Classification of oral and maxillofacial fractures and corresponding fixation methods?

Lefort fracture: also known as maxillary low fracture or horizontal fracture.

Le Fort II fracture: also known as maxillary median fracture or conus fracture.

Le FortIII fracture: also known as maxillary high fracture or zygomatic arch fracture.

How should jaw fracture be treated? After jaw fracture, the main sign of reduction and fixed jaw fracture reduction is to restore the normal occlusal relationship between upper and lower teeth, that is, the extensive contact relationship between teeth, otherwise it will affect the recovery of chewing function after fracture healing. There are three common reduction methods:

1. Manual reduction: In the early stage of jaw fracture, the displaced fracture segment can be restored to the normal position by hand.

2. Traction reduction: After a long time (more than three weeks of maxilla and more than four weeks of mandible), some fibrous tissues at the fracture site have healed. If manual reset is unsuccessful, traction reset method can be used. Intermaxillary traction is to place the segmented dental arch splint (Figure 1) on the displaced fracture segment of mandible, and then use a small rubber band to elastically traction with the maxillary dental arch splint to gradually restore the normal occlusion relationship, such as the maxillary fracture segment. After moving backward, the dental arch splint can be placed on the maxillary dentition to make a plaster cap with metal brackets on the head. Elastic traction can be made between the dental arch splint and the metal bracket, so that the maxillary fracture segment can recover forward (Figure 2). When large traction is needed, horizontal gravity traction can also be used.

Figure 1 Segmented dental arch splint

Fig. 2 metal bracket plaster cap is used for traction reduction of maxillary fracture segment.

3. Open reduction: Open reduction has wider indications. When the fracture segment is displaced for a long time, and there is fiber healing or bone malposition healing that cannot be recovered by manual traction, surgical incision and reduction should be performed to remove the fiber tissue formed in the malposition healing of the fracture end or chisel away the callus, so as to restore the jaw to its normal position. For fresh fractures or open fractures that are difficult to be manually reduced or unstable after reduction, surgical open reduction is generally adopted.

Fixation after reduction of jaw fracture is an important link in treatment. The commonly used fixation methods include single jaw dental arch splint fixation, intermaxillary fixation, intermaxillary ligation fixation, mini-plate fixation, craniomandibular fixation, and other methods include periodontal fixation and compression plate fixation.

1. Single-jaw dental arch splint fixation method: the dental arch splint is shaped according to the shape of the dental arch with aluminum wire with a diameter of 2 mm or the finished product with hooks, and then the dental arch splint is tied to part or all of the teeth on both sides of the fracture line through the gap with thin metal ligating wire (Figure 3) to fix the fracture segment. This method is suitable for fractures without obvious displacement, such as midline fracture of mandibular chin and localized alveolar process fracture.

2. Intermaxillary fixation: The common method is to place a hooked dental arch splint on the upper and lower teeth, and then use a small rubber band for intermaxillary fixation to keep the mandible in a normal occlusion position (Figure 4). This method is reliable and suitable for all kinds of mandibular fractures. The advantage is that it can heal the position of the jaw well and help restore the function. The disadvantage is that the wounded can't eat with their mouths open, and it is not easy to keep their mouths clean and hygienic. So we should strengthen nursing.

Fig. 3 Single jaw dental arch splint fixation

Fig. 4 Intermaxillary traction fixation

3. Interosseous ligation and fixation: In the case of surgical open reduction, the two broken ends of the fracture can be drilled and then fixed with stainless steel wire (Figure 5). This is also a reliable fixation method, and children's jaw fractures and edentulous jaw fractures can also be fixed by this method.

Fig. 5 Interosseous ligation and fixation

4. Small steel plate or mini-steel plate fixation: On the basis of manual incision and reduction, a small steel plate or mini-steel plate with suitable length and shape is placed horizontally on the bone surface of the two broken ends of the fracture, and special screws are used to penetrate into the cortical bone to fix the fracture (Figure 6). Small steel plates are generally used for mandible and small steel plates are suitable for maxilla.

5. Cranio-mandibular fixation method: The transverse fracture of maxilla can not be fixed by mandible alone, otherwise the middle part of the face is easy to elongate and deform. The fixation method is to first place an arch splint on the maxillary teeth, and then tie one end of a stainless steel wire to the arch splint in the posterior tooth area, and the other end of the stainless steel wire passes through the buccal soft tissue in the oral cavity and is hung on a bracket with a plaster cap (Figure 7).

Fig. 6 Fixing method of small steel plate or miniature steel plate

Figure 7 Cranio-maxillofacial fixation

The fixed time of jaw fracture can be determined according to the patient's injury, age and general condition. Generally speaking, the maxilla is 3-4 weeks, and the mandible is 4-8 weeks. The combination of static and dynamic fixation can shorten the time of intermaxillary fixation. After 2-3 weeks of fixation, remove the rubber band when eating and allow appropriate activities. After rigid internal fixation with small steel plate or mini steel plate, functional training can be carried out in advance to promote fracture healing.