# Bone graft in bilateral mandibular sagittal split osteotomy: the current state of practice in France

C. Billon, A. Gueutier, C. Moreau, A. Rohée-Traoré, J.D. Kün-Darbois

► To cite this version:

C. Billon, A. Gueutier, C. Moreau, A. Rohée-Traoré, J.D. Kün-Darbois. Bone graft in bilateral mandibular sagittal split osteotomy: the current state of practice in France. Journal of Stomatology, Oral and Maxillofacial Surgery, 2025, 126 (5), pp.102419. 10.1016/j.jormas.2025.102419. hal-05328091

HAL Id: hal-05328091

https://hal.science/hal-05328091v1

Submitted on 23 Oct 2025

HAL is a multi-disciplinary open access
archive for the deposit and dissemination of sci-
entific research documents, whether they are pub-
lished or not. The documents may come from
teaching and research institutions in France or
abroad, or from public or private research centers.

L'archive ouverte pluridisciplinaire HAL, est
destinée au dépôt et à la diffusion de documents
scientifiques de niveau recherche, publiés ou non,
émanant des établissements d'enseignement et de
recherche français ou étrangers, des laboratoires
publics ou privés.

<figure><img src="image_1.png" /></figure>

Distributed under a Creative Commons Attribution 4.0 International License
<figure><img src="image_2.png" /></figure>

ELSEVIER

Available online at

ScienceDirect

www.sciencedirect.com

Elsevier Masson France

EM|consulte

www.em-consulte.com

<figure><img src="image_3.png" /></figure>

Original Article

# Bone graft in bilateral mandibular sagittal split osteotomy: the current state of practice in France

<figure><img src="image_4.png" /></figure>

Check for
updates

C. Billon<sup>a,*</sup>, A. Gueutier<sup>a,b</sup>, C. Moreau<sup>c</sup>, A. Rohée-Traoré<sup>a</sup>, J.D. Kün-Darbois<sup>a,b</sup>

ARTICLE INFO

Keywords:

Bone grafting

Maxillofacial surgery

Orthognathic surgery

ABSTRACT

**Introduction:** Bilateral sagittal split osteotomy of the mandible (BSSO) is the most common orthognathic surgery procedure. The use of bone grafting seems widely used whereas its interest has not been shown to date. The aim of this study was to describe the current state of practice of bone graft in BSSO in France.

**Materials and methods:** An online survey was used to collect data about the use of bone grafting in BSSO procedures among French maxillofacial surgeons.

**Results:** One hundred and forty-eight surgeons responded to the survey, mostly maxillo-facial surgeons (96 %). Only 31.8 % of participants had already performed grafts in BSSO and the majority did it in less than 10 % of cases. The main grafting indication was the degree of advancement especially for advances over 10 mm. Different types of grafts were used, mainly: autologous bone grafting (mandibular or hip) or other bone grafting (xenograft, allograft).

**Conclusion:** This survey shows the diversity of practices in France regarding the use of grafting in BSSO. Further studies are needed to investigate prospectively the utility of such procedures.

## 1. Introduction

Bilateral sagittal split osteotomy of the mandible (BSSO) is one of the most commonly used orthognathic surgical techniques to correct mandibular deformities, particularly mandibular retrognathism (i.e. Angle class II). The procedure aims to achieve a functional and esthetic outcome by restoring normal dental occlusion (i.e. Angle class I) and improving facial harmony. However, despite its overall reliability, several intraoperative and postoperative complications may arise, such as unfavorable bone healing and defects at the mandibular inferior border. These complications are influenced by various patient and surgery-related factors, including patient's background, the degree of mandibular advancement (>10 mm), and surgical technique [1-3].

Bone grafting at the osteotomy site has been proposed as a strategy to enhance healing and reduce complications, particularly in large advancements. Autologous grafts (mandibular, maxillar, craniial, hip or teeth harvesting), xenografts, allografts, and biomaterials such as titanium or ceramic have been used in clinical practice [4]. While evidence supports the utility of bone grafts in maxillary osteotomies (e.g., Le Fort I) to promote bone union and stability [5-7], data on their effectiveness in BSSO remain scarce. Only a few studies have addressed their role in preventing defects at the

mandibular border or pseudarthrosis, and no consensus exists regarding the best indications or materials to use [8-12].

The aim of this study was to assess and describe the current practices regarding bone grafting in BSSO among French orthognathic surgeons through a nationwide online survey, in order to better understand prevailing trends and inform future clinical recommendations.

## 2. Material and methods

### 2.1. Design of the study and target population

A prospective multicentric observational study was designed. All the facial surgeons, of private or public exercise, who usually perform orthognathic surgery in France, were targeted to participate to the study. It includes maxillofacial surgeons (MFS) but also a few other specialty surgeons (otorhinolaryngologists or plastic surgeons and stomatologists). Their email addresses were collected using databases of all the main national French associations of MFS (i.e. Association française des jeunes chirurgiens maxillo-faciaux (AFJCMF), Société française de stomatologie, Chirurgie maxillo-faciale et Chirurgie orale (SFSCMFCO) et Association française des chirurgiens de la face (AFCF)). All the surgeons

ARTICLE INFO

<footnote><sup>a</sup> CHU Angers, Service de Chirurgie Maxillo-faciale, F-49933 Angers, France</footnote>

<footnote><sup>b</sup> Univ Angers, Nantes Université, Oniris, Inserm, RMeS, REGOS, SFR ICAT, F-49000 Angers, France</footnote>

<footnote><sup>c</sup> CHU Angers, Direction de la Recherche Clinique et de l'Innovation, F-49933 Angers, France</footnote>

<footnote>*Correspondence author at. Service de Chirurgie Maxillo-faciale, CHU d'Angers, 49933 ANGERS Cedex - France.</footnote>

<footnote>E-mail address: charlotte.billon@chu-angers.fr (C. Billon).</footnote>
<table><caption>**Table 1**
Online survey.</caption><thead><tr><th></th><th></th></tr></thead><tbody><tr><td>Questions about the surgeon</td><td></td></tr><tr><td>Name</td><td>...</td></tr><tr><td>First name</td><td>...</td></tr><tr><td>Speciality</td><td>Maxillo-facial surgery<br/>Other: ...</td></tr><tr><td>Place of practice (among French departments)</td><td>...</td></tr><tr><td>Type of exercise</td><td>Public<br/>Private<br/>Mixed</td></tr><tr><td>Status in the case of public or mixed practice</td><td>Praticien Hospitalier (pH) (i.e. Hospital practitioner)<br/>Praticien Hospitalier Contractuel (PHC) (i.e. contractual Hospital practitioner)<br/>Praticien Hospitalier Universitaire (PHU) (i.e. University and Hospital practitioner)<br/>Maitre de conférences des universités et Praticien hospitalier (MCUPH) (i.e. Assistant Professor and Hospital Practitioner)<br/>Professeur des Universités et Praticien hospitalier (PUPH) (i.e. University Professor and Hospital Practitioner)<br/>Chef de clinique, Assistant Hospitalier (i.e. Medical Fellow)<br/>Other: ...</td></tr><tr><td>Years of experience in orthognathic surgery<br/>Without initial formation (residency)</td><td>&lt;5 years<br/>Between 5 and 15 years<br/>&gt;15 years</td></tr><tr><td>Questions about the surgeon's practices</td><td></td></tr><tr><td>Average number of mandibular osteotomies per year</td><td>&lt;20<br/>Between 20 and 50<br/>Between 50 and 100<br/>&gt;100</td></tr><tr><td>Type of mandibular ostotomy</td><td>Epker<br/>Obwegeser-Dalpont<br/>Hunsuck<br/>Supra-basilaire<br/>Other: ...</td></tr><tr><td>Grafts</td><td>Yes<br/>No</td></tr><tr><td>Questions if you answer yes to "grafts"<br/>Proportion of mandibular osteotomies with grafts</td><td>&lt;10 %<br/>Between 10 and 50 %<br/>&gt;50 %</td></tr><tr><td>Type of graft</td><td>Autologous bone grafting, mandibular harvesting<br/>Autologous bone grafting, cranial harvesting<br/>Autologous bone grafting, hip harvesting<br/>Other bone grafting (xenograft, allograft)<br/>Biomaterial (titanium, ceramic, ...)<br/>Other: ...</td></tr><tr><td>Grafts indications</td><td>Systematic indication<br/>Degree of advancement<br/>Presence of an intraoperative notch<br/>Stability of the surgical set-up<br/>Type of osteosynthesis<br/>Type of osteotomy<br/>Patient background<br/>Other: ...</td></tr><tr><td>In case of degree of advancement in the previous question, degree of advancement from which a bone graft performed</td><td>&gt;6mm<br/>&gt;8mm<br/>&gt;10mm<br/>&gt;12mm<br/>Other: ...</td></tr><tr><td>Open questions</td><td></td></tr><tr><td>Details about grafts indications</td><td>...</td></tr><tr><td>Trigger(s) that led to grafting or element(s) that made people stop grafting</td><td>...</td></tr><tr><td>Free text commentary</td><td>...</td></tr></tbody></table>

working in the departments of maxillofacial surgery in French public hospitals have also been invited to participate to the study.

Invitations to participate to the survey were sent by e-mails addressed to every surgeon and head of department: one invitation e-mail followed by at least 4 reminder e-mails. The data collection period lasted four months, from December 2023 to March 2024.

## 2.2. Survey design

The online survey was designed using the Sphinx platform (Sphinx Declic 4.30, Chavanod, France) and emailed to the participants.

The survey is reported in Table 1. It includes 17 questions related to:

- Surgeon's characteristics (identity, specialty, experience in orthognathic surgery, type of exercise (private or public))

- Surgeon's habits in bone grafting (indications, type of graft, etc...)

- Personal comments

## 2.3. Ethical approval

The approval of an ethics committee was not necessary given the type of study carried out (cross-sectional descriptive study). The study was
<figure><img src="image_5.png" /><figcaption>Fig. 1. Geographical breakdown of participants (yellow<1%; orange 1–5%; red >5%).</figcaption></figure>

conducted in accordance with the institutional guidelines of the French Ethical Committee and with the 1964 Helsinki declaration and its later amendments.

## 2.4. Data analysis

All statistical analyses were performed using R software (version 4.0.5). Descriptive statistics were expressed as numbers (%) for all qualitative variables. To compare the characteristics of surgeons from the private/mixed sector versus those from the public sector, Exact Fisher tests were performed. For participants performing grafts in BSSO, the number of indications for grafting were presented via the median with 1st and 3rd quartiles. A comparison of the number of indications ticked between public and private/mixed surgeons was performed using a Mann-Whitney test. Finally, the minimum degree of advancement according to

which surgeons graft was compared between the two previously mentioned groups via a Cochran-Armitage test. Differences were considered statistically significant when a p-value < 0.05.

## 3. Results

### 3.1. Participants' characteristics and surgical practices

Of the 256 surgeons contacted for this study, 148 (57.8%) returned the completed questionnaire.

About twenty of these 256 surgeons did not perform the survey since they did not perform orthognathic surgery or had retired. The geographic distribution of the participants is shown in Fig. 1. Table 2 shows the characteristics of the study participants. Almost all participants were maxillofacial surgeons (96.6%). The medical specialty was not specified
<table><caption>**Table 2**
Descriptive of participant's characteristics and surgical practice (n = 148).</caption><thead><tr><th></th><th>All surgeons<br>n = 148</th><th>Private & mixed practice<br>n = 78</th><th>Public practice<br>n = 70</th></tr></thead><tbody><tr><td><strong>Exercise type</strong></td><td></td><td></td><td></td></tr><tr><td>Mixed</td><td>30 (20.3 %)</td><td>30 (38.5 %)</td><td>0 (0.00 %)</td></tr><tr><td>Private</td><td>48 (32.4 %)</td><td>48 (61.5 %)</td><td>0 (0.00 %)</td></tr><tr><td>Public</td><td>70 (47.3 %)</td><td>0 (0.00 %)</td><td>70 (100 %)</td></tr><tr><td><strong>Speciality</strong></td><td></td><td></td><td></td></tr><tr><td>Maxillofacial surgeons</td><td>143 (96.6 %)</td><td>74 (94.9 %)</td><td>69 (98.6 %)</td></tr><tr><td>Stomatologist</td><td>2 (1.35 %)</td><td>2 (2.56 %)</td><td>0 (0.00 %)</td></tr><tr><td>Otorhinolaryngologist</td><td>1 (0.68 %)</td><td>1 (1.28 %)</td><td>0 (0.00 %)</td></tr><tr><td>Plastic surgeon</td><td>1 (0.68 %)</td><td>1 (1.28 %)</td><td>0 (0.00 %)</td></tr><tr><td>Others</td><td>1 (0.68 %)</td><td>0 (0.00 %)</td><td>1 (1.43 %)</td></tr><tr><td><strong>Experience, years</strong></td><td></td><td></td><td></td></tr><tr><td>&lt;5</td><td>44 (29.7 %)</td><td>15 (19.2 %)</td><td>29 (41.4 %)</td></tr><tr><td>5-15</td><td>64 (43.2 %)</td><td>34 (43.6 %)</td><td>30 (42.9 %)</td></tr><tr><td>&gt;15</td><td>40 (27.0 %)</td><td>29 (37.2 %)</td><td>11 (15.7 %)</td></tr><tr><td><strong>Number of BSSO, per year</strong></td><td></td><td></td><td></td></tr><tr><td>&lt;20</td><td>53 (35.8 %)</td><td>24 (30.8 %)</td><td>29 (41.4 %)</td></tr><tr><td>20-50</td><td>49 (33.1 %)</td><td>20 (25.6 %)</td><td>29 (41.4 %)</td></tr><tr><td>50-100</td><td>17 (11.5 %)</td><td>10 (12.8 %)</td><td>7 (10.0 %)</td></tr><tr><td>&gt;100</td><td>29 (19.6 %)</td><td>24 (30.8 %)</td><td>5 (7.14 %)</td></tr><tr><td><strong>Osteotomy type</strong></td><td></td><td></td><td></td></tr><tr><td>Kater (High osteotomy)</td><td>2 (1.4 %)</td><td>2 (2.6 %)</td><td>0 (0.00 %)</td></tr><tr><td>Epker</td><td>111 (75.0 %)</td><td>58 (74.4 %)</td><td>53 (75.7 %)</td></tr><tr><td>Epker modifié</td><td>1 (0.7 %)</td><td>1 (1.3 %)</td><td>0 (0.00 %)</td></tr><tr><td>Hunsuck</td><td>2 (1.4 %)</td><td>0 (0.00 %)</td><td>2 (2.86 %)</td></tr><tr><td>Hunsuck-Epker</td><td>1 (0.7 %)</td><td>0 (0.00 %)</td><td>1 (1.43 %)</td></tr><tr><td>Obwegeser-Dalpont</td><td>23 (15.5 %)</td><td>14 (17.9 %)</td><td>9 (12.9 %)</td></tr><tr><td>Obwegeser-Epker</td><td>1 (0.7 %)</td><td>1 (1.3 %)</td><td>0 (0.00 %)</td></tr><tr><td>Loncle (Supra-basilar osteotomy)</td><td>7 (4.7 %)</td><td>2 (2.6 %)</td><td>5 (7.14 %)</td></tr><tr><td>Grafts in BSSO</td><td>47 (31.8 %)</td><td>33 (42.3 %)</td><td>14 (20.0 %)</td></tr></tbody></table>

<table><caption>**Table 3**
Descriptive of participants who have already performed grafts in BSSO (n = 47).</caption><thead><tr><th></th><th>All surgeons<br>n = 47</th><th>Private & mixed practice<br>n = 33</th><th>Public practice<br>n = 14</th></tr></thead><tbody><tr><td>Proportion of osteotomy time with graft, %</td><td></td><td></td><td></td></tr><tr><td>&lt;10 %</td><td>26 (55.3 %)</td><td>16 (48.5 %)</td><td>10 (71.4 %)</td></tr><tr><td>10-50 %</td><td>13 (27.7 %)</td><td>10 (30.3 %)</td><td>3 (21.4 %)</td></tr><tr><td>&gt;50 %</td><td>8 (17.0 %)</td><td>7 (21.2 %)</td><td>1 (7.14 %)</td></tr><tr><td>Graft types</td><td></td><td></td><td></td></tr><tr><td>Autologous bone grafting (mandibular, maxillar), yes</td><td>14 (29.8 %)</td><td>7 (21.2 %)</td><td>7 (50.0 %)</td></tr><tr><td>Autologous bone grafting (cranial), yes</td><td>1 (2.13 %)</td><td>0 (0.00 %)</td><td>1 (7.14 %)</td></tr><tr><td>Autologous bone grafting (hip), yes</td><td>5 (10.6 %)</td><td>3 (9.09 %)</td><td>2 (14.3 %)</td></tr><tr><td>Other bone grafting (xenograft, allograft), yes</td><td>35 (74.5 %)</td><td>26 (78.8 %)</td><td>9 (64.3 %)</td></tr><tr><td>Graft indications</td><td></td><td></td><td></td></tr><tr><td>Systematic, yes</td><td>5 (10.6 %)</td><td>4 (12.1 %)</td><td>1 (7.14 %)</td></tr><tr><td>Degree of advancement, yes</td><td>37 (78.7 %)</td><td>26 (78.8 %)</td><td>11 (78.6 %)</td></tr><tr><td>Background, yes</td><td>16 (34.0 %)</td><td>10 (30.3 %)</td><td>6 (42.9 %)</td></tr><tr><td>Stability of the surgical set-up, yes</td><td>8 (17.0 %)</td><td>5 (15.2 %)</td><td>3 (21.4 %)</td></tr><tr><td>Presence of an intraoperative notch, yes</td><td>12 (25.5 %)</td><td>10 (30.3 %)</td><td>2 (14.3 %)</td></tr><tr><td>Osteosynthesis type, yes</td><td>2 (4.26 %)</td><td>2 (6.06 %)</td><td>0 (0.00 %)</td></tr><tr><td>Osteotomy type, yes</td><td>3 (6.38 %)</td><td>2 (6.06 %)</td><td>1 (7.14 %)</td></tr><tr><td>Pre-existing defect, yes</td><td>1 (2.13 %)</td><td>0 (0.00 %)</td><td>1 (7.14 %)</td></tr></tbody></table>

for only one respondent. The most performed type of osteotomy was the Epker osteotomy (75.0 %) followed by Obwegeser-Dalpont osteotomy (15.5 %). It is interesting to note that all types of exercise were represented. A few differences could be observed between private/mixed surgeons versus public surgeons. Surgeons from the mixed and private sectors were more experienced (p-value = 0.002) and were more numerous to perform graft in BSSO (p-value = 0.005) than those from the public sector. Only 47 (i.e. 31.8 %) of the 148 participants had already performed grafts in BSSO.

## 3.2. Graft practices characteristics

Table 3 gives details on graft practices characteristics in BSSO among the 47 surgeons performing grafts. It seems that surgeons practicing in

the private/mixed sector transplanted more frequently than surgeons in the public sector, although this was not significant.

A few surgeons declared to use more than one type of graft, this fact explains that there are more than 47 responses for this item. Many different types of grafts were used: autologous bone grafting (mandibular, maxillar, cranial, or hip), other bone grafting (xenograft, allograft). Maxillar bone harvest was performed only in case of associated Le Fort I osteotomy. No other type of biomaterial (titanium, ceramic) were used.

The main indication that prompted surgeons to perform grafts was the degree of mandibular advancement (78.7 %). Other main indications were the patient background (34 %) and the presence of an intraoperative notch (25.5 %). It is interesting to note that only 5 surgeons (10.6 %) declared to systematically perform bone grafting in BSSO. The main indications are shown in Fig. 2.
<figure><img src="image_6.png" /><figcaption>Fig. 2. Indications of grafts between public and private/mixed surgeons.</figcaption></figure>

<figure><img src="image_7.png" /><figcaption>Fig. 3. Degree of advance.</figcaption></figure>

Fig. 3 shows the proportion of surgeons who performed graft accord-
ing to the exact degree of advancement (in mm) at which the indication
for bone grafting is retained. It is interesting to note that the degree of
advancement of 10 mm is the most chosen but also that many surgeons
perform bone grafting for smaller degree of advancement (6 mm). This
figure also shows very interestingly that the higher the degree of
advancement was, the more public surgeons performed bone grafting
unlike private or mixed surgeons who performed grafting independently
from the degree of advancement.

3.3. *Comparative analysis of graft practice according to participants' characteristics*

Regarding the type of activity of surgeons performing grafts, 14 (29.8 %) had a public practice and 33 (70.2 %) had a private or mixed practice (Table 3). No difference could be observed regarding the number of retained indications of graft between private and public practice surgeons (p = 0.970). There was also no significant difference (p-value = 0.052) for the degree of advancement required for grafting between public and private/mixed surgeons.

3.4. *Qualitative outcomes: expressed free comments*

The open-ended comments were mainly about the pros and cons of grafting based on the surgeon's personal experience. Many surgeons consider bone grafting beneficial for the correction or prevention of the notch, the reduction of the risk of pseudarthrosis and the stability of the surgical set-up. Some surgeons consider that post-operative edema can be prevented by bone grafting while others think the contrary. A few participants consider other bone grafting systematic indications: bad-split occurrence, complex malformation surgery or asymmetry correction. Some surgeons consider that bone grafting should be considered only secondarily in case of post-operative complications such as the occurrence of pseudarthrosis or a notch. On the other hand, a few surgeons raised some negative consequences regarding bone grafting: increased risk of infection and increased operating time.

4. Discussion

Through this questionnaire, we sought to examine the practices of
surgeons in France concerning the use of grafts in BSSO, as no standard-
ized guidelines currently exist.
<table><caption>**Table 4**
Main type of indications to perform bone grafting in BSSO.</caption><thead><tr><th>I</th><th>II</th><th>III</th><th>IV</th></tr></thead><tbody><tr><td>= Degree of mandibular advancement<br>No consensus has been reached to date.</td><td>= Intraoperative findings<br>Presence of visible notch<br>Step-off between segments</td><td>= Patient-related risk factors<br>Age<br>Underlying diseases<br>Treatments (NSAIDs)</td><td>= Specific surgical scenarios<br>Congenital malformations<br>Acquired malformations<br>Facial asymmetries<br>Bad split</td></tr></tbody></table>

Out of a total number of 1000 maxillo-facial surgeons in France, it is estimated that only 500 of them regularly perform orthognathic surgery. We can say that a number of 148 responding surgeons in the present study can thus be considered as representative of current practice since it represents 29.6 % of the total of orthognathic practicing surgeons. In addition, participants were geographically distributed throughout France.

Only 31.8 % of orthognathic surgeons had ever performed grafts and the indications that stood out, although not significant, seemed to be the degree of advancement (especially for advancements greater than 10 mm), the patient background and the presence of an intraoperative notch.

The 10 mm advancement threshold appears to be a critical factor influencing grafting decisions. This threshold can be explained by bio-mechanical principles: when mandibular advancement exceeds 10 mm, there is often reduced contact between the proximal and distal bony segments at the osteotomy site, particularly at the inferior mandibular border. This creates a void that compromises the surface area available for natural bone healing. Additionally, large advancements generate increased tension in adjacent soft tissues, exerting unfavorable forces on the fixation system and bony segments, which may lead to instability, pseudarthrosis, or formation of a notch. Bone grafts, in such cases, can serve both as space fillers and structural supports, enhancing stability and facilitating bone regeneration. Several studies have shown that the use of grafts (particularly allografts) may reduce the occurrence of lower border defects in cases of large advancements [2,10,13–15].

Based on the study results and consistent with available literature, the main indications for bone grafting during BSSO can be grouped into four categories (Table 4). First, the degree of mandibular advancement, particularly when exceeding 10 mm, was the most commonly cited indication. In such cases, the risk of inferior border defects, mechanical instability, and non-union increases due to insufficient bony contact between segments. Second, intraoperative findings, such as the presence of a visible notch or step-off between segments, may prompt the surgeon to perform immediate grafting to restore mandibular contour and continuity. Third, patient-related risk factors including age, active smoking, underlying diseases, and treatments such as non-steroidal anti-inflammatory drugs (NSAIDs) [3] are often considered as indications to reinforce bone regeneration with grafts. Finally, specific surgical scenarios, such as cases involving congenital or acquired malformations, facial asymmetries, or the occurrence of a bad split, may justify the use of grafts to ensure stability and minimize the risk of postoperative complications. In some cases, surgeons reported using bone grafts secondarily, in response to complications such as pseudarthrosis or persistent defects. These heterogeneous practices underline the lack of consensus in the field and reinforce the need for clinical studies to establish standardized grafting indications in BSSO.

In this study, xenografts and allografts were more used than autologous grafts (74.5 % vs 36.13 %). This might be explained by a few differences between autologous and other grafts: no harvesting, no morbidity of the donor site, malleability of the sample. However, the gold standard remains autologous grafts because of its osteointegration capacity and its compatibility with the host [13,16].

No statistically significant difference was found in grafting indications between public and private/mixed surgeons. Nevertheless, a trend

was observed whereby surgeons in the private/mixed sector used grafts more frequently and tended to prefer xenografts and allografts, while public sector surgeons made more use of autologous grafts.

Finally, our results suggest a discrepancy between perceived usefulness and actual frequency of grafting, with many surgeons performing it in fewer than 10 % of cases. This may reflect the ongoing debate over its preventive value versus its role in salvage situations. Clarifying the risk-benefit ratio of grafting in BSSO (particularly in large advancements) remains a priority for future research.

This study has some limitations. As it was based on a voluntary online survey, it is subject to response bias. Despite this, the study achieved a broad geographic and professional coverage, providing meaningful insights into current clinical practices in France.

In conclusion, our findings reveal the variability in grafting practices among French surgeons performing BSSO. While bone grafting is not systematically performed, it is more commonly indicated in cases of large mandibular advancements or when risk factors for poor healing are present. These results call for further prospective and comparative studies (both national and international) to better define the indications, materials, and outcomes of bone grafting in BSSO and ultimately develop evidence-based guidelines.

## Funding

This research did not receive any specific grant from funding agencies in the public, commercial or not-for-profit sectors.

## Declaration of competing interest

The authors declare that they have no known competing financial interests or personal relationship that could have appeared to influence the work reported in this paper.

## CRediT authorship contribution statement

C. Billon: Writing – review & editing, Writing – original draft, Investigation, Data curation, Conceptualization. A. Gueutier: Visualization. C. Moreau: Writing – review & editing, Writing – original draft, Visualization, Formal analysis, Data curation. A. Rohée-Traoré: Visualization. J.D. Kün-Darbois: Writing – review & editing, Writing – original draft, Visualization, Validation, Supervision, Conceptualization.

## Acknowledgments

The authors thank all the surgeons that responded to the survey.

## References

[1] Verweij JP, Van Rijssel JG, Fiocco M, Mensink G, Gooris PJJ, Van Merkesteyn JPR. Are there risk factors for osseous mandibular inferior border defects after bilateral sagittal split osteotomy? J Cranio-Maxillofac Surg 2017;45:192–7.

[2] Agbaje JO, Sun Y, Vrielinck L, Schepers S, Lambrichts I, Politis C. Risk factors for the development of lower border defects after bilateral sagittal split osteotomy. J Oral Maxillofac Surg 2013;71:588–96.

[3] Gaston MS, Simpson A. Inhibition of fracture healing. J Bone Surg. British Vol. 2007;89-B(12):1553–60.
[4] Louis PJ. Bone grafting the mandible. Dent Clin North Am 2011;55(4):673-95.

[5] Zanettini LMS, Fritscher GG, De Marco RG, de Oliveira Andriola F, Pagnoncelli RM. Bone substitutes in the fort i osteotomy to promote bone union and skeletal stability. J Craniofac Surg 2017;28:492-5.

[6] Lye KW, Deatherage JR, Waite PD. The use of demineralized bone matrix for grafting during le fort i and chin osteotomies: techniques and complications. J Oral Maxillofac Surg 2008;66:1580-5.

[7] Sharma AP, Stringer DE. Autogenous mandibular bone graft for maxillary le fort i osteotomy interpositional gap in orthognathic surgery: a technique case series. J Oral Maxillofac Surg 2019;77(5):1068. e1-1068.e36.

[8] Kang MG, Yun KI, Kim CH, Park J-U. Postoperative condylar position by sagittal split ramus osteotomy with and without bone graft. J Oral Maxillofac Surg 2010;68:2058-64.

[9] Agbaje JO, Gemels B, Salem AS, Anumendem D, Vrielinck L, Politis C. Modified mandibular inferior border sagittal split osteotomy reduces postoperative risk for developing inferior border defects. J Oral Maxillofac Surg 2016;74:1062. e1-1062.e9.

[10] Trevisiol L, Nocini PF, Albanese M, Sbarbati A, D'Agostino A. Grafting of large mandibular advancement with a collagen-coated bovine bone (bio-oss collagen) in orthognathic surgery. J Craniofac Surg 2012;23:1343-8.

[11] Stoor P, Apajajahti S. Osteotomy site grafting in bilateral sagittal split surgery with bioactive glass s53p4 for skeletal stability. J Craniofac Surg 2017;28:1709-16.

[12] Da Hora, Sales PH, Maffia F, Vellone V, Ramieri V, Leão JC. Is it necessary to use bone grafts to prevent defects at the lower border of the mandible after mandibular advancement?—a systematic review. Oral Maxillofac Surg 2022;27:581-9.

[13] Burchardt H. The biology of bone graft repair. Clin Orthop Relat Res 1983(174):28-42.

[14] Cifuentes J, Yanine N, Jerez D, Barrera A, Agbaje JO, Politis C. Use of bone grafts or modified bilateral sagittal split osteotomy technique in large mandibular advancements reduces the risk of persisting mandibular inferior border defects. J Oral Maxillofac Surg 2018;76:189. e1-189.e6.

[15] Alyahya A, Swennen GRJ. Bone grafting in orthognathic surgery: a systematic review. Int J Oral Maxillofac Surg 2019;48:322-31.

[16] Albrektsson T, Johansson C. Osteoinduction, osteoconduction and osseointegration. Eur Spine J 2001;10(Suppl 2):S96-101 Suppl 2.