Arch bars and intermaxillary fixation (IMF) screws are the most popular ways to achieve IMF in oral and maxillofacial surgery. Both techniques have advantages and limitations. The author proposes a simple modification of the conventional arch bar in order to place it with 1.5 mm screws in a quicker procedure that is safer for the surgical team.
Intermaxillary fixation (IMF) has been used in oral and maxillofacial surgery as a method of immobilizing maxillo-mandibular fractures, to help maxillo-mandibular positioning in orthognathic surgery, and the use of elastics in the postoperative period of fractures or orthognathic surgery. Different IMF techniques are described in the literature, using arch bars or bone screws. Basically, IMF has been performed with the use of wires applied directly on the teeth, or with arch bars wired to them. In general, these procedures are time consuming, and manipulation of the wires leads to the risk of glove puncture and needlestick injury to the surgeon or assistants. These problems have led to the development of alternative techniques, such as IMF screws, on which wires or elastics may be fixed for IMF. In this article, a simple modification to the arch bar used for IMF is described, in order to fix it to the alveolar bone with 1.5 mm screws in a quicker procedure that ensures the safety of the surgical team.
A conventional arch bar was modified by making perforations in the spaces between the winglets along the entire extension of the bar, using a No. 701 bur adapted to a high speed handpiece ( Fig. 1 ). In a patient, the arch bar is adapted to the vestibular surface of the maxilla and mandible, close to the cervical portion of the teeth, and a perforation is made in the inter radicular-spaces with a 1.1 mm bur, taking care to avoid perforation of the tooth roots. After this, a 1.5 mm screw is placed to fix the bar. It is not necessary to tighten the screw much, just enough to achieve stabilization of the arch bar, so that the gingival tissue is not compressed, which could lead to ischaemia and necrosis. 4 screws (2 anterior and 2 posterior) are sufficient for good stabilization of the arch bar in order to perform the IMF ( Fig. 2 ). Additional screws may be used, if necessary. Is important to note that not all holes will necessarily match the inter radicular spaces in all teeth, but if the first hole is centred on the midline (between the incisors), a sufficient number of holes will be coincident with the inter radicular spaces required for fixation of the bar. Thus, the arch bars will be ready for the application of wires or elastics for IMF ( Fig. 3 ).