Anterior Mandibular Fractures

Armamentarium

  • #9 Periosteal elevator

  • #15 Scalpel blades

  • Antibacterial irrigant

  • Appropriate sutures

  • Elastic tape chin dressing

  • Erich arch bars, 24- and 26-gauge wire

  • Fixation device (plates, screws, lag screw)

  • Local anesthetic with vasoconstrictor

  • Minnesota retractor

  • Needle electrocautery

  • Obwegeser retractors (curved up and curved down)

  • Reduction forceps (screw retained)

  • Self-retaining cheek retractors

History of the Procedure

Until the nineteenth century, when new methods for internal and external fixation were introduced, treatment of mandibular fractures followed the original principles described by Hippocrates. Hippocrates’ method for treating fractures of the mandible by wiring the teeth and immobilizing the jaw with closed reduction remains timeless. He addressed anterior mandibular fractures specifically in Chapter 34 of the voluminous Hippocratic Collection :

Anyone can treat separations of the symphysis at the chin. With the two ends of the bone forcefully separated, the protruding part is pushed inwards while the collapsed end is forced outwards … with completion of the reduction, the teeth are wired to each other … not only the two adjacent but several—using gold wire, or lacking that, linen thread until the bone has consolidated.

The next advance in treatment of mandibular fractures came in the nineteenth century, when surgeons improved techniques for maxillomandibular fixation, especially in the design of various interocclusal splints, such as Hamilton’s gutta-percha splint, Kingsley’s apparatus, and the Gunning splint. The predecessor to the current treatment plan of model surgery and arch bars is credited to London dentist Gurnell Hammond, a technique he devised in 1871. After realigning the displaced stone segments, a heavy iron wire was adapted to the teeth on the model. The bar was then subsequently wired to the patient’s natural teeth.

With the development of osteosynthesis in modern traumatology, Bigelow described its first use for mandibular fractures in 1943. Michelet, Champy, and Lodde introduced miniplate osteosynthesis between 1973 and 1975. Of particular interest for anterior mandibular fractures is the lag screw technique, which was first published by Boateng in 1976, although it had been used by Brons and Boering since the early 1970s. As they described it, “When appropriate conditions are present, it is possible by lag screw osteosynthesis alone, using two lag screws to achieve a functionally stable union of the lamellar fracture fragments by means of the interfragmentary pressure produced.” They did not specifically discuss the technique and results when used for anterior mandibular fractures. It wasn’t until 1991 that Ellis and Ghali presented a series on lag screw technique specific to the anterior mandible and further championed its use for factures in this region, over plate osteosynthesis, as long as there was no comminution or bone loss in the fracture gap.

History of the Procedure

Until the nineteenth century, when new methods for internal and external fixation were introduced, treatment of mandibular fractures followed the original principles described by Hippocrates. Hippocrates’ method for treating fractures of the mandible by wiring the teeth and immobilizing the jaw with closed reduction remains timeless. He addressed anterior mandibular fractures specifically in Chapter 34 of the voluminous Hippocratic Collection :

Anyone can treat separations of the symphysis at the chin. With the two ends of the bone forcefully separated, the protruding part is pushed inwards while the collapsed end is forced outwards … with completion of the reduction, the teeth are wired to each other … not only the two adjacent but several—using gold wire, or lacking that, linen thread until the bone has consolidated.

The next advance in treatment of mandibular fractures came in the nineteenth century, when surgeons improved techniques for maxillomandibular fixation, especially in the design of various interocclusal splints, such as Hamilton’s gutta-percha splint, Kingsley’s apparatus, and the Gunning splint. The predecessor to the current treatment plan of model surgery and arch bars is credited to London dentist Gurnell Hammond, a technique he devised in 1871. After realigning the displaced stone segments, a heavy iron wire was adapted to the teeth on the model. The bar was then subsequently wired to the patient’s natural teeth.

With the development of osteosynthesis in modern traumatology, Bigelow described its first use for mandibular fractures in 1943. Michelet, Champy, and Lodde introduced miniplate osteosynthesis between 1973 and 1975. Of particular interest for anterior mandibular fractures is the lag screw technique, which was first published by Boateng in 1976, although it had been used by Brons and Boering since the early 1970s. As they described it, “When appropriate conditions are present, it is possible by lag screw osteosynthesis alone, using two lag screws to achieve a functionally stable union of the lamellar fracture fragments by means of the interfragmentary pressure produced.” They did not specifically discuss the technique and results when used for anterior mandibular fractures. It wasn’t until 1991 that Ellis and Ghali presented a series on lag screw technique specific to the anterior mandible and further championed its use for factures in this region, over plate osteosynthesis, as long as there was no comminution or bone loss in the fracture gap.

Indications for the Use of the Procedure

Described on the AAOMS 2007 Parameters of Care, closed reduction is appropriate in cases of stable fracture, adequate fixation possible with maxillomandibular fixation, and medical contraindications to open reduction. Additional indications for closed reduction may include atrophic edentulous mandibular fracture, loss of soft tissue coverage over a fracture, and fractures in children. Closed reduction of fractures is most commonly achieved by applying Erich arch bars with circumdental soft stainless steel wires. Other closed reduction methods include Ivy loops, intermaxillary fixation bone screws, and Gunning-type occlusal splints.

For open reduction and internal fixation (ORIF), indications include unstable fracture, continuity defect, preference for early or immediate mobilization, injuries to associated soft or bony tissue, and need for vascular or neurologic exploration or repair. In cases where there is delayed treatment with soft tissue in between the fracture, or malunion/non-union of the fracture, ORIF is also recommended. Semi-rigid internal fixation includes the use of mini-plates, lag screw, or bicortical positioning screws. Rigid fixation includes the use of reconstruction plate (locking or non-locking) and bicortical screws. With anterior mandible fractures, ORIF with lag screw fixation is uniquely favored due to the curvature of the anterior mandible, thickness of the bony cortices, and absence of anatomic hazards below apices of the teeth and between the mental foramina.

The goals are the same for either treatment modality, which include the restoration of pre-trauma occlusion, teeth, bone structure, and nerve function (motor and/or sensory). There should also be the re-establishment of an adequate range of motion, facial and mandibular arch form, in the setting of pain-free function.

Limitations and Contraindications

Although the type of fracture is the primary determinant of closed versus open treatment of anterior mandible fractures, certain patient and operative factors contribute to treatment planning. Open reduction is preferred in the care of non-compliant patients, patients who require early access to the oral cavity (ICU patients), patients with special nutritional needs (diabetics, alcoholics), and patients with seizure disorders.

On the flip side, surgeons should be aware that HIV-infected patients have shown increased risk of postoperative infections especially after open treatment. In comminuted fractures where residual mandibular fragments are associated with a tenuous blood supply, there is also support for closed reduction. This is also a contraindication to the lag screw technique.

In the era of managed care, cost-effectiveness also enters the consideration for choice of treatment. As an example, although closed reduction is cheaper, open reduction may yield better outcome in indigent populations for social reasons. Nonetheless, outside of absolute contraindications to either open or closed treatment, it is the severity of the fracture and positive medical findings that contribute most to postoperative complications, after controlling for age, type of treatment, and time from injury to repair.

Technique: Open Reduction with Internal Fixation of Anterior Mandibular Fractures

Step 1:

Intubation

The preferred method is nasoendotracheal intubation with a nasal Ring-Adair-Elwyn (RAE) tube that exits superiorly across the forehead, allowing the tube to be secured to a head drape. The endotracheal tube is secured either with tape or with a nasal septal suture. Intermaxillary fixation is required to establish preinjury occlusion, and this makes oral intubation less desirable. If nasal intubation is not possible, submental intubation or tracheostomy should be considered.

Step 2:

Oral Prep

Once the airway has been secured, the patient is prepped and draped for surgery. The oral pharynx is suctioned, and a throat pack is placed. After this, the oral cavity is cleansed with a chlorhexidine solution and suctioned. A local anesthetic with epinephrine then is injected. Dental extractions, if required, are completed at this point.

Step 3:

Maxillomandibular Fixation

Only gold members can continue reading. Log In or Register to continue

Jun 3, 2016 | Posted by in Oral and Maxillofacial Surgery | Comments Off on Anterior Mandibular Fractures
Premium Wordpress Themes by UFO Themes