Comminuted mandibular fractures can be successfully treated by a number of methods, including IMF, external fixation with Kirschner pin, and ORIF with small plates or reconstruction plates[6, 8, 9]. ORIF with load-bearing reconstruction plates is advocated by an increasing number of scholars [10, 11] and has been regarded as the first place internationally for the treatment of comminuted mandibular fractures.
However, in clinical practice, the imageologies of comminuted mandibular fractures are widely divergent from each other and the applicable treatment methods are also different. Especially for comminuted mandibular fractures with high comminution degrees, reconstruction plates are difficult to handle and shape, which usually leads to secondary facial deformity and it is also hard to retain small fracture segments[11]. Thus, an appropriate classification with treatment algorithm is necessary.
There are plenty of factors which would exert an influence on the management choices of comminuted mandibular fractures. Our treatment-oriented classification is based on the following factors, namely, whether a stable occlusal relationship could be regained, the morphology of the mandible after trauma, the degree of comminution and whether or not a segmental mandibular bone defect occurred (Fig. 1).
Facing comminuted mandibular fractures treatment, the top priority task is judging whether a segmental mandibular bone defect has occurred. If it has, then a bone transplantation should be performed. This type of patients is the most severe type of all comminuted fractures of the mandible. It is mostly caused by severe injuries such as explosions and gunshots. The treatment is also the most complicated. (type V)
When no segmental bone defect is found, mandibular morphology is the key factor that determines the management method. An intact or slightly damaged mandibular shape may only require conservative treatment like observation or IMF since the continuity of mandible is not damaged. In other words, the displacement extent of the comminuted bone segments directly determines whether an open surgery is necessary or not and in most cases of the patients with intact mandibular morphology, their occlusal relationships are also intact or can be restored through IMF. (type I)
In cases of damaged mandibular morphologies without segmental bone defects, comminution degree may pose a significant effect on determining the treatment methods. Damaged mandibular morphology is an indication for open surgery as it can only be restored by open surgeries and the specific surgery approaches depend on the degree of comminution. In the patients with a low or minimum degree of comminution, the bone segments are big enough to maintain blood supply well. Thus, it is almost the same as the management method of mandibular multiple fracture that is fixed with miniplates. The postoperative infection is often related to the inappropriate soft tissue management which would lead to blood supply damage during surgery. (type II)
However, when it comes to fractures with high comminution degree, it is the occlusal relationship that plays an important role in the choice of management methods. If a stable occlusal relationship could be obtained based on the relatively intact dentition, then IMF in the primary debridement should be performed. When intraoral soft tissue wounds heal, the second stage ORIF with titanium meshes can be performed[7]. For titanium mesh is easier to adapt and bent to the desired shape than reconstruction plates, thus it is suitable for mandibular reconstruction and in particular for the treatment of complex mandibular fractures, which can achieve better stabilization of these fractures than miniplates do. Complications such as infection and bone un-union can largely be avoided and bone tissues can be reserved[12]. (type III)
In terms of those severely comminuted mandibular fractures with seriously impaired dentition in which a stable occlusal relationship cannot be pieced, it is better to follow the principle of AO/ASIF. A load-bearing fixation appliance, the reconstruction plate, should be used to totally bear the functional bite force and to avoid relative motion and functional load[2]. (type IV)
It is worth noting that this classification mainly considers restoring the patient's morphology and function with the least potential trauma while minimizing the occurrence of complications. When difficult-definition fractures or misjudgment occurred, other treatment methods should be applied without hesitation. For example, if it is judged as a type III fracture before surgery and a stable occlusal relationship cannot be obtained during surgery, then the titanium mesh should be immediately abandoned and replaced with traditional reconstruction plates. If always stereotyping to the classification, both function or morphology will not be guaranteed, which will affect the surgical effect.
In conclusion, we believe that the traditional management using reconstruction plates cannot cover all kinds of comminuted mandibular fractures. In this study, a new treatment-oriented classification and algorithm for comminuted mandibular fractures were created, which has a certain guiding effect on the choice of treatment methods and is able to decrease complication rate, but further clinical research is needed.