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The use of mandibular buccal cortical grafts in bimaxillary surgery
t, CHNICAL
or
J Oral Maxitlol ac Surg 51 :1282·1 283.1993
The Use of Mandibular Buccal Cortical Grafts in Bimaxillary Surgery ANDREW A.C. HEGGIE, DDS, MD* Maxillomandibular osteotomies are performed to correct a large proportion of anteroposterior discrepancies. In the class III patient exhibiting maxillary hypoplasia and mandibular excess, advancement of the maxilla is generally performed first using an intermediate splint followed by the mandibular reduction. If the magnitude of the advancement dictates the need
,"
FIGURE 2.
Harvested conical plate for interpositional grafting.
for an interpositional graft, a decision must be made to select the most suitable bone or bone-substitute material. Autogenous bone (iliac crest, rib, calvarium and mandibular symphysis), freeze-dried bone, and hydroxylapatite blocks all have been used successfully. This report details the use of mandibular buccal cortical bone in bimaxillary surgery for grafting the advanced maxilla, thus avoiding a separate donor site and facilitating the initiation of the mandibular sagittal osteotomies.
Technique
FIGURE I.
After advancement ofthe maxilla and miniplate stabilization, the gap between the anterior maxillary walls is measured. The maxillary wound is packed and mandibular surgery is commenced. The medial and upper border osteotomies are made as recommended by Epker, I but the latter osteotomy is carried to approximately 5 to 10 mm posterior to the mental foramen. A vertical buccal cut is performed down to and through the inferior border and a second identical parallel vertical osteotomy is made posteriorly approximately 2 to 3 mm greater than the measured space for the graft (Fig I). An inferior border osteotomy is made with a reciprocating saw' to connect both vertical osteotomies
Upper border and vertical buccal osteotomies.
Received from the Division of Oral and Maxillofacial Surgery, Epworth Hospital, Melbourne, Australia . • Oral and Maxillofacial Surgeon . Address correspondence and reprint requ ests to Dr Heggie: 7-12 Collins St, Melbourne Vic 3000, Australia .
© 1993 American Association of Oral and Maxillofacial Surgeons 0278.2391/93/5111-0021$3.00/0
1282
1283
ANDREW A.C. HEGGIE
fragments is required because ofthe previous harvesting of the distal bone. Bicortical position screws are placed to stabilize the proximal fragments. The interpositional bone grafts are trimmed as required to fit neatly into place (Fig 3) and, if unstable, can be anchored with a single bone screw.
Discussion This grafting technique has been used successfully in 15 patients. Mandibular buccal cortical plate (membranous bone) has a density and width similar to calvarial bone and also may have a place as an onlay material. The advantages of this technique are as follows:
FIGURE 3.
Gra ft wedged into position.
and it is then carried a further 5 to 10 mm proximally from the posterior vertical cut. Careful malleting and leverage from the upper border osteotomy delivers the rectangular segment of buccal plate (Fig 2), which should separate at the midlower border. Removal of the segment of buccal plate allows easy access for commencing the sagittal sectioning. It also permits accurate bisection of the inferior border with an osteotome if desired. 3 The mandibular osteotomies are completed; usually, no trimming of the pro ximal
I) The morbidity ofa separate or distant donor site is avoided. 2) The graft size can be accurately tailored to the recipient site. 3) Good control of the sagittal section can be achieved because of improved access to the lower border. 4) Trimming of the proximal fragments is usually not necessary. 5) Placement of a lower border position screw is possible with less risk because the presence of bone beneath the neurovascular bundle is guaranteed. The buccal cortical bone graft also requires less operating time for the single operator.
References I. Epker BN: Modifications in the sagittal osteotomy of the man-
dible. J Oral Surg ]5:157, 1977 2. Wolford lM, Davis W Mcl: The mandibular inferior border split: A modification in the sagittal split osteotomy. J Oral Maxillofac Surg 48:92, 1990 3. Gallia L: Modification ofthe sagittal ramus osteotomy to produce a more accurate inferior bord er split. J Oral Maxillofac Surg 50:1136, 1992
or
J Oral Maxitlol ac Surg 51 :1282·1 283.1993
The Use of Mandibular Buccal Cortical Grafts in Bimaxillary Surgery ANDREW A.C. HEGGIE, DDS, MD* Maxillomandibular osteotomies are performed to correct a large proportion of anteroposterior discrepancies. In the class III patient exhibiting maxillary hypoplasia and mandibular excess, advancement of the maxilla is generally performed first using an intermediate splint followed by the mandibular reduction. If the magnitude of the advancement dictates the need
,"
FIGURE 2.
Harvested conical plate for interpositional grafting.
for an interpositional graft, a decision must be made to select the most suitable bone or bone-substitute material. Autogenous bone (iliac crest, rib, calvarium and mandibular symphysis), freeze-dried bone, and hydroxylapatite blocks all have been used successfully. This report details the use of mandibular buccal cortical bone in bimaxillary surgery for grafting the advanced maxilla, thus avoiding a separate donor site and facilitating the initiation of the mandibular sagittal osteotomies.
Technique
FIGURE I.
After advancement ofthe maxilla and miniplate stabilization, the gap between the anterior maxillary walls is measured. The maxillary wound is packed and mandibular surgery is commenced. The medial and upper border osteotomies are made as recommended by Epker, I but the latter osteotomy is carried to approximately 5 to 10 mm posterior to the mental foramen. A vertical buccal cut is performed down to and through the inferior border and a second identical parallel vertical osteotomy is made posteriorly approximately 2 to 3 mm greater than the measured space for the graft (Fig I). An inferior border osteotomy is made with a reciprocating saw' to connect both vertical osteotomies
Upper border and vertical buccal osteotomies.
Received from the Division of Oral and Maxillofacial Surgery, Epworth Hospital, Melbourne, Australia . • Oral and Maxillofacial Surgeon . Address correspondence and reprint requ ests to Dr Heggie: 7-12 Collins St, Melbourne Vic 3000, Australia .
© 1993 American Association of Oral and Maxillofacial Surgeons 0278.2391/93/5111-0021$3.00/0
1282
1283
ANDREW A.C. HEGGIE
fragments is required because ofthe previous harvesting of the distal bone. Bicortical position screws are placed to stabilize the proximal fragments. The interpositional bone grafts are trimmed as required to fit neatly into place (Fig 3) and, if unstable, can be anchored with a single bone screw.
Discussion This grafting technique has been used successfully in 15 patients. Mandibular buccal cortical plate (membranous bone) has a density and width similar to calvarial bone and also may have a place as an onlay material. The advantages of this technique are as follows:
FIGURE 3.
Gra ft wedged into position.
and it is then carried a further 5 to 10 mm proximally from the posterior vertical cut. Careful malleting and leverage from the upper border osteotomy delivers the rectangular segment of buccal plate (Fig 2), which should separate at the midlower border. Removal of the segment of buccal plate allows easy access for commencing the sagittal sectioning. It also permits accurate bisection of the inferior border with an osteotome if desired. 3 The mandibular osteotomies are completed; usually, no trimming of the pro ximal
I) The morbidity ofa separate or distant donor site is avoided. 2) The graft size can be accurately tailored to the recipient site. 3) Good control of the sagittal section can be achieved because of improved access to the lower border. 4) Trimming of the proximal fragments is usually not necessary. 5) Placement of a lower border position screw is possible with less risk because the presence of bone beneath the neurovascular bundle is guaranteed. The buccal cortical bone graft also requires less operating time for the single operator.
References I. Epker BN: Modifications in the sagittal osteotomy of the man-
dible. J Oral Surg ]5:157, 1977 2. Wolford lM, Davis W Mcl: The mandibular inferior border split: A modification in the sagittal split osteotomy. J Oral Maxillofac Surg 48:92, 1990 3. Gallia L: Modification ofthe sagittal ramus osteotomy to produce a more accurate inferior bord er split. J Oral Maxillofac Surg 50:1136, 1992