PEDIATRIC/CRANIOFACIAL Management of Failed Alveolar Bone Grafts: Improved Outcomes and Decreased Morbidity with Allograft Alone Wesley N. Sivak, M.D., Ph.D. Zoe M. MacIsaac, M.D. S. Alex Rottgers, M.D. Joseph E. Losee, M.D. Anand R. Kumar, M.D. Pittsburgh, Pa.
Background: This study demonstrates the safety and efficacy of allograft alone in revision alveolar bone graft surgery. Methods: A retrospective review of the authors’ institution’s alveolar bone graft experience (from 2004 to 2012) with open iliac crest bone graft, minimalaccess iliac crest bone graft plus supplemental allograft, and revision allograft alone was performed. All patients (n = 47) were treated with alveolar fistula repair with primary closure. Results: Group 1 patients (12 male, 10 female; average age, 10 years) received iliac crest bone graft alone; 17 had unilateral and five had bilateral clefts. Group 2 (eight male, six female; average age, 9 years) received an iliac crest bone graft plus allograft; six clefts were unilateral and eight were bilateral. Group 3 (six male, five female; average age, 13 years) received revision allograft alone; seven clefts were unilateral and four were bilateral. Average operative time/alveolus was shortest in group 3 compared with groups 1 and 2 (p < 0.0005). Average engraftment was better in group 3 than in group 1 (p < 0.001) and similar to that in group 2 (p < 0.079). Revision alveolar bone graft with allograft alone improved Enemark scores from 3.7 preoperatively to 1.0 postoperatively (p < 0.0001). Hospital stay was shortest in group 3 compared with groups 1 and 2 (p < 0.0001). Bone graft extrusion occurred in six patients (27.3 percent) in group 1, no complications occurred in group 2, and a single necrotic central incisor was lost at the time of revision bone grafting in group 3 (9.1 percent). Conclusion: Allograft alone is safe and effective and provides a reliable alternative when traditional alveolar bone graft with iliac crest bone graft has failed. (Plast. Reconstr. Surg. 133: 345, 2014.) CLINICAL QUESTIONS/LEVEL OF EVIDENCE: Therapeutic, III.
P
ersistent cleft alveolar fistula and inadequate bone stock after bone grafting procedures remain a significant source of morbidity and present a reconstructive challenge for many patients with cleft alveolus. Revision From the Department of Pediatric Plastic and Reconstructive Surgery, University of Pittsburgh, Cleft/Craniofacial Center, Children’s Hospital of Pittsburgh. Received for publication June 7, 2013; accepted August 23, 2013. Presented at the Ohio Valley Society of Plastic Surgeons 55th Annual Meeting, in Cleveland, Ohio, May 18 and 19, 2012; the Northeastern Society of Plastic Surgeons 29th Annual Meeting, in Boston, Massachusetts, September 27 through 29, 2012; and at the 12th International Congress on Cleft Lip/Palate and Related Craniofacial Anomalies, in Orlando, Florida, May 5 through 10, 2013. Copyright © 2013 by the American Society of Plastic Surgeons DOI: 10.1097/01.prs.0000436855.17280.c4
rates as high as 32 percent have been reported by Goudy et al. for bilateral cleft alveolus, with an average graft revision rate of 23 percent in their reported cohort.1 Currently, autograft iliac crest bone remains the most commonly used graft material and is accepted as the clinical standard procedure for repair of cleft alveolar fistulas. Donor-site morbidity, including pain, hematoma, intestinal injury, wound infection, and surgicalsite fractures, complicates this approach, particularly with revision bone harvest procedures.2,3 In order to minimize revision autograft morbidity, minimal-access autograft harvest techniques and allograft-only bone grafting techniques have been developed, but these approaches can be limited Disclosure: The authors have no financial interest to declare in relation to the content of this article.
www.PRSJournal.com
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Plastic and Reconstructive Surgery • February 2014 by the available autograft volume and allograft retention, respectively.4–7 Allograft bone grafting of the cleft maxillary and alveolar defect is an attractive alternative to use of an autograft, but safety and efficacy have not been adequately reported.8 An allograft-only technique, first described by Kraut in 1987, demonstrated successful treatment of alveolar cleft defects using freeze-dried allograft bone marrow, with canine tooth eruption in 80 percent of the cohort.8 Beitlitum et al. described their experience using particulate allograft bone to augment atrophic alveolar ridges in 50 patients.9 They demonstrated effective augmentation of deficient alveolar ridges using allograft particulate bone grafts with and without the addition of autogenous bone. Our group has previously reported improved results using autograft bone harvested via minimalaccess techniques in conjunction with supplemental allograft for the treatment of alveolar defects in patients with mixed dentition.4 Studies reporting the use of only allograft bone with demineralized bone matrix for salvage reconstruction of persistent cleft maxillary and alveolar defects are scarce. Therefore, patients presenting to our center with persistent alveolar fistula and bone defects after failed initial autograft bone graft procedures were evaluated for salvage treatment using an allograftonly method. Patients either lacked suitable autograft donor sites or refused to undergo another traditional autograft procedure. The objective of this study was to analyze and report our experience in treating patients for whom initial secondary bone grafting has failed and who present with persistent cleft maxilla and alveolus. We highlight our treatment strategy and improved outcomes using only allograft bone mixed with demineralized bone matrix (DBX Mix; Synthes, Inc., West Chester, Pa.).
PATIENTS AND METHODS Using inclusion and exclusion criteria, we identified patients referred to the Children’s Hospital of Pittsburgh of the University of Pittsburgh Medical Center Cleft/Craniofacial Center for evaluation and treatment of persistent cleft alveolar and maxilla bone defects with a persistent fistula after prior bone grafting. Patients who required bilateral revision procedures were staged with unilateral revision grafting and contralateral side revision after a minimum of 3 months’ time. Two previously studied and published groups of patients from our institution who underwent repair for cleft alveolus and an oronasal fistula with either traditional open iliac crest bone graft
346
alone (group 1) or minimal-access iliac crest bone graft plus supplemental allograft bone/demineralized bone matrix mix (group 2) served as the comparison groups to evaluate bone graft take and perioperative morbidity.4 Revision bone graft patients (group 3) met the following inclusion criteria: syndromic and nonsyndromic with complete cleft lip and alveolus, with or without cleft palate; failed primary iliac crest bone grafting; and a persistent bone defect and persistent fistula precluding further orthodontic movement of teeth or placement of a permanent dental implant into the deficient cleft alveolus region. Members of the Cleft-Craniofacial Center at Children’s Hospital of Pittsburgh of the University of Pittsburgh Medical Center, including a pediatric orthodontist and a cleft/craniofacial surgeon, evaluated patients based on the following clinical criteria: (1) presence of a persistent maxillary and/or alveolar cleft on Panorex or peri-apical/ occlusal dental radiographs (Fig. 1); (2) partial, complete, or unerupted maxillary lateral incisor or canine teeth that appeared salvageable; and (3) a persistent nasoalveolar fistula identified at the time of operation. Excluded from group 3 analysis were patients with incomplete cleft alveolus, patients who had undergone prior gingivoperiosteoplasty, and patients requiring complex flap closure of the fistula (i.e., tongue flap or facial artery myomucosal flap). Data collected were readily available to the investigators via electronic medical and radiographic records systems and were entered into a password-protected database. At no time was anyone other than the principal and associate investigators able to access names or personal identifying information of the participating patients. Approval was obtained from the Institutional Review Board of the Children’s Hospital of Pittsburgh of the University of Pittsburgh Medical Center before initiation of the study. After successful identification of patients based on the above criteria, patient-related data variables were collected in a retrospective fashion. Variables collected included patient age, patient sex, unilateral or bilateral cleft alveolus, date of surgery, operative time, hospital length of stay, perioperative complications, perioperative mortality rate, canine eruption, need for revision surgery, bone graft success based on radiographic criteria using the Enemark grading system, and tooth damage or loss. Revision Allograft Bone Graft Technique The revision allograft-only procedure began and ended in the oral cavity, where medial and
Volume 133, Number 2 • Allograft-Only Alveolar Bone Grafting
Fig. 1. (Above, left) Occlusal dental radiograph of a persistent alveolar cleft. Note the paucity of bone bridging the cleft defect and encompassing the adjacent tooth roots. (Above, right) Occlusal dental radiograph after revision allograft-only bone grafting. Note the greatly improved ossification fully bridging adjacent tooth roots. (Below) Panograph dental radiograph demonstrating adequate bone stock after staged revision allograft bone graft of the bilateral cleft defects, resulting in a solid one-piece maxilla.
lateral gingivoperiosteal flaps were elevated to expose the anterior aspects of the maxillary and alveolar cleft defect. In order to completely expose the posterior, medial, and lateral walls of the cleft defect, the residual cleft alveolar fistula was incised from the incisive foramen to the anterior maxilla. The fully defined maxillary defect would be shaped as a tetrahedron extending posteriorly from the incisive foramen to the alveolar ridge anteriorly. The roof of the defect would be the nasal closure, and the floor would be the palatal closure. The base of the tetrahedron would then be the anterior labial closure area (Fig. 2, above, left). The alveolar fistula was closed by repairing the nasal and oral mucosal layers separately, thereby creating a large pocket in which to place the allograft bone graft material. After ensuring hemostasis and watertight mucosal closure, demineralized bone matrix mix, consisting of freeze-dried matrix and cortical chips (DBX Mix;
Synthes), was packed in the residual alveolar cleft defect, with a total graft volume of 2 to 7.5 ml per side (Fig. 2, above, right). The material was packed within the cleft defect, filling the entire tetrahedral-shaped defect up to the border of the pyriform rim (Fig. 2, below). The gingivoperiosteal flaps were then reapproximated with suture over the grafted site, incising the periosteum and creating a lateral relaxing incision at the level of the permanent first molar in order to increase mobility of the lateral flap (Fig. 3). When appropriate, Coe-Pak (GC America, Inc., Alslip, Ill.) was placed over the incision lines as a surgical dressing. Patients were then dismissed when they could tolerate a full liquid diet. The liquid diet was continued for 2 weeks and then converted to a soft diet for 4 additional weeks; a normal diet was allowed at 6 weeks after surgery. A palate expander or transpalatal arch was left in place during the repair and left intact to act as a splint in the immediate postoperative period.
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Plastic and Reconstructive Surgery • February 2014
Fig. 2. (Above, left) Intraoperative photograph demonstrating a revision cleft alveolar bone defect. Note the complete removal of excessive soft tissue from the cleft. (Above, right) Intraoperative photograph demonstrating the allograft bone/demineralized bone matrix mix allograft-only bone graft material before implantation. (Below) Intraoperative photograph demonstrating complete filling of the revision cleft alveolar bone defect. Note the overfilling of graft material to properly shape the piriform contour.
All patients were evaluated at 4- to 6-week intervals for orthodontic adjustment. Panorex images, apical/occlusal dental films, and lateral cephalograms were then obtained at 3, 6, and 12 months after grafting for evaluation of retained viable bone graft using the Enemark grading scale; additional radiographs were obtained as needed. The bone graft relative to the length of the canine root at 100 percent to 75 percent take was graded as level 1; 75 percent to 50 percent take was graded as level 2; 50 percent to 25 percent take was graded as level 3; and 25 percent to 0 percent take was graded as level 4.10 Patients returned for routine cleft clinic follow-up at 6-month intervals.
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Additional data collected included tooth eruption, tooth loss, bone graft loss, infection, persistent alveolar fistula, and death. Cost Analysis In order to define the costs associated with the use of allograft in alveolar bone graft revision, a literature search was performed utilizing PubMed (National Center for Biotechnology Information, Bethesda, Md.). The average cost of allograft bone/demineralized bone matrix mix, operating room hourly costs, and daily hospital admission charges were defined from studies as selected by the senior author of the study (A.R.K.). When
Volume 133, Number 2 • Allograft-Only Alveolar Bone Grafting
Fig. 3. Intraoperative photograph demonstrating complete closure of the cleft defect after bone grafting using a sliding gingival periosteal flap.
possible, values from multiple studies were combined, and an average value was extracted and used for analysis. The average cost of 5 ml of allograft bone/demineralized bone matrix mix is approximately $1000 (all dollar amounts reported in U.S. dollars).11–14 Operating room costs vary widely and have been reported in the literature to range from $21 to $133 per minute, averaging $62 per minute.15–20 The average cost of pediatric hospital admission was estimated to be $1500 per day.21,22 Data Analysis Statistical comparisons were performed utilizing SPSS version 20.0 software (IBM Corp., Armonk, N.Y.), with a 0.05 significance level. To compare Enemark scores among groups 1, 2, and 3, a Mann-Whitney U test was performed. To compare preoperative and postoperative Enemark scores for group 3, a Wilcoxon signed rank test was performed. Operative time, length of stay, and length of follow-up were compared using the t test. Complications and need for second surgery were compared by chi-square test, and canine eruption was compared using a Fisher exact probability test. Patient demographics, including sex and unilateral or bilateral clefting, were compared by chi-square test, while age at operation was compared by t test.
RESULTS Group 1: Traditional Open Iliac Crest Bone Graft From October of 2004 to December of 2006 (26 months), 22 patients were identified with maxillary and alveolar clefts (17 unilateral and five
bilateral; 27 total defects) who met inclusion criteria and were treated with traditional open iliac crest bone graft alone by a single surgeon. The average patient age was 10 years (range, 8 to 13 years). The sex distribution of the patients was 12 male (54.5 percent) and 10 female (45.5 percent). The average operative time per defect was 147 minutes (range, 60 to 292 minutes), and the average hospital stay was 2.4 days (range, 2 to 4 days). The average radiographic follow-up period was 47.5 months (range, 12 to 66 months). Twelve repairs (44.4 percent) demonstrated grade 1 engraftment. Five repairs (18.6 percent) demonstrated grade 2 engraftment. Nine repairs (33.3 percent) demonstrated grade 3 engraftment. There was one (3.7 percent) grade 4 engraftment. Canine eruption was complete in 20 treated defects (74.1 percent), partial in six (22.2 percent), and absent in one (3.7 percent). One patient (4.5 percent) required secondary surgery for alveolar bone graft failure. Short-term complications included wound dehiscence in six patients (27.3 percent); there were no cases of delayed mucosal healing. There were no postsurgical wound infections, bleeding requiring reoperation, or deaths. No patients underwent reoperation for wound disruption. These results are summarized in Table 1. Group 2: Minimal-Access Iliac Crest Bone Graft Plus Supplemental Allograft From August of 2010 to August of 2012 (24 months), 14 patients were identified with maxillary and alveolar clefts (six unilateral and eight bilateral; 22 total defects) meeting inclusion criteria and were treated with our described mixed alveolar bone graft technique by a single surgeon. The average age of the patients was 9 years (range, 7 to 11 years). The sex distribution of the patients was eight male (57.1 percent) and six female (42.9 percent). The average operative time per defect was 111 minutes (range, 67 to 179 minutes), and the average hospital stay was 2.7 days per patient (range, 2 to 4 days). The average radiographic follow-up was 20.4 months (range, 14 to 24 months). Sixteen repairs (80 percent) demonstrated grade 1 engraftment. Four patients (20 percent) demonstrated grade 2 engraftment. No patients demonstrated grade 3 or 4 engraftment. Canine eruption was complete in six cases (27.3 percent), partial in 12 (54.5 percent), and absent in four (18.2 percent). No patients required secondary surgery for alveolar bone graft failure. There were no short-term complications of delayed mucosal healing or wound dehiscence. There were no postsurgical wound infections, bleeding requiring
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Plastic and Reconstructive Surgery • February 2014 Table 1. Group 1: Traditional Open Iliac Crest Bone Graft
Patient 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
Age (yr) Sex 9 11 8 10 11 9 8 10 9 10 11 11 10 18 9 9 13 11 9 9 8 9
F F F M M F M F F M F M M M F F M M M M F M
Cleft Alveolus
Operative Operative Time per Time per Length Required Patient Defect of Stay Later (min) (min) (days) Complication Revision
Bilateral Bilateral Bilateral Bilateral Bilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral
360 155 171 163 263 207 123 240 141 158 229 146 119 60 292 130 109 129 223 130 180 240
180 77.5 85.5 81.5 131.5 207 123 240 141 158 229 146 119 60 292 130 109 129 223 130 180 240
4 2 2 2 2 3 2 4 2 2 2 2 2 2 3 3 3 2 3 2 2 2
Yes* No No No No Yes* No Yes* No Yes* No No No No No No No Yes* Yes* No No No
Yes No No No No No No No No No No No No No No No No No No No No No
Canine Eruption L/R partial L/R complete L/R complete L/R complete L/R complete Complete Complete Complete Complete Complete Complete Complete Partial Complete Complete Partial Complete Complete Complete Partial Partial None
Radiographic Enemark Follow-Up Score (mo) 3L, 3R 3L, 3R 2L, 1R 3L, 3R 4L, 3R 2 1 1 1 1 1 1 2 1 3 1 3 2 1 1 2 1
60 47 51 66 58 54 48 46 62 60 65 52 52 34 46 45 45 22 43 34 12 42
F, female; M, male; L, left; R, right. *Exposed bone graft.
reoperation, or deaths. No patients underwent reoperation for wound disruption. These results are summarized in Table 2. Group 3: Allograft Bone Graft Using Allograft Only From February of 2011 to January of 2012 (11 months), 11 patients were identified with maxillary and alveolar clefts (four unilateral and seven bilateral; 18 total defects) meeting inclusion criteria and were treated with our described
allograft-only alveolar bone graft technique by a single surgeon. The average age of the patients was 13 years (range, 10 to 19 years). The sex distribution of the patients was six male (55.0 percent) and five female (45.0 percent). The average operative time per defect was 78 minutes (range, 42 to 119 minutes), and the average hospital stay was 0.9 days per patient (range, 0 to 1 day). The average radiographic follow-up was 13.3 months (range, 6 to 23 months). Eleven repairs (100 percent) demonstrated grade 1 engraftment. No
Table 2. Group 2: Minimal-Access Iliac Crest Bone Graft Plus Supplemental Allograft
Patient
Age (yr)
Operative Operative Time per Time per Length Required Cleft Patient Defect of Stay Later Sex Alveolus (min) (min) (days) Complication Revision
1
7
M
Bilateral
225
112.5
2
No
No
2 3 4 5
8 11 7 9
M F F F
Bilateral Bilateral Bilateral Bilateral
180 165 202 134
90 82.5 101 67
2 4 2 2
No No No No
No No No No
6 7 8 9 10 11 12 13 14
10 9 10 10 8 9 9 10 9
M M M M F M M F F
Bilateral Bilateral Bilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral
163 216 240 169 179 107 174 126 154
207 108 123 169 179 107 174 126 154
3 3 4 2 2 2 3 4 2
No No No No No No No No No
No No No No No No No No No
F, female; M, male; L, left; R, right.
350
Canine Eruption L/R Partial L partial, R complete L/R complete L/R complete L partial, R complete L/R none L/R none L/R partial Partial Partial Partial Partial Partial Partial
Radiographic Enemark Follow-Up Score (mo) 1L, 1R
15
1L, 1R 1L, 1R 2L, 1R 1L, 1R
24 19 22 14
1L, 1R 1L, 1R 1L, 2R 1 1 1 1 1 2
24 19 20 22 21 24 18 21 22
10 14 15 10 16 12 11 17 19 16 14
Patient
1 2 3 4 5 6 7 8 9 10 11
L partial, R none L/R complete L/R complete L/R partial L/R complete L partial, R complete L/R partial Complete Complete Complete Complete
4L, 4R 4L, 2R 4L, 4R 4R 4L, 4R 4L, 4R 4L, 4R 3 4 3 4
1L, 1R 1L, 1R 1L, 1R 1R 1L, 4R 1L, 1R 1L, 1R 1 1 1 1
12 15 14 18 8 8 12 17 13 23 6
patients demonstrated grade 2, 3, or 4 engraftment. Canine eruption was complete in 11 cases (61.1 percent), partial in six (33.3 percent), and absent in one (5.5 percent). No patients required secondary surgery for alveolar bone graft failure. One patient lost a necrotic central incisor during the bone graft procedure, and there was no delayed mucosal healing or wound dehiscence. There were no postsurgical wound infections, bleeding requiring reoperation, or deaths. No patients underwent reoperation for wound disruption. These results are summarized in Table 3.
F, female; M, male; L, left; R, right. *Necrotic central incisor lost at the time of revision alveolar bone grafting.
M M F M F M F M M F F
Bilateral Bilateral Bilateral Bilateral Bilateral Bilateral Bilateral Unilateral Unilateral Unilateral Unilateral
122 140 109 106 84 112 140 93 119 64 89
61 70 54.5 53 42 56 70 93 119 64 89
1 1 1 0 1 1 1 1 1 1 1
No No Yes* No No No No No No No No
No No No No No No No No No No No
Operative Operative Time per Time per Length Required Age Patient Defect of Stay Later (yr) Sex Cleft Alveolus (min) (min) (days) Complication Revision
Table 3. Group 3: Allograft Bone Graft Using Allograft Only
Canine Eruption
Preoperative Enemark Postoperative Radiographic Score Enemark Score Follow-up (mo)
Volume 133, Number 2 • Allograft-Only Alveolar Bone Grafting
Group 3 versus Groups 1 and 2 Average radiographic follow-up was 47.5, 20.4, and 13.3 months for groups 1 through 3, respectively. Average operative time per alveolus was 78 minutes for group 3, shorter than the 147 and 111 minutes for groups 1 and 2, respectively (p
Background: This study demonstrates the safety and efficacy of allograft alone in revision alveolar bone graft surgery. Methods: A retrospective review of the authors’ institution’s alveolar bone graft experience (from 2004 to 2012) with open iliac crest bone graft, minimalaccess iliac crest bone graft plus supplemental allograft, and revision allograft alone was performed. All patients (n = 47) were treated with alveolar fistula repair with primary closure. Results: Group 1 patients (12 male, 10 female; average age, 10 years) received iliac crest bone graft alone; 17 had unilateral and five had bilateral clefts. Group 2 (eight male, six female; average age, 9 years) received an iliac crest bone graft plus allograft; six clefts were unilateral and eight were bilateral. Group 3 (six male, five female; average age, 13 years) received revision allograft alone; seven clefts were unilateral and four were bilateral. Average operative time/alveolus was shortest in group 3 compared with groups 1 and 2 (p < 0.0005). Average engraftment was better in group 3 than in group 1 (p < 0.001) and similar to that in group 2 (p < 0.079). Revision alveolar bone graft with allograft alone improved Enemark scores from 3.7 preoperatively to 1.0 postoperatively (p < 0.0001). Hospital stay was shortest in group 3 compared with groups 1 and 2 (p < 0.0001). Bone graft extrusion occurred in six patients (27.3 percent) in group 1, no complications occurred in group 2, and a single necrotic central incisor was lost at the time of revision bone grafting in group 3 (9.1 percent). Conclusion: Allograft alone is safe and effective and provides a reliable alternative when traditional alveolar bone graft with iliac crest bone graft has failed. (Plast. Reconstr. Surg. 133: 345, 2014.) CLINICAL QUESTIONS/LEVEL OF EVIDENCE: Therapeutic, III.
P
ersistent cleft alveolar fistula and inadequate bone stock after bone grafting procedures remain a significant source of morbidity and present a reconstructive challenge for many patients with cleft alveolus. Revision From the Department of Pediatric Plastic and Reconstructive Surgery, University of Pittsburgh, Cleft/Craniofacial Center, Children’s Hospital of Pittsburgh. Received for publication June 7, 2013; accepted August 23, 2013. Presented at the Ohio Valley Society of Plastic Surgeons 55th Annual Meeting, in Cleveland, Ohio, May 18 and 19, 2012; the Northeastern Society of Plastic Surgeons 29th Annual Meeting, in Boston, Massachusetts, September 27 through 29, 2012; and at the 12th International Congress on Cleft Lip/Palate and Related Craniofacial Anomalies, in Orlando, Florida, May 5 through 10, 2013. Copyright © 2013 by the American Society of Plastic Surgeons DOI: 10.1097/01.prs.0000436855.17280.c4
rates as high as 32 percent have been reported by Goudy et al. for bilateral cleft alveolus, with an average graft revision rate of 23 percent in their reported cohort.1 Currently, autograft iliac crest bone remains the most commonly used graft material and is accepted as the clinical standard procedure for repair of cleft alveolar fistulas. Donor-site morbidity, including pain, hematoma, intestinal injury, wound infection, and surgicalsite fractures, complicates this approach, particularly with revision bone harvest procedures.2,3 In order to minimize revision autograft morbidity, minimal-access autograft harvest techniques and allograft-only bone grafting techniques have been developed, but these approaches can be limited Disclosure: The authors have no financial interest to declare in relation to the content of this article.
www.PRSJournal.com
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Plastic and Reconstructive Surgery • February 2014 by the available autograft volume and allograft retention, respectively.4–7 Allograft bone grafting of the cleft maxillary and alveolar defect is an attractive alternative to use of an autograft, but safety and efficacy have not been adequately reported.8 An allograft-only technique, first described by Kraut in 1987, demonstrated successful treatment of alveolar cleft defects using freeze-dried allograft bone marrow, with canine tooth eruption in 80 percent of the cohort.8 Beitlitum et al. described their experience using particulate allograft bone to augment atrophic alveolar ridges in 50 patients.9 They demonstrated effective augmentation of deficient alveolar ridges using allograft particulate bone grafts with and without the addition of autogenous bone. Our group has previously reported improved results using autograft bone harvested via minimalaccess techniques in conjunction with supplemental allograft for the treatment of alveolar defects in patients with mixed dentition.4 Studies reporting the use of only allograft bone with demineralized bone matrix for salvage reconstruction of persistent cleft maxillary and alveolar defects are scarce. Therefore, patients presenting to our center with persistent alveolar fistula and bone defects after failed initial autograft bone graft procedures were evaluated for salvage treatment using an allograftonly method. Patients either lacked suitable autograft donor sites or refused to undergo another traditional autograft procedure. The objective of this study was to analyze and report our experience in treating patients for whom initial secondary bone grafting has failed and who present with persistent cleft maxilla and alveolus. We highlight our treatment strategy and improved outcomes using only allograft bone mixed with demineralized bone matrix (DBX Mix; Synthes, Inc., West Chester, Pa.).
PATIENTS AND METHODS Using inclusion and exclusion criteria, we identified patients referred to the Children’s Hospital of Pittsburgh of the University of Pittsburgh Medical Center Cleft/Craniofacial Center for evaluation and treatment of persistent cleft alveolar and maxilla bone defects with a persistent fistula after prior bone grafting. Patients who required bilateral revision procedures were staged with unilateral revision grafting and contralateral side revision after a minimum of 3 months’ time. Two previously studied and published groups of patients from our institution who underwent repair for cleft alveolus and an oronasal fistula with either traditional open iliac crest bone graft
346
alone (group 1) or minimal-access iliac crest bone graft plus supplemental allograft bone/demineralized bone matrix mix (group 2) served as the comparison groups to evaluate bone graft take and perioperative morbidity.4 Revision bone graft patients (group 3) met the following inclusion criteria: syndromic and nonsyndromic with complete cleft lip and alveolus, with or without cleft palate; failed primary iliac crest bone grafting; and a persistent bone defect and persistent fistula precluding further orthodontic movement of teeth or placement of a permanent dental implant into the deficient cleft alveolus region. Members of the Cleft-Craniofacial Center at Children’s Hospital of Pittsburgh of the University of Pittsburgh Medical Center, including a pediatric orthodontist and a cleft/craniofacial surgeon, evaluated patients based on the following clinical criteria: (1) presence of a persistent maxillary and/or alveolar cleft on Panorex or peri-apical/ occlusal dental radiographs (Fig. 1); (2) partial, complete, or unerupted maxillary lateral incisor or canine teeth that appeared salvageable; and (3) a persistent nasoalveolar fistula identified at the time of operation. Excluded from group 3 analysis were patients with incomplete cleft alveolus, patients who had undergone prior gingivoperiosteoplasty, and patients requiring complex flap closure of the fistula (i.e., tongue flap or facial artery myomucosal flap). Data collected were readily available to the investigators via electronic medical and radiographic records systems and were entered into a password-protected database. At no time was anyone other than the principal and associate investigators able to access names or personal identifying information of the participating patients. Approval was obtained from the Institutional Review Board of the Children’s Hospital of Pittsburgh of the University of Pittsburgh Medical Center before initiation of the study. After successful identification of patients based on the above criteria, patient-related data variables were collected in a retrospective fashion. Variables collected included patient age, patient sex, unilateral or bilateral cleft alveolus, date of surgery, operative time, hospital length of stay, perioperative complications, perioperative mortality rate, canine eruption, need for revision surgery, bone graft success based on radiographic criteria using the Enemark grading system, and tooth damage or loss. Revision Allograft Bone Graft Technique The revision allograft-only procedure began and ended in the oral cavity, where medial and
Volume 133, Number 2 • Allograft-Only Alveolar Bone Grafting
Fig. 1. (Above, left) Occlusal dental radiograph of a persistent alveolar cleft. Note the paucity of bone bridging the cleft defect and encompassing the adjacent tooth roots. (Above, right) Occlusal dental radiograph after revision allograft-only bone grafting. Note the greatly improved ossification fully bridging adjacent tooth roots. (Below) Panograph dental radiograph demonstrating adequate bone stock after staged revision allograft bone graft of the bilateral cleft defects, resulting in a solid one-piece maxilla.
lateral gingivoperiosteal flaps were elevated to expose the anterior aspects of the maxillary and alveolar cleft defect. In order to completely expose the posterior, medial, and lateral walls of the cleft defect, the residual cleft alveolar fistula was incised from the incisive foramen to the anterior maxilla. The fully defined maxillary defect would be shaped as a tetrahedron extending posteriorly from the incisive foramen to the alveolar ridge anteriorly. The roof of the defect would be the nasal closure, and the floor would be the palatal closure. The base of the tetrahedron would then be the anterior labial closure area (Fig. 2, above, left). The alveolar fistula was closed by repairing the nasal and oral mucosal layers separately, thereby creating a large pocket in which to place the allograft bone graft material. After ensuring hemostasis and watertight mucosal closure, demineralized bone matrix mix, consisting of freeze-dried matrix and cortical chips (DBX Mix;
Synthes), was packed in the residual alveolar cleft defect, with a total graft volume of 2 to 7.5 ml per side (Fig. 2, above, right). The material was packed within the cleft defect, filling the entire tetrahedral-shaped defect up to the border of the pyriform rim (Fig. 2, below). The gingivoperiosteal flaps were then reapproximated with suture over the grafted site, incising the periosteum and creating a lateral relaxing incision at the level of the permanent first molar in order to increase mobility of the lateral flap (Fig. 3). When appropriate, Coe-Pak (GC America, Inc., Alslip, Ill.) was placed over the incision lines as a surgical dressing. Patients were then dismissed when they could tolerate a full liquid diet. The liquid diet was continued for 2 weeks and then converted to a soft diet for 4 additional weeks; a normal diet was allowed at 6 weeks after surgery. A palate expander or transpalatal arch was left in place during the repair and left intact to act as a splint in the immediate postoperative period.
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Plastic and Reconstructive Surgery • February 2014
Fig. 2. (Above, left) Intraoperative photograph demonstrating a revision cleft alveolar bone defect. Note the complete removal of excessive soft tissue from the cleft. (Above, right) Intraoperative photograph demonstrating the allograft bone/demineralized bone matrix mix allograft-only bone graft material before implantation. (Below) Intraoperative photograph demonstrating complete filling of the revision cleft alveolar bone defect. Note the overfilling of graft material to properly shape the piriform contour.
All patients were evaluated at 4- to 6-week intervals for orthodontic adjustment. Panorex images, apical/occlusal dental films, and lateral cephalograms were then obtained at 3, 6, and 12 months after grafting for evaluation of retained viable bone graft using the Enemark grading scale; additional radiographs were obtained as needed. The bone graft relative to the length of the canine root at 100 percent to 75 percent take was graded as level 1; 75 percent to 50 percent take was graded as level 2; 50 percent to 25 percent take was graded as level 3; and 25 percent to 0 percent take was graded as level 4.10 Patients returned for routine cleft clinic follow-up at 6-month intervals.
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Additional data collected included tooth eruption, tooth loss, bone graft loss, infection, persistent alveolar fistula, and death. Cost Analysis In order to define the costs associated with the use of allograft in alveolar bone graft revision, a literature search was performed utilizing PubMed (National Center for Biotechnology Information, Bethesda, Md.). The average cost of allograft bone/demineralized bone matrix mix, operating room hourly costs, and daily hospital admission charges were defined from studies as selected by the senior author of the study (A.R.K.). When
Volume 133, Number 2 • Allograft-Only Alveolar Bone Grafting
Fig. 3. Intraoperative photograph demonstrating complete closure of the cleft defect after bone grafting using a sliding gingival periosteal flap.
possible, values from multiple studies were combined, and an average value was extracted and used for analysis. The average cost of 5 ml of allograft bone/demineralized bone matrix mix is approximately $1000 (all dollar amounts reported in U.S. dollars).11–14 Operating room costs vary widely and have been reported in the literature to range from $21 to $133 per minute, averaging $62 per minute.15–20 The average cost of pediatric hospital admission was estimated to be $1500 per day.21,22 Data Analysis Statistical comparisons were performed utilizing SPSS version 20.0 software (IBM Corp., Armonk, N.Y.), with a 0.05 significance level. To compare Enemark scores among groups 1, 2, and 3, a Mann-Whitney U test was performed. To compare preoperative and postoperative Enemark scores for group 3, a Wilcoxon signed rank test was performed. Operative time, length of stay, and length of follow-up were compared using the t test. Complications and need for second surgery were compared by chi-square test, and canine eruption was compared using a Fisher exact probability test. Patient demographics, including sex and unilateral or bilateral clefting, were compared by chi-square test, while age at operation was compared by t test.
RESULTS Group 1: Traditional Open Iliac Crest Bone Graft From October of 2004 to December of 2006 (26 months), 22 patients were identified with maxillary and alveolar clefts (17 unilateral and five
bilateral; 27 total defects) who met inclusion criteria and were treated with traditional open iliac crest bone graft alone by a single surgeon. The average patient age was 10 years (range, 8 to 13 years). The sex distribution of the patients was 12 male (54.5 percent) and 10 female (45.5 percent). The average operative time per defect was 147 minutes (range, 60 to 292 minutes), and the average hospital stay was 2.4 days (range, 2 to 4 days). The average radiographic follow-up period was 47.5 months (range, 12 to 66 months). Twelve repairs (44.4 percent) demonstrated grade 1 engraftment. Five repairs (18.6 percent) demonstrated grade 2 engraftment. Nine repairs (33.3 percent) demonstrated grade 3 engraftment. There was one (3.7 percent) grade 4 engraftment. Canine eruption was complete in 20 treated defects (74.1 percent), partial in six (22.2 percent), and absent in one (3.7 percent). One patient (4.5 percent) required secondary surgery for alveolar bone graft failure. Short-term complications included wound dehiscence in six patients (27.3 percent); there were no cases of delayed mucosal healing. There were no postsurgical wound infections, bleeding requiring reoperation, or deaths. No patients underwent reoperation for wound disruption. These results are summarized in Table 1. Group 2: Minimal-Access Iliac Crest Bone Graft Plus Supplemental Allograft From August of 2010 to August of 2012 (24 months), 14 patients were identified with maxillary and alveolar clefts (six unilateral and eight bilateral; 22 total defects) meeting inclusion criteria and were treated with our described mixed alveolar bone graft technique by a single surgeon. The average age of the patients was 9 years (range, 7 to 11 years). The sex distribution of the patients was eight male (57.1 percent) and six female (42.9 percent). The average operative time per defect was 111 minutes (range, 67 to 179 minutes), and the average hospital stay was 2.7 days per patient (range, 2 to 4 days). The average radiographic follow-up was 20.4 months (range, 14 to 24 months). Sixteen repairs (80 percent) demonstrated grade 1 engraftment. Four patients (20 percent) demonstrated grade 2 engraftment. No patients demonstrated grade 3 or 4 engraftment. Canine eruption was complete in six cases (27.3 percent), partial in 12 (54.5 percent), and absent in four (18.2 percent). No patients required secondary surgery for alveolar bone graft failure. There were no short-term complications of delayed mucosal healing or wound dehiscence. There were no postsurgical wound infections, bleeding requiring
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Plastic and Reconstructive Surgery • February 2014 Table 1. Group 1: Traditional Open Iliac Crest Bone Graft
Patient 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
Age (yr) Sex 9 11 8 10 11 9 8 10 9 10 11 11 10 18 9 9 13 11 9 9 8 9
F F F M M F M F F M F M M M F F M M M M F M
Cleft Alveolus
Operative Operative Time per Time per Length Required Patient Defect of Stay Later (min) (min) (days) Complication Revision
Bilateral Bilateral Bilateral Bilateral Bilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral
360 155 171 163 263 207 123 240 141 158 229 146 119 60 292 130 109 129 223 130 180 240
180 77.5 85.5 81.5 131.5 207 123 240 141 158 229 146 119 60 292 130 109 129 223 130 180 240
4 2 2 2 2 3 2 4 2 2 2 2 2 2 3 3 3 2 3 2 2 2
Yes* No No No No Yes* No Yes* No Yes* No No No No No No No Yes* Yes* No No No
Yes No No No No No No No No No No No No No No No No No No No No No
Canine Eruption L/R partial L/R complete L/R complete L/R complete L/R complete Complete Complete Complete Complete Complete Complete Complete Partial Complete Complete Partial Complete Complete Complete Partial Partial None
Radiographic Enemark Follow-Up Score (mo) 3L, 3R 3L, 3R 2L, 1R 3L, 3R 4L, 3R 2 1 1 1 1 1 1 2 1 3 1 3 2 1 1 2 1
60 47 51 66 58 54 48 46 62 60 65 52 52 34 46 45 45 22 43 34 12 42
F, female; M, male; L, left; R, right. *Exposed bone graft.
reoperation, or deaths. No patients underwent reoperation for wound disruption. These results are summarized in Table 2. Group 3: Allograft Bone Graft Using Allograft Only From February of 2011 to January of 2012 (11 months), 11 patients were identified with maxillary and alveolar clefts (four unilateral and seven bilateral; 18 total defects) meeting inclusion criteria and were treated with our described
allograft-only alveolar bone graft technique by a single surgeon. The average age of the patients was 13 years (range, 10 to 19 years). The sex distribution of the patients was six male (55.0 percent) and five female (45.0 percent). The average operative time per defect was 78 minutes (range, 42 to 119 minutes), and the average hospital stay was 0.9 days per patient (range, 0 to 1 day). The average radiographic follow-up was 13.3 months (range, 6 to 23 months). Eleven repairs (100 percent) demonstrated grade 1 engraftment. No
Table 2. Group 2: Minimal-Access Iliac Crest Bone Graft Plus Supplemental Allograft
Patient
Age (yr)
Operative Operative Time per Time per Length Required Cleft Patient Defect of Stay Later Sex Alveolus (min) (min) (days) Complication Revision
1
7
M
Bilateral
225
112.5
2
No
No
2 3 4 5
8 11 7 9
M F F F
Bilateral Bilateral Bilateral Bilateral
180 165 202 134
90 82.5 101 67
2 4 2 2
No No No No
No No No No
6 7 8 9 10 11 12 13 14
10 9 10 10 8 9 9 10 9
M M M M F M M F F
Bilateral Bilateral Bilateral Unilateral Unilateral Unilateral Unilateral Unilateral Unilateral
163 216 240 169 179 107 174 126 154
207 108 123 169 179 107 174 126 154
3 3 4 2 2 2 3 4 2
No No No No No No No No No
No No No No No No No No No
F, female; M, male; L, left; R, right.
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Canine Eruption L/R Partial L partial, R complete L/R complete L/R complete L partial, R complete L/R none L/R none L/R partial Partial Partial Partial Partial Partial Partial
Radiographic Enemark Follow-Up Score (mo) 1L, 1R
15
1L, 1R 1L, 1R 2L, 1R 1L, 1R
24 19 22 14
1L, 1R 1L, 1R 1L, 2R 1 1 1 1 1 2
24 19 20 22 21 24 18 21 22
10 14 15 10 16 12 11 17 19 16 14
Patient
1 2 3 4 5 6 7 8 9 10 11
L partial, R none L/R complete L/R complete L/R partial L/R complete L partial, R complete L/R partial Complete Complete Complete Complete
4L, 4R 4L, 2R 4L, 4R 4R 4L, 4R 4L, 4R 4L, 4R 3 4 3 4
1L, 1R 1L, 1R 1L, 1R 1R 1L, 4R 1L, 1R 1L, 1R 1 1 1 1
12 15 14 18 8 8 12 17 13 23 6
patients demonstrated grade 2, 3, or 4 engraftment. Canine eruption was complete in 11 cases (61.1 percent), partial in six (33.3 percent), and absent in one (5.5 percent). No patients required secondary surgery for alveolar bone graft failure. One patient lost a necrotic central incisor during the bone graft procedure, and there was no delayed mucosal healing or wound dehiscence. There were no postsurgical wound infections, bleeding requiring reoperation, or deaths. No patients underwent reoperation for wound disruption. These results are summarized in Table 3.
F, female; M, male; L, left; R, right. *Necrotic central incisor lost at the time of revision alveolar bone grafting.
M M F M F M F M M F F
Bilateral Bilateral Bilateral Bilateral Bilateral Bilateral Bilateral Unilateral Unilateral Unilateral Unilateral
122 140 109 106 84 112 140 93 119 64 89
61 70 54.5 53 42 56 70 93 119 64 89
1 1 1 0 1 1 1 1 1 1 1
No No Yes* No No No No No No No No
No No No No No No No No No No No
Operative Operative Time per Time per Length Required Age Patient Defect of Stay Later (yr) Sex Cleft Alveolus (min) (min) (days) Complication Revision
Table 3. Group 3: Allograft Bone Graft Using Allograft Only
Canine Eruption
Preoperative Enemark Postoperative Radiographic Score Enemark Score Follow-up (mo)
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Group 3 versus Groups 1 and 2 Average radiographic follow-up was 47.5, 20.4, and 13.3 months for groups 1 through 3, respectively. Average operative time per alveolus was 78 minutes for group 3, shorter than the 147 and 111 minutes for groups 1 and 2, respectively (p
