OS - difficulty of xla Flashcards
why do older teeth pose more risks with xLA?
more brittle
heavily restored
loss of elasticity - potential fracture tuberosity/ alveolus
what type of ethnic background makes xLA more difficult?
african
dense alveolar bone
why do lone standing molars increase difficulty of xLA?
subject to occlusal force = thickening of alveolar bone and PDL = risk of fracture and OAC
describe impaction?
tooth is prevented from achieving a functional occlusal position
what are the commonest impacted teeth?
mandibular third molars
maxillary canines
maxillary incisors
second premolars
(teeth that erupt last)
what is a soft tissue impaction?
an operculum over the 8s commonly
why do teeth get crowded?
teeth that erupt later if there is a lack of space or teeth are positioned badly
how does crowding affect xLA?
prevents access for beaks of forceps
how is access difficult to third maxillary molars sometimes?
mouth opening brings coronoid process into the space lateral to max third molar
teeth are often slightly buccal inclined
what forceps may need to be used for xla of maxillary third molars?
bayonets
what happens to the maxillary antrum in the area of a lone standing molar?
it will expand in to the space where adjacent teeth would occupy
how does abrasion affect the difficulty of xla?
predisposes crown to fracture
if beaks not firmly on solid root then the crown will fracture off
how do endodontically treated teeth affect the difficulty of xla?
brittle and more likely to fracture
if the crown of a tooth has fractured off, in what circumstance are we still able to remove without surgery?
if root still visible above levels of alveolus - use elevators
why are impacted teeth removed?
orthodontic reasons
restorative/ aesthetic reasons
pathology
why may teeth become submerged?
deciduous molars when there is no permanent successor
list radiographic features of difficulty?
bulbous roots
dilacerated roots/ convergent roots
fused roots
multi-rooted teeth
hypercementosis
ankylosis
lone-standing molars
deeply impacted 3rd molars
why can teeth be bulbous?
can be bulbous apically or along the whole length of root
can be due to genetic formation or excess cementum
why do deciduous molars have very divergent roots?
tooth bud sitting in between the roots
when would you see a marked curvature of the roots of a tooth?
lower 8s due to the IDC
what pathology is associated to bulbous roots?
hypercementosis
what is cemento-osseous dysplasia?
sclerotic tooth fused to sclerotic dysplastic tissue within mandible
list types of osteolytic lesions?
cysts
odontogenic tumours
primary cancers
metastatic cancers
metabolic bone disorders
fibro-osseous lesions
what are the types of root resorption and what are their aetiology?
external (apical or coronal)
internal
inflammatory aetiology
what are 3 types of pathology that can be seen around the roots of a tooth?
periapical
periodontal
osteomyelitis
list types of extrinsic obstacles for xla?
adjacent teeth
displaced teeth
ectopic teeth
tilted teeth
proximity to IDN
maxillary antrum
list types of intrinsic obstacles to xla
root morphology
multi rooted teeth
fused teeth
bulbous roots
resorption
why must you not use high speed handpieces to section roots?
it causes surgical emphysema and introduces air in to the tissue which can lead to cellulitis
what is good clinical practice when sectioning roots?
lifting a mucoperiosteal flap
