narrow palate, maxilla hypoplastic, retained primary teeth, supernumary teeth, delayed eruption
c) Autosomal dominant
What syndromes are known to affect the size of teeth?
- Ehlers Danlos syndrome
- Downs syndrome
- Congenital heart disease
For Ehler’s Danlos syndrome, what are the:
a) General features
b) Dental anomalies
a) Defect of collagen, hypermobile joints, hyperextensibility of skin
b) Microdontia, short roots, pulp stones, fragile mucosa, juvenile periodontitis (aggressive as collagen not produced)
What is a) fusion and b) gemination that create double teeth?
a) Union between dentine and/or enamel of 2 or more separate teeth (will find 2 roots)
b) The partial development of 2 teeth from a single tooth bud following incomplete division
What are the different abnormalities of form in the shape of teeth?
- Double teeth
- Concresence
- Taurodontism
- Dilaceration
- Peg-shaped laterals
What are the different abnormalities of form in the shape of teeth?
- Double teeth
- Concresence
- Taurodontism
- Dilaceration
- Peg-shaped laterals
What is concrescence? (affects shape of teeth)
The roots of 2 or more teeth are united by cementum alone after formation of the crown