Noninvasive mandibular and symphyseal management (Proceedings)
There are many techniques currently employed for Mandibular fracture repair. They range from simple tape muzzle placement to various forms of invasive surgical reduction. Surgical reduction techniques include intra oral wire cerclage or ligation, osseous plating, inter medullary pining to extra-oral fixation appliances or combinations thereof. These techniques require special instrumentation and added investment in equipment. They require longer surgical time to perform with added trauma and subsequent postoperative discomfort to the patient. The major complication with invasive Mandibular fracture reduction is post reduction dental malocclusion. Most surgical reductions, especially those that employ external fixation or plating tend to displace the fracture segments when they are secured. The clinician must be able to evaluate the alignment and occlusion of the mandible throughout the procedure.
Most reductions have been performed while the patient is conventionally intubated. This prevents occlusal evaluation during reduction. The mouth cannot be closed to evaluate dental or occlusal alignment due to interference from the endotracheal tube. To insure proper dental occlusion, Mandibular fracture reduction must be performed with pharyngeal-tracheal intubation or intravenous anesthesia with appropriate monitoring and support. These protocols permit occlusal evaluation during reduction without obstruction of the dental arcades by an endotracheal tube. The clinician is then able to place the mandible into proper occlusion at all times during the procedure.
Mandibular fracture reduction can be accomplished without invasive procedures with the use of inexpensive dental materials. These include forming wax or a like boxing material such as caulking compound, orthophosphoric acid, (enamel etching gel), dental acrylic and the new non-exothermic, chemically cured temporary dental composite materials.Procedure for acrylic splint construction
1. The entire oral cavity is flushed with a dilute Chlorhexadine solution. All open lesions if present, are debrided, thoroughly flushed and sutured.
2. The lower dentition is scaled and polished with non-fluoridated pumice, (flour pumice) rinsed and thoroughly air-dried.
3. The lower dentition is acid etched with orthophosphoric acid for one minute, thoroughly rinsed with water and air-dried.
4. Forming wax or caulking compound is placed 1/2 to 1 cm. below the marginal gingiva, forming a tightly adapted circumferential dam completely around the lower dental arch.
5. The upper dentition is coated with a petroleum jelly being careful not to contaminate the lower dentition with petroleum jelly. This would prevent retention of the acrylic.
6. Dental acrylic such as repair acrylic is dispensed as powder and liquid, (polymer and monomer) in the following manner. The liquid is first dispensed over the lower dentition and mucosa from a pipette or syringe followed by the powder usually dispensed from a plastic dispensing bottle. This in effect mixes the acrylic directly over the dentition and mucosa allowing the viscous mixture to flow into all possible undercuts and the etch surfaces of the enamel for retention.
7. The placement of powder and liquid is repeated until the teeth and mucosa are covered with three to four mm of soft acrylic.
8. The tongue is rolled back into the throat removing the lateral borders of the tongue from dental interference. The mouth can now be closed with complete occlusal contact.
9. The mandible is completely closed into a positive correct occlusal relationship while the acrylic is still soft. This position is held until the acrylic has polymerized, usually within five minutes. Flowing warm water over the acrylic can accelerate polymerization.
10. After polymerization, the mouth is opened, the dam removed, and all rough edges of acrylic removed with an acrylic bur and slow speed hand piece or Dremel tool. This procedure produces a very strong positive locking splint that insures proper occlusal position throughout the reduction. The acrylic has received an exact indexing from the upper dentition while allowing for complete closure without premature contact from the acrylic splint.
a. The acrylic cast is carefully removed with an acrylic bur or sectioned with a small hand held blade. The teeth are polished with dental prophylactic paste and the soft tissue cleansed and flushes with a Chlorhexadine solution.
b. The acrylic split has formed a very rigid reduction mechanism that is non-invasive without postoperative malocclusion.
c. The difficulty with the use of acrylic for splint construction is the ability to confine the mixture to the occlusal surfaces of the teeth. The wax dams are difficult to keep in place. The acrylic mixture flows into the sublingual and muco-buccal areas of the mouth.