J Oral Maxillofac Surg48 :559-560, 1990

Discussion

Reconstruction of Alveolar Clefts WithMandibular or Iliac Crest Bone Grafts:

A Comparative Study

Mohamed El Deeb, DDS, MSUniversity ofMinnesota, Minneapolis

Bone grafting of alveolar cleft defects (ACD) in patientswith cleft palate is now a common practice. It is generallyagreed that an autograft is superior to an allogenic graft oralloimplant for reconstruction of an ACD. Sindet­·Pedersen and Enemark tried to compare results ofrecon­struction of the ACD using grafts of iliac crest bone (ICB)and mandibular symphyseal bone grafts (MBG). Theystate that observed levels of marginal bone in the cleftrelated to teeth were similar in the two groups, but thisstudy has other variables that might affect their observa­tions as well. These factors are:

l. In the group grafted with MBG, orthodontic manip­ulation and expansion of the maxillae was per­formed aftergrafting, while in the group grafted withICB, orthodontic expansion was done presurgically.Orthodontic expansion and movement of teeth maystimulate further formation of bone in the graftedACD.

2. In determining levels of marginal bone in the graftedACD, these authors used nonstandardized intraoralradiographs that represented various degrees ofmagnification. They had adapted this techniquefrom Johansson and coworkers;' but the latter usedstandardized cephalometric radiographs. Accurateassessment of levels of marginal bone is difficult toaccomplish using nonstandardized intraoral radio­graphs.

Surgical procedures for grafting an ACD should aimtoward optimal physiologic function and lead to minimalinterference and impairment of growth and developmentin the maxillofacial complex. In this study, the mean ageof patients at surgery was 9.1 years for those receivingMBG, and 10.3 years for those receiving ICB. This isconsistent with recommendations of previous reports.P"We have found that prognosis for canine eruption throughgrafted ACD is most favorable if the graft is performedwhen the root of the canine is one fourth to one halfformed and the patient is 9 to 12 years 01d.4 Now weprefer to graft earlier, performing surgery after eruptionof the central incisors and with patients 7 to 9 years old.During that time, the surgery should not interfere withanteroposterior or vertical maxillary growth. By age 6,90% of horizontal maxillary growth is usually reached, sothat any interference with such growth should be minimaland can be compensated for orthodontically. Age at sur­gery was usually I year less for girls than boys becausetheir teeth mature and erupt somewhat earlier."

This study reports no periodontal complications found

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in any patient and similar amounts of attached gingivae inthe two groups. An accurate periodontal evaluationshould be made after complete eruption of canines andafter completion of the orthodontic treatment. When theages of patients and periods of postoperative observation(12 to 33 months) are considered, it seems that canines inmost cases would not have reached full eruption or thatorthodontic treatment had not been completed. Both fac­tors can significantly affect final results in evaluating peri­odontal condition. In our previous publications related toevaluation of periodontal status of canines eruptedthrough ACD in 26 patients with cleft lip and palate, wefound that grafting of these ACDs resulted in a clinicallysatisfactory periodontia supporting canines eruptedthrough the grafts."

Anatomic and functional demands determine types ofautografting material a surgeon may select. If these de­mands require support, strength, and obliteration of thedefect, a cortical or corticocancellous graft is selected; ifthe surgeon desires a graft with high osteogenic capabil­ity, then a cancellous graft is favored. The superiority ofcancellous bone compared with cortical bone is in theabundance of osteogenic cells in the former. Use of au­togenous particulate marrow and cancellous bone(PMCB), therefore, has become the preference in recon­struction of alveolar clefts.t-" Rib bone is now less fa­vored in repair of ACD because it contains more corticalthan cancellous bone and because spontaneous eruptionof teeth and orthodontic movement of teeth through ribbone is extremely difficult. There is also a tendency to­ward formation of residual alveolar notches in the re­paired area.

This study has demonstrated that an MBG graft (com­bination of corticocancellous bone) can successfully treatsmaller ACDs. In our experience using corticocancellousbone from the iliac crest to repair an ACD, 50% of ca­nines later needed surgical and/or orthodontic assistanceto accomplish full eruption. We, therefore, now prefer touse PMCB.4 It will be interesting to see whether theseauthors will have similar findings.

One of the advantages of an MBG stated by the authorsis that since it is intramembranous in origin it should re­vascularize faster than endochondral bone grafts. How­ever, LaRossa et al performed a comparative study ofcranial and iliac bone grafts in repair of ACD in patientswith cleft palate and found that levels of marginal bone inACDs repaired with ICB were superior to those graftedwith cranial bone." Cohen et al,? in a similar comparisonin 30 patients, concluded that both grafts were equallygood for grafting ACDs, and selection should be based onother factors. I believe grafts using PMCB revascularizefaster than those using corticocancellous bone, regardlessof their origin. We have used this technique in most caseswithout any major morbidity and with an average hospi­talization of 2 days. In the study discussed here, averagehospitalization was 3.2 days after using MBG.

These authors have demonstrated that using mandibu­lar bone grafts in reconstruction of small ACDs, when

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combined with postsurgical orthodontic treatment, is suc­cessful over short postoperative periods. Long-term fol­lowup is needed to determine the final levels of boneassociated with fully erupted canines, the periodontalcondition around the fully erupted canines, and percent­ages of canines that erupted on their own.

References

1. Johansson B, Ohlsson A, Friede H, et al: A follow-up studyof cleft lip and palate patients treated with orthodontics,secondary bone grafting, and prosthetic rehabilitation.Scand J Plast Reconstr Surg 8:121, 1974

2. Boyne PI, Sands NR: Secondary bone grafting of residualalveolar and palatal clefts. J Oral Surg 30:87, 1972

DISCUSSION

3. Boyne PJ: Use of marrow-cancellous bone grafts in maxil­lary alveolar and palatal clefts. J Dent Res 53:821, 1974

4. EI Deeb ME, Messer LB, Lehnert MW, et al: Canine erup­tion into grafted bone in maxillary alveolar cleft defects.Cleft Palate J 19:9, 1982

5. EI Deeb ME: Repair of alveolar cleft defects with autoge­nous bone grafting. Cleft Palate J 23:126, 1986

6. LaRossa SD, Mayro R, Rothkopf D, et al: A comparison ofcranial and iliac bone grafts in alveolar clefts. Presented atthe 46th Annual Meeting for the American Cleft Palate­Craniofacial Association, San Francisco, CA, 1988, p 41(abstr #84)

7. Cohen M, Schafer MG, Figueroa A, et al: Cranial vs iliaccancellous bone for secondary grafting of alveolar clefts.Presented at the 46th Annual Meeting for the AmericanCleft Palate-Craniofacial Association, San Francisco,CA, 1988, p 41 (abstr #83)