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An Algorithm for the Treatment of Noncondylar Mandibular Fractures
Accepted Manuscript An Algorithm for the Treatment of Non-Condylar Mandibular Fractures Edward Ellis PII:
S0278-2391(13)01437-7
DOI:
10.1016/j.joms.2013.11.026
Reference:
YJOMS 56144
To appear in:
Journal of Oral and Maxillofacial Surgery
Received Date: 17 October 2013 Accepted Date: 25 November 2013
Please cite this article as: Ellis III E, An Algorithm for the Treatment of Non-Condylar Mandibular Fractures, Journal of Oral and Maxillofacial Surgery (2013), doi: 10.1016/j.joms.2013.11.026. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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An Algorithm for the Treatment of Non-Condylar Mandibular Fractures
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Edward Ellis III, DDS, MS Professor and Chair Department of Oral and Maxillofacial Surgery University of Texas Health Science Center at San Antonio 7703 Floyd Curl Drive Mail Code 7908 San Antonio, TX 78229 [email protected] Phone: 210-567-3470 Fax: 210-567-2995
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Abstract An algorithm for the treatment of non-condylar mandibular fractures is presented based on outcomes from studies that have been performed over the past 30 years. It is designed to assist clinicians in formulating a treatment plan that can be expected to provide the patient with a predictable outcome.
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INTRODUCTION Mandibular fractures are common facial injuries, constituting either the most prevalent or the second most prevalent (after nasal) facial fracture.1,2 Treatment of mandibular fractures varies considerably among regions, countries, and practitioners. This should not be surprising given the differences in health care availability, quality and delivery strategies in different locations.
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The advent of stable internal fixation over the past 40 years has considerably changed how mandibular fractures are treated, but not all locations have this technology available. There have been many studies published on the outcomes of various treatment strategies for mandibular fractures treated with stable internal fixation. Interestingly, even in those locations that do have or apply stable internal fixation devices, different fixation schemes are applied to the same fracture by various practitioners. The reason treatment varies so considerably is that most surgeons tend to treat patients according to their training and past experience rather than scientific data. It is therefore not surprising that patients receive different treatments for similar mandibular fractures.
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The purpose of this paper is to present an algorithm for the treatment of non-condylar fractures of the mandible using available evidence as a guide. Condylar fractures have not been included because they present unique considerations that complicate a treatment algorithm, such as the ability to treat without reduction and/or fixation of the fracture. The algorithm to be presented will assess several factors about the mandibular fracture(s) that have an effect on the treatment (Figure 1). The algorithm also will take into account confounders that directly affect treatment choices.
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ALGORITHM (Figure 1) The assumption that is made with the algorithm presented (Figure 1) is that any fractures that the surgeon chooses to treat with open reduction and internal fixation (ORIF) will have ample fixation applied so that no postoperative intermaxillary fixation (IMF) will be necessary. Thus, the fixation requirements for the fractures may be more than would be required if one were to employ a period of IMF after ORIF. When a patient presents with a fractured mandible, there are several conditions or factors that should be considered to help define appropriate treatment. The Presence or Absence of Teeth The most basic factor in determining what treatment to provide for a fractured mandible is whether or not the patient has adequate teeth that would permit the application of IMF. If the patient has adequate teeth to permit the application of IMF and/or application of an
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arch bar, they can be treated according to the Dentulous Algorithm. If not, they are placed into the Edentulous Algorithm. Algorithm for Treating Dentate Patients with Mandibular Fractures
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The presence of Teeth on One or Both Sides of the Fracture Line When teeth are present on only one side of a fracture, closed techniques of treatment will often be unsuccessful because there is nothing to stabilize the fragment that contains no teeth. This situation is most common with fractures through the angle, but also occurs with body fractures when no teeth are present distal to the fracture line. Most of these fractures are “unfavorable,” meaning that the direction and/or bevel of the fracture line offers no resistance to the pull of the elevator muscles, allowing the ramus to rotate and the fracture to displace (Figure 2). For purposes of the algorithm, it will be assumed that fractures that do not have teeth on both sides of the fracture will be “unfavorable” fractures, meaning that they cannot be satisfactorily treated closed with IMF. However, there may be an occasional patient whose fracture is “favorable” and such a patient could be treated closed. In practice, however, these are uncommon.
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The presence of stable teeth on both sides of a fracture line is of paramount importance for two reasons. First, it is what will determine whether or not the patient can be treated closed, i.e. with a period of IMF. Simple linear (Figure 3) and comminuted (Figure 4) fractures can be treated closed as long as there are stable teeth on each side of the fracture (and of course teeth in the maxilla). Similarly, the presence of acute or chronic infection at the fracture site does not obviate the possibility of treating such fractures closed. Additional treatment for the infection may also be required (eg. incision and drainage, antibiotics, etc.).
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The second reason that the presence of teeth on both sides of the fracture is important is because if the surgeon chooses open reduction and internal fixation for the fracture, the dentition can be used as a second point of fixation. In fact, when treating a fracture through the body of the mandible, the application of an arch bar to the mandibular teeth almost, by itself, neutralizes the fracture under functional movements because it is applied in the most biomechanically-beneficial location, i.e. the zone of separation (tension).3,4 This means that the amount of internal fixation applied can be minimal, such as a single miniplate, because the arch bar is providing most of the stabilization for the fracture (Figure 5). When teeth are not present on both sides of the fracture, for instance fractures through the angle (Figure 6A) and some fractures through the body (Figure 6B), open treatment becomes necessary to prevent rotation of the ramus from the pull of the elevator muscles. A single miniplate applied along the superior border is adequate fixation in such cases when this is the only fracture of the mandible, or when other fractures have been made “rigid” by application of rigid internal fixation devices (see below).5 A single miniplate applied in this location neutralizes the functional forces generated from elevation of the ramus and depression of the symphysis from the attached muscles by sharing the loads with the bone along the fracture and compressing them together.6
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Summarizing, when teeth are present on both sides of the fracture, the surgeon has the choice of treating the fracture closed or open. However, when teeth are present on only one side of the fracture, the only choice is to treat the fracture open unless the fracture line happens to be “favorable.”
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If Open Treatment is Chosen, Does the Fracture Require Load-Bearing or Load-Sharing Fixation? Load-bearing fixation, a form of rigid fixation, is the application of internal fixation devices that are of sufficient strength that they can bear all the loads of mastication transmitted across the fractured area.7 The bone does not have to share any of the loads. In practice, this is most often accomplished by application of a reconstruction bone plate with a minimum of three screws on each side of the fracture. Any mandibular fracture can be treated with load-bearing fixation. When the surgeon is not sure what fixation to apply to a given fracture, they will never be wrong by applying load-bearing fixation. Load-sharing fixation is the application of internal fixation devices that require that the bone fragments participate in transferring functional loads across the fractured area.7 Examples are the application of miniplates, compression plates, lag screws, etc. across a fracture (Figures 5 and 6). All of these techniques load the bony interfaces during mandibular function so the broader the area of bone contact, the more stable the fixation provided.
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The character of the fracture determines what type of fixation is required. Simple linear fractures can undergo either load-bearing or load-sharing fixation (Figures 5 and 6), whereas comminuted or defect fractures must undergo only load-bearing fixation (Figures 7 and 8). Chronically-infected fractures should also have load-bearing fixation applied when treated open because the bony interfaces may have become demineralized and will not provide a stable interface for load-sharing fixation. Infections present for a week or two (acute infections) can be treated with either load-sharing or load-bearing fixation because their bony fragments have not yet undergone demineralization and provide a stable interface for load-sharing fixation.8-14
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Summarizing, load-sharing fixation can only be applied to fractures that have broad areas of healthy bone contact. Whenever this is not the case, for example in comminuted, defect, chronically-infected, or atrophic fractures, load-bearing fixation should be used. Unlike load-bearing fixation that can be applied to any fracture, load-sharing fixation can only be applied to some fractures. When in doubt, use load-bearing fixation (reconstruction bone plate)! Is the Mandible Fractured in More than One Location? Most studies show that over 50% of patients presenting with mandible fractures have more than one fracture.15-19 Thus, the multiply-fractured mandible is more common than an isolated fracture. Perhaps the most common mandibular fracture seen in the United
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States is a fracture through the angle combined with a contralateral fracture through the symphysis or body fracture.
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As in isolated fractures, in cases where more than one fracture exists and there are usable teeth in all fragments, the surgeon has a choice of either closed or open treatment. Such fractures can be treated closed whether or not they are infected and/or comminuted (Figure 9). If open treatment is selected, the choice of internal fixation hardware becomes more complicated because the biomechanics of the multiply-fractured mandible is more complex than in an isolated fracture of the mandible.5
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If the surgeon selects load-sharing fixation for the fractures, it is important to consider what hardware is applied. Within the category of load-sharing fixation, there are many internal fixation schemes--some more stable than others. For instance, the Champy technique of applying a single miniplate for mandibular body and/or angle fractures is not “rigid” fixation, but instead allows some motion between the bone fragments during function (i.e. the fixation is non-rigid). This choice of fixation functions well when applied to an isolated fracture of the mandible.18,19 However, when applied to bilateral fractures of the mandible, a single miniplate in both locations is associated with more complications then when at least one of the fractures is treated with “rigid” fixation.5 “Rigid” fixation can be applied by use of a reconstruction bone plate (load-bearing fixation) or the application of lag screws, two miniplates, compression plates, two locking plates, etc. (i.e. load-sharing fixation)(Figure 10). Therefore, a general principle is that when multiple mandibular fractures are present, only one of the fractures can be treated with non-rigid fixation—all the others must be treated with rigid fixation.
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Algorithm for Treating Edentulous Patients with Mandibular Fractures When teeth are not present, closed techniques are of limited success. Several studies have shown that using splints, dentures, or external pin fixation are associated with higher rates of complication than is open reduction and stable internal fixation.20-27 Thus, when teeth are not present, ORIF is the only choice that one can usually employ.
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Is the Mandible Atrophic? The fixation requirements of an edentulous fracture are dependent upon the amount of residual bone remaining. An edentulous mandible with a fracture through it may be treated with load-sharing fixation when there is ample volume of bone remaining to provide bone-buttressing. For instance, an edentulous mandible like the one shown in Figure 11A can be treated with load-sharing fixation because there is a large volume of bone in the area of the fracture whereas the one shown in Figure 11B requires loadbearing fixation. The key to the decision on the amount of fixation required for the treatment of a fractured edentulous mandible is the vertical height of bone at the fracture site. When the vertical height of bone is great, load-bearing fixation can be used, assuming no comminution, defect or chronic infection is present. The reason that this is possible is because when fixation is applied in a biomechanically-favorable location, such as the superior border of the mandible, the fracture is neutralized during function by compression of the bone fragments below the point of fixation (Figure 12A).
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On the other hand, when a fracture occurs through an atrophic mandible (Figure 12B), it usually fractures in the thinnest area with the least bone height. A plate applied across this fracture will have to bear all the functional loads transferred across the fracture because there is too little bone for load-sharing. Thus, load-bearing fixation must be used in atrophic mandibles. Thus the adage, the smaller the mandible, the bigger the bone plate must be!28
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Unlike fractures in the dentate mandible, one should also consider the addition of autogenous bone or products that promote bone formation when dealing with fractures through the atrophic mandible. These mandibles have little endosteum or periosteum with osteocompetent cells to promote osseous union.27 Without the addition of bone or bonepromoting products, atrophic mandibles may not heal and instead a “titanium union” maintains the reduction. In time, the plate can fail and the non-healed fracture becomes obvious. Alternatively, the bone plate may be electively removed to facilitate prosthetic reconstruction and a non-union then becomes apparent.
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DISCUSSION The purpose of the algorithm presented is to help clinicians prescribe treatment for a given fracture. As with all algorithms, other variables must also be considered because each patient and each injury has its own unique personality and character. For instance, when there is doubt about whether or not a patient may come back for follow-up care, one might wish to use ORIF rather than closed techniques. When choosing fixation schemes for these patients, it might be prudent to apply rigid internal fixation rather than non-rigid functionally-stable fixation. Similarly, the use of load-bearing fixation even when the fracture would otherwise be treatable with load-sharing fixation is added insurance. Doing either will allow the clinician to either not use or to remove the arch bars immediately after the internal fixation is applied. The lower arch bar will then not be available as another point of fixation for a fracture that has teeth on both sides but if enough fixation is applied directly on the bone, it becomes unnecessary. This should be considered when it is doubtful a patient may return for follow-up. In such cases, the arch bar can become a liability to the patient because it facilitates the development of periodontitis when left in place for long periods of time in patients with poor oral hygiene.
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One might wonder why an algorithm presented in 2014 includes the use of closed treatment for fractures of the mandible. The reason for its inclusion is because closed treatment works very well when applied to the appropriate fracture. When a fracture occurs in the dentate portion of the mandible where there are sound teeth on each side and in the maxilla, the application of IMF not only restores the occlusion, but helps reduce the fracture and also provides fixation to allow healing to progress. When there are areas of comminution, open treatment becomes more complicated because a long reconstruction bone plate must be adapted to the mandible that spans the area of comminution. If there are good teeth on each side of a comminuted fracture, closed treatment can be very easy treatment for this otherwise difficult fracture.
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Treatment may also be prescribed based on convenience. Often, patients will show up in the oral and maxillofacial surgeon’s office with a fractured mandible being self-referred or referred from a local hospital. If the fracture lends itself to closed treatment, this can be performed readily in the surgeon’s office with little cost or effort. If open treatment is chosen, it requires more inconvenience for the surgeon and the patient because the patient usually must be admitted to the hospital for treatment. Thus, closed treatment is still being successfully used by many practitioners and it definitely has a place in the management of mandibular fractures.
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The surgical approaches for those fractures treated open were not mentioned in the algorithm. The choice of surgical approaches does not affect the fixation requirements and can be determined by the experience and desires of the surgeon. In general, the vast majority of mandibular fractures in the dentate mandible can be treated using an intraoral surgical approach. This is especially so for simple (linear) fractures from the angle forward. When comminution occurs, especially in the posterior mandible, it will be more difficult to adapt and secure a reconstruction bone plate through a transoral approach. The surgeon might choose a transfacial approach in such cases. In the edentulous and especially the atrophic mandible, a transfacial approach certainly facilitates open treatment. Such fractures are easier to instrument through a transfacial approach, simplifying the reduction and the application of internal fixation devices.
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This algorithm does not include fractures of the condylar process. The reason for not including them is that these fractures are unique among facial fractures in that they can be treated open or closed without IMF. When treated closed, condylar process fractures can be treated with or without immobilization of the mandible. All other mandibular fractures treated closed require a period of IMF. This makes them unique. Because condylar process fractures are often, if not mostly, associated with other mandibular fractures, including them would greatly complicate a treatment algorithm. Although not included, condylar process fractures follow similar rules as discussed above. For instance, in the case where there are fractures of the mandibular angle, body, and/or symphysis as well as the condylar process, if ORIF is chosen, non-rigid fixation can only be applied to one of them.5 That means that if the condylar process fracture will be treated closed, all the other fractures should be stabilized with rigid internal fixation.
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SUMMARY The algorithm for the treatment of non-condylar mandibular fractures presented here can help the clinician decide on a reasonable treatment plan. Certainly, the treatment for each case must be individualized, but the principles presented should be considered because they are based on sound scientific outcomes.
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Figure Legends Figure 1. Algorithm for the treatment of non-condylar mandibular fractures. Fx=fracture; RIF=rigid internal fixation; Redn=reduction; Infxn=infection)
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Figure 2. A, “favorable” fracture from the standpoint of preventing the mandibular ramus from rotating when using IMF to treat the fracture. B, “unfavorable” fracture from the standpoint of preventing the mandibular ramus from rotating when using IMF to treat the fracture. C, Panoramic radiograph taken 3 weeks after a patient with an unfavorable fracture through the right mandibular angle was treated closed. Note the anterosuperior rotation of the mandibular ramus secondary to the uninhibited pull of the elevator muscles because of lack of teeth on the proximal segment which might have prevented this.
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Figure 3. Fracture of the mandibular body with teeth on both sides of the fracture treated closed. This treatment could be employed whether or not there was infection present, whether or not there was comminution, and whether or not there were other mandibular fractures, as long as all fractures had teeth on both sides to provide reduction and fixation by IMF. Obviously, sufficient maxillary teeth would also be necessary to facilitate IMF.
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Figure 4. Comminuted fracture of the mandibular body with teeth on both sides of the fracture treated closed. This treatment could be employed whether or not there was infection present, and whether or not there were other mandibular fractures, as long as all fractures had teeth on both sides to provide reduction and fixation by IMF. Obviously, sufficient maxillary teeth would also be necessary to facilitate IMF.
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Figure 5. Fracture of the mandibular body with teeth on both sides of the fracture treated open. The use of an arch-bar and a miniplate placed either above the mental nerve (A) or below it (B) is all that is required for an isolated fracture of the body/symphysis region. This treatment could also be applied to an acutely-infected fracture but NOT to a chronically-infected fracture or a comminuted fracture. When ORIF is chosen as the treatment in such cases, the fixation requirements call for load-bearing fixation and a reconstruction bone plate would be indicated. If there were bilateral fractures and ORIF was selected as the treatment, at least one of the fractures should be treated with loadsharing or load-bearing rigid fixation; the other could be treated with load-sharing nonrigid fixation. If chronic infection and/or comminution were present, load-bearing fixation would be required. Figure 6. Fracture of the angle (A) or body (B) of the mandible with teeth on only one side treated open. Closed treatment will not be reliable in such instances because of the tendency for the mandibular ramus to rotate from the pull of the elevator muscles. A single miniplate placed at the superior border is adequate fixation if this is the only fracture present. When the plate is placed along the lateral surface of the mandible (B), one should consider a stronger bone plate because standard miniplates can deform under function from the torqueing of the segments.
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Figure 7. Comminuted fracture of the mandibular body with teeth on both sides of the fracture treated open. This fracture requires load-bearing fixation so a reconstruction bone plate is employed. This treatment could be employed whether or not infection was present. Maintenance of an arch bar in this case is not necessary from the standpoint of providing additional fixation across the fracture. The reconstruction bone plate alone is ample fixation.
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Figure 8. Comminuted fracture of the angle or body of the mandible when there are teeth on only one side treated open. This fracture requires load-bearing fixation so a reconstruction bone plate is employed. This treatment could be employed whether or not infection was present.
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Figure 9. Bilateral fractures in the tooth-bearing region of the mandible treated closed. This treatment could be employed whether or not there was infection present, whether or not there was comminution, and whether or not there were other mandibular fractures, as long as all fractures had teeth on both sides to provide reduction and fixation by IMF. Obviously, sufficient maxillary teeth would also be necessary to facilitate IMF.
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Figure 10. Bilateral fracture of the mandible treated open. This fracture could not be treated closed because of there are no teeth behind the angle fracture to prevent rotation of the ramus. With open treatment, only one of the fractures can be treated with non-rigid fixation. In practice, it is easier to make the more anterior fracture rigid by the application of two miniplates, a stronger, thicker bone plate, etc. The angle fracture can then be treated with non-rigid fixation (single miniplate).
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Figure 11. Radiographs of fractures through an edentulous non-atrophic mandible (A) and an atrophic mandible (B). Although both cases are edentulous, the fixation requirements are very different. The atrophic mandible requires more fixation than the non-atrophic mandible.
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Figure 12. Illustrations of fractures through an edentulous, non-atrophic mandible (A) and an atrophic mandible (B). The red arrows indicate the muscle forces acting on the mandible. When there is a large vertical height of bone in the area of the fracture (“H” in Figure A), load-sharing fixation can be used. The functional forces will be neutralized by the small bone plate at the superior surface of the fractured mandible by compressing the bone along the inferior border. When there is atrophy (B), there is inadequate bone to form a fulcrum point so the plate must take on all the loads generated across the fracture. Figure 13. Illustration showing use of a single miniplate at the superior border of an edentulous but not atrophic mandibular fracture. This fixation scheme works on fractures that are located through an area of the mandible with a large vertical dimension. Figure 14. Illustration showing a reconstruction bone plate used on an atrophic edentulous mandible. Because there is little vertical dimension of bone remaining at the fracture site, this fracture requires load-bearing fixation.
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References 1. Costello BJ, Papadopoulos H, Ruiz R: Pediatric craniomaxillofacial trauma. Clin Pediatr Emerg Med 6:32-40, 2001 2. Hwang K, You SH: Analysis of facial bone fractures: an 11-year study of 2,094 patients. Indian J Plast Surg 43:42-48, 2010 3. Pauwels F: Grundriss einer biomechanik der frakturheilung. Verh Dtsch Orthop Ges 34:62, 1940. 4. Spiessl B, Schargus G: Das Okklusionsproblem bei der funktionsstabilen Osteosynthese des bezahnten Unterkiefers. (The problem of occlusion in functionally stable osteosynthesis of the dentulous mandible). Dtsch Zahn- Mund u Kieferheilk, 57:293-6, 1971 5. Ellis E: Open reduction and internal fixation of combined angle and body/symphysis fractures of the mandible: How much fixation is enough? J Oral Maxillofac Surg 71:726-733, 2013 6. Champy M, Lodde JP, Schmitt R, et al. Mandibular osteosynthesis by miniature screwed plates via a buccal approach. J Maxillofacial Surg 6:14-9, 1978 7. Sugar A, Bentley R: Biomechanics of the bone-implant-unit. Chapter 1.5.5 in: Principles of Internal Fixation of the Craniomaxillofacial Skeleton – Trauma and Orthognathic Surgery, Ehrenfeld M, Manson PN, Prein J (eds), Thieme, Stuttgart, 2012, pp. 91-93 8. Friedrich B, Klaue P: Mechanical stability and post-traumatic osteitis: An experimental evaluation of the relation between infection of bone and internal fixation. Injury 9:23-29, 1977 9. Beckers HL: Treatment of initially infected mandible fractures with bone plates. J Oral Surg 37:310, 1979 10. Johansson B, Krekmanov L, Thomasson M: Miniplate osteosynthesis of infected mandibular fractures. J Cranio Maxillofac Surg 16:22-29, 1988 11. Koury M, Ellis E: Rigid internal fixation for the treatment of infected mandibular fractures. J Oral Maxillofac Surg 50:434-443, 1992 12. Koury M, Perrott D, Kaban L: Use of rigid internal fixation in mandibular fractures complicated by osteomyelitis. J Oral Maxillofac Surg 52:1114-1120, 1994 13. Schiel H, Hammer B, Ehrenfeld M, et al: Therapy of infected mandibular fractures. Fortschr Kiefer Gesichtschir 41:170-177, 1996 14. Mehra P, Van Heukelom E, Cottress DA: Rigid internal fixation of infected mandibular fractures. J Oral Maxillofac Surg 67:1046-1051, 2009 15. Feller KU, Schneider M, Hlawitschka M, et al: Analysis of complications in fractures of the mandibular angle—A study with finite element computation and evaluation of data of 277 patients. J Craniomaxillofac Surg 31:290, 2008 16. Paza AO, Abuabara A, Passeri LA: Analysis of 115 mandibular angle fractures. J Oral Maxillofac Surg 66:73, 2008 17. Ellis E 3rd, Walker L: Treatment of mandibular angle fractures using two noncompression miniplates. J Oral Maxillofac Surg 52:1032, 1994 18. Ellis E 3rd, Walker LR: Treatment of mandibular angle fractures using one noncompression miniplate. J Oral Maxillofac Surg 54:864, 1996 19. Ellis E 3rd: A prospective study of 3 treatment methods for isolated fractures of the mandibular angle. J Oral Maxillofac Surg 68:2743, 2010
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20. Bruce RA, Strachan DS: Fractures of the edentulous mandible: The Chalmers J. Lyons Academy study. J Oral Surg 34:973, 1976 21. Bruce RA, Ellis E: The second Chalmers J. Lyons Academy study of fractures of the edentulous mandible. J Oral Maxillofac Surg 51:904, 1993 22. Buchbinder D: Treatment of fractures of the edentulous mandible, 1943 to 1993: A review of the literature. J Oral Maxillofac Surg 51:1174, 1993 23. Luhr HG, Reidick T, Merten HA: Results of treatment of fractures of the atrophic edentulous mandible by compression plating. J Oral Maxillofac Surg 54:250, 1996 24. Eyrich GK, Gratz KW, Sailer HF: Surgical treatment of fractures of the edentulous mandible. J Oral Maxillofac Surg 55:1081, 1997 25. Iatrou I, Samaras C, Lygidakis NT: Miniplate osteosynthesis for fractures of the edentulous mandible: A clinical study, 1989–1996. J Craniomaxillofac Surg 26:400, 1998 26. Kunz C, Hammer B, Prein J: Fractures of the edentulous atrophic mandible: Management and complications [in German]. Mund Kiefer Gesichtschir 5:227, 2001 27. Ellis E, Price C: Treatment protocol for fractures of the atrophic mandible. J Oral Maxillofac Surg 66:421-435, 2008 28. Schilli W, Stoll P, Bahr W, Prein J: Mandibular Fractures. Chapter 3 in: Manual of Internal Fixation in the Cranio-Facial Skeleton, Prein J (ed), Springer, Berlin, 1998, p. 87
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Non-Rigid Load Sharing Fixation OK on only one fx: RIF on any others
Simple (linear) Fx(s) (+/- Acute Infection)
Chronically Infected
Teeth Missing on at least one side of any Fx
Load Bearing Fixation Required
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ORIF
Teeth on Both Sides of Fx(s)
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Mandible Fracture
Closed Redn + IMF (+/- Infxn or Comminution
Edentulous
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Atrophic
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Chronically Infected
Non-Atrophic
Load Bearing Fixation Required
Comminuted Fx(s)
Simple (linear) Fx(s) (+/- Acute Infection)
Non-Rigid Load Sharing Fixation OK on only one fx: RIF on any others
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S0278-2391(13)01437-7
DOI:
10.1016/j.joms.2013.11.026
Reference:
YJOMS 56144
To appear in:
Journal of Oral and Maxillofacial Surgery
Received Date: 17 October 2013 Accepted Date: 25 November 2013
Please cite this article as: Ellis III E, An Algorithm for the Treatment of Non-Condylar Mandibular Fractures, Journal of Oral and Maxillofacial Surgery (2013), doi: 10.1016/j.joms.2013.11.026. This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain.
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An Algorithm for the Treatment of Non-Condylar Mandibular Fractures
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Edward Ellis III, DDS, MS Professor and Chair Department of Oral and Maxillofacial Surgery University of Texas Health Science Center at San Antonio 7703 Floyd Curl Drive Mail Code 7908 San Antonio, TX 78229 [email protected] Phone: 210-567-3470 Fax: 210-567-2995
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Abstract An algorithm for the treatment of non-condylar mandibular fractures is presented based on outcomes from studies that have been performed over the past 30 years. It is designed to assist clinicians in formulating a treatment plan that can be expected to provide the patient with a predictable outcome.
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INTRODUCTION Mandibular fractures are common facial injuries, constituting either the most prevalent or the second most prevalent (after nasal) facial fracture.1,2 Treatment of mandibular fractures varies considerably among regions, countries, and practitioners. This should not be surprising given the differences in health care availability, quality and delivery strategies in different locations.
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The advent of stable internal fixation over the past 40 years has considerably changed how mandibular fractures are treated, but not all locations have this technology available. There have been many studies published on the outcomes of various treatment strategies for mandibular fractures treated with stable internal fixation. Interestingly, even in those locations that do have or apply stable internal fixation devices, different fixation schemes are applied to the same fracture by various practitioners. The reason treatment varies so considerably is that most surgeons tend to treat patients according to their training and past experience rather than scientific data. It is therefore not surprising that patients receive different treatments for similar mandibular fractures.
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The purpose of this paper is to present an algorithm for the treatment of non-condylar fractures of the mandible using available evidence as a guide. Condylar fractures have not been included because they present unique considerations that complicate a treatment algorithm, such as the ability to treat without reduction and/or fixation of the fracture. The algorithm to be presented will assess several factors about the mandibular fracture(s) that have an effect on the treatment (Figure 1). The algorithm also will take into account confounders that directly affect treatment choices.
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ALGORITHM (Figure 1) The assumption that is made with the algorithm presented (Figure 1) is that any fractures that the surgeon chooses to treat with open reduction and internal fixation (ORIF) will have ample fixation applied so that no postoperative intermaxillary fixation (IMF) will be necessary. Thus, the fixation requirements for the fractures may be more than would be required if one were to employ a period of IMF after ORIF. When a patient presents with a fractured mandible, there are several conditions or factors that should be considered to help define appropriate treatment. The Presence or Absence of Teeth The most basic factor in determining what treatment to provide for a fractured mandible is whether or not the patient has adequate teeth that would permit the application of IMF. If the patient has adequate teeth to permit the application of IMF and/or application of an
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arch bar, they can be treated according to the Dentulous Algorithm. If not, they are placed into the Edentulous Algorithm. Algorithm for Treating Dentate Patients with Mandibular Fractures
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The presence of Teeth on One or Both Sides of the Fracture Line When teeth are present on only one side of a fracture, closed techniques of treatment will often be unsuccessful because there is nothing to stabilize the fragment that contains no teeth. This situation is most common with fractures through the angle, but also occurs with body fractures when no teeth are present distal to the fracture line. Most of these fractures are “unfavorable,” meaning that the direction and/or bevel of the fracture line offers no resistance to the pull of the elevator muscles, allowing the ramus to rotate and the fracture to displace (Figure 2). For purposes of the algorithm, it will be assumed that fractures that do not have teeth on both sides of the fracture will be “unfavorable” fractures, meaning that they cannot be satisfactorily treated closed with IMF. However, there may be an occasional patient whose fracture is “favorable” and such a patient could be treated closed. In practice, however, these are uncommon.
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The presence of stable teeth on both sides of a fracture line is of paramount importance for two reasons. First, it is what will determine whether or not the patient can be treated closed, i.e. with a period of IMF. Simple linear (Figure 3) and comminuted (Figure 4) fractures can be treated closed as long as there are stable teeth on each side of the fracture (and of course teeth in the maxilla). Similarly, the presence of acute or chronic infection at the fracture site does not obviate the possibility of treating such fractures closed. Additional treatment for the infection may also be required (eg. incision and drainage, antibiotics, etc.).
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The second reason that the presence of teeth on both sides of the fracture is important is because if the surgeon chooses open reduction and internal fixation for the fracture, the dentition can be used as a second point of fixation. In fact, when treating a fracture through the body of the mandible, the application of an arch bar to the mandibular teeth almost, by itself, neutralizes the fracture under functional movements because it is applied in the most biomechanically-beneficial location, i.e. the zone of separation (tension).3,4 This means that the amount of internal fixation applied can be minimal, such as a single miniplate, because the arch bar is providing most of the stabilization for the fracture (Figure 5). When teeth are not present on both sides of the fracture, for instance fractures through the angle (Figure 6A) and some fractures through the body (Figure 6B), open treatment becomes necessary to prevent rotation of the ramus from the pull of the elevator muscles. A single miniplate applied along the superior border is adequate fixation in such cases when this is the only fracture of the mandible, or when other fractures have been made “rigid” by application of rigid internal fixation devices (see below).5 A single miniplate applied in this location neutralizes the functional forces generated from elevation of the ramus and depression of the symphysis from the attached muscles by sharing the loads with the bone along the fracture and compressing them together.6
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Summarizing, when teeth are present on both sides of the fracture, the surgeon has the choice of treating the fracture closed or open. However, when teeth are present on only one side of the fracture, the only choice is to treat the fracture open unless the fracture line happens to be “favorable.”
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If Open Treatment is Chosen, Does the Fracture Require Load-Bearing or Load-Sharing Fixation? Load-bearing fixation, a form of rigid fixation, is the application of internal fixation devices that are of sufficient strength that they can bear all the loads of mastication transmitted across the fractured area.7 The bone does not have to share any of the loads. In practice, this is most often accomplished by application of a reconstruction bone plate with a minimum of three screws on each side of the fracture. Any mandibular fracture can be treated with load-bearing fixation. When the surgeon is not sure what fixation to apply to a given fracture, they will never be wrong by applying load-bearing fixation. Load-sharing fixation is the application of internal fixation devices that require that the bone fragments participate in transferring functional loads across the fractured area.7 Examples are the application of miniplates, compression plates, lag screws, etc. across a fracture (Figures 5 and 6). All of these techniques load the bony interfaces during mandibular function so the broader the area of bone contact, the more stable the fixation provided.
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The character of the fracture determines what type of fixation is required. Simple linear fractures can undergo either load-bearing or load-sharing fixation (Figures 5 and 6), whereas comminuted or defect fractures must undergo only load-bearing fixation (Figures 7 and 8). Chronically-infected fractures should also have load-bearing fixation applied when treated open because the bony interfaces may have become demineralized and will not provide a stable interface for load-sharing fixation. Infections present for a week or two (acute infections) can be treated with either load-sharing or load-bearing fixation because their bony fragments have not yet undergone demineralization and provide a stable interface for load-sharing fixation.8-14
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Summarizing, load-sharing fixation can only be applied to fractures that have broad areas of healthy bone contact. Whenever this is not the case, for example in comminuted, defect, chronically-infected, or atrophic fractures, load-bearing fixation should be used. Unlike load-bearing fixation that can be applied to any fracture, load-sharing fixation can only be applied to some fractures. When in doubt, use load-bearing fixation (reconstruction bone plate)! Is the Mandible Fractured in More than One Location? Most studies show that over 50% of patients presenting with mandible fractures have more than one fracture.15-19 Thus, the multiply-fractured mandible is more common than an isolated fracture. Perhaps the most common mandibular fracture seen in the United
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States is a fracture through the angle combined with a contralateral fracture through the symphysis or body fracture.
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As in isolated fractures, in cases where more than one fracture exists and there are usable teeth in all fragments, the surgeon has a choice of either closed or open treatment. Such fractures can be treated closed whether or not they are infected and/or comminuted (Figure 9). If open treatment is selected, the choice of internal fixation hardware becomes more complicated because the biomechanics of the multiply-fractured mandible is more complex than in an isolated fracture of the mandible.5
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If the surgeon selects load-sharing fixation for the fractures, it is important to consider what hardware is applied. Within the category of load-sharing fixation, there are many internal fixation schemes--some more stable than others. For instance, the Champy technique of applying a single miniplate for mandibular body and/or angle fractures is not “rigid” fixation, but instead allows some motion between the bone fragments during function (i.e. the fixation is non-rigid). This choice of fixation functions well when applied to an isolated fracture of the mandible.18,19 However, when applied to bilateral fractures of the mandible, a single miniplate in both locations is associated with more complications then when at least one of the fractures is treated with “rigid” fixation.5 “Rigid” fixation can be applied by use of a reconstruction bone plate (load-bearing fixation) or the application of lag screws, two miniplates, compression plates, two locking plates, etc. (i.e. load-sharing fixation)(Figure 10). Therefore, a general principle is that when multiple mandibular fractures are present, only one of the fractures can be treated with non-rigid fixation—all the others must be treated with rigid fixation.
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Algorithm for Treating Edentulous Patients with Mandibular Fractures When teeth are not present, closed techniques are of limited success. Several studies have shown that using splints, dentures, or external pin fixation are associated with higher rates of complication than is open reduction and stable internal fixation.20-27 Thus, when teeth are not present, ORIF is the only choice that one can usually employ.
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Is the Mandible Atrophic? The fixation requirements of an edentulous fracture are dependent upon the amount of residual bone remaining. An edentulous mandible with a fracture through it may be treated with load-sharing fixation when there is ample volume of bone remaining to provide bone-buttressing. For instance, an edentulous mandible like the one shown in Figure 11A can be treated with load-sharing fixation because there is a large volume of bone in the area of the fracture whereas the one shown in Figure 11B requires loadbearing fixation. The key to the decision on the amount of fixation required for the treatment of a fractured edentulous mandible is the vertical height of bone at the fracture site. When the vertical height of bone is great, load-bearing fixation can be used, assuming no comminution, defect or chronic infection is present. The reason that this is possible is because when fixation is applied in a biomechanically-favorable location, such as the superior border of the mandible, the fracture is neutralized during function by compression of the bone fragments below the point of fixation (Figure 12A).
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On the other hand, when a fracture occurs through an atrophic mandible (Figure 12B), it usually fractures in the thinnest area with the least bone height. A plate applied across this fracture will have to bear all the functional loads transferred across the fracture because there is too little bone for load-sharing. Thus, load-bearing fixation must be used in atrophic mandibles. Thus the adage, the smaller the mandible, the bigger the bone plate must be!28
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Unlike fractures in the dentate mandible, one should also consider the addition of autogenous bone or products that promote bone formation when dealing with fractures through the atrophic mandible. These mandibles have little endosteum or periosteum with osteocompetent cells to promote osseous union.27 Without the addition of bone or bonepromoting products, atrophic mandibles may not heal and instead a “titanium union” maintains the reduction. In time, the plate can fail and the non-healed fracture becomes obvious. Alternatively, the bone plate may be electively removed to facilitate prosthetic reconstruction and a non-union then becomes apparent.
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DISCUSSION The purpose of the algorithm presented is to help clinicians prescribe treatment for a given fracture. As with all algorithms, other variables must also be considered because each patient and each injury has its own unique personality and character. For instance, when there is doubt about whether or not a patient may come back for follow-up care, one might wish to use ORIF rather than closed techniques. When choosing fixation schemes for these patients, it might be prudent to apply rigid internal fixation rather than non-rigid functionally-stable fixation. Similarly, the use of load-bearing fixation even when the fracture would otherwise be treatable with load-sharing fixation is added insurance. Doing either will allow the clinician to either not use or to remove the arch bars immediately after the internal fixation is applied. The lower arch bar will then not be available as another point of fixation for a fracture that has teeth on both sides but if enough fixation is applied directly on the bone, it becomes unnecessary. This should be considered when it is doubtful a patient may return for follow-up. In such cases, the arch bar can become a liability to the patient because it facilitates the development of periodontitis when left in place for long periods of time in patients with poor oral hygiene.
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One might wonder why an algorithm presented in 2014 includes the use of closed treatment for fractures of the mandible. The reason for its inclusion is because closed treatment works very well when applied to the appropriate fracture. When a fracture occurs in the dentate portion of the mandible where there are sound teeth on each side and in the maxilla, the application of IMF not only restores the occlusion, but helps reduce the fracture and also provides fixation to allow healing to progress. When there are areas of comminution, open treatment becomes more complicated because a long reconstruction bone plate must be adapted to the mandible that spans the area of comminution. If there are good teeth on each side of a comminuted fracture, closed treatment can be very easy treatment for this otherwise difficult fracture.
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Treatment may also be prescribed based on convenience. Often, patients will show up in the oral and maxillofacial surgeon’s office with a fractured mandible being self-referred or referred from a local hospital. If the fracture lends itself to closed treatment, this can be performed readily in the surgeon’s office with little cost or effort. If open treatment is chosen, it requires more inconvenience for the surgeon and the patient because the patient usually must be admitted to the hospital for treatment. Thus, closed treatment is still being successfully used by many practitioners and it definitely has a place in the management of mandibular fractures.
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The surgical approaches for those fractures treated open were not mentioned in the algorithm. The choice of surgical approaches does not affect the fixation requirements and can be determined by the experience and desires of the surgeon. In general, the vast majority of mandibular fractures in the dentate mandible can be treated using an intraoral surgical approach. This is especially so for simple (linear) fractures from the angle forward. When comminution occurs, especially in the posterior mandible, it will be more difficult to adapt and secure a reconstruction bone plate through a transoral approach. The surgeon might choose a transfacial approach in such cases. In the edentulous and especially the atrophic mandible, a transfacial approach certainly facilitates open treatment. Such fractures are easier to instrument through a transfacial approach, simplifying the reduction and the application of internal fixation devices.
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This algorithm does not include fractures of the condylar process. The reason for not including them is that these fractures are unique among facial fractures in that they can be treated open or closed without IMF. When treated closed, condylar process fractures can be treated with or without immobilization of the mandible. All other mandibular fractures treated closed require a period of IMF. This makes them unique. Because condylar process fractures are often, if not mostly, associated with other mandibular fractures, including them would greatly complicate a treatment algorithm. Although not included, condylar process fractures follow similar rules as discussed above. For instance, in the case where there are fractures of the mandibular angle, body, and/or symphysis as well as the condylar process, if ORIF is chosen, non-rigid fixation can only be applied to one of them.5 That means that if the condylar process fracture will be treated closed, all the other fractures should be stabilized with rigid internal fixation.
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SUMMARY The algorithm for the treatment of non-condylar mandibular fractures presented here can help the clinician decide on a reasonable treatment plan. Certainly, the treatment for each case must be individualized, but the principles presented should be considered because they are based on sound scientific outcomes.
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Figure Legends Figure 1. Algorithm for the treatment of non-condylar mandibular fractures. Fx=fracture; RIF=rigid internal fixation; Redn=reduction; Infxn=infection)
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Figure 2. A, “favorable” fracture from the standpoint of preventing the mandibular ramus from rotating when using IMF to treat the fracture. B, “unfavorable” fracture from the standpoint of preventing the mandibular ramus from rotating when using IMF to treat the fracture. C, Panoramic radiograph taken 3 weeks after a patient with an unfavorable fracture through the right mandibular angle was treated closed. Note the anterosuperior rotation of the mandibular ramus secondary to the uninhibited pull of the elevator muscles because of lack of teeth on the proximal segment which might have prevented this.
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Figure 3. Fracture of the mandibular body with teeth on both sides of the fracture treated closed. This treatment could be employed whether or not there was infection present, whether or not there was comminution, and whether or not there were other mandibular fractures, as long as all fractures had teeth on both sides to provide reduction and fixation by IMF. Obviously, sufficient maxillary teeth would also be necessary to facilitate IMF.
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Figure 4. Comminuted fracture of the mandibular body with teeth on both sides of the fracture treated closed. This treatment could be employed whether or not there was infection present, and whether or not there were other mandibular fractures, as long as all fractures had teeth on both sides to provide reduction and fixation by IMF. Obviously, sufficient maxillary teeth would also be necessary to facilitate IMF.
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Figure 5. Fracture of the mandibular body with teeth on both sides of the fracture treated open. The use of an arch-bar and a miniplate placed either above the mental nerve (A) or below it (B) is all that is required for an isolated fracture of the body/symphysis region. This treatment could also be applied to an acutely-infected fracture but NOT to a chronically-infected fracture or a comminuted fracture. When ORIF is chosen as the treatment in such cases, the fixation requirements call for load-bearing fixation and a reconstruction bone plate would be indicated. If there were bilateral fractures and ORIF was selected as the treatment, at least one of the fractures should be treated with loadsharing or load-bearing rigid fixation; the other could be treated with load-sharing nonrigid fixation. If chronic infection and/or comminution were present, load-bearing fixation would be required. Figure 6. Fracture of the angle (A) or body (B) of the mandible with teeth on only one side treated open. Closed treatment will not be reliable in such instances because of the tendency for the mandibular ramus to rotate from the pull of the elevator muscles. A single miniplate placed at the superior border is adequate fixation if this is the only fracture present. When the plate is placed along the lateral surface of the mandible (B), one should consider a stronger bone plate because standard miniplates can deform under function from the torqueing of the segments.
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Figure 7. Comminuted fracture of the mandibular body with teeth on both sides of the fracture treated open. This fracture requires load-bearing fixation so a reconstruction bone plate is employed. This treatment could be employed whether or not infection was present. Maintenance of an arch bar in this case is not necessary from the standpoint of providing additional fixation across the fracture. The reconstruction bone plate alone is ample fixation.
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Figure 8. Comminuted fracture of the angle or body of the mandible when there are teeth on only one side treated open. This fracture requires load-bearing fixation so a reconstruction bone plate is employed. This treatment could be employed whether or not infection was present.
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Figure 9. Bilateral fractures in the tooth-bearing region of the mandible treated closed. This treatment could be employed whether or not there was infection present, whether or not there was comminution, and whether or not there were other mandibular fractures, as long as all fractures had teeth on both sides to provide reduction and fixation by IMF. Obviously, sufficient maxillary teeth would also be necessary to facilitate IMF.
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Figure 10. Bilateral fracture of the mandible treated open. This fracture could not be treated closed because of there are no teeth behind the angle fracture to prevent rotation of the ramus. With open treatment, only one of the fractures can be treated with non-rigid fixation. In practice, it is easier to make the more anterior fracture rigid by the application of two miniplates, a stronger, thicker bone plate, etc. The angle fracture can then be treated with non-rigid fixation (single miniplate).
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Figure 11. Radiographs of fractures through an edentulous non-atrophic mandible (A) and an atrophic mandible (B). Although both cases are edentulous, the fixation requirements are very different. The atrophic mandible requires more fixation than the non-atrophic mandible.
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Figure 12. Illustrations of fractures through an edentulous, non-atrophic mandible (A) and an atrophic mandible (B). The red arrows indicate the muscle forces acting on the mandible. When there is a large vertical height of bone in the area of the fracture (“H” in Figure A), load-sharing fixation can be used. The functional forces will be neutralized by the small bone plate at the superior surface of the fractured mandible by compressing the bone along the inferior border. When there is atrophy (B), there is inadequate bone to form a fulcrum point so the plate must take on all the loads generated across the fracture. Figure 13. Illustration showing use of a single miniplate at the superior border of an edentulous but not atrophic mandibular fracture. This fixation scheme works on fractures that are located through an area of the mandible with a large vertical dimension. Figure 14. Illustration showing a reconstruction bone plate used on an atrophic edentulous mandible. Because there is little vertical dimension of bone remaining at the fracture site, this fracture requires load-bearing fixation.
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References 1. Costello BJ, Papadopoulos H, Ruiz R: Pediatric craniomaxillofacial trauma. Clin Pediatr Emerg Med 6:32-40, 2001 2. Hwang K, You SH: Analysis of facial bone fractures: an 11-year study of 2,094 patients. Indian J Plast Surg 43:42-48, 2010 3. Pauwels F: Grundriss einer biomechanik der frakturheilung. Verh Dtsch Orthop Ges 34:62, 1940. 4. Spiessl B, Schargus G: Das Okklusionsproblem bei der funktionsstabilen Osteosynthese des bezahnten Unterkiefers. (The problem of occlusion in functionally stable osteosynthesis of the dentulous mandible). Dtsch Zahn- Mund u Kieferheilk, 57:293-6, 1971 5. Ellis E: Open reduction and internal fixation of combined angle and body/symphysis fractures of the mandible: How much fixation is enough? J Oral Maxillofac Surg 71:726-733, 2013 6. Champy M, Lodde JP, Schmitt R, et al. Mandibular osteosynthesis by miniature screwed plates via a buccal approach. J Maxillofacial Surg 6:14-9, 1978 7. Sugar A, Bentley R: Biomechanics of the bone-implant-unit. Chapter 1.5.5 in: Principles of Internal Fixation of the Craniomaxillofacial Skeleton – Trauma and Orthognathic Surgery, Ehrenfeld M, Manson PN, Prein J (eds), Thieme, Stuttgart, 2012, pp. 91-93 8. Friedrich B, Klaue P: Mechanical stability and post-traumatic osteitis: An experimental evaluation of the relation between infection of bone and internal fixation. Injury 9:23-29, 1977 9. Beckers HL: Treatment of initially infected mandible fractures with bone plates. J Oral Surg 37:310, 1979 10. Johansson B, Krekmanov L, Thomasson M: Miniplate osteosynthesis of infected mandibular fractures. J Cranio Maxillofac Surg 16:22-29, 1988 11. Koury M, Ellis E: Rigid internal fixation for the treatment of infected mandibular fractures. J Oral Maxillofac Surg 50:434-443, 1992 12. Koury M, Perrott D, Kaban L: Use of rigid internal fixation in mandibular fractures complicated by osteomyelitis. J Oral Maxillofac Surg 52:1114-1120, 1994 13. Schiel H, Hammer B, Ehrenfeld M, et al: Therapy of infected mandibular fractures. Fortschr Kiefer Gesichtschir 41:170-177, 1996 14. Mehra P, Van Heukelom E, Cottress DA: Rigid internal fixation of infected mandibular fractures. J Oral Maxillofac Surg 67:1046-1051, 2009 15. Feller KU, Schneider M, Hlawitschka M, et al: Analysis of complications in fractures of the mandibular angle—A study with finite element computation and evaluation of data of 277 patients. J Craniomaxillofac Surg 31:290, 2008 16. Paza AO, Abuabara A, Passeri LA: Analysis of 115 mandibular angle fractures. J Oral Maxillofac Surg 66:73, 2008 17. Ellis E 3rd, Walker L: Treatment of mandibular angle fractures using two noncompression miniplates. J Oral Maxillofac Surg 52:1032, 1994 18. Ellis E 3rd, Walker LR: Treatment of mandibular angle fractures using one noncompression miniplate. J Oral Maxillofac Surg 54:864, 1996 19. Ellis E 3rd: A prospective study of 3 treatment methods for isolated fractures of the mandibular angle. J Oral Maxillofac Surg 68:2743, 2010
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20. Bruce RA, Strachan DS: Fractures of the edentulous mandible: The Chalmers J. Lyons Academy study. J Oral Surg 34:973, 1976 21. Bruce RA, Ellis E: The second Chalmers J. Lyons Academy study of fractures of the edentulous mandible. J Oral Maxillofac Surg 51:904, 1993 22. Buchbinder D: Treatment of fractures of the edentulous mandible, 1943 to 1993: A review of the literature. J Oral Maxillofac Surg 51:1174, 1993 23. Luhr HG, Reidick T, Merten HA: Results of treatment of fractures of the atrophic edentulous mandible by compression plating. J Oral Maxillofac Surg 54:250, 1996 24. Eyrich GK, Gratz KW, Sailer HF: Surgical treatment of fractures of the edentulous mandible. J Oral Maxillofac Surg 55:1081, 1997 25. Iatrou I, Samaras C, Lygidakis NT: Miniplate osteosynthesis for fractures of the edentulous mandible: A clinical study, 1989–1996. J Craniomaxillofac Surg 26:400, 1998 26. Kunz C, Hammer B, Prein J: Fractures of the edentulous atrophic mandible: Management and complications [in German]. Mund Kiefer Gesichtschir 5:227, 2001 27. Ellis E, Price C: Treatment protocol for fractures of the atrophic mandible. J Oral Maxillofac Surg 66:421-435, 2008 28. Schilli W, Stoll P, Bahr W, Prein J: Mandibular Fractures. Chapter 3 in: Manual of Internal Fixation in the Cranio-Facial Skeleton, Prein J (ed), Springer, Berlin, 1998, p. 87
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Non-Rigid Load Sharing Fixation OK on only one fx: RIF on any others
Simple (linear) Fx(s) (+/- Acute Infection)
Chronically Infected
Teeth Missing on at least one side of any Fx
Load Bearing Fixation Required
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ORIF
Teeth on Both Sides of Fx(s)
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Mandible Fracture
Closed Redn + IMF (+/- Infxn or Comminution
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Chronically Infected
Non-Atrophic
Load Bearing Fixation Required
Comminuted Fx(s)
Simple (linear) Fx(s) (+/- Acute Infection)
Non-Rigid Load Sharing Fixation OK on only one fx: RIF on any others
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