Impacted Teeth Flashcards
What are some hereditary factors that could result in delayed eruption of maxillary incisors?
Supernumerary teeth
Cleft lip and palate
Cleidocranial dysostosis
Odontomes
Abnormal tooth/tissue ratio
Generalised retarded eruption
What are some reasons for impacted 6s?
Bulbous Es
Crowding
Mesial path of eruption
PFE (primary failure of eruption)
What are some reasons for impacted teeth?
Delayed exfoliation of the deciduous tooth
Abnormal position of tooth germ
Supernumerary teeth
Odontomes
Cysts
Trauma (e.g. trauma to A’s)
Ankylosis (fusion of alveolar bone & root cementum)
Tumours
Systemic causes
Genetic causes
What are the disadvantages of a lateral cephalogram?
Increased radiation – low dose but exposes all head & neck region (susceptible tissue)
2D image of a 3D shape
What are some disadvantages of OPGs?
Poor quality (especially in midline)
Narrow focal trough (we don’t always see the true picture)
Often require supplementary views to confirm location (parallax)
How does the abbrevitaion SLOB help us with the parallax technique?
SLOB
Same Lingual (palatal)
Opposite Buccal (labial)
The tube shift is up in occlusal, If tooth moves upwards (towards root apex) it is SAME, therefore Lingual/Palatal
What are the treatment options for impacted 5s?
- No treatment - Pt accepts
- Removal/incorporate into ortho ext pattern
- Expose & bond
Why are impacted teeth an indicator of a ‘great need’ for tx according to the IOTN?
5i on IOTN
Tx will provide the following:
- Minimise damage to adjacent teeth
- Speech benefits
- Occlusal function benefits
- Psychosocial benefits
What are the advantages and disadvantages of upper/lower standard occlusals?
Avantages
- Good detail
- Low dosage
Disadvantages
- Findings need to be compared against complementary radiograph (parallax)
What is usually the cause of imapcted 5s?
Likely premature loss of 2nd primary molars (E)
Which position do impacted 5s normally erupt and why?
Impacted lower 5’s will often erupt lingually (through lingual cortex) to avoid thicker buccal cortical bone
As teeth erupt into path of least resistance
What are some environmental factors that could result in delayed eruption of maxillary incisors?
Trauma to As
Early extraction or loss of deciduous teeth
Retained deciduous teeth
Cystic formation
Endocrine abnormalities
Bone disease
What are the risks of aligning impacted canines?
- Root resorption to adjacent teeth
- Canine root resorption
- Loss of vitality
- Ankylosis
- Poor tissue contour at completion of treatment
Increased pocket depths
What are some visual indicators of impaction?
- Obvious bulges buccally or palatal/lingually
- Angulation of lateral incisor
- Colour changes in deciduous teeth (indicates previous trauma or possible resorption from an impacted tooth)
What would you do during a clinical examination of an impacted tooth?
- Inspect
- Palpate (buccally)
- Compare charting to expected eruption dates & other arches/side of px mouth
What are the treatment options for impacted canines?
- No treatment
- Interceptive treatment - Removal of C’s (bilaterally to avoid centreline shift)
- Exposure & orthodontic alignment
- Surgical removal
- Transalveolar Implant
- Surgical repositioning
How do you manage delayed eruption of maxillary incisors?
- Remove obstruction (primary tooth or supernumerary tooth and wait for impacted tooth to come through)
- Ensure sufficient space (Sectional Fixed Appliance or Retainer)
- Review for 3-6 months
What is a Lateral Cephalogram used for?
Show A-P plane skeletal relationship
Trace various landmarks & compare to average values
Show position of unerupted canines (in A-P & vertical planes)
A-P = Anteroposterior
What may happen to lateral incisors if there is an impacted canine?
Resorption of the lateral roots
What are flared lateral incisors an indicator of?
Flared laterals are a good indication of unerupted canine presence
What is the most and second most common impacted tooth
- 3rd molars (25% incidence)
- 5s (20% incidence)
What are the risks of impacted teeth?
Root resorption (of adjacent teeth in pathway of impacted teeth)
Cyst formation
Poor aesthetics
What are some reasons for impacted canines?
- Long path of eruption (Maxillary canine close to zygomatic process, high in maxilla)
- Earlier development than adjacent 2’s
- Small or absent 2’s – Lack of guided eruption by 2’s
- C’s resistant to resorption
- Polygenic inheritance
What information do OPGs reveal?
Unerupted teeth
Root position, shape & apex closure
Stages of tooth development
Bone support
Condyles
Pathology (e.g. cysts, supernumaries, tumours & periapical radiolucency’s)
