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or nonunion
J Oral Maxillofac Surg 47:206-208. 1989
A Method for Repositioning a Mandibular Fracture With Delayed Union and/or Nonunion AURASA WAIKAKUL, SSe, DDS, MS* Introduction
gressive expansion of the dental arch. Turning the screw at intervals alters the form of the splint and, provided that the alteration is not made too quickly, the teeth and the fragments will move properly in response to the force applied." Master plaster casts of the maxilla and mandible are made. The lower cast is then cut along the fracture line and, using the upper cast as a guide, it is readjusted into proper alignment and acceptable occlusion. The corrected model is duplicated, and a modified lingual splint is fabricated. The expansion screw is covered at both ends with autopolymerizing acrylic resin and expanded before placement in the splint (Fig 1). The position and location of the screw are determined by the direction of the expansion needed. The lingual splint, which is connected at both ends by screw, is made of autopolymerizing acrylic resin (Fig 2). This splint is easily removed from the model by turning the screw and retracting the splint. Holes are placed in the splint so that it can be fixed to the collapsed lower arch by wires. Figure 3 shows use of the splint on a patient with a malaligned mandibular fracture.
When a mandible is fractured, the fragments can be displaced in different directions by the forces of the muscles of mastication and/or the suprahyoid muscles. Union will generally occur if these fragments are placed in proper position early. However, if the initial treatment is inadequate or delayed, infection, 1 delayed union, malunion, or nonunion may occur," particularly in the case of a compound, comminuted fracture. Nonunion and malunion of fractures present some of the most challenging surgical conditions for oral and maxillofacial surgeons. Bone healing occurs in five overlapping phases: induction, inflammation, soft callus formation, hard callus formation, and remodeling." The position of the bone fragments can be altered up to the early period of soft callus formation; therefore, this period of bone healing is the last opportunity for the surgeon to place the fragments into their proper position by conservative methods. When fractures occur in the symphyseal region, a lingual splint is often used to position the fragments. However, if treatment has been delayed and there is already decreased mobility of the fragments, this procedure cannot be used. To overcome this problem, a modified lingual splint has been developed that includes an orthodontic expansion screw.
Discussion
The modified lingual splint with the orthodontic expansion screw is adjustable and can expand or
Procedure
The orthodontic expansion screw is a commonly known orthodontic device used to provide a pro* Staff, Oral Surgery Department, School of Dentistry, Mahidol University, Bangkok 10400.Thailand. Address correspondence and reprint requests to Dr Waikakul: Oral Surgery Department, School of Dentistry, Mahidol University, Bangkok 10400,Thailand. © 1989 American Association of Oral and Maxillofacial Surgeons
FIGURE I. The orthodontic expansion screw covered at each end by acrylic resin, ready for installation into the acrylic lingual splint.
0278-2391/89/4702-0016$3.00/0
206
207
AURASA WAIKAKUL
FIGURE 2. lIIustration of the modified lingual splint reconstruction. A, Master cast showing mandibular collapse. B, Sectioned cast with proper arch alignment. C, Completed splint.
A
B
retract each fragment in a separate direction. Combined with the elastic traction, force can be applied in three dimensions, and the displaced fragments can be properly aligned. Such three-dimensional force cannot be achieved through maxiIIomandibular fixation with upper and lower arch bars alone,
c The modified lingual splint is a most appropriate alternative when the patient has a mandibular fracture with collapsed displaced fragments, the fracture fragments are not easily reduced because of scar contraction, the fracture site is confined within the premolar-to-premolar region, where dentition is
FIGURE 3. Correction of malpositioned, fractured mandible by use of a lingual splint and expansion screw. A, Preoperative view. B, Postoperative view showing expansion of the arch.
208 adequate to stabilize the splint, and when the correction can begin before the final phase of soft callus formation. However, the method is not useful, or can be injurious to the remaining teeth and lingual soft tissues if too much force and too rapid expansion are used, very few strong teeth are present, or if the splint is poorly adapted to some portions of the lingual gingiva.
MANDIBULAR FRACTURE: COMPLICATION, CORRECTION
References 1. Fischer-Brandies E, Dielert E: The infected mandibular frac-
ture. Arch Orthop Trauma Surg 103:337, 1984 2. Mathog RH: Nonunion of the mandible. Otolaryngol Clin North Am 16:533, 1983 3. Heppenstall RB: Fracture Treatment and Healing. Philadelphia, Saunders, 1980, pp 41-45 4. Faster TD: A Textbook of Orthodontics (ed 2). London, Blackwell, 1984, pp 233-234
A Method for Repositioning a Mandibular Fracture With Delayed Union and/or Nonunion AURASA WAIKAKUL, SSe, DDS, MS* Introduction
gressive expansion of the dental arch. Turning the screw at intervals alters the form of the splint and, provided that the alteration is not made too quickly, the teeth and the fragments will move properly in response to the force applied." Master plaster casts of the maxilla and mandible are made. The lower cast is then cut along the fracture line and, using the upper cast as a guide, it is readjusted into proper alignment and acceptable occlusion. The corrected model is duplicated, and a modified lingual splint is fabricated. The expansion screw is covered at both ends with autopolymerizing acrylic resin and expanded before placement in the splint (Fig 1). The position and location of the screw are determined by the direction of the expansion needed. The lingual splint, which is connected at both ends by screw, is made of autopolymerizing acrylic resin (Fig 2). This splint is easily removed from the model by turning the screw and retracting the splint. Holes are placed in the splint so that it can be fixed to the collapsed lower arch by wires. Figure 3 shows use of the splint on a patient with a malaligned mandibular fracture.
When a mandible is fractured, the fragments can be displaced in different directions by the forces of the muscles of mastication and/or the suprahyoid muscles. Union will generally occur if these fragments are placed in proper position early. However, if the initial treatment is inadequate or delayed, infection, 1 delayed union, malunion, or nonunion may occur," particularly in the case of a compound, comminuted fracture. Nonunion and malunion of fractures present some of the most challenging surgical conditions for oral and maxillofacial surgeons. Bone healing occurs in five overlapping phases: induction, inflammation, soft callus formation, hard callus formation, and remodeling." The position of the bone fragments can be altered up to the early period of soft callus formation; therefore, this period of bone healing is the last opportunity for the surgeon to place the fragments into their proper position by conservative methods. When fractures occur in the symphyseal region, a lingual splint is often used to position the fragments. However, if treatment has been delayed and there is already decreased mobility of the fragments, this procedure cannot be used. To overcome this problem, a modified lingual splint has been developed that includes an orthodontic expansion screw.
Discussion
The modified lingual splint with the orthodontic expansion screw is adjustable and can expand or
Procedure
The orthodontic expansion screw is a commonly known orthodontic device used to provide a pro* Staff, Oral Surgery Department, School of Dentistry, Mahidol University, Bangkok 10400.Thailand. Address correspondence and reprint requests to Dr Waikakul: Oral Surgery Department, School of Dentistry, Mahidol University, Bangkok 10400,Thailand. © 1989 American Association of Oral and Maxillofacial Surgeons
FIGURE I. The orthodontic expansion screw covered at each end by acrylic resin, ready for installation into the acrylic lingual splint.
0278-2391/89/4702-0016$3.00/0
206
207
AURASA WAIKAKUL
FIGURE 2. lIIustration of the modified lingual splint reconstruction. A, Master cast showing mandibular collapse. B, Sectioned cast with proper arch alignment. C, Completed splint.
A
B
retract each fragment in a separate direction. Combined with the elastic traction, force can be applied in three dimensions, and the displaced fragments can be properly aligned. Such three-dimensional force cannot be achieved through maxiIIomandibular fixation with upper and lower arch bars alone,
c The modified lingual splint is a most appropriate alternative when the patient has a mandibular fracture with collapsed displaced fragments, the fracture fragments are not easily reduced because of scar contraction, the fracture site is confined within the premolar-to-premolar region, where dentition is
FIGURE 3. Correction of malpositioned, fractured mandible by use of a lingual splint and expansion screw. A, Preoperative view. B, Postoperative view showing expansion of the arch.
208 adequate to stabilize the splint, and when the correction can begin before the final phase of soft callus formation. However, the method is not useful, or can be injurious to the remaining teeth and lingual soft tissues if too much force and too rapid expansion are used, very few strong teeth are present, or if the splint is poorly adapted to some portions of the lingual gingiva.
MANDIBULAR FRACTURE: COMPLICATION, CORRECTION
References 1. Fischer-Brandies E, Dielert E: The infected mandibular frac-
ture. Arch Orthop Trauma Surg 103:337, 1984 2. Mathog RH: Nonunion of the mandible. Otolaryngol Clin North Am 16:533, 1983 3. Heppenstall RB: Fracture Treatment and Healing. Philadelphia, Saunders, 1980, pp 41-45 4. Faster TD: A Textbook of Orthodontics (ed 2). London, Blackwell, 1984, pp 233-234