Perhaps no area of facial trauma has inspired more controversy than the management of mandibular subcondylar fractures. Fractures of the condylar region. Clinically, this equates to open treatment of condylar neck fractures or subcondylar (caudal) fractures (A). The surgeon may elect to place one or two plates. Background and objective: Mandibular fractures are the most frequent and sub condylar region is a common site of fracture. Proper.
|Published (Last):||13 November 2008|
|PDF File Size:||2.47 Mb|
|ePub File Size:||10.91 Mb|
|Price:||Free* [*Free Regsitration Required]|
Open reduction and anatomic reduction can create better function for the temporomandibular joint, compared with closed treatment in mandible fracture surgery. Therefore, the double miniplate fixation technique via mini-retromandibular incision was used in order to make the most stable fixation when performing subcondylar fracture surgery. Those approaches provide good visualization of the subcondyle from the posterior edge of the ramus, allow the surgeon to work perpendicularly to the fracture, and enable direct fracture management.
Understanding the biomechanical load in the fixation of subcondylar fractures is also necessary in order to optimize fixation methods. Therefore, we measured the biomechanical loads of four different plate fixation techniques in the experimental model regarding mandibular subcondylar fractures. It was found that the loads measured in the two-plate fixation group with one dynamic compression plate DCP and one adaption plate showed the highest deformation and failure loads among the four fixation groups.
The loads measured in the one DCP plate fixation group showed higher deformation and failure loads than the loads measured in the two adaption plate fixation group.
Therefore, we conclude that the selection of the high profile plate DCP is also important in order to create a stable load in the subcondylar fracture. The treatment for condylar neck and subcondylar fractures remains one of the most controversial topics of mandible surgery despite the high incidence of these fractures [ 1 ].
For decades, closed reduction has been the preferred treatment, but closed treatment requires varying periods of maxillomandibular fixation MMF, 0 to 4 weeks [ 2 ] and long term complications like pain, ankylosis, internal derangement of the temporomandibular joint TMJas well as the inadequate restoration of the vertical height of the ramus, can possibly occur [ 2 ]. The debate continues over how to best manage subcondylar fractures and the question of which fractures should be treated surgically has yet to be answered [ 3 ].
Surgical Management of a Mandible Subcondylar Fracture
However, in recent years, due to the enormous development of the osteosynthesis technique and the refinement of surgical techniques, the attitude towards the treatment of a condylar neck fracture has changed from an exclusively nonsurgical approach toward surgical treatment [ 4 ].
Recently, anatomic reduction and early mobilization of the jaw following surgery have been considered important for the functional rehabilitation of the TMJ [ 5 ].
When we operate on a subcondylar fracture, the treatment plan depends mandobular, 1 whether open or closed reduction must be performed, 2 which approach to the fracture site will be used, and 3 what type of osteosynthesis is required. During the application of surgical approaches, it is important to ensure that the surgeon is able to conduct anatomic reduction subconfylar direct vision of the completely exposed fractured end [ 4 ].
To treat subcondylar fractures, several surgical approaches have been reported and each approach has its own set of advantages and disadvantages.
Surgical Management of a Mandible Subcondylar Fracture
Therefore, the choice of surgical approach depends on the need to create an optimal view of the whole subcondyle without injury to the facial nerve or to the vascularization to the condylar head during surgery. The retromandibular incision was first proposed by Hinds and Girotti [ 6 ] in It is favored by surgeons because it provides good visualization of the lower subcondyle and the entire ramus from the posterior border [ 7 ].
Compared with the submandibular incision, this incision is closer to the subcondyle; therefore, it provides direct access to the fractured line of the subcondyle and it enables straightforward fracture management, thus facilitating the reduction of the subcondyle. Furthermore, it allows the surgeon to work perpendicularly to the fracture so that excessive retraction can be avoided and use of a transfacial trochar is not necessary [ 1 ]. It can also avoid direct contact with the facial nerve and preserves the integrity of the parotid gland as well as its capsule and leaves a barely noticeable scar in a relatively hidden region [ 1 ].
The skin incision of this approach is located just posterior to the mandibular ramus and the most proximal point of the incision is just below the ear lobe, runs parallel down to the posterior border of the mandible, and is limited to 25 mm in length Fig. After the skin incision, the subcutaneous dissection allows for the extension of the surgical wound to the level of the fracture. Blunt dissection is made through the parotid gland and masseteric fascia towards the posterior border of the mandible.
This permits preservation of the facial nerve fibers, which are easily identified when they pass superficially to the masseter muscle and can be protected with a retractor [ 1 ]. After reaching the mandibular angle, the pterygomasseteric sling is thinned out until the bone surface becomes visible.
A sharp cut is made through the periosteum at the posterior border of the ascending ramus, opening access to the whole ramus, which is dissected subperiosteally. The periosteum at the posterior border of the ramus is then incised, and subperiosteal dissection is continued to the condylar area until the fracture line and the displaced or dislocated proximal fragment are identified. The fragment is then repositioned under direct visualization of the fracture line.
Anatomical adjustment can be facilitated by pulling the mandible downwards. After aligning the fragment, stable plate or screw osteosynthesis is carried out. The posterior border of the ramus and the mandibular notch serve as reference lines for correct three dimensional repositioning. A Preoperative design of a mini-retromandibular incision.
The proximal point of the incision is just below the ear lobe, runs parallel down to the posterior border of the mandible, and is limited to 25 mm in length. B It provides good visualization of the lower subcondyle and allows straightforward fracture management. C Postoperative X-ray, the two 2. D The postoperative scar is hardly visible. Wound closure is performed in layers after checking mandibular mobility and dental occlusion.
A silastic drain is inserted close to the fracture line, with the exit location at the lower border of the incision line. The first step is refixation of the pterygomasseteric sling, followed by closure of the subcutaneous and cutaneous layers.
Mandibular Subcondylar Fractures: A Review on Treatment Strategies
The skin sutures are removed one week later. After the wound has fully healed, the scar is hardly visible. There are some limitations with regard to retromandibular approaches, in that, if the subcondylar fractures are located in the high subcondyle and close to the condylar head, the space that can be exposed with this approach is restricted; therefore, we modify the retromandibular incision.
The modified retromandibular approach provides the same exposure as the retromandibular and preauricular accesses combined, and it may be useful for procedures involving the high subcondylar region [ 8 ]. This approach provides a direct approach to the high subcondylar region and the distance from the skin incision to that region is reduced, compared to that of the routine retromandibular approach.
The skin incision runs from the intertragal notch through the use of a gently curved incision around the ear lobule and uses the upper part of the retromandibular incision Fig. After transection of the skin, the skin flap is elevated, taking care not to injure the great auricular nerve, which lies over the sternocleidomastoid muscle, and the subcutaneous dissection is extended to the level of the fracture.
As soon as the globular parotid tissue appears from the fascial incision, blunt dissection with a mosquito is used. When the trunk of the facial nerve or the temporofacial and cervicofacial division is exposed, the branches are retracted either superiorly or inferiorly depending on the location of the condylar fracture [ 7 ].
Once the posterior border of the mandible is reached, an incision is made through the pterygomasseteric sling. A periosteal elevator is used in order to strip the masseter muscle from the ramus and dissect superiorly to expose the fractured end along the posterior border of the condylar process. After fracture reduction and plating, the pterygomasseteric sling is reapproximated with sutures. The wound is also reapproximated in layers, and the SMAS is resuspended.
Any violation of the parotid gland capsule must be closed tightly to prevent salivary fistula. A small drain placed into the subcutaneous space may be necessary to prevent a hematoma. The skin and subcutaneous tissue are then closed. A Preoperative design of modified retromandibular incision, black line. B It provides good visualization of the high subcondyle and allows straightforward fracture management. D The postoperative scar is cosmetically acceptable.
In treating subcondylar fractures, osteosynthesis is still a functionally challenging problem. The subcondyle constitutes a relatively small bone that must withstand high compression and tensional force during the mouth opening exercise [ 910 ]. The introduction of metal micro- and miniplates and screws partially solves the problem of the stabilization of this fracture, in that it is now possible to stabilize the fracture with one or two plates in a more anatomic position than can be achieved with wires or with closed treatment [ 24 ].
Metal plates and fixation screws are continually being improved, and new forms and profiles of hardware are regularly developed and tested. The single-plate fixation technique does not provide sufficient strength to withstand the strains occurring in subcondylar fractures. Therefore, more and more authors advocate the use of a two-plate fixation technique, which seems to have the beneficial effect of restoring the tension and compression trajectories in subcondylar fractures.
Ideally, two miniplates should be applied at the posterior and anterior border of the condylar neck in a triangular fashion with one plate below the sigmoid notch and another plate along the posterior border of the ramus [ 10 ]. There are several options for plate selection that can be used in subcondylar fractures, but we used the 2. A Repeated tensile and compression forces are exerted on the subcondyle during mouth opening exercises.
It remains uncertain whether plate fixation in condylar neck fractures is rigid enough to dispense with MMF and whether fixation techniques are strong enough to withstand functional loads encountered during the period of bone healing [ 1011 ]. Although there is consensus that double miniplate fixation is the most stable fixation technique, there are few reports regarding which fixation technique provides functional stability in the fractures of this region [ 710 ].
Therefore, we measured the biomechanical load of four different two-plate fixation techniques in an experimental model of the mandibular subcondylar fracture [ 5 ]. Each of the four sets of tibia bones was cut to mimic a perpendicular subcondylar fracture in the center area. The osteotomized tibia bone was fixed using one of the four different fixation groups A-D.
The fixation systems included the single 2. The load for permanent deformation and maximum load of failure were measured in the load displacement curve with the chart recorder Fig. Fixation technique for subcondylar fractures with a 2. E Measuring the load for permanent deformation and the maximum load for failure with an table top system, MTS. F Load displacement curve in the MTS chart recorder. The results of the mandibuar performed fractture our model are shown in Fig.
From the study, group D, to which was applied double fixation with a 2. Therefore, we can conclude that the use of a two-plate fixation method provides more a stable fixation load than single-plate fixation. In addition to that, the loads measured in the one DCP plate fixation group showed a higher deformation and failure load than the loads measured in the two adaption plate fixation group.
Therefore, we conclude that the selection of the high profile plate DCP is also important in order to create a stable load when treating subcondylar fracture [ 5 ]. The two-plate technique seems to be a gold A B standard in subcondylar fracture fixation but the insertion of many screws in a small condylar fragment is often difficult, particularly in the case of high subcondylar fractures.
Miniaturized osteosynthesis devices are essential for stabilization of subcondylar fractures because of the small size of the subcondylar fragments [ 4 ]. Therefore, several kinds of plates have been specifically designed for the stabilization of subcondylar fractures, and they were subjected to rigorous experimental testing before clinical use [ 4 ].
The trapezoid shape of the TCP plate Medartis, Basel, Switzerland ensures the best possible stability of the fracture site and an optimal resistance of the plates to local mechanical strains Fig. The delta plate from Medartis is triangular in shape, oriented towards the angle of the mandible, and the lines of tensile and compressive stress run parallel to both sides of the triangle.
However, all of those plates made by Medartis are not yet available in the Republic of Korea. The drain was removed within 3 to 4 days and the stitches removed within 7 days. MMF was not generally needed but restricted jaw movement with bandaging and a soft diet were used for 1 week. In a few patients who had malocclusion, elastic traction with a rubber band was used for several days.
In most of the patients, limited mouth opening exercises were started several days after surgery and normal occlusion and mouth opening was restored within 1 month. Treatment of subcondylar fractures can follow two different routes: Previously, conservative management of condylar fractures was favored. However, a open reduction was first applied to a low subcondylar fracture in [ 12 ], and recently it has become more common, probably because of the introduction of plate and screw fixation devices that allow for the stabilization of such injuries [ 1 ].
Today, many surgeons prefer open reduction of displaced fractures, because such reduction and rigid fixation enables good anatomic repositioning and immediate function.
Although there is still debate concerning therapy for subcondylar fractures, a number of reports have now suggested that, compared with non-operative treatment, the treatment of condylar fractures by open reduction and rigid fixation creates more favorable results [ 25 ].