Fractures of the Mandible Flashcards
What is the first thing to consider when patient has suffered from trauma?
Airways
Breathing
Circulation
What nerve can damage to the mandible affect?
Inferior alveolar nerve
-> presents as numbness in lower lip
What are the clinical signs and symptoms of mandibular fracture
Limitation of function- difficulty opening and lateral movement
Occlusal derangement- altered bite, teeth do not interdigitate
Tooth mobility- might be a group of teeth
Bleeding- limited to area where fracture is
AOB- occurs when ramus is shortened by fracture
->Sub-condylar fracture (bilateral)
Asymmetry- deviation of mandible to opposite side
Bleeding in floor of mouth- sublingual haematoma
Step deformity- separation between teeth
Bleeding between the teeth
Condylar fracture- bleeding around the ear
How are mandibular fractures classified?
- Involvement of soft tissue- simple/compound
- Number- single, double, multiple
- Side- unilateral, bilateral
- Site
- Direction of fracture line
- Displacement
- Specific fractures
What is the difference between simple, compound and comminuted fractures?
Simple- if surrounding soft tissue is intact
Compound- if fracture exposed to outside environment (surrounding soft tissue is disturbed- communication/tear within ST)
-> Alters management- required AB
Comminuted- multiple fragments (often caused by gun shot)
What are the different sites a mandibular fracture can occur in?
Angle
Sub-condylar region
Para-symphyseal- central region
Body
Ramus
Coronoid
Condyle (intracapsular- within)
Alveolar process
What are the classifications for direction of fracture line?
Unfavourable direction- direction of fracture line encourages displacement of fracture
Favourable- limits displacement of fracture
What is a green-stick fracture?
Soft bone in children means that the bone doesn’t break completely (attachment within cortices remains)
What are the reasons for pathological fractures?
Osteoporosis
Osteomyelitis
Paget’s disease
Expanding cystic lesion
Osteogenesis imperfecta
Hyperparathyroidism
ORN
Primary and secondary tumours
Which factors affect displacement of mandibular fractures?
Direction of fracture line
Opposing occlusion may prevent unfavourable fracture line from displacing fracture
Magnitude of force- more force is more likely to cause displacement
Mechanism- punch, gun shot, car
Intact ST- displacement is less likely
Other fractures
What are the steps in management of mandibular fractures?
- Clinical exam
- Radiographic assessment- confirm diagnosis
- Treatment
How is radiographic assessment of mandibular fractures carried out?
If plain (2 at right angles)- OPT and PA mandible
-> others- occlusal, SMV, lateral oblique
Now- mostly using CBCT/CT
Which features are commonly seen radiographs indicate fracture of mandible?
Radiolucent lines- can be wide if large displacement
Step deformity on inferior border or occlusion
Loss of posterior continuity
What is the issue with using PA mandible and OPT combination to assess mandibular fracture?
Doesn’t give information about medio-lateral displacement
Why is any fracture in teeth bearing area automatically considered compound? What is the significance of this?
In contact with PDL and gingival crevice which is in contact with oral cavity
AB required
How are mandibular fractures treated?
Control pain and infection- NSAIDS and ABs
-> If undisplaced- no treatment
-> If displaced- closed reduction with fixation (IMF) OR ORIF
What is meant by reduction?
Reduction- reduce displacement to normal anatomical orientation of fracture segments
Not required for non-displaced fractures (no treatment required)
What is meant by fixation?
Fix fragments in place using plates and screws (internal fixation)
Plates are 2mm thick, screws are 5mm
What is meant by closed reduction with fixation?
Reduce fracture to normal anatomical orientation without exposing fracture line
-> no cutting patient opening- no periostea exposure
-> done under LA
-> Uses intermaxillary fixation- wiring teeth together
What can be done to check mandibular fracture has been reduced to correct position in closed reduction with IMF?
Check that teeth are occluding normally- either in perfect occlusion or previous malocclusion
-> look at facets to help
What are the drawbacks with closed reduction with fixation?
Patient must be on soft diet for 4-6 weeks
Difficulty in OH
Contraindicated in Epilepsy- patients can suffocate if they have a fit
What is meant by Open reduction and Internal fixation (ORIF)? (more common option)
Reflect tissue with mucoperiosteal flap and expose bone
-> then reduce and fixate
-> done under GA
Uses plates and screw instead of wiring as in IMF
What is the issue if a plate/screws are required in lower premolar region?
Risks damaging mental nerve
What can the issue with a thin atrophic mandible be in the event of fracture? What can be done in this case?
Can be too thin to support plate
-> may require bone graft harvested from ribs
What are the absolute indications for ORIF in mandibular fracture?
Bilateral subcondylar fracture with AOB
Displaced condylar fracture that interferes with mouth opening
Displace fracture in middle cranial fossa
Displaced fracture causing occlusal derangement
Displaced fracture that causes ramus shortening
What material are resorbable plates made of ?
Polylactic acid- resorbable thermoplastic
What treatment is indicated if fracture becomes infected?
Closed reduction with IMF
What are the surgical approaches used in mandibular fracture surgery?
Retro-mandibular approach
Raisdon Approach
Preauricular approach
Bi-coronal flap
Endoscopic reduction and fixation
