With increasing mandibular atrophy, the physical size of the mandible
decreases. In the severely atrophic mandible, even very minor trauma can cause
fracture. Additionally, pathologic fracture during mastication can occur. Very
often, due to the fragile nature of the jaw, these fractures occur
Orthopantomogram (OPG), mandible series radiograph and CT scans can be used
to diagnose and plan the treatment of the atrophic edentulous mandible
The patient shows extraoral ecchymosis associated with an atrophic
edentulous mandible fracture.
The patient exhibits pain and mobility of the anterior mandible.
Patient shows intraoral ecchymosis in the floor of the mouth associated with
an atrophic edentulous mandible fracture.
Typical example of an atrophic edentulous mandible fracture.
Axial CT scan showing bilateral fractures.
Note that although there appears to be a large bone stock, this patient’s
mandible has only approximately 7 mm of vertical height.
Panoramic radiograph of atrophic edentulous mandible fractures.
Note the extreme amount of vertical atrophy.
3-D reconstruction of the same case.
Observation and soft diet
Observation may be indicated for patients medically unfit for general
anesthesia. Atrophic edentulous mandible fracture patients are often elderly
with medical problems presenting severe anesthetic risks.
One major complication of observation and soft diet would be nonunion of the
Historically, atrophic edentulous fractures were treated closed by wiring in
the patients dentures or fabricating Gunning style splints with postoperative
mandibulomaxillary fixation (MMF).
Standard treatment with closed reduction often resulted in prolonged periods of
MMF which was difficult for these patients. Additionally, the fractures were
often poorly aligned. Postoperative malunions and nonunions were very
Photograph shows a patient denture.
Photograph shows a Gunning style splint.
Indications for ORIF are any displaced atrophic mandible fracture requiring
Following the AO principles of anatomic reduction of fractures and immediate
function, ORIF of atrophic edentulous mandible fractures with load-bearing
osteosynthesis has a distinct advantage for these patients. The technique has
evolved to provide the patient with an excellent chance for mandibular union
while the ability to masticate is preserved.
Literature has supported the efficacy of this technique.
Indications of external fixator might be the temporary stabilization of a
fracture while the patient is treated medically, or if soft-tissue maturation
around the fracture site is required.
Complications,including malunion and nonunion are significant when external
fixators are used as they do not provide absolute stability at the fracture
In the following, the treatment of an edentulous atrophic fracture with a
reconstruction plate is described step-by-step.
When treating atrophic edentulous mandible fractures, the surgeon will
generally find it easier to use an extraoral surgical approach. The fracture
fragments can be manipulated under direct visualization and stabilized while
the reconstruction plate is being bent and applied to the mandible.
Click here for a listing with all approaches described in
An intraoral approach is possible but technically more difficult as the
surgeon will need several sets of trained hands just to retract the soft
tissues of the cheeks and tongue. Additionally, stabilization and fixation of
the fractures is much more difficult via an intraoral approach. One should also
be aware that the inferior alveolar nerve is located on the superior surface of
the atrophic mandible. Therefore one must be extremely careful making intraoral
incisions to expose atrophic fractures, or the nerve can be damaged.
The atrophic edentulous mandible fracture presents with several factors
which make treatment very difficult. There is a lack of bone which is generally
cortical in nature and has a lower healing potential. There are no teeth
present to help reduce the fractures. Often the patients are elderly and
Atrophic mandible fractures require transfacial open reduction, load-bearing
internal fixation, and often immediate bone grafting.
Load-bearing osteosynthesis is indicated in treatment of the atrophic
edentulous mandible fracture. We currently recommend the locking reconstruction
plate 2.4. The plate must be of sufficient length to place screws in adequate
bone which is generally found in the symphysis and angle regions. The body
region of the mandible is a common area of fracture and generally has bone of
poorer quality unsuitable for screw placement. When dealing with bilateral
fractures, the plate must span from angle to angle, covering the entire lateral
surface of the mandible. At least three screws on either side of the fracture
are recommended. Often more screws are necessary due to the poor quality of the
The locking reconstruction plate is generally left in place and not removed
unless clinical symptoms require hardware removal.
Pitfall: insufficiently stable implant
It may be tempting to use small plates when treating fractures in an
atrophic “small” jaw. However, when using small plates, plate fracture and
displacement is very common secondary to the muscle pull involved in the
atrophic edentulous mandible.
X-ray shows fractured plate and fracture displacement.
Clinical photograph shows same case.
Alternatives to the locking reconstruction plate 2.4
There are fractures involving the edentulous jaws which are not atrophic in
nature. When there is sufficient bone to buttress the fracture and provide
adequate healing, the surgeon may choose to use a smaller reconstruction
The locking plate system 2.0 (large or extra-large profile) provides all the
advantages of a locking reconstruction plate 2.4 but with a smaller profile.
Many surgeons have successfully used the locking system 2.0 on edentulous
The locking reconstruction plate combines all the advantages of a standard
reconstruction plate with the locking principle.
The thread in the plate holes provides rigid anchorage for the 2.4 mm
locking screw. This construction acts as an “internal fixator”. 3.0 mm screws
are also available.
The conventional 2.4 mm nonlocking cortex screw can also be used with this
plate. Wide angulation of the screw is possible which, in certain clinical
situations, can be an advantage.
Other advantages of the locking principle are:
- The plate needs only limited adaptation
- It exerts no pressure on the bone
- The risk of screws loosening is reduced.
for further details on the locking plate principles.
It is very common to use large reconstruction plates that span from angle to
angle. By using a template the bending process is facilitated.
Clinical image shows the template and the reconstruction plate bent
for a detailed description of plate bending.
Pearl: reduction and temporary fixation
It can be very helpful to reduce and stabilize the fracture with adaptation
plates to allow appropriate bending of the template and reconstruction plate.
This is particularly applicable in fractures that are widely displaced, mobile,
The adaptation plates are placed on the inferior border to allow excellent
reconstruction plate adaption to the lateral surface of the mandible.
After the locking reconstruction plate has all planned screw holes used, the
adaptation plates are removed.
Pearl: perfect adaptation
Perfect adaptation of the plate is not required as the locking
reconstruction plate 2.4 acts as an “internal external fixator”.
The locking reconstruction plate 2.4 is fixed to the native mandible using
either 2.4 mm or 3.0 mm screws. At least three screws must be present on either
side of the fracture. In the atrophic edentulous mandible fracture, the screws
are generally placed in the symphyseal region and the angular region. The bone
in the symphysis is very often dense cortical bone which may require tapping of
the screw hole.
Applying the plate
Apply the plate and stabilize it either with digital pressure or
plate-holding forceps. One of the benefits of using a locking reconstruction
plate is that perfect adaptation is not required and small discrepancies can be
Placement of first screws
Place one screw on either side of fracture in the planned holes closest to
A threaded drill guide must be used to allow for centric placement of the drill
hole for use with the locking screw. Copious irrigation must be applied to cool
the bone. A depth gauge is used to determine the appropriate screw length.
for a detailed description of screw placement in a reconstruction
Additional screw placement
Once the screws are placed on either side of the fracture (on the first
side) the surgeon has the option of completing all screws on that one side or
placing one screw on either side of the fracture (on the opposite side) before
completing all screws.
Clinical image shows the plate fixed to the mandible.
Harvesting of bone graft
Due to the poor healing quality of the bone, an autogenous bone graft is
often used to facilitate bony union. Common sites of bone graft harvest include
the iliac crest or tibia.
Clinical images show ...
... the bone graft harvest site in the tibia.
Bone graft application
Autogenous cancellous bone grafts can be added to fracture sites and can be
used to augment the native mandible to facilitate healing.
X-ray shows the completed osteosynthesis.
If MMF screws are used intraoperatively in conjunction with the patient’s
prostheses, they are usually removed at the conclusion of surgery if proper
anatomic fracture reduction and fixation have been achieved.
Postoperative x-rays are taken within the first days after surgery. In an
uneventful course, follow-up x-rays are taken after 4–6 weeks.
The patient is examined approximately 1 week postoperatively and
periodically thereafter to assess the stability of the fracture and to check
for infection of the surgical wound. During each visit, the surgeon must
evaluate the patients ability to perform adequate oral hygiene and wound care,
and provide additional instructions if necessary.
Follow-up appointments are at the discretion of the surgeon, and depend on
the stability of the mandible on the first visit. Weekly appointments are
recommended for the first 4 postoperative weeks.
Postoperatively, patients will have to follow three basic
Depending upon the stability of the internal fixation, the diet can vary
between liquid and semi-liquid to “as tolerated”, at the discretion of the
2. Oral hygiene
Patients having only extraoral approaches are not compromised in their routine
oral hygiene measures and should continue with their daily schedule.
Patients with intraoral wounds must be instructed in appropriate oral hygiene
procedures. A soft toothbrush (dipping in warm water makes it softer) should be
used to clean the oral cavity. Chlorhexidine oral rinses should be prescribed
and used at least three times each day to help sanitize the mouth. For larger
debris, a 1:1 mixture of hydrogen peroxide/chlorhexidine can be used. The
bubbling action of the hydrogen peroxide helps remove debris.
Physiotherapy can be prescribed at the first visit and opening and excursive
exercises begun as soon as possible. Goals should be set, and, typically, 40 mm
of maximum interincisal jaw opening should be attained by 4 weeks
postoperatively. If the patient cannot fully open his mouth, additional passive
physical therapy may be required such as Therabite or tongue-blade
Long-term dental rehabilitation
An existing dental prosthesis (denture) must often be remade. Dental
implants may be placed in the anterior mandible after symphyseal screws have
been removed. Implant reconstruction is undertaken when bony union of the
mandible has been achieved.