METHODS OF TREATING FRACTURE OF THE MANDIBULAR ANGLE.

Fracture angle of mandible has always been presented with the highest rate of complication of all mandibular fractures. Over the years many treatment modalities were developed ranging from closed reduction with external fixation to open reduction internal fixation.

E.Ellis III (1999), has described 8 methods in treating mandibular angle fracture:-

1. Closed reduction or intraoral open reduction and non rigid fixation.

2. Extra-oral open reduction and internal fixation with an AO/ASIF reconstruction bone plate.

3. Intra-oral open reduction and internal fixation using a solitary lag screw

4. Intra-oral open reduction and internal fixation using two dynamic compression plates.

5. Intra-oral open reduction and internal fixation using two 2.4mm mandibular dynamic compression plates.

6. Intra-oral open reduction and internal fixation using two non compression mini-plates.

7. Intra-oral open reduction and internal fixation using a single non-compression mini-plate.

8. Intra-oral open reduction and internal fixation using a single malleable non compression mini-plate.

The postsurgical complications rate in mandibular angle fractures, ranges from 0% to 32% (Ellis, 1999).

Treatment for angle fractures (Parkland Memorial Hospital)

Treatment Study Reference SamplesMajor Complication

(%)

Non rigid fixation PASSERI et.al., 1993 99 17AO reconstruction plate(2.7mm) ELLIS, 1993 52 7.5Solitary lag screw ELLIS & GHALI, 1991 88 132 mini dynamic compression plates (2.0mm) ELLIS & KARAS, 1992 30 132 mandibular dynamic compression plates (2.4mm) ELLIS & SINN, 1993 65 32

2 non-compression mini-plates (2.0mm)ELLIS & WALKER, 1994 67 23

1 non compression mini-plate (2.0mm)ELIIS & WALKER, 1996 81 2.5

1 malleable non compression mini-plate (1.3mm) POTTER ELLIS, 1999 51 0The complications tabulated in these studies only include major complications which needed hospitalization.

Infections were the biggest culprit recorded in non rigid fixation with 13 cases presented with infection and 4 cases presented with a combination of infection, malunion and malocclusion.

The extra-oral open reduction and internal fixation using AO/ASIF reconstruction plate presented with 4 cases of postsurgical infection requiring surgical intervention, of which one case needed plate removal. Other minor complication recorded with this treatment modality was malocclusion, 4 patients had occlusal disharmony and were placed on elastic traction for 2-3 week.

Lag screw technique presented with 17 cases (19%) of unstable fixation but in only 3 cases was supplemented with 2.0mm compression bone plates at the inferior border of the mandible (placed intra-operatively). The rest of the cases were placed on IMF. 11 patients developed minor postsurgical complication of which 6 cases resolved with oral antibiotic therapy. 5 patients were hospitalized for removal of screws and bony sequestra. One of these 5 patients also developed non-union and subsequently grafted. The option of using lag screw for treatment of angle fracture must be approached with caution as instability is recorded in 1/5 of the cases which may lead to malunion or non-union.

The placement of two 2.0mm mini-dynamic compression plates on the superior and inferior aspect of the buccal cortex to treat mandibular angle fractures as recommended by the AO/ASIF presented with 29% ( 9 cases) of complications requiring secondary surgical intervention. 8 cases needed removal of plates secondary to infection and one case of non-union with malocclusion.

Other AO/ASIF recommendations were two 2.4mm mandibular dynamic compression plates and two non-compression miniplates placed with the same method as two 2.0mm mini-dynamic compression plates. The rate of complication that were recorded were almost similar, 32% in 2.4mm mandibular dynamic compression group and 28% in the non- compression mini-plates.

The surgical technique used in all these 3 groups were same, an intraoral approach. The major complication was infection, malunion and non-union recorded one case each. The stripping of a large area of the periosteum to accommodate these plates compromised the blood supply to the fractured region and hence compromised healing.

On the other hand, open reduction and internal fixation using single non compression plate with the Champy technique presented with the least major complications, 2.5%. Although the overall recorded complications were 13 cases but only two needed hospitalization. The rest of the complications were dealt on outpatient basis. The complication ranged from pain, swelling to wound dehiscence which required plate removal. The removal of plates were done under local anaesthetic as the placement of it were superficial.

Siddiqui (2006) study compared two treatment modalities, one mini-plate versus two mini-plate. The study took into account the minor and major complications which show no significant difference in these groups. Placement of a second plate shows no added advantage in treating mandibular angle fracture but on the other hand increases the cost and adds up to the operative time.

Intraoral open reduction and internal fixation using one malleable non compression mini-plate presented with 14% complication of which 9% required surgical intervention. All of these complications were considered minor and consisted of plate fracture, local infection or both.

In 1996 Kuriokose made a comparative review of 266 mandibular fracture cases with internal fixation using rigid (AO/ASIF) plates and mini-plates. He concluded that better treatment outcome for angle and comminuted fracture with rigid fixation with extraoral approach. This result is parallel with that of Ellis III (1999) research

Gerlach et.al. ,(1984) and Tate et.al., (1994) showed that the bite forces are subnormal for many weeks after fracture of the mandible and therefore there is no real need to have an absolute rigid fixation for treatment of fracture.

The high infection rate in mandibular angle fractures were usually attributed to the presence of lower third molar. This hypothesis were studied by Ellis (2002) and Jeevan Ramakrishnan (2009). Both agreed that the presence of the lower third molars does make the mandible susceptible to fracture due to the reduced cross sectional width. The question of removal of this tooth if it is involved in the line of fracture mandatory is greatly debated. The retrospective study done by Jeevan Ramakrishnan concluded that there was no significant difference by having the tooth retained or removed in the management of angle fracture. Ellis (2002) also showed that the presence of the lower third molar tooth at the fracture line increases the risk of post operative complication but the increase is not statistically significance.

The removal of third molars in management of angle fractures should be dealt on case to case basis weighing the risk against benefit. Fractured or damaged roots, pericoronal/periodontal infection, gross caries, tooth mobility and inability to reduce the fracture without tooth removal should be considered as criteria in removing the tooth.

The need of IMF post surgery is another area of controversy; Cawood (1990) demonstrated that tidal volume may be reduced by up to 40% in patients whose teeth are wired together. Kuriakose (1996) in his study regarded mini-plates as semi-rigid fixation system allowing the use of elastic traction to correct small occlusal discrepancies, this flexibility which was lacking in a rigid fixation.