Aesthetic and reconstructivesurgery
Primary reconstruction of the mandibular alveolar ridge following resection
Z h e Chert, Yun Z h a n g Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Tianjin Second Medical College, Tianjin, China
Z. Chen, Y. Zhang: Primary reconstruction o f the mandibular alveolar ridge following resection. Int. J. Oral MaxilloJ'ac. Surg. 1992; 21:253 255. Abstract. Standard techniques of mandibular reconstruction aim at the restoration of function. However, the height and shape of the alveolar ridge are often neglected and reconstruction often results in difficulty in subsequent denture wear. Immediate reconstruction of the alveolar process with particulate autologous iliac bone is described, a technique used in 10 patients since 1978.
Reconstruction of mandibular discontinuity defects following trauma, infection, or resection secondary to the presence of tumor or cyst should be directed at both the restoration of continuity, and the restoration of normal anatomic contour in order to provide optimum function, i.e. chewing ability. In the past, the emphasis in mandibular reconstruction has been to ensure survival of the graft by avoiding tension on intraoral mucosal suture lines. This often resulted in insufficient height of the bone graft and, in turn, a p o o r al-
veolar ridge contour. Consequently, in m a n y cases a secondary reconstruction of the alveolar process was necessary 5 to 6 months after the initial bone graft operation in order to create a functional alveolar ridge. Since 1978 10 patients have undergone immediate reconstruction of the resection defect and the alveolar ridge in one operation. All operations resulted in a well-shaped alveolar ridge. The following data give a brief report of the surgical technique and the longterm recovery o f these patients.
Key words: mandible; alveolar ridge; particulate autologous iliac bone. Accepted for publication 16 April 1992
bed prepared. The operation now focuses on trimming the remaining attached gingiva and suturing the buccal and lingual tissues in interrupted fashion with silk suture in order to prepare a firm, soft tissue covering for the reconstructed alveolar ridge. The gingival margins are sutured in two layers: the oral mucosa and submucosa. The discontinuity defect is bridged with a large piece of cortical cancellous iliac bone. A portion of iliac crest containing cancellous bone is removed and reduced to small particles which are placed in the space between the
Material and methods
Fig. 1. Reconstructed mandible with autogenous anterior ilial crest bone block. Particulate autogenous bone grafts are placed between bone block and the gingiva.
Ten patients, 5 males and 5 females, ages 14 to 60, underwent en bloc resection of portions of the mandible containing teeth because of a tumor or cyst. All underwent immediate reconstruction as described below. Clinical and radiographic observation was continued for between 1 and 12 years (Table 1). Reconstruction of the alveolar ridge consisted of two important aspects, namely a) preservation of ample uninvolved gingival tissue, and b) placing the particulate iliac bone on top of the large piece of cortical cancellous bone used to restore the continuity defect. Resection of the diseased portion of the mandible begins by making the skin incision at the lower margin of the mandible. Reflection of soft tissue flaps from the surface of the mandible is carried superiorly to the gingival margin, both buccally and lingually. As the dissection reaches the crest of the alveolar process, the gingiva, including the intradental papillae, should be detached and preserved as long as it is intact, free from laceration, and free from tumor infiltration. The diseased portion of the mandible, including any involved teeth, is then resected and the graft
Fig. 2. Intraoral situation about half a year later. Notice contour and shape of alveolar ridge.
Fig. 3. Radiograph taken 4 months postoperatively. Note top layer of particulate autogenous bone graft.
Chen and Zhang
254
Table 1. Characteristics of 10 patients who underwent reconstruction of the alveolar ridge Patient 1 2 3 4 5 6 7 8 9 10
Age (years) Sex 14 M 32 F 52 M 33 M 28 M 32 M 53 F 58 F 60 F 44 M
Tumor
Year of operation
Resected area
Postop. course
ameloblastoma ameloblastoma ameloblastoma keratocyst ameloblastoma ameloblastoma keratocyst keratocyst myxoma ameloblastoma
1978 1978 1985 1985 1985 1985 1986 1987 1988 1989
1. bicuspid molar area r. mand. angle to 1st bicuspid r. condyle to bicuspid 1. condyle to 1st incisor r. bicuspid molar area r. condyle to 2nd bicuspid 1. condyle to bicuspid 1. condyle to canine r. condyle to canine 1. condyle to 1st molar
primary healing primary healing primary healing primary healing primary healing primary healing primary healing primary healing primary healing primary healing
newly repaired gingiva and the top of the cortical cancellous bone block. The amount of particulate bone needed is determined by the size of the defect and the amount required for a normally shaped reconstructed ridge (Fig. 1). The mandible is immobilized by intermaxillary fixation during the healing period. Results
All 10 patients in this series healed by primary intention. The resultant alveolar crest contour simulated that of a normM alveolar ridge and felt firm. In each case a denture was easily made and was worn without discomfort (Fig. 2). All patients have been observed for between 1 and 12 years. Although a small a m o u n t of crestal resorption has been noted (Figs. 3, 4, 5), this appears to be consistent with the type of long-term mandibular atrophy seen in edentulous,
Fig. 4. Radiograph taken 1 year postoperatively in same patient. Note condensation of particulate bone graft.
Fig. 5. Radiograph taken 11 years postoperatively in same patient. Note the presence of the newly formed alveolar ridge.
unoperated patients rather than frank resorption of the bone graft. Radiographic examination of the grafted bed 4 months after surgery showed a blurred shadow of the particulate bone at the level of the new alveolar ridge, with new bone formation occurring among the bone particles. By the 6th m o n t h after surgery, the particulate bones appeared to have coalesced and connected as a whole; yet full remodeling had not yet been completed. Between the 8th and 10th months, postoperatively, the grafted bone had fused into a single entity with new b o n y trabeculae forming along the long axis of the bone graft and restoration of a normalized density of the alveolar ridge (Figs. 3-5). Discussion Advantages of particulate bone graft RAPPAPORT 3 in 1971 pointed out that the use of particulate bone and bone marrow affords a higher rate of osteogenesis and a lower rate of surgical complication than do cortical grafts. The use of particulate iliac bone as reported in this paper agrees with this philosophy. BOYNE2 in 1973 proposed the use of rib or cortical cancellous iliac bone for mandibular reconstruction and this was soon superseded by the use of particulate bone and bone marrow transplants. Particulate bone was stated to have the advantage of providing better potential for revascularization than large blocks of bone. Likewise, the use of particulate bone permits better contouring of the alveolar crest. In this way, tension on the gingival suture margin can be reduced as well, because overpacking due to the size and shape of large blocks of bone will not occur. Preservation of the gingival margin without perforation into the oral environment during the healing period ap-
Follow-up period (yr) 12 12 5 5 5 5 4 3 2 1
pears to be important in preventing early resorption of the bone graft. Indications
This technique of alveolar ridge reconstruction is indicated in any situation where immediate reconstruction is permissible following resection. Cases in which there is excessive loss of soft tissue due to tumor infiltration, or where it is anticipated that tension will be created at the gingival suture margin present contraindications to the use of this technique. Likewise, the presence of secondary mandibular infection or
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attachment of epithelium freegingiva attached gingiva
I
Fig. 6. Diagram showing direction of the gingival cuts.
/ /
\
Fig. 7. Diagram showing contour of alveolar ridge after gingival closure.
Mandibular reconstruction
severe periodontal disease is a contraindication to the use of this technique. Reconstruction in these types of cases may have to be deferred until the infection is eliminated. Trimming of the gingival edges
This is a method which gives the gingiva a firm texture, and together with the keratinized squamous epithelium enables the gingiva to sustain the pressure of a dental prosthesis. Preservation of a sufficient amount of intact gingiva is important in minimizing tension on the intraoral tissues. The gingival crevice in the healthy state is approximately 2 m m deep. Often the gingival margin, including the crevice, is torn after it is removed from its attachment to the teeth and periodontal ligament. Hence, it must be trimmed. It is recommended that the cut surface of the gingiva should be slanted so that it forms a 45 ° angle with the long axis of the tooth (Fig. 6). When the cut edges of the gingiva on the inner and outer aspects are approximated, a 90 ° dome is thus created (Fig. 7). This allows for the restoration of an ideal alveolar ridge form.
Interrupted silk sutures are used for the gingival edges. Preservation of the gingival papillae on both the lingual and buccal aspects of the wound allows their interdigitation in such a way that the suture margin as a whole will form a zigzag pattern, eliminating the potential for scar contraction that would occur if the suture line was straight (Fig. 8). Quantity of bone particles
After the gingival margins are approximated, the space formed between the newly closed mucosa and the superior surface of the cortical cancellous bone graft is filled with particulate bone. The quantity of bone utilized should be enough to restore the alveolar ridge in height and width, although particular case should be taken not to overfill the area. Otherwise, the tension thus created on the suture margin will jeopardize the gingival closure, risking disruption of the suture margin and subsequent loss of the particulate bone graft. The upper surface of the bone block should be contoured as a platform to facilitate holding the particulate bone. Restoration of the continuity defect is performed first, followed by placement of the particulate bone graft, and then by closure of the inferior soft tissue wound margin in layers.
255
late bone is placed on the graft bone and tied over several layers of Iodoform gauze. The authors suggest that these sutures be inserted prior to placement of the particulate bone graft which restores the alveolar crest. The sutures are then tied over the pressure dressing, eliminating dead space, and only then are the soft tissues of the extraoral incision closed. This technique results in both elimination of dead space and immobilization of the particulate bone graft immediately after its placement. This aspect of the technique appears to play a role in promoting survival of the particulate bone graft. -~'~-~t
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Immobilization of the particulate bone graft
Fig. 8. Gingival closure in a zigzag pattern.
Fig. 9. Pressure dressing held in place with three circum-mandibular sutures.
It is important to place the particulate bone superior to the bone block. Yet it is also necessary to approximate the soft tissues closely to the buccal and lingual aspects of the large bone block used for the continuity defect. If these soft tissues are not well approximated, then portions of the particulate graft will slide inferiorly along the buccal and lingual surfaces of the bone block, thus creating an immediate post-surgical loss of height of the newly augmented alveolar ridge. The authors prefer a technique in which an external pressure dressing is placed along with transcutaneous sutures to eliminate dead space (Figs. 9 and 10). Up to 6 sutures of heavy #4 silk are used, entering through the skin lateral to the bone graft and crossing over the superior surface of the large bone fragment. The sutures then pass through the soft tissue of the floor of the mouth and exit below the bone block. After that, the prepared particu-
References
1. BOYNEPJ. Implants and transplants: review of recent research in this area of oral surgery. J Am Dent Assoc 1973: 87: 1074. 2. CHENZHE, Wu TING CHUN. Reconstruction of mandibular defects with composite autologous iliac bone and freezetreated allogeneic rib grafts. J Oral Maxillofacial Surg 1982: 40: 29-33. 3. RArPAPORTI. The particulate graft in tumor surgery. Am J Surg 1971: 122: 748.
Address: Dr Zhe Chen Department of Oral and Maxillofacial Surgery Affiliated Hospital of Tianjin Second Medical College No. 13 Jiufiang Road Hexi District Tianfin 300203, China
Primary reconstruction of the mandibular alveolar ridge following resection
Z h e Chert, Yun Z h a n g Department of Oral and Maxillofacial Surgery, Affiliated Hospital of Tianjin Second Medical College, Tianjin, China
Z. Chen, Y. Zhang: Primary reconstruction o f the mandibular alveolar ridge following resection. Int. J. Oral MaxilloJ'ac. Surg. 1992; 21:253 255. Abstract. Standard techniques of mandibular reconstruction aim at the restoration of function. However, the height and shape of the alveolar ridge are often neglected and reconstruction often results in difficulty in subsequent denture wear. Immediate reconstruction of the alveolar process with particulate autologous iliac bone is described, a technique used in 10 patients since 1978.
Reconstruction of mandibular discontinuity defects following trauma, infection, or resection secondary to the presence of tumor or cyst should be directed at both the restoration of continuity, and the restoration of normal anatomic contour in order to provide optimum function, i.e. chewing ability. In the past, the emphasis in mandibular reconstruction has been to ensure survival of the graft by avoiding tension on intraoral mucosal suture lines. This often resulted in insufficient height of the bone graft and, in turn, a p o o r al-
veolar ridge contour. Consequently, in m a n y cases a secondary reconstruction of the alveolar process was necessary 5 to 6 months after the initial bone graft operation in order to create a functional alveolar ridge. Since 1978 10 patients have undergone immediate reconstruction of the resection defect and the alveolar ridge in one operation. All operations resulted in a well-shaped alveolar ridge. The following data give a brief report of the surgical technique and the longterm recovery o f these patients.
Key words: mandible; alveolar ridge; particulate autologous iliac bone. Accepted for publication 16 April 1992
bed prepared. The operation now focuses on trimming the remaining attached gingiva and suturing the buccal and lingual tissues in interrupted fashion with silk suture in order to prepare a firm, soft tissue covering for the reconstructed alveolar ridge. The gingival margins are sutured in two layers: the oral mucosa and submucosa. The discontinuity defect is bridged with a large piece of cortical cancellous iliac bone. A portion of iliac crest containing cancellous bone is removed and reduced to small particles which are placed in the space between the
Material and methods
Fig. 1. Reconstructed mandible with autogenous anterior ilial crest bone block. Particulate autogenous bone grafts are placed between bone block and the gingiva.
Ten patients, 5 males and 5 females, ages 14 to 60, underwent en bloc resection of portions of the mandible containing teeth because of a tumor or cyst. All underwent immediate reconstruction as described below. Clinical and radiographic observation was continued for between 1 and 12 years (Table 1). Reconstruction of the alveolar ridge consisted of two important aspects, namely a) preservation of ample uninvolved gingival tissue, and b) placing the particulate iliac bone on top of the large piece of cortical cancellous bone used to restore the continuity defect. Resection of the diseased portion of the mandible begins by making the skin incision at the lower margin of the mandible. Reflection of soft tissue flaps from the surface of the mandible is carried superiorly to the gingival margin, both buccally and lingually. As the dissection reaches the crest of the alveolar process, the gingiva, including the intradental papillae, should be detached and preserved as long as it is intact, free from laceration, and free from tumor infiltration. The diseased portion of the mandible, including any involved teeth, is then resected and the graft
Fig. 2. Intraoral situation about half a year later. Notice contour and shape of alveolar ridge.
Fig. 3. Radiograph taken 4 months postoperatively. Note top layer of particulate autogenous bone graft.
Chen and Zhang
254
Table 1. Characteristics of 10 patients who underwent reconstruction of the alveolar ridge Patient 1 2 3 4 5 6 7 8 9 10
Age (years) Sex 14 M 32 F 52 M 33 M 28 M 32 M 53 F 58 F 60 F 44 M
Tumor
Year of operation
Resected area
Postop. course
ameloblastoma ameloblastoma ameloblastoma keratocyst ameloblastoma ameloblastoma keratocyst keratocyst myxoma ameloblastoma
1978 1978 1985 1985 1985 1985 1986 1987 1988 1989
1. bicuspid molar area r. mand. angle to 1st bicuspid r. condyle to bicuspid 1. condyle to 1st incisor r. bicuspid molar area r. condyle to 2nd bicuspid 1. condyle to bicuspid 1. condyle to canine r. condyle to canine 1. condyle to 1st molar
primary healing primary healing primary healing primary healing primary healing primary healing primary healing primary healing primary healing primary healing
newly repaired gingiva and the top of the cortical cancellous bone block. The amount of particulate bone needed is determined by the size of the defect and the amount required for a normally shaped reconstructed ridge (Fig. 1). The mandible is immobilized by intermaxillary fixation during the healing period. Results
All 10 patients in this series healed by primary intention. The resultant alveolar crest contour simulated that of a normM alveolar ridge and felt firm. In each case a denture was easily made and was worn without discomfort (Fig. 2). All patients have been observed for between 1 and 12 years. Although a small a m o u n t of crestal resorption has been noted (Figs. 3, 4, 5), this appears to be consistent with the type of long-term mandibular atrophy seen in edentulous,
Fig. 4. Radiograph taken 1 year postoperatively in same patient. Note condensation of particulate bone graft.
Fig. 5. Radiograph taken 11 years postoperatively in same patient. Note the presence of the newly formed alveolar ridge.
unoperated patients rather than frank resorption of the bone graft. Radiographic examination of the grafted bed 4 months after surgery showed a blurred shadow of the particulate bone at the level of the new alveolar ridge, with new bone formation occurring among the bone particles. By the 6th m o n t h after surgery, the particulate bones appeared to have coalesced and connected as a whole; yet full remodeling had not yet been completed. Between the 8th and 10th months, postoperatively, the grafted bone had fused into a single entity with new b o n y trabeculae forming along the long axis of the bone graft and restoration of a normalized density of the alveolar ridge (Figs. 3-5). Discussion Advantages of particulate bone graft RAPPAPORT 3 in 1971 pointed out that the use of particulate bone and bone marrow affords a higher rate of osteogenesis and a lower rate of surgical complication than do cortical grafts. The use of particulate iliac bone as reported in this paper agrees with this philosophy. BOYNE2 in 1973 proposed the use of rib or cortical cancellous iliac bone for mandibular reconstruction and this was soon superseded by the use of particulate bone and bone marrow transplants. Particulate bone was stated to have the advantage of providing better potential for revascularization than large blocks of bone. Likewise, the use of particulate bone permits better contouring of the alveolar crest. In this way, tension on the gingival suture margin can be reduced as well, because overpacking due to the size and shape of large blocks of bone will not occur. Preservation of the gingival margin without perforation into the oral environment during the healing period ap-
Follow-up period (yr) 12 12 5 5 5 5 4 3 2 1
pears to be important in preventing early resorption of the bone graft. Indications
This technique of alveolar ridge reconstruction is indicated in any situation where immediate reconstruction is permissible following resection. Cases in which there is excessive loss of soft tissue due to tumor infiltration, or where it is anticipated that tension will be created at the gingival suture margin present contraindications to the use of this technique. Likewise, the presence of secondary mandibular infection or
I I
.. 4 5 ° ~ ,, \J
).:
attachment of epithelium freegingiva attached gingiva
I
Fig. 6. Diagram showing direction of the gingival cuts.
/ /
\
Fig. 7. Diagram showing contour of alveolar ridge after gingival closure.
Mandibular reconstruction
severe periodontal disease is a contraindication to the use of this technique. Reconstruction in these types of cases may have to be deferred until the infection is eliminated. Trimming of the gingival edges
This is a method which gives the gingiva a firm texture, and together with the keratinized squamous epithelium enables the gingiva to sustain the pressure of a dental prosthesis. Preservation of a sufficient amount of intact gingiva is important in minimizing tension on the intraoral tissues. The gingival crevice in the healthy state is approximately 2 m m deep. Often the gingival margin, including the crevice, is torn after it is removed from its attachment to the teeth and periodontal ligament. Hence, it must be trimmed. It is recommended that the cut surface of the gingiva should be slanted so that it forms a 45 ° angle with the long axis of the tooth (Fig. 6). When the cut edges of the gingiva on the inner and outer aspects are approximated, a 90 ° dome is thus created (Fig. 7). This allows for the restoration of an ideal alveolar ridge form.
Interrupted silk sutures are used for the gingival edges. Preservation of the gingival papillae on both the lingual and buccal aspects of the wound allows their interdigitation in such a way that the suture margin as a whole will form a zigzag pattern, eliminating the potential for scar contraction that would occur if the suture line was straight (Fig. 8). Quantity of bone particles
After the gingival margins are approximated, the space formed between the newly closed mucosa and the superior surface of the cortical cancellous bone graft is filled with particulate bone. The quantity of bone utilized should be enough to restore the alveolar ridge in height and width, although particular case should be taken not to overfill the area. Otherwise, the tension thus created on the suture margin will jeopardize the gingival closure, risking disruption of the suture margin and subsequent loss of the particulate bone graft. The upper surface of the bone block should be contoured as a platform to facilitate holding the particulate bone. Restoration of the continuity defect is performed first, followed by placement of the particulate bone graft, and then by closure of the inferior soft tissue wound margin in layers.
255
late bone is placed on the graft bone and tied over several layers of Iodoform gauze. The authors suggest that these sutures be inserted prior to placement of the particulate bone graft which restores the alveolar crest. The sutures are then tied over the pressure dressing, eliminating dead space, and only then are the soft tissues of the extraoral incision closed. This technique results in both elimination of dead space and immobilization of the particulate bone graft immediately after its placement. This aspect of the technique appears to play a role in promoting survival of the particulate bone graft. -~'~-~t
o ~a
~
~
~
~ ~ , ~ g , ~ ~d~_
r#l qg ~ - ~
,
~ ~,~,
~, ~ ~ | ~
~ ~ ~ ~- ~I~- ~ '
~ • ~ ~~
Immobilization of the particulate bone graft
Fig. 8. Gingival closure in a zigzag pattern.
Fig. 9. Pressure dressing held in place with three circum-mandibular sutures.
It is important to place the particulate bone superior to the bone block. Yet it is also necessary to approximate the soft tissues closely to the buccal and lingual aspects of the large bone block used for the continuity defect. If these soft tissues are not well approximated, then portions of the particulate graft will slide inferiorly along the buccal and lingual surfaces of the bone block, thus creating an immediate post-surgical loss of height of the newly augmented alveolar ridge. The authors prefer a technique in which an external pressure dressing is placed along with transcutaneous sutures to eliminate dead space (Figs. 9 and 10). Up to 6 sutures of heavy #4 silk are used, entering through the skin lateral to the bone graft and crossing over the superior surface of the large bone fragment. The sutures then pass through the soft tissue of the floor of the mouth and exit below the bone block. After that, the prepared particu-
References
1. BOYNEPJ. Implants and transplants: review of recent research in this area of oral surgery. J Am Dent Assoc 1973: 87: 1074. 2. CHENZHE, Wu TING CHUN. Reconstruction of mandibular defects with composite autologous iliac bone and freezetreated allogeneic rib grafts. J Oral Maxillofacial Surg 1982: 40: 29-33. 3. RArPAPORTI. The particulate graft in tumor surgery. Am J Surg 1971: 122: 748.
Address: Dr Zhe Chen Department of Oral and Maxillofacial Surgery Affiliated Hospital of Tianjin Second Medical College No. 13 Jiufiang Road Hexi District Tianfin 300203, China
