Transcript Mandibular Fixation: Angle, Ramus, and Condylar Neck Fractures

Mandibular Fixation: Angle,
Ramus, and Condylar Neck
Approaches
Craniofacial Rounds
Thursday April 21, 2011
Anatomic considerations
• Nerve: inferior alveolar n., lingual n., facial n.
• Vasculature: inferior alveolar a/v, facial a/v,
• Muscle: buccinator, masseter, temporalis,
medial/lateral pterygoid
• Fat: buccal fat pad
• Gland: parotid,
• Bone: temporal crest, mylohyoid line, oblique line
3rd molar
Ramus and Angle
• Indications for ORIF
– All displaced fractures
– Non-compliant pt for MMF
• Approaches
– Intra-oral vs. external
• Techniques
– Load sharing vs. load bearing
Ramus and Angle
• Approaches
– Intra-oral
• Intra-oral + transbuccal technique
– External
• Submandibular
• Retromandibular
• Rhytidectomy
Intra-oral approaches
- For simple angle #
• Vestibular incision
– 5 mm from gingiva
• Access
– Extend up the external oblique
ridge
– Protect buccal sensory nerve in
region of coronoid notch
• Adv: Simple access to fracture
• Disadv: Limited exposure for
recon plate placement, injury to n,
Intra-oral approaches
- For complex angle #
• Add transbuccal trocar
• Adv: manipulation at 90
degree angle possible
• Disadv: scar, limited
movement, risk injury to
mental nerve
External Approaches
Submandibular
– Skin incision
• Parallel to border, existing crease
• 2-3 cm below inferior border
– Access
•
•
•
•
Platysmal dissection
Avoid injury to marginal mandibular nerve
Ligate facial vessels
Incise pterygomasseteric sling at inferior border to expose
fracture
– Adv: Optimal visualization for complex fractures,
control of lingual cortex
– Disadv: External scar, risk of injury to marginal
mandibular nerve
External Approaches
• Retromandibular
• Adv: Good exposure of posterior ramus, condylar neck/head
• Disadv: Risk injury to facial n, parotid gland, hypertrophic
scarring, increased operating room time
• Transparotid
– Adv: close proximity to the site of injury
• Retroparotid
– Adv: no parotid dissection
• Rhytidectomy
External Approaches
• Transparotid
• Skin incision
– Parallel to the posterior ramus
• Access
– Identify SMAS and incise
– Blunt dissection in the direction of
facial n branches
– Incise pterygomasseteric fascia,
subperiosteal dissection
– Layered closure, parotid capsule
closure
• Adv: Good exposure of ramus,
condylar neck
• Disadv: Scar, risk injury to facial n,
salivary fistula
External Approaches
• Retroparotid
• Skin incision
– Extended posterior to ramus
• Access
– Identify SMAS and incise
– Blunt dissection in the direction of
facial n branches
– Incise pterygomasseteric fascia,
subperiosteal dissection
– Layered closure, parotid capsule
closure
• Adv: Good exposure of ramus,
condylar neck, avoids parotid dissection
• Disadv: Scar, risk injury to facial n, ,
retromandibular vein, parotid
External Approaches
• Rhytidectomy
• Skin incision
– More cosmetically acceptable
• Access
– Similar to trans/retroparotid approach
• Adv: Good exposure of ramus,
condylar neck, more cosmetically
acceptable location
• Disadv: Scar, risk injury to facial n,
great auricular n , retromandibular vein,
parotid
Ramus and Angle
• Techniques
– Load sharing
• Wire
– Minimize rotation with MMF
• Single monocortical, noncompression plate:
– Simple fractures, isolated, other mandible fractures stabilized by
rigid fixation
• Two miniplates
– Increased stability (presence of other fractures not amenable to
rigid fixation, bilat angle, LeFort)
– Load bearing
• Reconstruction plate
– Atrophic mandible, non-compliant patient, infected fracture,
osteotomy
Ramus andAngle Fixation
• Non-rigid fixation
– Monocortical, non-compression plates
• Popularized by Champy et al. 1978
• Ellis and Lee 1996
– 81 patients, non-comminuted angle #
– 16% (n=13) complication rate
• Adv: simple access, intraoral incision
• Disadv: non-rigid fixation, does not control torsional/bending
forces, gap formation at inferior border (reversal of
tension/compression zones)
– Two miniplates – to control torsion and tension
• Addition of a lower border plate
• Monocortical or bicortical
• Locking or non-locking
Ramus and Angle Fixation
Ramus and Angle Fixation
Rigid Fixation
– 2.0 to 2.4 mm mandibular reconstruction plates
• Minimum 3 holes each fragment
Condyle Neck, Head
• Indications for ORIF
– Displaced fractures
– Enough room to allow
fixation of the superior
segment
Condylar head/neck
• Preauricular
– Skin incision
• Preauricular skin crease
– Access
•
•
•
•
ID superficial temporal fascia
*frontal branch of VII is superficial*
Protect sup. Temporal vessels
Incise fascia, deep subperiosteal
dissection to expose lateral
zygomatic arch, TMJ capsule,
condylar neck
– Adv: Good exposure of high condylar neck
and TMJ
– Disadv: Limited exposure to low condylar
neck, risk injury to facial n, superficial
temporal vessels