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Control of the proximal segment during application of rigid internal fixation of sagittal split osteotomy of the mandible
J Oral Maxillofac Surg 61:1113-1114, 2003
Control of the Proximal Segment During Application of Rigid Internal Fixation of Sagittal Split Osteotomy of the Mandible Gerald Alexander, DDS,* and Mark Stivers, DDS† Control of the proximal fragment during sagittal ramus osteotomy is important to achieve a stable desired change in centric relation of the mandible after either anterior or posterior repositioning. Failure to accomplish this often leads to decreased stability of the surgical result, adversely affects the temporomandibular joint apparatus, and decreases masticatory efficiency.1 Failure to control the proximal fragment can result in occlusal discrepancies that cannot be fully corrected with orthodontic therapy. Several methods of controlling the proximal fragment have been reported. Originally, clamping the fragments after maxillomandibular fixation and seating the condyle before screw fixation was common practice.1-4 Unintended posterior open bites can occur with this method. Other modalities have included wiring the segments (as was common before rigid fixation), then placement of rigid fixation.2 Nickerson5 described a technique of filleting the proximal end of a plate, engaging the anterior border of the proximal fragment while passively seating the condyle. This position is then maintained by placing screws in the plate at the anterior fragment. Placing a wire in the anterior superior aspect of the seated proximal fragment before screw fixation has also been done.2 Another common procedure involves plating. The proximal fragment is secured to the plate with screws, allowing the unsecured anterior portion of the plate to be used to seat the proximal fragment before the final screw placement in the anterior portion of the plate. Epker et al1 describe a technique using a condyle proximal segment control device. Some authors describe a technique in which the prox-
*Attending Surgeon, Oral and Maxillofacial Surgery, UMCFresno/Community Medical Centers; Private Practice, Fresno Oral/ Maxillofacial Surgery Group, Fresno, CA. †Resident, Oral and Maxillofacial Surgery, UMC-Fresno/Community Medical Centers, Fresno, CA. Address correspondence and reprint requests to Dr Alexander: Oral and Maxillofacial Surgery, UMC-Fresno/Community Medical Centers, 445 South Cedar Ave, Fresno, CA 93702; [email protected]. © 2003 American Association of Oral and Maxillofacial Surgeons
0278-2391/03/6109-0024$30.00/0 doi:10.1016/S0278-2391(03)00329-X
imal segment is seated and plated to the zygoma before the osteotomy. The plate is removed, osteotomies are completed, and occlusion is established; then the plate is reapplied and rigid fixation is achieved with the condyle in the plated position.6,7 Our experience has shown that the most practical and predictable method of positioning and fixating the proximal fragment of the sagittal split osteotomy involves a controlled screw fixation. After maxillomandibular fixation, a transbuccal trocar system with a pointed rotating cannula (K.L.S. Martin, Jacksonville, FL) is passed to the region corresponding to the anterosuperior portion of the proximal fragment (Fig 1). The point of the cannula is adjusted so that the pointed portion of the cannula is anterior. Then, an initial monocortical hole of small diameter is drilled into the anterior superior aspect of the proximal fragment. The pointed end of the cannula is placed in this small hole, and the trocar is removed, allowing control of the proximal fragment and the engaged cannula. The proximal fragment is then brought posteriorly and slightly superiorly with the aid of finger pressure applied extra orally at the angle. With the condyle being gently seated and being held in position with the extraoral finger and the cannula point, the first bicortical hole can then be drilled without changing the position of the cannula (Fig 1, inset). The remaining bicortical screw can then be placed in the normal fashion. This technique allows for accurate and predictable proximal fragment placement without the use of excessive plating hardware.
References 1. Epker BN, Wylie G, Wylie A: Control of the condylar-proximal mandibular segments after sagittal split osteotomies to advance the mandible. J Oral Maxillofac Surg 62:613, 1986 2. Wolford LM, Bennett MA: Modification of the mandibular ramus sagittal split osteotomy. J Oral Maxillofac Surg 64:146, 1987 3. Alexander G: Modified Kocher clamp for fragment stabilization after sagittal ramus osteotomy. J Oral Maxillofac Surg 42:649, 1985 4. Jeter TS, Van Sickels JE, Dolwick MF: Modified techniques for internal fixation of sagittal ramus osteotomies. J Oral Maxillofac Surg 42:270, 1984 5. Nickerson TS: Stabilization of the proximal segment in sagittal split osteotomy: A new technique. J Oral Maxillofac Surg 41:683, 1983 6. Hiatt WR, Schelkun PM, Moore DL: Condylar positioning in orthognathic surgery. J Oral Maxillofac Surg 46:110, 1988 7. Merten HA, Halling F: A new condyler positioning technique in orthognathic surgery. J Craniomaxillofac Surg 20:310, 1992
1113
1114
ALEXANDER AND STIVERS
FIGURE 1. Seating of proximal segment using both point of sheath engaging the first monocortical hole drilled and extra oral finger pressure gently seating condyle. (Inset) Engaged sheath and the drill ready for the first bicortical hole.
Control of the Proximal Segment During Application of Rigid Internal Fixation of Sagittal Split Osteotomy of the Mandible Gerald Alexander, DDS,* and Mark Stivers, DDS† Control of the proximal fragment during sagittal ramus osteotomy is important to achieve a stable desired change in centric relation of the mandible after either anterior or posterior repositioning. Failure to accomplish this often leads to decreased stability of the surgical result, adversely affects the temporomandibular joint apparatus, and decreases masticatory efficiency.1 Failure to control the proximal fragment can result in occlusal discrepancies that cannot be fully corrected with orthodontic therapy. Several methods of controlling the proximal fragment have been reported. Originally, clamping the fragments after maxillomandibular fixation and seating the condyle before screw fixation was common practice.1-4 Unintended posterior open bites can occur with this method. Other modalities have included wiring the segments (as was common before rigid fixation), then placement of rigid fixation.2 Nickerson5 described a technique of filleting the proximal end of a plate, engaging the anterior border of the proximal fragment while passively seating the condyle. This position is then maintained by placing screws in the plate at the anterior fragment. Placing a wire in the anterior superior aspect of the seated proximal fragment before screw fixation has also been done.2 Another common procedure involves plating. The proximal fragment is secured to the plate with screws, allowing the unsecured anterior portion of the plate to be used to seat the proximal fragment before the final screw placement in the anterior portion of the plate. Epker et al1 describe a technique using a condyle proximal segment control device. Some authors describe a technique in which the prox-
*Attending Surgeon, Oral and Maxillofacial Surgery, UMCFresno/Community Medical Centers; Private Practice, Fresno Oral/ Maxillofacial Surgery Group, Fresno, CA. †Resident, Oral and Maxillofacial Surgery, UMC-Fresno/Community Medical Centers, Fresno, CA. Address correspondence and reprint requests to Dr Alexander: Oral and Maxillofacial Surgery, UMC-Fresno/Community Medical Centers, 445 South Cedar Ave, Fresno, CA 93702; [email protected]. © 2003 American Association of Oral and Maxillofacial Surgeons
0278-2391/03/6109-0024$30.00/0 doi:10.1016/S0278-2391(03)00329-X
imal segment is seated and plated to the zygoma before the osteotomy. The plate is removed, osteotomies are completed, and occlusion is established; then the plate is reapplied and rigid fixation is achieved with the condyle in the plated position.6,7 Our experience has shown that the most practical and predictable method of positioning and fixating the proximal fragment of the sagittal split osteotomy involves a controlled screw fixation. After maxillomandibular fixation, a transbuccal trocar system with a pointed rotating cannula (K.L.S. Martin, Jacksonville, FL) is passed to the region corresponding to the anterosuperior portion of the proximal fragment (Fig 1). The point of the cannula is adjusted so that the pointed portion of the cannula is anterior. Then, an initial monocortical hole of small diameter is drilled into the anterior superior aspect of the proximal fragment. The pointed end of the cannula is placed in this small hole, and the trocar is removed, allowing control of the proximal fragment and the engaged cannula. The proximal fragment is then brought posteriorly and slightly superiorly with the aid of finger pressure applied extra orally at the angle. With the condyle being gently seated and being held in position with the extraoral finger and the cannula point, the first bicortical hole can then be drilled without changing the position of the cannula (Fig 1, inset). The remaining bicortical screw can then be placed in the normal fashion. This technique allows for accurate and predictable proximal fragment placement without the use of excessive plating hardware.
References 1. Epker BN, Wylie G, Wylie A: Control of the condylar-proximal mandibular segments after sagittal split osteotomies to advance the mandible. J Oral Maxillofac Surg 62:613, 1986 2. Wolford LM, Bennett MA: Modification of the mandibular ramus sagittal split osteotomy. J Oral Maxillofac Surg 64:146, 1987 3. Alexander G: Modified Kocher clamp for fragment stabilization after sagittal ramus osteotomy. J Oral Maxillofac Surg 42:649, 1985 4. Jeter TS, Van Sickels JE, Dolwick MF: Modified techniques for internal fixation of sagittal ramus osteotomies. J Oral Maxillofac Surg 42:270, 1984 5. Nickerson TS: Stabilization of the proximal segment in sagittal split osteotomy: A new technique. J Oral Maxillofac Surg 41:683, 1983 6. Hiatt WR, Schelkun PM, Moore DL: Condylar positioning in orthognathic surgery. J Oral Maxillofac Surg 46:110, 1988 7. Merten HA, Halling F: A new condyler positioning technique in orthognathic surgery. J Craniomaxillofac Surg 20:310, 1992
1113
1114
ALEXANDER AND STIVERS
FIGURE 1. Seating of proximal segment using both point of sheath engaging the first monocortical hole drilled and extra oral finger pressure gently seating condyle. (Inset) Engaged sheath and the drill ready for the first bicortical hole.