J Oral Maxillofac 49:102&1027.
Surg
1991
New Appliance for Repositioning the Proximal Segment During Rigid Fixation of the Sagittal Split Ramus Osteotomy N. FUJIMURA,
DDS, PHD,* AND H. NAGURA, DDS, PtiDt
Description of Appliance and Application Procedure
Rigid fixation with plates or screws has been widely favored following sagittal split ramus osteotomy of the mandible. Its advantages include early recovery of jaw function, rapid bone healing, and decreased potential for relapse. However, when improper positioning of the proximal segment occurs during the fixation procedure, various problems can result, including limitation of mouth opening, pain and/or clicking in the temporomandibular joint, and skeletal relapse. To avoid these problems, a number of methods have been proposed to maintain the original position of the proximal segment. These methods are based on the use of a standard point that does not change before and after splitting of the mandible. For this point, the zygoma’.’ or maxillary teeth3-6 are usually chosen. The advantage of choosing the zygoma as a standard point is that it is available even in two-jaw surgery. The disadvantage is that adjustment of a miniplate extending from the zygoma to the proximal segment is time consuming3 because of the complicated contour of the zygoma and ramus. Alternatively, choice of the maxillary teeth as a standard point has the disadvantage of being fairly unstable, and the procedure can affect the orthodontic appliance. We have, therefore, developed a new appliance that uses the alveolus and teeth as the standard point.
The appliance consists of five parts: 1) an acrylic portion fitting the buccal aspect of maxillary molar alveolus bilaterally, 2) an arch wire running on the buccal alveolar mucosa from one side of the molar region to the other, 3) an extension connected to a buccal tube of orthodontic appliance, 4) an extension at the center of the arch wire, and 5) miniplates running from the acrylic portion to the ramus (Fig 1). Construction of the appliance is done on a cast. A 1.5mm-diameter wire is bent so as to touch the buccal aspect of the alveolar mucosa from the maxillary molar region on one side to the opposite one, and is twisted at the midpoint to form an extension to be inserted in the interdental space between the upper central incisors. Acrylic is then contoured at the ends of the wire to fit the buccal mucosa in the maxillary molar region. An extension wire is placed in the acrylic, before it begins to set, that will be inserted in the buccal tube attached to the maxillary second molars. The next procedure is done during surgery. Just before the split, maxillomandibular fixation is established in centric relation and the appliance is applied to the maxillary alveolus and teeth. Then a Y-, T-, or L-shaped miniplate is adjusted so as to extend from the acrylic part of the appliance to the lateral aspect of the mandibular ramus, which will be a part of the proximal segment after the split. After one end of the miniplate is fixed to the acrylic with screws, the lateral aspect of the ramus is drilled and the other end is fixed to the mandible with screws (Fig 2). A similar procedure is performed on the opposite side. This establishes the spatial relation of the proximal segment. The appliance is then removed and the split is performed. After the mandible is placed in its new occlusal position with maxillomandibular fixation, the appliance is reapplied and the miniplates are
Received from the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Tokyo Medical and Dental University, Tokyo. * Instructor. t Associate Professor. Address correspondence and reprint requests to Dr Fujimura: DeDartment of Oral and Maxillofacial Surgery, Faculty of Dentisiry, Tokyo Medical and Dental Univeisity, 5-45. i-Chome, Yushima, Bunkyo-ku. Tokyo 113. Japan. 0 1991 American Association of Oral and Maxillofacial
Sur-
geons 0278-2391/91/4909-0021$3.00/0
1026
1027
FIGURE 1. Repositioning appliance consists of acrylic portion fitting the buccal aspect of maxillary molar alveolus bilaterally, an arch wire (w) connecting the acrylic blocks, an extension (E) inserted into a buccal tube of orthodontic appliance, an extension (H) inserted into the interdental space of the upper central incisors, and miniplates (P). (A)
repositioned with screws in the previously drilled holes of the appliance and the ramus. The correct position of the proximal segment is now reproduced and the mandible can be rigidly fixed in the centric relation position that was determined before the split without displacement of the proximal segments. Discussion
FIGURE 2. Diagram showing the appliance applied after the split. Maxillomandibular fixation is established in centric relation. One end of the L-shaped miniplate (P) is fixed to the acrylic (A) and the other end is fixed to the proximal segment (s). w. An arch wire: T. a buccal tube attached to the maxillary second molar; E. an extension inserted into a buccal tube: H. an extension inserted into the interdental space of the upper central incisors.
References This appliance has proved to have the following advantages in osteosynthesis of mandibular osteotomy: 1. It is easy and rapid to construct and apply. 2. Its application does not interfere with the orthodontic appliance and the occlusion. 3. It allows for precise reproduction of the proximal segment because it joins the parts bilaterally. 4. Osteosynthesis with screw or plate is easy and secure because the osteotomized segments are firmly fixed by the miniplates of the appliance.
1. Raveh J, Vuillemin T, Ladrach K. et al: New techniques for reproduction of the condyle relation and reduction of complications after sagittal ramus split osteotomy of the mandible. J Oral Maxillofac Sura 46:751. 1988 2. Hiatt WR, Schelkun PM, Moore DL: Condylar positioning in orthognathic surgery. J Oral Maxillofac Surg 46: I 110, 1988 3. Niederdellmann H. Shetty V: Technical improvements in the sagittal split ramus osteotomy. Oral Surg 67:25, 1989 4. Leonard M: Preventing rotation of the proximal fragment in the sagittal ramus split operation. J Oral Surg 34:942, 1976 5. Zecha JJ, Esser RJ, Cnossen J: Adjustable retainer in sagittal ramus-split osteotomy. Int J Oral Surg 7:36, 1978 6. Leonard MS: Maintenance of condylar position after sagittal split osteotomy of the mandible. J Oral Maxillofac Surg 43:391. 1985
Surg
1991
New Appliance for Repositioning the Proximal Segment During Rigid Fixation of the Sagittal Split Ramus Osteotomy N. FUJIMURA,
DDS, PHD,* AND H. NAGURA, DDS, PtiDt
Description of Appliance and Application Procedure
Rigid fixation with plates or screws has been widely favored following sagittal split ramus osteotomy of the mandible. Its advantages include early recovery of jaw function, rapid bone healing, and decreased potential for relapse. However, when improper positioning of the proximal segment occurs during the fixation procedure, various problems can result, including limitation of mouth opening, pain and/or clicking in the temporomandibular joint, and skeletal relapse. To avoid these problems, a number of methods have been proposed to maintain the original position of the proximal segment. These methods are based on the use of a standard point that does not change before and after splitting of the mandible. For this point, the zygoma’.’ or maxillary teeth3-6 are usually chosen. The advantage of choosing the zygoma as a standard point is that it is available even in two-jaw surgery. The disadvantage is that adjustment of a miniplate extending from the zygoma to the proximal segment is time consuming3 because of the complicated contour of the zygoma and ramus. Alternatively, choice of the maxillary teeth as a standard point has the disadvantage of being fairly unstable, and the procedure can affect the orthodontic appliance. We have, therefore, developed a new appliance that uses the alveolus and teeth as the standard point.
The appliance consists of five parts: 1) an acrylic portion fitting the buccal aspect of maxillary molar alveolus bilaterally, 2) an arch wire running on the buccal alveolar mucosa from one side of the molar region to the other, 3) an extension connected to a buccal tube of orthodontic appliance, 4) an extension at the center of the arch wire, and 5) miniplates running from the acrylic portion to the ramus (Fig 1). Construction of the appliance is done on a cast. A 1.5mm-diameter wire is bent so as to touch the buccal aspect of the alveolar mucosa from the maxillary molar region on one side to the opposite one, and is twisted at the midpoint to form an extension to be inserted in the interdental space between the upper central incisors. Acrylic is then contoured at the ends of the wire to fit the buccal mucosa in the maxillary molar region. An extension wire is placed in the acrylic, before it begins to set, that will be inserted in the buccal tube attached to the maxillary second molars. The next procedure is done during surgery. Just before the split, maxillomandibular fixation is established in centric relation and the appliance is applied to the maxillary alveolus and teeth. Then a Y-, T-, or L-shaped miniplate is adjusted so as to extend from the acrylic part of the appliance to the lateral aspect of the mandibular ramus, which will be a part of the proximal segment after the split. After one end of the miniplate is fixed to the acrylic with screws, the lateral aspect of the ramus is drilled and the other end is fixed to the mandible with screws (Fig 2). A similar procedure is performed on the opposite side. This establishes the spatial relation of the proximal segment. The appliance is then removed and the split is performed. After the mandible is placed in its new occlusal position with maxillomandibular fixation, the appliance is reapplied and the miniplates are
Received from the Department of Oral and Maxillofacial Surgery, Faculty of Dentistry, Tokyo Medical and Dental University, Tokyo. * Instructor. t Associate Professor. Address correspondence and reprint requests to Dr Fujimura: DeDartment of Oral and Maxillofacial Surgery, Faculty of Dentisiry, Tokyo Medical and Dental Univeisity, 5-45. i-Chome, Yushima, Bunkyo-ku. Tokyo 113. Japan. 0 1991 American Association of Oral and Maxillofacial
Sur-
geons 0278-2391/91/4909-0021$3.00/0
1026
1027
FIGURE 1. Repositioning appliance consists of acrylic portion fitting the buccal aspect of maxillary molar alveolus bilaterally, an arch wire (w) connecting the acrylic blocks, an extension (E) inserted into a buccal tube of orthodontic appliance, an extension (H) inserted into the interdental space of the upper central incisors, and miniplates (P). (A)
repositioned with screws in the previously drilled holes of the appliance and the ramus. The correct position of the proximal segment is now reproduced and the mandible can be rigidly fixed in the centric relation position that was determined before the split without displacement of the proximal segments. Discussion
FIGURE 2. Diagram showing the appliance applied after the split. Maxillomandibular fixation is established in centric relation. One end of the L-shaped miniplate (P) is fixed to the acrylic (A) and the other end is fixed to the proximal segment (s). w. An arch wire: T. a buccal tube attached to the maxillary second molar; E. an extension inserted into a buccal tube: H. an extension inserted into the interdental space of the upper central incisors.
References This appliance has proved to have the following advantages in osteosynthesis of mandibular osteotomy: 1. It is easy and rapid to construct and apply. 2. Its application does not interfere with the orthodontic appliance and the occlusion. 3. It allows for precise reproduction of the proximal segment because it joins the parts bilaterally. 4. Osteosynthesis with screw or plate is easy and secure because the osteotomized segments are firmly fixed by the miniplates of the appliance.
1. Raveh J, Vuillemin T, Ladrach K. et al: New techniques for reproduction of the condyle relation and reduction of complications after sagittal ramus split osteotomy of the mandible. J Oral Maxillofac Sura 46:751. 1988 2. Hiatt WR, Schelkun PM, Moore DL: Condylar positioning in orthognathic surgery. J Oral Maxillofac Surg 46: I 110, 1988 3. Niederdellmann H. Shetty V: Technical improvements in the sagittal split ramus osteotomy. Oral Surg 67:25, 1989 4. Leonard M: Preventing rotation of the proximal fragment in the sagittal ramus split operation. J Oral Surg 34:942, 1976 5. Zecha JJ, Esser RJ, Cnossen J: Adjustable retainer in sagittal ramus-split osteotomy. Int J Oral Surg 7:36, 1978 6. Leonard MS: Maintenance of condylar position after sagittal split osteotomy of the mandible. J Oral Maxillofac Surg 43:391. 1985
