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Complications of facial plating
® COMPLICATIONS OF FACIAL PLATING KEVIN A. SHUMRICK, MD, FACS
The introduction of plates and screws to provide rigid internal fixation of facial fractures has been a significant advance over the use of simple interfragment wiring. Modern-day plates and screws provide a means of spanning areas of bony loss or comminution, and because the screw contacts 360 degrees of the drill hole, it provides a much stronger grip than a wire. The first plates used for rigid internal fixation of the facial skeleton were mandibular plates made of stainless steel and with screw diameters of 2.7 m m and plate screw profiles of as much as 3.0 mm. Since that time there has been steady advancement in the engineering of plates, with the introduction of superior metals such as titanium and vitallium and progressive miniaturization of the systems to such a degree, that there are now microplating systems with profiles and screw diameters of less than I mm. Complications were relatively common with the initial mandibular plating systems, probably because they were made of stainless steel and m a n y of the surgeons using these systems were relatively inexperienced with the use of plates. However, with improvement in the design of plating systems and the routine teaching of plating techniques during medical residencies, the incidence of complications has steadily decreased and the recently published series comparing plates and older techniques have shown fewer complications with plates. 16 However, complications do arise with the use of plates and screws, and this article presents these possible pitfalls and their causes, so that complications may be decreased even further. When considering complications of facial plating there are two broad categories. The first category relates to plating of incompletely reduced or mal-aligned fractures. When plates are used to secure bone segments that have not been restored to their pretrauma position rigid internal fixation may actually be worse than simple wire fixation, suspension or intermaxillary fixation. With these other techniques, the fractures are not rigidly fixed and there is some room for modification of the fracture position through the use of elastics and intermaxillary fixation. With plates providing rigid fixation of teethbearing bone, if the fracture is rigidly fixed even one or two millimeters out of position malocclusion will occur that can only be corrected by another operation or osteotomy. However, it should be noted that failure to
From the Universtty of Cincmnati Medtcal Center, Department of Otolaryngology--Head and Neck Surgery Address reprint requests to Kevm A. Shumrick, MD, FACS, University of Cincinnatt Medical Center, Department of Otolaryngology-Head and Neck Surgery, P.O Box 670528, Cincinnati, OH 452670528. Copyright © 1995 by W.B. Saunders Company 1043-1810/95/0602-0003505.00/0
accurately align the fracture segments is not really a complication of the plates as much as it is a failure of the surgeon to adequately and accurately reduce the fracture. The second category of complications ascribed to the use of plating are those related directly to the plates and screws. It should be stated at the outset that m a n y of these complications are primarily related to improper use of the plates or poor clinical judgement as to plate selection, placement technique, or clinical situation. Again, it is the surgeon's responsibility to make sure he/she is properly trained in the use of plating systems and their indications before using t h e m in clinical situations. Within this category of complications related to plate use are two distinct groups related to the anatomical location of the plate: complications related to plating of the mandible and complications related to plating of the rest of the facial skeleton.
COMPLICATIONS OF MANDIBULAR PLATING When the initial mandibular systems were introduced with thick plates and wide screws made of stainless steel, complications were relatively common, although not so commonly reported. Starting in the late 1980s, all mandibular plates were made of biocompatible materials and the size of the plates became smaller. Additionally, changes in technique were introduced that made plating simpler and more reliable. For instance, today almost all mandibular screws are self-tapping and eccentric dynamic compression plating (EDCP) has been virtually abandoned because of the high incidence of complications. Even compression plating, which was once the mainstay of mandibular plating, is being used less frequently in favor of simple rigid fixation. As these techniques have been simplified, the size of the plates has been significantly decreased with authors now advocating the use of simple miniplates for rigid internal fixation of mandibular fractures. 4 The reason for these simplifications in technique is that almost all complications associated with plating are caused by technical error by the surgeon and systems that were excessively techniquedependent (such as the EDCP plate) were associated with an unacceptable complication rate w h e n used by surgeons who were inexperienced with the system. Plate thickness and screw diameter have been steadily decreasing because of the realization that adequate fixation may be obtained with smaller plates and the larger the plate and screw, the greater the damage that can occur if a complication arises. 7 Finally, it is well accepted that the single major cause of serious complications related to mandibular plating is lack of rigid fixation of the fracture. If there is any mo-
OPERATIVE TECHNIQUES IN OTOLARYNGOLOGY--HEAD AND NECK SURGERY, VOL 6, NO 2 (JUN), 1995: PP 135-141
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tion across the fracture site or screw holes there will be resorption of bone, which will cause further instability and further bone resorption. This situation of an unstable fracture and loose plate and screw then leads to nonunion, plate infection, plate extrusion, and rapid destruction of the mandible.
PLATE EXPOSURE Postoperative exposure of the plate w h e n using an intraoral incision for reduction and fixation of mandibular fractures is not an uncommon occurrence. 7,s Plate exposure may occur for a number of reasons including improper closure technique, the w o u n d breaking down because of inadequate suture material, or an underlying w o u n d problem. If the plate has been properly placed and the fracture is rigidly fixed, plate exposure is of little consequence and the mucosa will often grow over the exposed mandible and plate or the mucosa may be closed secondarily with the patient under local anesthesia (Fig 1). However, if a plate becomes exposed and there are associated findings or symptoms such as drainage or pain, the possibility of an underlying problem with the fracture site should be considered and a panorex obtained to rule out a nonunion of the fracture or evidence of bone resorption around a screw hole. If either of these situations exists the problem with the plate or fracture site will need to be addressed before the mucosa will heal. Often the w o u n d will need to be explored and a loose plate removed or a nonstable fracture refixated. It is rare for a mandibular plate to become exposed externally and such an occurrence almost surely indicates a serious problem with the wound, requiring a complete radiological workup and w o u n d exploration. We have seen several patients in w h o m a sinus developed over a plate months after repair of the fracture, when healing should be complete with no evidence of bone resorption on panorex. Exploration of the w o u n d revealed a screw
that had loosened. After removal of the screw the wound closed without further difficulty.
COLD INTOLERANCE OF THE PLATE Before the introduction of titanium and vitallium plates and the downsizing that has recently taken place, there were reports of patients experiencing discomfort in the region of the plate with cold exposure. This probably relates to the use of large stainless steel plates with high profiles. With the new plating systems available, during the last six years this author has not encountered a single patient complaining of cold intolerance over the region of the plate. Thus, it seems likely that this complication should be of historical interest only. If a patient does present with this complaint, the only solutions are to remove the plate or advise the patient to move to warmer environs.
PALPABLE PLATE Palpation of a mandibular plate was not uncommon with the larger mandibular plates (2.7-mm diameter screws), especially in a thin individual. However, with the introduction of thinner plates this complaint has become uncommon and the only solution would seem to be plate removal after allowing sufficient time for the fracture to stabilize.
TRAUMA TO TOOTH ROOTS Trauma to tooth roots with the drill and/or screw is a definite possibility w h e n using plates and screws for rigid fixation of the mandible. Review of the literature does not show any good data on the incidence of this complication, but it seems to be relatively common. The results of violating a tooth root with a drill and screw range
FIGURE 1. Mandibular plate placed via an intraoral incision that has become exposed. However, the plate was stable without other symptomatology and the panorex showed no evidence of bone resorption. Therefore, the plate was left in place for 2 months and then removed.
136
COMPLICATIONS OF FACIAL PLATING
from loss of the tooth to chronic infection causing bone resorption, plate and screw loosening, and nonunion of the fracture. To avert these adverse sequelae the general rule to avoid injury to tooth roots is to place the drill holes below the level of the inferior alveolar nerve. If plates are to be placed above the level of the mental nerve the screw holes should be monocortical.
TRAUMA TO MENTAL NERVE Injury to the mental nerve with resultant ipsilateral, lower lip hypesthesia is a relatively common occurrence with management of mandible fractures. However, it should also be recognized that injury to the mental nerve commonly occurs from the fracture itself and lower lip
FIGURE 2. (A) Nonunion of angle fracture resulting from an inadequate fixation with a wire (B) Nonunion treated with a mandibular plate and rigid internal fixation.
FIGURE 3. Poorly contoured plate with incomplete stability. Movement of the mandible around the plate and screw has resulted in a nonunion and resorption of a significant portion of the mandible. SHUMRICK
137
FIGURE 4. (A) Nonunion of mandible assoaated with the use of mandibular reconstruction plate and resorption of a large portion of the mandible. (B) The wound is explored and the plate removed. Fixation is provided by an external fixator. (C) Panorex showing that after 8 weeks the mandible was repaired with bone grafting and a miniplate in conjunction with the external fixator. 138
COMPLICATIONS OF FACIAL PLATING
sensation should be documented before surgery to avoid confusion as to w h e n the lip numbness occurred. The mental nerve may be injured at two points during repair of a mandible fracture. First, with an intraoral approach if the fracture line involves the mental foramen (which it commonly does) the nerve may be drawn into the fracture line with inferior retraction of the lip. Once drawn into the fracture line, the nerve may be lacerated or severed by the sharp edges of bone. If it becomes apparent during an intraoral approach for mandibular fracture that the mental nerve is being drawn into the fracture line then the surgeon should consider converting to an open approach for fracture repair. An alternative to converting to an open approach, which the author has used on several occasions with some success, is to drill out a portion of the alveolar canal and release the nerve so that it is not drawn into the fracture so tightly. The second cause of mental nerve injury during mandibular plating is drilling into the nerve canal during screw hole placement. This should be avoidable by careful review of the preoperative panorex, noting where the nerve canal lies and its relative course. The nerve should be routinely identified at its foramen in mandibular fracture repair (particularly fractures of the anterior two thirds of the mandible) and knowing its course and anatomic location should allow safe placement of the screw holes. Difficulty with estimating the location of the nerve may arise at the angle and when the mandible has undergone atrophy secondary to tooth removal. In cases of mandibular atrophy, there may be so little bone left that a mandibular plate would have insufficient space for screw placement under the nerve and this may require using a smaller plate or monocortical screws.
INFECTION OF FRACTURE LINE Infection after mandibular plating can usually be traced to either a technical error or patient-related factor. One important patient factor is alcoholism. Alcohol abuse
and mandibular fractures are strongly related. Alcohol is an etiologic agent and, in all relevant studies, alcoholics have significantly increased rates of complications, particularly infections and nonunions. 9"1° Teeth in the fracture line may well contribute to an increased incidence of frac~re line infection. 9 As a general rule, if the fracture line crosses a tooth root and has an intraoral communication, we will remove the tooth. Without doubt, the major cause of fracture line infection is lack of rigid fixation with movement of the fracture segments or a loose plate. In this situation, steps will need to be taken to rigidly fixate the fracture and/or remove the loose hardware, or the w o u n d will not heal.
NONUNION OF FRACTURE The most serious complication associated with mandibular plating is nonunion. This complication is almost always the result of a technical error. Most series show that the incidence of nonunions is lower with plating than wiring (Figs 2A, B). 4'6"9"12 The major cause for nonunion is inadequate fixation of the fracture by the plate and subsequent movement of the fracture and/or movement of the plate relative to the mandible. In this situation, in which plates have been used and inadequate fixation results, plating can result in complications far more significant than if simple interosseous wiring and intermaxillary fixation had been used. When movement occurs across a fracture line, the first reaction of the b o d y is to initiate bone resorption. This occurs at not only the fracture site, but also around screw holes. The more movement and the larger the plate (and screw holes), the faster the bone resorption. This can result in rapid resorption of large portions of the mandible and we consider this an indication for an urgent return to the operating room, where the goal is to provide immobilization of the mandible (Fig 3). Although some authors will state that it is safe to go ahead and reapply an additional
FIGURE 5. Exposure of a miniplate placed on the maxilla via a sublabial approach. The rest of the plate and wound was stable and the exposed portion of the plate was simply observed until the fracture was healed and then the plate was removed. SHUMRICK
139
plate to provide fixation (presumably correcting whatever technical problem was present with the first plate), we feel that in a situation in which a portion of the mandible has been lost, it is safest to fixate the mandible with an external fixator such as Joe Hall Morris apparatus and place the patient in intermaxillary fixation. After 4 to 6 weeks, w h e n the w o u n d has stabilized, the w o u n d is reexplored and bone grafted with plate fixation (Figs 4A, B,C).
COMPLICATIONS OF MIDFACE PLATING In contrast to mandible fractures in which complications with plating are magnified and the resulting damage to the bone greater than if just d o s e d or wire techniques were used, midface plates are associated with relatively minor complications. This is particularly true with the introduction of smaller and smaller miniplates and even microplates.
FIGURE 6. (A) Lateral view of skull showing plate placed over the maxillary sinus with protrusion of the screw into the sinus. (B) Computed tomography showing recurrent sinusitis of maxillary sinus m association with the screw protruding into it. Without any other clear etiologic agents for the recurrent infections, the plate and screw were removed and there have been no further infections.
140
COMPLICATIONS OF FACIAL PLATING
PALPABLE PLATE Previously, with use of plates in the midface, patients often complained of being able to palpate the plate u n d e r the skin, particularly in the frontal a n d frontozygomatic region. This most c o m m o n l y occurred with the use of relatively large miniplates m a d e of stainless steel a n d profiles of 1.5 to 2.0 ram. With the introduction of microplates with profiles u n d e r 1.0 m m , this complication has virtually disappeared.
COLD TOLERANCE Cold intolerance was another complaint that seems to have been caused by the use of relatively large miniplates in the thin skinned frontal orbital region. With the introduction of appropriately sized microplates, this complaint is n o w a distinct rarity.
SINUSITIS In almost every case involving plating of the midface, a paranasal sinus will be involved to some degree. Therefore, it is surprising to note h o w infrequently complications related to the sinuses occur after midface plating. The frontal sinus is well k n o w n to have the propensity to develop mucoceles, but this is usually related to blockage of the nasofrontal ducts a n d not the plates. This a u t h o r has not seen a definite complication of plating involving the frontal sinus. Occasionally, a patient will present w i t h recurrent sinusitis that is clearly related to the plate or screw. This usually involves the maxillary sinus a n d resolves with removal of the plate and screws (Figs 6A, B).
SUMMARY PLATE EXPOSURE Plate exposure is not u n c o m m o n in the maxillary and zygomaticomaxillary region w h e n placed t h r o u g h a sublabial incision (Fig 5). If the plate a n d screws are stable, nothing needs to be done initially a n d the mucosa will often grow over the plate. However, if the plate or a screw are loose, the mucosa will not close and the hardware should be removed. The plate should not be rem o v e d before 4 to 6 weeks postoperatively to allow the fracture to heal sufficiently; t h e n the plate is no longer necessary for fixation. Exposure of plates at other sites in the midface is distinctly u n c o m m o n and usually the result of loss of tissue overlying the plate. If the plate is stable and there is no evidence of bone resorption, nothing needs to be done. However, if the plate is unstable or seems to be hindering w o u n d healing, it should be removed.
INJURY TO TOOTH ROOTS Although m u c h less c o m m o n t h a n with mandibular fractures, tooth roots m a y also be injured with plating of maxillary fractures. The most c o m m o n l y involved tooth root is that of the canine tooth because of its superior extent into the canine fossa. Avoidance of this complication is rather simple because in the majority of cases the surgeon can see the outline of the tooth root a n d should be able to avoid it.
INFECTION OF PLATE SITE Infections of the plate site are rare. If the plate seems stable, simply opening the incision line a n d allowing drainage will usually solve the problem. If signs of infection persist or there is evidence of bone resorption, the w o u n d should be explored for possible causes such as foreign bodies or bone sequestra. If no other source of infection other t h a n the plate is found, the plate should be removed.
NONUNION OF FRACTURE Because the bones of the midface are, for practical purposes, n o n weight-bearing, true n o n u n i o n of fractures in the midface is extremely rare, with most fractures healing rapidly and strongly by 4 weeks postoperatively. SHUMRICK
Plating systems for the m a n a g e m e n t of facial t r a u m a have been a t r e m e n d o u s advance over the previous m e t h o d s that were available such as intermaxillary fixation a n d suspension wires. Not only do patients recover more quickly with plates, they usually have a more accurate a n d stable reduction. Complications can arise w i t h the use of plating systems, but t h e y are becoming rarer as the plates improve a n d more surgeons are fully trained in their use. In experience obtained at our institution a complication related to plating can be traced to a technical error on our part a n d these are continuing to decrease as the plating systems improve a n d experience is gained.
REFERENCES 1. Klotch DW, GiUilandR: Internal fLxabonversus conventional therapy in mid-face fractures. J Trauma 27:1136-1145, 1987 2. Nlshioka GJ, Slckels JEV: Transoral plating of mandibular angle fractures: A technique. Oral Surg Oral Med Oral Patho166:531-534, 1988 3. RavehJ, VmUemin, T, Ladrach K, et al: Plate osteosynthesis of 367 mandibular fractures: The unrestricted mdication for mtraoral approach. J CramomaxiUofacSurg 15:244-253, 1987 4. Thaller SR: Management of mandibular fractures. Arch Otolaryngol Head Neck Surg 120:44-48, 1994 5. Wald RM, Jr, Abemayor E, Zemplenyl J, et al: The transoral treatment of mandibular fractures using noncompression miniplates: A prospective study. Ann Plast Surg 20:409-413, 1988 6. Zachariades N, Papademetriou I, RaUisG: Complicationsassociated with ngld internal fixabon of facialbone fractures. J Oral MaxiUofac Surg 51:275-278, 1993 7. Gruss JS: Comphcations of ngid internal fixabon of the mandible, in Yaremchuk MJ, Gruss JS, Manson PN (eds): Rigid Fixation of the Craniomaxillofaclal Skeleton. Boston, MA, ButterworthHeinemann, 1992, pp 217-232 8. Dierks EJ: Transoral approach to fractures of the mandible. Laryngoscope 97:4-6, 1987 9. Bruce R, Fonseca RJ: Mandibular fractures, in Fonseca RJ, Walker RV (eds): Oral and MaxillofacialTrauma, vol 1. Philadelphia, PA, Saunders, 1991, pp 359-417 10. Adele R, Eriksson B, Nylin O, et al: Delayed healing of fractures of the mandibular body. Int J Oral MaxlUofacSurg 16:15-21, 1987 11. Ardary WC: Plate and screw fixation in the management of mandible fractures. Clin Plast Surg 16(1):61-67, 1989 12. BochlogyrosPN: Non-umon of fractures of the mandible. J Maxillofac Surg 16:189-195, 1985 141
The introduction of plates and screws to provide rigid internal fixation of facial fractures has been a significant advance over the use of simple interfragment wiring. Modern-day plates and screws provide a means of spanning areas of bony loss or comminution, and because the screw contacts 360 degrees of the drill hole, it provides a much stronger grip than a wire. The first plates used for rigid internal fixation of the facial skeleton were mandibular plates made of stainless steel and with screw diameters of 2.7 m m and plate screw profiles of as much as 3.0 mm. Since that time there has been steady advancement in the engineering of plates, with the introduction of superior metals such as titanium and vitallium and progressive miniaturization of the systems to such a degree, that there are now microplating systems with profiles and screw diameters of less than I mm. Complications were relatively common with the initial mandibular plating systems, probably because they were made of stainless steel and m a n y of the surgeons using these systems were relatively inexperienced with the use of plates. However, with improvement in the design of plating systems and the routine teaching of plating techniques during medical residencies, the incidence of complications has steadily decreased and the recently published series comparing plates and older techniques have shown fewer complications with plates. 16 However, complications do arise with the use of plates and screws, and this article presents these possible pitfalls and their causes, so that complications may be decreased even further. When considering complications of facial plating there are two broad categories. The first category relates to plating of incompletely reduced or mal-aligned fractures. When plates are used to secure bone segments that have not been restored to their pretrauma position rigid internal fixation may actually be worse than simple wire fixation, suspension or intermaxillary fixation. With these other techniques, the fractures are not rigidly fixed and there is some room for modification of the fracture position through the use of elastics and intermaxillary fixation. With plates providing rigid fixation of teethbearing bone, if the fracture is rigidly fixed even one or two millimeters out of position malocclusion will occur that can only be corrected by another operation or osteotomy. However, it should be noted that failure to
From the Universtty of Cincmnati Medtcal Center, Department of Otolaryngology--Head and Neck Surgery Address reprint requests to Kevm A. Shumrick, MD, FACS, University of Cincinnatt Medical Center, Department of Otolaryngology-Head and Neck Surgery, P.O Box 670528, Cincinnati, OH 452670528. Copyright © 1995 by W.B. Saunders Company 1043-1810/95/0602-0003505.00/0
accurately align the fracture segments is not really a complication of the plates as much as it is a failure of the surgeon to adequately and accurately reduce the fracture. The second category of complications ascribed to the use of plating are those related directly to the plates and screws. It should be stated at the outset that m a n y of these complications are primarily related to improper use of the plates or poor clinical judgement as to plate selection, placement technique, or clinical situation. Again, it is the surgeon's responsibility to make sure he/she is properly trained in the use of plating systems and their indications before using t h e m in clinical situations. Within this category of complications related to plate use are two distinct groups related to the anatomical location of the plate: complications related to plating of the mandible and complications related to plating of the rest of the facial skeleton.
COMPLICATIONS OF MANDIBULAR PLATING When the initial mandibular systems were introduced with thick plates and wide screws made of stainless steel, complications were relatively common, although not so commonly reported. Starting in the late 1980s, all mandibular plates were made of biocompatible materials and the size of the plates became smaller. Additionally, changes in technique were introduced that made plating simpler and more reliable. For instance, today almost all mandibular screws are self-tapping and eccentric dynamic compression plating (EDCP) has been virtually abandoned because of the high incidence of complications. Even compression plating, which was once the mainstay of mandibular plating, is being used less frequently in favor of simple rigid fixation. As these techniques have been simplified, the size of the plates has been significantly decreased with authors now advocating the use of simple miniplates for rigid internal fixation of mandibular fractures. 4 The reason for these simplifications in technique is that almost all complications associated with plating are caused by technical error by the surgeon and systems that were excessively techniquedependent (such as the EDCP plate) were associated with an unacceptable complication rate w h e n used by surgeons who were inexperienced with the system. Plate thickness and screw diameter have been steadily decreasing because of the realization that adequate fixation may be obtained with smaller plates and the larger the plate and screw, the greater the damage that can occur if a complication arises. 7 Finally, it is well accepted that the single major cause of serious complications related to mandibular plating is lack of rigid fixation of the fracture. If there is any mo-
OPERATIVE TECHNIQUES IN OTOLARYNGOLOGY--HEAD AND NECK SURGERY, VOL 6, NO 2 (JUN), 1995: PP 135-141
135
tion across the fracture site or screw holes there will be resorption of bone, which will cause further instability and further bone resorption. This situation of an unstable fracture and loose plate and screw then leads to nonunion, plate infection, plate extrusion, and rapid destruction of the mandible.
PLATE EXPOSURE Postoperative exposure of the plate w h e n using an intraoral incision for reduction and fixation of mandibular fractures is not an uncommon occurrence. 7,s Plate exposure may occur for a number of reasons including improper closure technique, the w o u n d breaking down because of inadequate suture material, or an underlying w o u n d problem. If the plate has been properly placed and the fracture is rigidly fixed, plate exposure is of little consequence and the mucosa will often grow over the exposed mandible and plate or the mucosa may be closed secondarily with the patient under local anesthesia (Fig 1). However, if a plate becomes exposed and there are associated findings or symptoms such as drainage or pain, the possibility of an underlying problem with the fracture site should be considered and a panorex obtained to rule out a nonunion of the fracture or evidence of bone resorption around a screw hole. If either of these situations exists the problem with the plate or fracture site will need to be addressed before the mucosa will heal. Often the w o u n d will need to be explored and a loose plate removed or a nonstable fracture refixated. It is rare for a mandibular plate to become exposed externally and such an occurrence almost surely indicates a serious problem with the wound, requiring a complete radiological workup and w o u n d exploration. We have seen several patients in w h o m a sinus developed over a plate months after repair of the fracture, when healing should be complete with no evidence of bone resorption on panorex. Exploration of the w o u n d revealed a screw
that had loosened. After removal of the screw the wound closed without further difficulty.
COLD INTOLERANCE OF THE PLATE Before the introduction of titanium and vitallium plates and the downsizing that has recently taken place, there were reports of patients experiencing discomfort in the region of the plate with cold exposure. This probably relates to the use of large stainless steel plates with high profiles. With the new plating systems available, during the last six years this author has not encountered a single patient complaining of cold intolerance over the region of the plate. Thus, it seems likely that this complication should be of historical interest only. If a patient does present with this complaint, the only solutions are to remove the plate or advise the patient to move to warmer environs.
PALPABLE PLATE Palpation of a mandibular plate was not uncommon with the larger mandibular plates (2.7-mm diameter screws), especially in a thin individual. However, with the introduction of thinner plates this complaint has become uncommon and the only solution would seem to be plate removal after allowing sufficient time for the fracture to stabilize.
TRAUMA TO TOOTH ROOTS Trauma to tooth roots with the drill and/or screw is a definite possibility w h e n using plates and screws for rigid fixation of the mandible. Review of the literature does not show any good data on the incidence of this complication, but it seems to be relatively common. The results of violating a tooth root with a drill and screw range
FIGURE 1. Mandibular plate placed via an intraoral incision that has become exposed. However, the plate was stable without other symptomatology and the panorex showed no evidence of bone resorption. Therefore, the plate was left in place for 2 months and then removed.
136
COMPLICATIONS OF FACIAL PLATING
from loss of the tooth to chronic infection causing bone resorption, plate and screw loosening, and nonunion of the fracture. To avert these adverse sequelae the general rule to avoid injury to tooth roots is to place the drill holes below the level of the inferior alveolar nerve. If plates are to be placed above the level of the mental nerve the screw holes should be monocortical.
TRAUMA TO MENTAL NERVE Injury to the mental nerve with resultant ipsilateral, lower lip hypesthesia is a relatively common occurrence with management of mandible fractures. However, it should also be recognized that injury to the mental nerve commonly occurs from the fracture itself and lower lip
FIGURE 2. (A) Nonunion of angle fracture resulting from an inadequate fixation with a wire (B) Nonunion treated with a mandibular plate and rigid internal fixation.
FIGURE 3. Poorly contoured plate with incomplete stability. Movement of the mandible around the plate and screw has resulted in a nonunion and resorption of a significant portion of the mandible. SHUMRICK
137
FIGURE 4. (A) Nonunion of mandible assoaated with the use of mandibular reconstruction plate and resorption of a large portion of the mandible. (B) The wound is explored and the plate removed. Fixation is provided by an external fixator. (C) Panorex showing that after 8 weeks the mandible was repaired with bone grafting and a miniplate in conjunction with the external fixator. 138
COMPLICATIONS OF FACIAL PLATING
sensation should be documented before surgery to avoid confusion as to w h e n the lip numbness occurred. The mental nerve may be injured at two points during repair of a mandible fracture. First, with an intraoral approach if the fracture line involves the mental foramen (which it commonly does) the nerve may be drawn into the fracture line with inferior retraction of the lip. Once drawn into the fracture line, the nerve may be lacerated or severed by the sharp edges of bone. If it becomes apparent during an intraoral approach for mandibular fracture that the mental nerve is being drawn into the fracture line then the surgeon should consider converting to an open approach for fracture repair. An alternative to converting to an open approach, which the author has used on several occasions with some success, is to drill out a portion of the alveolar canal and release the nerve so that it is not drawn into the fracture so tightly. The second cause of mental nerve injury during mandibular plating is drilling into the nerve canal during screw hole placement. This should be avoidable by careful review of the preoperative panorex, noting where the nerve canal lies and its relative course. The nerve should be routinely identified at its foramen in mandibular fracture repair (particularly fractures of the anterior two thirds of the mandible) and knowing its course and anatomic location should allow safe placement of the screw holes. Difficulty with estimating the location of the nerve may arise at the angle and when the mandible has undergone atrophy secondary to tooth removal. In cases of mandibular atrophy, there may be so little bone left that a mandibular plate would have insufficient space for screw placement under the nerve and this may require using a smaller plate or monocortical screws.
INFECTION OF FRACTURE LINE Infection after mandibular plating can usually be traced to either a technical error or patient-related factor. One important patient factor is alcoholism. Alcohol abuse
and mandibular fractures are strongly related. Alcohol is an etiologic agent and, in all relevant studies, alcoholics have significantly increased rates of complications, particularly infections and nonunions. 9"1° Teeth in the fracture line may well contribute to an increased incidence of frac~re line infection. 9 As a general rule, if the fracture line crosses a tooth root and has an intraoral communication, we will remove the tooth. Without doubt, the major cause of fracture line infection is lack of rigid fixation with movement of the fracture segments or a loose plate. In this situation, steps will need to be taken to rigidly fixate the fracture and/or remove the loose hardware, or the w o u n d will not heal.
NONUNION OF FRACTURE The most serious complication associated with mandibular plating is nonunion. This complication is almost always the result of a technical error. Most series show that the incidence of nonunions is lower with plating than wiring (Figs 2A, B). 4'6"9"12 The major cause for nonunion is inadequate fixation of the fracture by the plate and subsequent movement of the fracture and/or movement of the plate relative to the mandible. In this situation, in which plates have been used and inadequate fixation results, plating can result in complications far more significant than if simple interosseous wiring and intermaxillary fixation had been used. When movement occurs across a fracture line, the first reaction of the b o d y is to initiate bone resorption. This occurs at not only the fracture site, but also around screw holes. The more movement and the larger the plate (and screw holes), the faster the bone resorption. This can result in rapid resorption of large portions of the mandible and we consider this an indication for an urgent return to the operating room, where the goal is to provide immobilization of the mandible (Fig 3). Although some authors will state that it is safe to go ahead and reapply an additional
FIGURE 5. Exposure of a miniplate placed on the maxilla via a sublabial approach. The rest of the plate and wound was stable and the exposed portion of the plate was simply observed until the fracture was healed and then the plate was removed. SHUMRICK
139
plate to provide fixation (presumably correcting whatever technical problem was present with the first plate), we feel that in a situation in which a portion of the mandible has been lost, it is safest to fixate the mandible with an external fixator such as Joe Hall Morris apparatus and place the patient in intermaxillary fixation. After 4 to 6 weeks, w h e n the w o u n d has stabilized, the w o u n d is reexplored and bone grafted with plate fixation (Figs 4A, B,C).
COMPLICATIONS OF MIDFACE PLATING In contrast to mandible fractures in which complications with plating are magnified and the resulting damage to the bone greater than if just d o s e d or wire techniques were used, midface plates are associated with relatively minor complications. This is particularly true with the introduction of smaller and smaller miniplates and even microplates.
FIGURE 6. (A) Lateral view of skull showing plate placed over the maxillary sinus with protrusion of the screw into the sinus. (B) Computed tomography showing recurrent sinusitis of maxillary sinus m association with the screw protruding into it. Without any other clear etiologic agents for the recurrent infections, the plate and screw were removed and there have been no further infections.
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COMPLICATIONS OF FACIAL PLATING
PALPABLE PLATE Previously, with use of plates in the midface, patients often complained of being able to palpate the plate u n d e r the skin, particularly in the frontal a n d frontozygomatic region. This most c o m m o n l y occurred with the use of relatively large miniplates m a d e of stainless steel a n d profiles of 1.5 to 2.0 ram. With the introduction of microplates with profiles u n d e r 1.0 m m , this complication has virtually disappeared.
COLD TOLERANCE Cold intolerance was another complaint that seems to have been caused by the use of relatively large miniplates in the thin skinned frontal orbital region. With the introduction of appropriately sized microplates, this complaint is n o w a distinct rarity.
SINUSITIS In almost every case involving plating of the midface, a paranasal sinus will be involved to some degree. Therefore, it is surprising to note h o w infrequently complications related to the sinuses occur after midface plating. The frontal sinus is well k n o w n to have the propensity to develop mucoceles, but this is usually related to blockage of the nasofrontal ducts a n d not the plates. This a u t h o r has not seen a definite complication of plating involving the frontal sinus. Occasionally, a patient will present w i t h recurrent sinusitis that is clearly related to the plate or screw. This usually involves the maxillary sinus a n d resolves with removal of the plate and screws (Figs 6A, B).
SUMMARY PLATE EXPOSURE Plate exposure is not u n c o m m o n in the maxillary and zygomaticomaxillary region w h e n placed t h r o u g h a sublabial incision (Fig 5). If the plate a n d screws are stable, nothing needs to be done initially a n d the mucosa will often grow over the plate. However, if the plate or a screw are loose, the mucosa will not close and the hardware should be removed. The plate should not be rem o v e d before 4 to 6 weeks postoperatively to allow the fracture to heal sufficiently; t h e n the plate is no longer necessary for fixation. Exposure of plates at other sites in the midface is distinctly u n c o m m o n and usually the result of loss of tissue overlying the plate. If the plate is stable and there is no evidence of bone resorption, nothing needs to be done. However, if the plate is unstable or seems to be hindering w o u n d healing, it should be removed.
INJURY TO TOOTH ROOTS Although m u c h less c o m m o n t h a n with mandibular fractures, tooth roots m a y also be injured with plating of maxillary fractures. The most c o m m o n l y involved tooth root is that of the canine tooth because of its superior extent into the canine fossa. Avoidance of this complication is rather simple because in the majority of cases the surgeon can see the outline of the tooth root a n d should be able to avoid it.
INFECTION OF PLATE SITE Infections of the plate site are rare. If the plate seems stable, simply opening the incision line a n d allowing drainage will usually solve the problem. If signs of infection persist or there is evidence of bone resorption, the w o u n d should be explored for possible causes such as foreign bodies or bone sequestra. If no other source of infection other t h a n the plate is found, the plate should be removed.
NONUNION OF FRACTURE Because the bones of the midface are, for practical purposes, n o n weight-bearing, true n o n u n i o n of fractures in the midface is extremely rare, with most fractures healing rapidly and strongly by 4 weeks postoperatively. SHUMRICK
Plating systems for the m a n a g e m e n t of facial t r a u m a have been a t r e m e n d o u s advance over the previous m e t h o d s that were available such as intermaxillary fixation a n d suspension wires. Not only do patients recover more quickly with plates, they usually have a more accurate a n d stable reduction. Complications can arise w i t h the use of plating systems, but t h e y are becoming rarer as the plates improve a n d more surgeons are fully trained in their use. In experience obtained at our institution a complication related to plating can be traced to a technical error on our part a n d these are continuing to decrease as the plating systems improve a n d experience is gained.
REFERENCES 1. Klotch DW, GiUilandR: Internal fLxabonversus conventional therapy in mid-face fractures. J Trauma 27:1136-1145, 1987 2. Nlshioka GJ, Slckels JEV: Transoral plating of mandibular angle fractures: A technique. Oral Surg Oral Med Oral Patho166:531-534, 1988 3. RavehJ, VmUemin, T, Ladrach K, et al: Plate osteosynthesis of 367 mandibular fractures: The unrestricted mdication for mtraoral approach. J CramomaxiUofacSurg 15:244-253, 1987 4. Thaller SR: Management of mandibular fractures. Arch Otolaryngol Head Neck Surg 120:44-48, 1994 5. Wald RM, Jr, Abemayor E, Zemplenyl J, et al: The transoral treatment of mandibular fractures using noncompression miniplates: A prospective study. Ann Plast Surg 20:409-413, 1988 6. Zachariades N, Papademetriou I, RaUisG: Complicationsassociated with ngld internal fixabon of facialbone fractures. J Oral MaxiUofac Surg 51:275-278, 1993 7. Gruss JS: Comphcations of ngid internal fixabon of the mandible, in Yaremchuk MJ, Gruss JS, Manson PN (eds): Rigid Fixation of the Craniomaxillofaclal Skeleton. Boston, MA, ButterworthHeinemann, 1992, pp 217-232 8. Dierks EJ: Transoral approach to fractures of the mandible. Laryngoscope 97:4-6, 1987 9. Bruce R, Fonseca RJ: Mandibular fractures, in Fonseca RJ, Walker RV (eds): Oral and MaxillofacialTrauma, vol 1. Philadelphia, PA, Saunders, 1991, pp 359-417 10. Adele R, Eriksson B, Nylin O, et al: Delayed healing of fractures of the mandibular body. Int J Oral MaxlUofacSurg 16:15-21, 1987 11. Ardary WC: Plate and screw fixation in the management of mandible fractures. Clin Plast Surg 16(1):61-67, 1989 12. BochlogyrosPN: Non-umon of fractures of the mandible. J Maxillofac Surg 16:189-195, 1985 141