Management of Atrophic Mandibular Fractures

David R. Telles, DDSDiplomate of the American Board of Oral and

Maxillofacial Surgery

Overview Treating Atrophic mandibular fractures can be

challenging due to patient population and surgical difficulty

Conflicting thoughts about treatment options – conservative vs. aggressive

Statistics Historically Treatment options

Statistics by the year 2050 the population over the age

of 65 will exceed 85 million people by 2050 the percentage of our patients 65

years or older would be about double what it is today

Historically Before the 1960s, management of the fractured atrophic

mandible generally involved the use of closed treatment for reduction and stabilization or no treatment at all, ‘‘skillful neglect.’’

The advent of Rigid internal fixation changed Tx In some cases, the patient’s denture was attached with

circummandibular wires and used to stabilize the fracture (monomandibular fixation)

If more stabilization was necessary upper denture could be fixed to the maxilla via direct wiring, circumzygomatic

wiring, or pyriform aperture wiring two dentures could be secured together using maxillomandibular fixation (MMF)

Techniques Gunning Splints / CRMMF Circum-mandibular wires External pin fixation ORIF

Gunning Splints Technique created by Thomas Gunning in 1863 Impressions made of upper and lower arch Mandibular casts is cut and realigned when there is

considerable displacement Separate units made for maxillary and mandibular

arches Opening made in the anterior region for nutritional

purposes Use is favorable when extreme mandibular atrophy

is not present and the fracture is not comminuted NOTE: fracture must lie in the denture bearing area

Gunning Splints

Gunning Splints Also have been used with open reduction non-

rigid fixation techniques i.e. intraosseous wires

Peralveolar wires can be used in the maxilla if it is atrophic

Circummandiublar wires Can be used with oblique

fractures withoutgunning splints

Frequently leads to complications in healing

May lead to fracture instability

External Pin Fixation Often indicated with severely comminuted

fractures Advantage = does not require subperiosteal

dissection – therefore the blood supply is not compromised

Healing improved 2 limiting factors

Amount of bone available Appearance of the patient

Anterior and posterior in area placed with a transverse bar spanning the fracture Additional pin on either side allows

for added support

Pearls Closed techniques

Do not provide typically adequate resistance to the elevator muscles of mastication

Development of new technology and improved surgical techniques is to address the abnormal anatomy often present in the fractured atrophic edentulous mandible Blood supply from the surrounding periosteum plays an

important role in healing Severe resorption may involve the mandibular canal

changing the blood supply pattern to the mandible Sclerotic bone and poor circulation contribute to the high

morbidity with atrophic mandibular fractures

Atrophic Mandibular classes Created by Luhr et. Al.

Class 1 (16–20 mm) Class 2 (11–15 mm) Class 3 (%10 mm)

Cadwood et. Al Further classified based on resorption patterns

following tooth extraction This type of resorption often results in knife ridge

followed by vertical resorption until the basal bone of the mandible is encountered

Current Therapy 2 schools of thought

Closed technique – conservative Philosophy Open Technique – aggressive Philosophy

Closed Techniques As the pt loses dentition – there is less successive

loss of osseous structure and a decreased blood supply

Reduction in vascularity can lead to diminished healing and increase risk for malunion/non-union

Bruce and Ellis et. al. reported that a decrease in height of the mandible increases the likelihood of complications related to fracture healing

Closed Technique is much less likely to result in complications compared to an open technique esp. in elderly pt.

With less bone Surface area – more precise open technique is required

Preferred esp in elderly population with multiple co-morbidities Under GA the geriatic pt will experience morbidity 4x that

of a younger pt

Closed Techniques

Open Techniques Involves direct exposure of the fracture site and

placement of internal fixation – preventing movement of Fx segments

Malocclusion not a concern – due to edentulism – hence Anatomic reduction is the goal

Approaches Transoral

Mandibular body and symphysis fractures Can be used to access most atrophic/edentulous mandibular

Fxs 2 biggest RFs: lip malpositioning, mental nerve damage Pro: no visible scar Greater association with Infection and Non-union noted by

Toma Et. Al. Extraoral

Mandibular body Fxs, Ramus, Inferior border, angle Concern = Facial Artery, Mental Nerve, Marginal Mandibular

branch of CN VII

Open Techniques 3 common methods of Fixation

2.4-mm reconstruction plate Strong enough to overcome the functional load +

counteract masticatory forces screws -- may cause another fracture upon

placement screws can fail by stripping the bone leads to

inflammation and bony necrosis Large bicortical screws injure the inferior

alveolar nerve leading lower lip dysesthesia is the AO/ASIF – Treatment of choice Allows for immediate function + resists hardware Fx

Titanium mesh Locking miniplate

Open Techniques Titanium Mesh Crib with Simultaneous ilac

crest / anterior tibial / calvarial bone graft Adv: use of autogenous bone graft – enchances

bone density @ the surgical site DisAdv: morbility at the donor site: hip/lower leg

gait disturbances, graft infection/resorption / non-union

Open Techniques Locking miniplate

Theory – “ the smaller the better” Least likely to result in periosteal stripping Adv: ease of placement

Does not require as much bone density as compared to Reconstruction plates

Eryrich et. Al. noted – miniplates are subject to faiure due to inability to withstand the load placed on them by maxillomandibular forces

Lag Screw – no indicated due to decreased surface area of the bone

Open Techniques

Open Techniques

Future developments Madsen et. Al. in an article in JOMS – suggested

the use of a 2.4 at the inferior border of the mandible via extraoral approach Modified apron incision used to expose the inferior

border of the mandible – provides good visualization for reduction and plating

Plate is secured by locking screws 3 adv

With us of EO – risk of wound Dehiscence and infection decreases

Biomechanics similar to a recon plate placed on the lateral border of the mandible

Pt may be able to continue to wear prosthesis– can further stabilize the fracture

Future Developments

Future developments Louis et. Al 2004 – provides a new technique –

with the use of resorbable mesh rather than titanium mesh – to rebuild the ridge in the site of atrophy using autogenous bone graft Mesh is contoured to encompass the defect and

secured with 1.5 mm tacks Adv

Maintains the shape/location of the graft during the consolidation phase

Does not require a 2nd surgery to remove it Can be shaped into different configurations to follow the

contour of the mandible Also involves stabilization of the Fx with a recon

plate

Future Developments Use of alloplastic material in place of autogenous grafts

increasingly favored – avoids morbidity of donor site No 2nd surgical site Alloplastic materials include: Hydroxyapatite, Tricalcium

Phosphate, Glass Ceramics, Glass Carbonate Materials vary and have limitations – permanent vs.

biodegradable, naturally occuring vs. synthetic, porosity, mechanical compatibility

Injectable Calcium Phosphate – shown to be biocompatible and have valid application in atrophic mandibular reconstruction can be used for ridge augmentation procedures

Covalent linking of cpds e.g BMP2 with meshes/plates – represents a novel growing method of delivering concentrated growth factors

Summary Many surgeons find repair of Fx atrophic

edentulous mandible difficult Conservative vs. Aggressive approaches to Tx At the population ages – the OMFS surgeon is

expected to Tx more of these types of fractures

Thorough understanding of all Tx options available necessary – as there are adv and disadv to each

References Madsen, M. Haug, R, et. al. Management of Atrophic Mandible Fractures.

Oral Maxillofacial Surg Clin N Am 21 (2009) 175–183. Zide MF, Ducic Y. Fibula microvascular free tissue reconstruction of the

severely comminuted atrophic mandible fracture case report. J Cranio-Maxillofac Surg 2003;31:296–8.

Scott RF. Oral and maxillofacial trauma in the geriatric patient. In: Fonseca RJ, Walker RV, editors. Oral and maxillofacial trauma, 2nd edition, vol. 2. Philadelphia: Saunders; 1997. p. 1045–72.

Spina AM, Marciani RD. Mandibular fractures. In: Fonseca RJ, Marciani RD, editors. Oral and maxillofacial surgery, vol. 3. Philadelphia: Saunders; 2000. p. 103–7

Ellis E. Treatment methods for fractures of the mandibular angle. J Craniomaxillofac Trauma 1999; 28:243–52.

Madsen MJ, Haug RH. A biomechanical comparison of two techniques for reconstructing atrophic edentulous mandible fractures. J Oral Maxillofac Surg 2006;64:457–65.

Louis P, Holmes J, Fernandes R. Resorbable mesh as a containment system in reconstruction of the atrophic mandible fracture. J Oral Maxillofac Surg 2004;62:719–23.

Newman I. The role of autogenous primary rib grafts in treating fractures of the atrophic edentulous mandible. Br J Oral Maxillofac Surg 1995;33:381–7.