Ease, harvesting, and accuracy of cancellous versus corticocancellous bone graft materials used in cleft alveolar bone grafting: A randomized controlled trial

Abhay Datarkar; Bhavana Valvi; Suraj Parmar

doi:10.4103/jclpca.jclpca_35_20

ORIGINAL ARTICLE

Year : 2021 | Volume : 8 | Issue : 2 | Page : 119-126

Ease, harvesting, and accuracy of cancellous versus corticocancellous bone graft materials used in cleft alveolar bone grafting: A randomized controlled trial

Abhay Datarkar, Bhavana Valvi, Suraj Parmar
Department of Oral and Maxillofacial Surgery, Government Dental College and Hospital, Nagpur, Maharashtra, India

Date of Submission	02-Oct-2020
Date of Acceptance	14-Jan-2021
Date of Web Publication	7-Jun-2021

Correspondence Address:
Dr. Bhavana Valvi
Department of Oral and Maxillofacial Surgery, Government Dental College and Hospital Nagpur - 440 003, Maharashtra
India

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/jclpca.jclpca_35_20

Abstract

Aim: The aim of this study was to compare and evaluate the difference between cancellous and corticocancellous bone graft harvested from the anterior iliac crest in the management of unilateral complete cleft alveolus patients. Materials and Methods: A total of 20 patients of unilateral complete cleft alveolus with age ranging from 7 to 15 years were enrolled. Patients were divided into two groups. Group I comprises 10 patients treated with cancellous bone graft and Group II consists of 10 patients treated with corticocancellous bone graft. Trapdoor technique for cancellous and enblock removal for corticocancellous bone graft was done. Both the grafts were evaluated for ease of harvesting and handling and ease, adequacy, and accuracy of graft filling. Results: Harvesting and graft handling was easy in Group I patients, whereas in patients of Group II, it was moderate. In Group I, ease of graft filling was adequate in 90% of patients and acceptable in 10% of patients. In Group II, ease of graft filling was acceptable in 100% of patients. In Group I, the mean time required for bone harvesting was 9.28 ± 2.97 min, whereas in Group II, it was 15.00 ± 1.98 min. Accuracy of graft filling was adequate in both the groups, and no statically significant difference was found between both the groups in terms of accuracy of graft filling. Conclusion: Corticocancellous bone graft is equally good as cancellous bone graft and it can be used successfully as a substitute for cancellous bone graft.

Keywords: Cancellous, cleft alveolus, corticocancellous

How to cite this article:
Datarkar A, Valvi B, Parmar S. Ease, harvesting, and accuracy of cancellous versus corticocancellous bone graft materials used in cleft alveolar bone grafting: A randomized controlled trial. J Cleft Lip Palate Craniofac Anomal 2021;8:119-26

How to cite this URL:
Datarkar A, Valvi B, Parmar S. Ease, harvesting, and accuracy of cancellous versus corticocancellous bone graft materials used in cleft alveolar bone grafting: A randomized controlled trial. J Cleft Lip Palate Craniofac Anomal [serial online] 2021 [cited 2023 Jun 6];8:119-26. Available from: https://www.jclpca.org/text.asp?2021/8/2/119/317785

Introduction

The cleft alveolus is a common congenital deformity with an incidence of 0.18–2.50 per 1000 births.^[1] Anterior iliac crest bone graft is the most commonly preferred procedure for surgical correction of alveolar bone defect and restoration of bony contour.^[2] Initially, cancellous bone graft was considered as a “Gold Standard,” but letter on it was proved that the resorption of cancellous bone graft is much more than expected, and it also does not provide resistance to soft-tissue contraction which further made its use controversial, especially for alveolar bone grafting.^[3] To prevent this resorption, many authors suggest overfilling of the cleft alveolus defect which may have other issues of wound dehiscence in postoperative healing.^[1] In 1981 Barun and Sotereno reported the use of corticocancellous bone graft where they used the cortical bone in the anterior region and cancellous bone in the interior of the cleft defect at the floor of the nose region and reported that the corticocancellous block graft provides adequate resistance towards overlying soft-tissue contraction and less resorption compare to the cancellous bone graft.^[4] The present study was conducted in the department of oral and maxillofacial surgery to evaluate the efficacy of cancellous versus corticocancellous anterior iliac crest bone graft in terms of ease of harvesting, handling, and accuracy in filling complete unilateral alveolar cleft defects.

Materials and Methods

The study was designed as a single-blind, randomized controlled trial. Institutional ethical clearance was obtained for this study. The sample size was calculated with the help of the difference in the mean formula at 80% power and 5% α error taking in to consideration of 6-month follow-up. The data were analyzed by descriptive and inferential statistics. The software used in the analysis was SPSS 24.0 and Graph Pad Prism 5.0 (Study was conducted at government Dental College and Hospital Nagpur, in the department of oral and maxillofacial surgery Maharashtra India) version and P < 0.05 is considered as the level of significance. The present study includes a total of 20 patients having complete unilateral cleft alveolus secondary to primary cleft lip and palate defect with age ranging from 7 to 15 years. Wider cleft defects were omitted from the study and were referred to the orthodontic department for making them suitable for secondary bone grafting by fixed orthodontic treatment. Only normal to moderate-sized cleft defects with volume ranging from 1 to 5 cm³ were included. Preoperatively volume of the cleft defect was calculated using CBCT software named Planmeca Romexis viewer5.2or using a similar technique given by Chen et al.^[3] According to the calculated volume of the cleft defect, intraoperatively needed amount of bone graft was harvested and the volume of the bone graft was calculated using 10 ml syringe for cancellous bone graft (similar technique as mentioned by Wu et al.)^[1] and with the help of measuring tools for corticocancellous bone graft [Figure 1] and [Figure 2]. Patients were divided into two groups. Group I comprises 10 patients (n = 10) treated with cancellous anterior iliac crest bone graft and Group II consists of 10 patients (n = 10) treated with corticocancellous anterior iliac crest bone graft. Student's unpaired t-test was applied for both the groups. The procedure to be performed was explained to the patients and patient's parents followed by informed written consent (consort [flow chart 1]).

Figure 1: Group 1 - Preparation of recipient site in group 1 patient

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Figure 2: Group 1 -Trapdoor technique for harvesting cancellous bone graft

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Inclusion criteria

Patients should be nonsyndromic
Patients with complete unilateral cleft of alveolus previously operated for primary cleft lip and palate defect
Age of patients ranging from 7 to 15 years
Patient medically fit to undergo general anesthesia
Patients willing for bone grafting procedure and to participate in the study with regular follow-up.

Exclusion criteria

Patients with systemic disease contraindicating general and local anesthesia
Patients with bilateral cleft of alveolus
Patients with poor oral hygiene.

All the patients were operated under general anesthesia using standard surgical protocols.^[5] The recipient site was prepared first, followed by the donor site [Group 1] - [Figure 1] and [Figure 3], [Figure 4], [Figure 5], [Figure 6] and [Group 2] [Figure 2] and [Figure 7], [Figure 8], [Figure 9], [Figure 10].

Figure 3: Group 1 - Measurement of volume of cancellous bone graft using 10 ml syringe

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Figure 4: Group 1 - Inset of the cancellous bone graft at recipient site in group I patient

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Figure 5: Group 1 - Final closure in group I patient

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Figure 6: Group 2 - Preparation of recipient site in group II patient

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Figure 7: Group 2 - Harvesting of the cortico-cancellous block graft

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Figure 8: Group 2 - Measurement of the harvested block graft in group II patient

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Figure 9: Group 2 - Inset of the graft at recipient site in group II patient

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Figure 10: Group 2 - Final closure in group II patient

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A block of corticocancellous bone was harvested from the lateral surface of the iliac crest. Cancellous bone graft was harvested using medial trapdoor approach for all the patients to avoid harvesting technique bias. Inset of the harvested graft was carried out at recipient site which includes nasal floor and complete alveolar cleft defect. Final closure was performed with a few interrupted sutures between the flap and the papilla using 3-0 and 4-0 absorbable suture material.

All the patients were operated by the same surgeon in both the groups starting from the preparation of the donor site, harvesting of the graft, and in-sighting of the graft at the recipient site to minimize the bias in this study. The evaluation of both the grafts was done intraoperatively by comparing the parameters such as ease of handling, ease of graft filling, time required for bone harvesting, and accuracy of graft filling.

Ease of harvesting and handling - ease of harvesting and handling was evaluated by a questionnaire made for an operating surgeon and the questions were asked by coworkers as follows:

Which graft is easy to harvest? The grading was done to check the ease of harvesting as (1) easy (2) moderate (3) difficult
Which graft shows more bleeding while harvesting? (a) cancellous (b) corticocancellous
Which graft requires more instrument handling? (a) cancellous (b) corticocancellous.

Ease of graft filling and adequacy of graft filling - Ease of graft filling was also evaluated by questionnaire and questions asked were, (a) Is it easy to inset cancellous bone graft at recipient site? It was graded as (1) easy (2) moderate (3) difficult. (b) Whether corticocancellous block graft or cancellous bone graft is placed accurately at the recipient site according to the defect? The grading kept was (1) adequate (2) acceptable (3) inadequate
Time required for bone harvesting with the help of a stopwatch timer was set from the beginning of the incision marking till complete harvesting of the bone graft, from the anterior iliac crest. The time required for bone harvesting was calculated for both the groups
Accuracy of graft filling – On postoperative day 3, a CBCT scan was taken for each patient and with the help of software name Planmeca Romexis viewer5.2 or volume of the graft was calculated for both the groups.

The final evaluation and validation of answers obtained from an operating surgeon was done by coworkers postoperatively. Evaluated data are suggestive of a more experienced surgeon may take less time to harvest the graft than a newly trained surgeon. Harvesting of an iliac crest requires practice to prevent damage to the important anatomical structures.

Results

In this study, a total of 20 patients of unilateral cleft alveolus were divided into two groups, each group consisting of 10 patients. The patients of both the groups were evaluated for ease of handling [Table 1] and [Graph 1], ease of graft filling and adequacy of graft filling [Table 2] and [Graph 2], time required for harvesting of the graft [Table 3] and [Graph 3], and accuracy of graft filling [Table 4] and [Table 5].

Table 1: Distribution of patients according to ease of harvesting and handling

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Table 2: Distribution of patients according to accuracy of graft filling

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Table 3: Comparison of time required for bone harvesting in two groups intraoperatively by student's unpaired t-test

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Table 4: Accuracy of graft filling for Group 1 patients

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Table 5: Accuracy of graft filling for Group 2 patients

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Harvesting and graft handling was easy in Group 1 patients whereas in patients of Group 2, it was moderate. By using unpaired Student's t-test, a statistically significant difference was found between patients of Group 1 and Group 2 (P = 0.001).

In Group 1, the adequacy of graft filling was adequate in 90% of patients and acceptable in 10% of patients. In Group 2, adequacy of graft filling was acceptable in 100% of patients. By using unpaired Student's t-test, a statistically significant difference was found betweven patients of Group 1 and Group 2 (P = 0.001). In Group 1, graft filling was the easy procedure for all the patients, while for Group 2, the graft filling procedure was moderately easy to perform.

In Group 1, the mean time required for bone harvesting was 9.28 ± 2.97 min, whereas in Group 2, it was 15.00 ± 1.98 min. By using Student's unpaired t-test, a statistically significant difference was found in the mean time required for bone harvesting in the patients of Group 1 and Group 2 (P = 0.001).

In Group 1, the mean obtained for accuracy of graft filling was 4.9 cm³, while in Group 2, it was 4.8 cm³. By using Student's unpaired t-test statistically, no significant difference was found between both the groups.

Discussion

Harvesting of cancellous and corticocancellous bone graft is a routinely performed procedure for correction of the alveolar cleft deformity.^[6] There are many studies published in the literature with advantages and disadvantages of both the techniques of cancellous and corticocancellous iliac crest bone graft such as Abyholm et al.^[5] described the fundamental difference between cancellous and corticocancellous bone graft that cancellous bone graft has less traumatic injury with rapid revascularization and rapid bone uptake, while corticocancellous bone graft takes more time as it depends on vascular ingrowth from surrounding soft tissues and small capillaries, which is a time-consuming process. Lilja^[7] conducted a study and concluded that cancellous bone has more viable cells, space, ingrowth, and regeneration capacity, while corticocancellous block graft will usually die and will get replaced by invasion of bone cells originating from the recipient site and remodeling of corticocancellous bone is also very slow. Alonso et al.^[4] have reported that corticocancellous block graft can be utilized for more stability of the dental arch, but cancellous bone graft gives better results as it gets easily incorporated in to the surrounding bone. Kang^[8] stated that cancellous bone has more osteoinduction and osteoconduction property than corticocancellous bone graft. Mücke and Haarmann^[9] stated that corticocancellous bone graft provides more stability and less resorption compared to cancellous bone graft, but it requires reshaping for adequate fit according to the defect. But not a single study compared the ease of harvesting and handling, ease of graft filling, time required for harvesting of graft, and accuracy of graft filling. Our study is the first form of the study carried in this direction to evaluate the efficacy of cancellous versus corticocancellous bone graft in terms of ease of harvesting, handling, adequacy, and accuracy in filling unilateral alveolar cleft defects.

In the present study, bone graft harvesting was easy for cancellous bone graft than cortico-cancellous bone graft. As for harvesting of cancellous bone graft, it requires opening through trapdoor technique and then to scoop out the cancellous bone from the core of the iliac crest.^[10] While harvesting of cortico-cancellous bone graft requires complete enblock removal of the graft by using an osteotome which can lead to bad split or fracture at iliac crest.^[11] There are other complications such as sensory disturbances, persistent pain, hematoma, fracture of the anterior iliac crest, limbic gait, difficulty in climbing stairs, and scar which were prevented by appropriate technique of harvesting of iliac crest bone graft.^[12] The bone morphogenic protein and growth factors get damaged while handling of corticocancellous graft due to inappropriate instrumentation.

In the present study, ease of graft filling and adequacy was evaluated and operator found that reshaping is required for corticocancellous bone graft because edge to edge inset of the graft at cleft defect was not possible, hence remaining discrepancy has to be closed with particulate cancellous bone graft and filling was always done using cancellous bone graft. In our study, we observed that cortical bone takes a longer time to incorporate because it relies on vascular ingrowth through a process called creeping substitution but shows resistance to soft-tissue contraction and prevents excess resorption. The findings of our study were similar with the study of Arrington et al. (1996).^[13]

In Group 1 patients, the volume of the harvested bone was calculated with the help of 10 ml syringe of similar selling company to avoid bias. Preoperatively, the volume of the cleft defect was calculated using CBCT software named Planmeca Romexis viewer5.2or. The volume of the cleft defect obtained pre-operatively was ranging from 1 to 5cm3in all the patients, and according the volume obtained preoperatively overfilling of the cleft defect was done by inserting 1 ml or 1 cc extra bone graft than the actual volume of the cleft defect in all the cases. As resorption of cancellous bone graft is more, it not only requires compression but also requires overfilling to prevent excess amount of resorption and accurate placement of the graft.^[1] In Group 2 patients, a corticocancellous bone block graft was placed at the cleft defect involving the floor of the nose and the remaining discrepancy was filled with particulate cancellous bone graft. The results obtained with the placement of cancellous bone graft were adequate while it was acceptable for corticocancellous bone graft and inset of cancellous bone graft was easy, while the placement of corticocancellous bone graft was moderately easy to place.

In the present study, the timer was set from the initiation of the incision over the iliac crest till the inset of graft at the recipient site. In our study, we observed that corticocancellous bone graft requires more time for harvesting and inset at recipient site than cancellous bone graft as corticocancellous bone graft requires reshaping. This finding of our study was similar with the study conducted by Kim et al.^[14] The harvesting of corticocancellous bone graft needs delicate work to prevent fracture at the iliac crest as a block is getting removed while harvesting a cancellous bone graft using trapdoor technique no cortical bone was removed and after harvesting the cancellous bone graft, close approximation of cortices was done.

In our study, the accuracy of graft filling was evaluated by a similar technique mentioned by Wu et al.^[1] using CBCT scan on the 3^rd postoperative day and there was no statistically significant difference between both the groups. The present study has a shortcoming of less sample size which is 10 patients per group. The controversy raised by the present study is that very less literature is available which has utilized the corticocancellous bone graft and majority of the surgeons do not prefer to use the corticocancellous block graft but we are promoting the use of corticocancellous bone graft through our study.

Conclusion

The present study concluded that harvesting the iliac crest bone graft requires a well-trained surgeon to prevent damage to important anatomical structures. Cancellous bone graft filling at the recipient site is adequate but requires excess graft filling as resorption is more with cancellous bone graft and it does not resist overlying soft-tissue contraction which further increases its resorption. While corticocancellous block requires reshaping before inset at nasal floor region and in the remaining area, the cancellous bone graft should be placed. As the block graft is placed at the recipient site, it shows resistance to soft-tissue contraction and prevents its unnecessary resorption which is the advantage of corticocancellous bone graft over cancellous bone graft, hence overfilling is not required. This study concludes that the cancellous and corticocancellous bone grafts both have advantages and disadvantages as the cancellous bone graft is easy to harvest with minimal damage to the donor site and filling at the recipient site is also good. The corticocancellous bone graft is difficult for harvesting with more tissue damage at the donor site and reshaping is required for filling, but the uptake of corticocancellous bone graft is equally good as cancellous bone graft and corticocancellous bone graft can also be used successfully as a substitute for cancellous bone graft.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

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