Transcript Management of Atrophic Mandibular Fractures
Management of Atrophic Mandibular Fractures
David R. Telles, DDS Diplomate 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 without gunning 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 and bony necrosis leads to inflammation Large bicortical screws leading injure the inferior alveolar nerve 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 2 nd 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 2 nd 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.