Indications for Maxillomandibular Fixation (MMF) for Occlusal Management
Maxillomandibular fixation is indicated primarily for mandibular fractures in the tooth-bearing area (symphyseal, parasymphyseal, and angle fractures) to restore and maintain proper dental occlusion during fracture healing, either as definitive treatment or as an adjunct to open reduction and internal fixation. 1, 2, 3
Primary Indications for MMF
Mandibular Fracture Management
- Isolated mandibular fractures in the symphyseal, parasymphyseal, or angle regions are the classic indication for MMF 2, 3
- MMF serves to restore premorbid occlusion prior to open reduction-internal fixation (ORIF) when surgical treatment is planned 2
- Definitive treatment with MMF alone can be used for selected non-comminuted fractures in the tooth-bearing area, particularly when surgical intervention is contraindicated or declined 3
Intraoperative Occlusal Maintenance
- MMF is used intraoperatively during ORIF to maintain proper dental occlusion until hardware fixation is achieved 1, 2
- Manual MMF (3MF) can replace rigid intraoperative MMF in selected cases, reducing operative time and allowing immediate postoperative mandible mobilization 1
Duration and Technique Considerations
Postoperative MMF Duration
- Traditional teaching of prolonged postoperative MMF may not be necessary for dentate patients with non-comminuted symphyseal, parasymphyseal, or angle fractures treated with ORIF 2
- A comparative study showed no significant difference in complications (wound dehiscence, infection, plate removal, nonunion, malunion, or malocclusion) between patients with and without postoperative MMF after ORIF 2
Short-Duration MMF Protocol
- A 2-week period of MMF followed by an arch bar splint wired to the lower jaw is a suitable alternative to conventional prolonged MMF for fractures of the mandibular tooth-bearing area 3
- This approach significantly reduces adverse effects of long-term MMF while maintaining treatment efficacy, with earlier restoration of mouth opening (P = .001) 3
- No significant differences were found in postoperative infection or malocclusion rates compared to conventional MMF 3
Technical Options for MMF Application
Available Fixation Methods
- Arch bars with wiring remain a standard technique but are associated with greater gingival inflammation (P < 0.05) compared to skeletal anchorage methods 4
- Skeletal anchorage screws (SAS) can be used in the maxilla or mandible, offering improved periodontal health outcomes 4
- Hybrid MMF using SAS in the maxilla combined with arch bars in the mandible reduces patient pain and discomfort while maintaining occlusal reproducibility 4
- Existing orthodontic brackets can be utilized for MMF when patients are undergoing orthodontic treatment at the time of fracture, avoiding bracket removal 5
Clinical Decision Algorithm
When to Use MMF as Definitive Treatment
- Patient has isolated mandibular fracture in tooth-bearing area 3
- Fracture is non-comminuted 2, 3
- Patient is dentate with adequate dentition for fixation 2, 3
- Surgical intervention is contraindicated or refused 3
- Consider short-duration protocol (2 weeks) followed by arch bar splint to minimize complications 3
When to Use MMF as Adjunct to ORIF
- Intraoperative use only to establish proper occlusion during plate fixation 1, 2
- Manual MMF can replace rigid fixation intraoperatively in selected cases, reducing operative time 1
- Postoperative MMF is not mandatory for dentate patients with non-comminuted fractures after adequate ORIF 2
Important Caveats
Complications to Monitor
- Gingival inflammation is significantly higher with arch bar techniques compared to skeletal anchorage methods 4
- Long-term MMF increases risk of temporomandibular dysfunction and restricted mouth opening 3
- Blood-borne disease transmission risk to surgical team is reduced with manual versus rigid MMF techniques 1