An-integrated-3D-driven-protocol-for-surgery-first.pdf

An integrated 3D-driven protocol for
surgery first orthognathic approach
(SFOA) using virtual surgical planning
(VSP)
Srirengalakshmi Muthuswamy Pandian, Narayan H. Gandedkar,
Suresh kumar Palani, Yoon-Ji Kim, and Samar M. Adel
Appropriate case selection, meticulous planning, and execution are essential
to the success of surgery-first orthognathic approach (SFOA). Some of the
drawbacks associated with the traditional method of SFOA planning include;
inaccurate bite registrations, along with tedious laboratory procedures to
generate bite-wafer for transitional occlusion. These limitations can be
addressed with the rise of contemporary new-age digital orthodontics
encompassing a wide spectrum of technologies, such as, intra-oral scanners,
prediction and designing software, 3D printers, and artificial intelligence (AI)
guided navigation systems. These technologies have shown immense prom-
ise and have been extensively used in surgical planning in recent times. It is
the need of the hour to generate evidence-based outcomes from high quality
randomised control trials (RCTs) and standard core outcomes (COS) for digi-
tal planning in SFOA to rise higher in the evidence pyramid ladder. The cur-
rent paper elaborates, in detail, on the various 3D technologies available and
their modes of implementation for SFOA cases. (Semin Orthod 2022; 28:320–
333) © 2022 Elsevier Inc. All rights reserved.
Introduction
S urgery-first orthognathic approach (SFOA)
has come a long way since its resurrection by
Lee et al. in 1994. For SFOA to be successful, it is
essential to understand and visualize the ‘transi-
tional occlusion’ that ensues post-surgery. A
‘transitional occlusion’ is set up such that skeletal
problems are corrected with surgery. Further,
post-surgery the dental problems will be
addressed within the orthodontic-realm of treat-
able dental malocclusion.1
Assessing the transi-
tional occlusion is challenging with conventional
two-dimensional (2D) records and planning, and
can be overcome with three-dimensional (3D)
technology. Some of the challenges with 2D
records and traditional model surgery are; bone
collisions in the ramus area, discrepancies in the
pitch, roll, and yaw rotation, and skewness in the
midsagittal plane, especially in the midline area.2
During the last two decades, enormous
advancements in surgical methods and fixation
techniques have been made. Modern navigation
technologies combined with computer-aided
designed and manufactured splints for surgical
transfer of virtual jaw planning, wafer-less sur-
gery, use of patient-specific implants, and the
availability of intra-operative computed tomogra-
phy (CT) or cone beam computed tomography
(CBCT) have improved the precision and accu-
racy of treatment processes. The digital revolu-
tion in SFOA is the widespread use of
technologies such as 3D computer simulation,
Dept of Orthodontics, Saveetha Dental College, Saveetha Institute
of Medical And Technical Sciences, 162, Poonamallee high road,
Velapanchavadi, Chennai, India; Discipline of Orthodontics, Fac-
ulty of Dentistry, The University of Sydney School of Dentistry, Faculty
of Medicine and Health., Sydney Dental Hospital, Sydney Local
Health District, Australia; Consultant maxillofacial surgeon, Chen-
nai, India; Department of Orthodontics, Asan Medical Center, Uni-
versity of Ulsan College of Medicine, South Korea; Faculty of
Dentistry, Alexandria University, Egypt.
Corresponding author.
E-mail addresses: rengalakshmi1910@gmail.com narayan.
gandedkar@sydney.edu.au
© 2022 Elsevier Inc. All rights reserved.
1073-8746/12/1801-$30.00/0
https://doi.org/10.1053/j.sodo.2022.11.006
320 Seminars in Orthodontics, Vol 28, No 4, 2022: pp 320 333

CAD/CAM (Computer-aided design/computer-
aided manufacturing), 3D printing, artificial intelli-
gence (AI), augmented reality (AR), virtual reality
(VR), and navigation, as well as the change from
analogue to digital systems. These advancements
have necessitated a complete overhaul of orthog-
nathic pedagogy, such as didactic training skills in
joint clinics that enhances both clinical and team
skills among practitioners (Figure. 1).
Diagnosis - Improved diagnostic precision
using AI enhanced maxillofacial imagery
Designing - treatment planning using 3D
models CAD/CAM
Manufacturing - Fabrication of custom ortho-
dontic and surgical appliances
Evaluation -Superimposition tools and colour
distance maps enhance our ability to predict,
evaluate, and compare outcomes3
Technique - Utilisation of navigation and
robotics in surgical procedures and embrac-
ing clear aligner therapy for orthodontic
regimen
Diagnosis
Applications of AI in the medical sciences are
developed with algorithms that can first learn
from the data during the training process and
then predict outcomes based on new, unknown
data during the testing process. Machine learn-
ing (ML) is a branch of artificial intelligence that
has found widespread use in computer-aided
diagnostic support. In this context, ML refers to
the process of embedding algorithms into com-
puters to help them learn from data and, ulti-
mately, solve problems without human
intervention. The most recent breakthrough in
AI is deep learning, a subfield of AI modelled
after the human brain's neural network. By run-
ning massive volumes of data through artificial
neural networks, AI is able to synthesise action-
able and relevant insights such as predicting peri
operative blood loss, planning OGS, segmenting
maxillofacial structures, and differential diagno-
sis in SFOA.
Different authors found that AI's accuracy in
diagnosis and deciding whether or not OGS was
necessary ranged from 91% to 96%. The accuracy
of AI in identifying facial asymmetry ranged from
78% to 90%. The typical 3D bone forms of
patients with facial deformities have also been suc-
cessfully estimated with the use of AI. Predicting
blood loss before operating is an intriguing use of
AI. There was a statistically significant relationship
between the projected and real blood loss using
the ML-based AI model. These models have dem-
onstrated superior performance compared to
Fig. 1. Impact of digital technologies on surgical - orthodontic protocols.
An integrated 3D-driven protocol for surgery first orthognathic approach (SFOA) 321

more traditional approaches. It has been shown
that these models are consistent and can be used
again and again. This makes them a useful tool
for helping practitioners with less experience
make better clinical decisions and improve
clinical outcomes.
Clinicians can benefit greatly from adopting
AI applications for early diagnosis and prediction
of the requirement for OGS in determining the
timing and duration of treatment. However,
these studies had a number of drawbacks, such as
a lack of replication and a relatively small sample
size. Hence, there's a pressing need for more
research in the future, and for it to have larger
sample sizes and involve many centres.4
Designing -virtual surgical planning (VSP)
A prerequisite of virtual surgical planning is acqui-
sition of a high-resolution patient’s craniofacial
skeletal structure scan using any (for instance
CBCT machine) state-of-art 3D image capturing
modality. Furthermore, it is imminent to ascertain
rendering the 3D scan, which is performed, either
indirectly (surface) or directly (volume).
Surface rendering (Figure 2) is an indirect
reconstruction method which employs segmenta-
tion based on the grey scales of the voxel data to
display surfaces on the screen based on the per-
spective of a virtual camera. A major advantage of
surface rendering is the ‘operators’ (Orthodontist
or Surgeons) ability to interact in a 3D milieu, com-
monly attributed as ‘3D virtual scene’ interaction.
For example, visualization of 3D cephalometric
landmarks, performance of 3D virtual osteotomies,
defining 3D virtual occlusal relationship (intermax-
illary), seamless movement of bony fragments, and
3D layering of different 3D datasets for composite
model creation.5
Volume rendering (Figure 3) is a more direct
method for the reconstruction of 3D structures
by rendering a volume of voxels. Based on shad-
ing algorithms, colour and opacity are allocated
to each voxel. “Volume rendering” has the bene-
fit over “surface rendering” in that the transitions
between various tissues (such as teeth and bone)
are seamless, resulting in a more detailed anat-
omy of the teeth and interdental gaps.
When “surface rendering” and “volume ren-
dering” are combined, 3D virtual treatment plan-
ning for orthognathic surgery can be done with
more accuracy (Fig. 2 and 3).
Workflow in VSP
The workflow encompasses three stages, namely,
(1) data Acquisition, (2) computer aided surgical
simulation (CASS), and (3) rapid prototyping
(Figure 4).
Data acquisition
Data acquisition involves a triad of high-resolu-
tion records of the cranio-facial skeleton,
Fig. 2. Surface rendering of the hard tissue.
Fig. 3. Volume rendering of hard tissue.
322 Muthuswamy Pandian et al

dentition, and soft tissue profile of the patient.
Patient's cranio-facial skeletal structure may be
obtained via a CT or CBCT scan. However not all
CBCT's possess the required technical specifica-
tion (Field of View) to capture the face in its
entirety. To ensure acquisition of accurate and
complete records, a Field of View (FoV) of
16cmX17cm is recommended. While performing
the scan, the following points must be consid-
ered: (Fig. 5)
The mandible must be in “centric relation (CR)”
and the patient’s “Natural Head Position (NHP)”
must be preserved for accurate planning.
Fig. 4. The digital workflow for SFOA cases.

Registration devices such as wax-bite wafers
and bite forks should not disturb the natural
shape or position of the soft tissue proﬁle.
The patient's head must be kept still and sta-
ble during the CBCT scan (Figure 5).
Chin rests or frontal bands that cover the fore-
head should be used with caution, since they
can stretch the soft tissues leading to an inac-
curate scan.
It is advisable to take a scout view before a
CBCT scan is performed to ensure normalcy
in the above-mentioned parameters.
Conventional wisdom dictates CR is needless
when the mandible is to be operated on ﬁrst or
as a single jaw surgery. However, if we generate
our digital plan to position the maxillo-mandibu-
lar complex, the maxilla will still be aligned with
Fig. 5. Patient positioning during CBCT
Table 1. Comparison of available softwares for planning Orthognathic surgical cases.
Serial
no
Software name Company name/ Website Dental/
Non-
Dental
Subscription/
Free to use
Ability to
design
surgical
splints
Ability to
design
cutting
guides
1 Dolphin 3D
Surgery
Dolphin Imaging
Management
Solutions
(http://www.dolphinimaging.com/product/
ThreeD#3D_Surgery)
Dental Paid Yes No
2 Invivo6 Anatomage
(https://anatomage.com/invivo/)
Dental Paid yes No
3 Mimics Care
Suite
Materialise
(http://www.materialise.com/en/medical/mimics-
care-suite)
Non-
Dental
Paid No No
4 NemoFAB 3D Software Nemotec
S.L. (http://nemotecstore.com/product/nemoceph-
fab-3d/)
Dental Paid Yes No
5 Osirix (v8.0.2) Pixmeo SARL
(http://www.osirix-viewer.com)
Non
Dental
Free No No
6 Planmeca
RomexisÒ
Planmeca
(http://www.planmeca.com/Software/Desktop/Plan
meca-Romexis/)
Dental Paid Yes No
7 Proplan CMF Materialise
(http://www.materialise.com/en/medical/software/
proplan-cmf)
Dental Paid Yes Yes
8 Surgicase CMF Materialise, Leuven,
Belgium
(www.materialise.com)
Dental/
Non-
Dental
Paid yes Yes
9 VSPÒ
Orthognathics
3D Systems (http://www.medicalmodeling.com/solu
tionsfor-surgeons/vsp-technology/vsp-orthognathics/)
Dental Paid Yes Yes
10 3dMD Vultus Atlanta, GA
(www.3dMD.com)
Dental Paid Yes Yes

the CR of the digital mandible in the ﬁnal splint.
Hence, it is always advised to give careful consid-
eration when using CR in CASS, irrespective of
the jaw surgery that is planned.
The next important objective is to obtain an
accurate and complete record of the dentition.
To facilitate this, an intraoral or model scanner
is utilized. The acquired data is exported in the
standard tessellation language (STL) format. It’s
recommended to capture at least 2 centimetres
of buccal gingiva and palatal rugaes to aid and
evaluate any potential errors in the merging pro-
cess. This step is a crucial one as any mistake
here could lead to an inaccurate splint.
Finally, standardised 2D/3D images of the
patient's head at rest in NHP are obtained to rec-
reate a complete soft tissue disposition that can
be overlaid over the craniofacial scan for diagno-
sis and treatment planning.
CASS
Following the careful acquisition of both hard
and soft tissue records, the next important step is
to visualize and plan the treatment outcomes dig-
itally. To facilitate this, many dental and non-
dental software’s exist (Table 1) in the market
for 3D planning. Since most non dental soft-
ware’s restrict cross compatibility across various
dental hardware and software platforms, their
use in orthognathic surgery is limited. Moreover,
the onus is on the practitioner to ensure
compatibility between scanning devices, CAD
software, and printing machines before investing
in them (Table 1).
Surgical Simulation in a SFOA begins by gen-
erating a 3D virtual augmented model (AUM)
which constitute a coalescence of various records
obtained earlier (Fig 6). Accurate rigid registra-
tion is an important mandate to process the
recorded image data for surgical planning.
Point-based, surface-based, and voxel-based rigid
registration are the three most used methods.
Surface to image registration (STI) is a combina-
tion technique that employs the surface and
voxel-based technique to map the intensity gra-
dients of surface images to their corresponding
voxels, thereby enhancing trueness of the resul-
tant image (Fig. 6).6
Perennial errors such as 2D representation of
3D images, cephalometric mis-tracing, errors
assimilated during face-bow transfers, or incor-
rect mounting of dental models, which in the
past, led to catastrophic but avoidable treatment
outcomes are now obsolete with AUM.
After the CT scan has been oriented to NHP,
the maxillary position must be assessed and
adjusted before the SFOA can be planned. A
series of steps followed in the digital planning
include - segmentation, osteotomies, 3d cephalo-
metric tracing.
A surgical treatment objective (STO) for
SFOA is essential and to arrive at it, a thorough
understanding of dento-facial characteristics is
vital. The maxillo-mandibular complex (MMC)
has six degrees of freedom (DoF) in three-
dimensional space—three translation coordinate
axes (the sagittal, transverse, and vertical) and
three rotational axes (the pitch, roll, and yaw).
After the maxilla has been positioned using 6
DoF, the mandible is placed depending on the
maxillary position and the transitional occlusion
position is taken care of. The optimal occlusal con-
tact pattern consists of three points: two posterior
contacts on each side and an anterior touch in the
centre. If this cannot be achieved, work must be
done to create bilateral two-point occlusal connec-
tions in the posterior portion. The transitional
occlusion is checked for collisions and veriﬁed.
Manufacturing
The Surge of Rapid Prototyping: Wafer Surgery
vs. Wafer-less Surgery:
Fig. 6. 3D generated AUM comprising of CBCT
superimposed with scanned models and 3D facial
scan.

To arrive at the planned transitional occlusion
in the theatre, we require surgical wafers to verify
the occlusion. These digital splints, however, do
not transmit the planned movements in a vertical
direction, hence problems in 3D virtual planning
often arise from changes planned on the “Z axis”
and vertical movements of the maxilla (impaction
or down-graft movements). To overcome this,
CAD programs and titanium 3D printers have
made it possible to do surgery without using splints,
commonly referred to as wafer-less surgery. In this
technique, we do not use a wafer to position the
jaw segments, but rather use repositioning guides
with patient specific implants to position them. For
this, a printed titanium plate and an osteotomy
guide embedded in the patient's bone are used to
determine the jaw position, and these patient-spe-
cific implants, plates, and surgical guidance have
been proven to be highly accurate. The surgical
wafers, cutting and positioning guides can be 3D
printed in resin or metal.
Usage of 3D printing, has seen significant
gains in the following areas: the visualisation of
malformations (77%), the refining of guides and
templates (53%), the reduction of operating
time (52%), the refinement of positioning
(13%), and the enhancement of information
transfer to patients (13%).7 9
In orthognathic surgery, fused deposition
material (FDM), selective laser sintering (SLS)
(Figure 7), and stereolithography (SLA/DLP)
are the most commonly used 3D printing pro-
cesses.polyacetic acid (PLA) and Acrylonitrile
Butadiene Styrene (ABS) are two of the most
common types of 3D printing material utilised
for the FDM technique. The SLA and DLP tech-
niques necessitate the use of biocompatible res-
ins, often referred to as Surgical Guide Resins.
The final mechanical properties of these are iso-
tropic and they can withstand steam sterilisation
treatments. For these reasons, stereolithography
is the method of choice when printing a surgical
guide. Production of intermediate and final
splints follows completion of the full creative
planning phase (Figure 8). Once the desired
Fig. 7. 3D printed model of a patient with asymmetry
fabricated using SLS technology.
Fig. 8. Steps in fabrication of intermediate and final surgical wafers using digital planning.

outcome is reached, the STL file of the surgical
wafer must be exported so that 3D printing may
be done (Figure 9).10,11
H. Chen et al. compared in a randomised con-
trolled trial (RCT) the accuracy of traditional
resin occlusal splints (CROS), digital occlusal
splints (DOS) (Figure 10), and digital templates
(DT). The average difference between pre-and
post-operative placements of eight sites on the
teeth in the upper jaw was measured in this study.
Among the three groups, this study found that
the use of printed cutting and repositioning tem-
plates helped contribute to the successful trans-
fer of the maxillary surgical plan to the operating
theatre with greater accuracy. As a bonus, there
was no statistically significant increase in the time
taken for performing the planned procedures
time when these templates were used instead of
the old ones.12
Another study by M. Hanafy et al. compared
computer-assisted orthognathic surgery to tradi-
tional occlusal wafers in a randomised controlled
trial. When compared to the occlusal wafer, the
CAD/CAM splints demonstrated more precise
plan transfer. However, there was no discernible
maxillary malpositioning and the final clinical
outcome was acceptable despite these slight
abnormalities in both groups. In addition, when
compared to traditional models, the average
time spent preparing a computer-assisted opera-
tion was just 113 minutes (from the conclusion
of the virtual plan to STL export). Between the
computer-assisted surgery and the traditional
inter-occlusal wafers, the average intra-operative
time was 49 minutes and 72 minutes, respectively.
This proves to us that the use of CAD/CAM
patient-specific osteo-synthesis and surgical guid-
ance was found to be highly accurate.13
In a recent meta-analysis conducted by Van
Den Bempt et al., it was found that using 3D sur-
gical cutting guidance ensured the maxillo-man-
dibular complex was positioned precisely as
planned in the 3D virtual environment. As a
result, the standard method for maxillary place-
ment may need to be revised, especially in aca-
demic settings, considering this new strategy.
The high price tag was the most significant draw-
back of the computer-aided workflow system
(Fig. 7 10).14
Evaluation
Airway analysis, soft tissue prediction for treat-
ment planning, and colour distance maps for
treatment evaluation are some of the evaluation
tools utilised in surgical planning. The cranio-
cervical inclination in the sagittal plane is used to
confirm the patient's head position for airway
analysis. The anatomical boundaries of the upper
pharyngeal airway and its subregions are defined
using thresholding from 3D CBCT (Figure 11).
It is preferable to use volume rendering for ana-
lysing the airway changes because of treatment.
Colour distance maps based on CBCT, and 3D
photographs can be used to assess the accuracy
of 3D virtual treatment planning and pre- and
post-operative skeletal and dental 3D changes.
The inter-surface distances are calculated after
completing the rigid registration (Figure 11).
Technique
Improved techniques in the orthodontic regi-
men include adoption of clear aligner therapy
during post-surgical orthodontics phase and on
the surgical technique front, it encompasses uti-
lisation of navigation system and robotics.
Fig. 9. 3D printed intermediate and final surgical
wafers using DLP technology.
Fig. 10. 3D printed final surgical wafer used to posi-
tion the jaw segments in the planned occlusion.

Clear aligner therapy (CAT) in SFOA
The combination of clear aligner therapy (e.g.,
InvisalignÒ
) and orthognathic surgery is a novel
concept supported by sparing evidence. There
are some challenges that need to be addressed,
such as, postoperative orthodontic regimen,
patient compliance, technical execution of
osteotomies and inter-maxillary fixation. The
technique of inter-maxillary fixation is a hurdle
encountered during surgery. Several techniques,
such as Erich arch bars and orthodontic bone
anchor screws, have been employed to accom-
plish fixation in patients using clear aligners.
However, each technique has its own limits.
Reports published by Azaripour et al., highlight
the fact that patients are more satisfied with CAT
than with fixed orthodontic appliances, and the
Invisalign patients exhibit superior gingival health
as well.15
This is particularly essential since inflam-
matory tissue incisions are potentially susceptible
to dehiscence. When clear-aligner therapy is uti-
lised as an alternative to standard fixed applian-
ces, perioperative results and postoperative
oedema are not dramatically altered. Therefore,
the use of Invisalign should not be regarded as a
contraindication for orthognathic surgery and
given its stated benefits, may be preferred by
many patients.16
Logistically, fewer appointments
are required to treat patients with aligners and
overall chair time is reduced, allowing for
enhanced treatment convenience. With recent
announcements of CBCT incorporation into digi-
tal aligner treatment planning procedures, the
end-to-end digital patient experience enables
certain predictabilities that are otherwise difficult
to realise in an analogue world.17
Procedure
There are two post-surgical orthodontics techni-
ques. In the first one, depending on the type and
magnitude of mobility, the final splint is removed
3 to 6 weeks after the treatment. The three-
dimensional STL files of the final occlusion
(including maxillary position) are provided to
the orthodontist and aligner manufacturer to
design an aligner that will retain the transverse
dimensions of the maxilla upon removal of
the final splint. If necessary, orthodontic bone
anchor screws may be retained in place for verti-
cal adjustment and bite retraining. A series of
aligners are created for the post-surgical phase of
orthodontic treatment.18
The alternative is to continue the post-surgical
splint for procedures involving relocation without
maxillary arch expansion. This splint is worn for
two to three weeks following surgery to assist the
patient in occlusion throughout the recovery
phase; and it may replace the aligners. In conjunc-
tion with elastics, it is primarily used to retrain the
muscles to avoid an acquired bite. The splint has
open occlusal holes, allowing for a more precise
evaluation of the occlusion than when two align-
ers are placed between the teeth. Once the sur-
geon and orthodontist are satisfied with the
occlusion, the patient may return to aligners dur-
ing recuperation instead of the splint. The ortho-
dontist visits patients within two weeks to confirm
Fig. 11. Airway analysis used to calculate the volume.

the proper usage of elastics from TSADs and then
every two to three weeks thereafter to continue
monitoring healing and elastic use. One month
after surgery, physical therapy begins to loosen
muscles and expand mandibular range of motion
to allow scanning for new additional aligners.
According to the most recent study published
by Kyungmin C. Lee, there were no statistically sig-
nificant differences between the fixed appliance
and clear aligner groups regarding surgical
relapse; However, when comparing the two
groups, the clear aligner treatment group exhib-
ited a greater tendency toward relapse than the
fixed appliance treatment group. Hence, the post-
operative management of patients receiving clear
aligner and surgery-first orthognathic treatment
requires careful consideration (Fig. 12 17).19
Navigation and robotics in OGS
Computer-assisted intra-operative navigation
(Ci-Navi) is an innovative tool for monitoring
surgical procedures and guiding surgeons. In
Ci-Navi surgery, a real-time navigation system is
employed as a supplementary tool to guide
the osteotomies, analyse bone movement, and
establish the ultimate bone position, all of which
have been previously determined by importing
the surgical protocol into the navigation work-
station. Since the surgical plan may be viewed in
real time, the operating surgeon can make revi-
sions as needed during the procedure. This
works great for moving the jaw during orthog-
nathic surgery in real time while the procedure
is happening.20
Fig. 12. Initial record of a patient who came with a chief complaint of facial asymmetry.
Fig. 13. Skeletal Class II with hyperdivergent facial pattern with a mentor deviation of 10.6mm was observed. A
mandible yaw of 7.5 degrees was seen.

The Global Positioning System (GPS) is used
exclusively by the surgical navigation system to
synchronise time and location data. The three
main parts of a Surgical Navigation System are
1. The localiser, which is like a satellite in orbit,
2. The CT scan data, which is like a ground con-
trol or road map.
3. The surgical probe, which is like the user
equipment.
During navigation-guided operations, this
localizer or satellite is put on the patient's fore-
head to produce signals that are picked up by a
surgical probe and transformed into a digital
image. The patient's current spatial position is
Fig. 14. Initial and after CASS. Canting correction of the maxilla, yaw correction of the mandible, and advanced
genioplasty was planned.
Fig. 15. After surgery, Invisalign treatment was performed.

displayed on a pre-registered CT, and this image
is taken digitally through a monitor. The naviga-
tion system combines the designer's 3D cranio-
facial model with the original 3D model. Using
patient-to-image registration, the navigation sys-
tem ﬁnds the precise location on the CT of the
probe's tip when it is positioned over an anatomi-
cal landmark in the patient's physical space.
While using this technique, for an osteotomy to
be performed, osteotomy guides will be required.
In the instance of a Lefort I osteotomy, the maxil-
la's ultimate location is identiﬁed by the navigation
Fig. 16. Settling of occlusion using clear aligners.
Fig. 17. As a result of treatment, facial asymmetry was corrected and the functional occlusion was achieved.

probe and displayed on the navigation station's
screen. If the maxilla wasn't positioned in the right
place, the navigation probe helps to move into the
desired position. Although intra-operative naviga-
tion has been used in numerous attempts at
orthognathic surgery, it remains difficult to move
the maxilla to the desired position and fine-tune
the maxillary position. Internal fixation methods,
like drilling holes and attaching a plate, are hard to
use because the maxilla is hard to hold in place.21
Contrary to this belief, the recent research by
Burgner et al. and Wang et al. states that these
drawbacks can be avoided by employing a robot
arm. When three-dimensional knowledge of the
head position is provided through navigation, a
robot arm can be used to successfully relocate the
segment to the target position.22,23
Conclusion
The use of 3D planning in diagnosis and treatment
of SFOA cases can provide consistent and predict-
able results. There is growing evidence, in literature,
to support its application. Better algorithms and AI
are starting to have a bigger impact on the predict-
ability and results of the appliance. Contraindica-
tions to 3D virtual planning are not fully explored,
at this time. However, costs, such as those associated
with computer gear and software, data processing
services, and the materials needed to make splints
and models, can be a significant impediment to the
process. With ease of material availability and pro-
cess simplification, this impediment can be over-
come in the future to make this technology more
accessible. To conclude, the predictability of this
technology in conjunction with sound clinical judge-
ment and planning may become the keystone to
effectively managing SFOA, in the future.
Patient consent
Patient consent was obtained.
Funding
No funding or grant support.
Author contributions
All authors attest that they meet the current
ICMJE criteria for Authorship.
Declaration of competing interest
The authors reported no competing financial
interests or personal relationships that could
appear to influence the work reported in this
paper.
References
1. Gandedkar NH, Chng CK, Tan W. Surgery-first orthog-
nathic approach case series: Salient features and guide-
lines. J Orthod Sci. 2016;5(1):35–42.
2. Lonic Daniel, et al. Computer-assisted orthognathic sur-
gery for patients with cleft lip/palate: from traditional
planning to three-dimensional surgical simulation. PloS
one. 2016;11(3): e0152014.
3. Bouletreau P, et al. Artificial intelligence: applications in
orthognathic surgery. J Stomatol, Oral and Maxillofac Surg.
2019;120(4):347–354.
4. Khanagar Sanjeev B, et al. Performance of artificial
intelligence models designed for diagnosis, treatment
planning and predicting prognosis of orthognathic sur-
gery (OGS)—a scoping review. Appl Sci. 2022;12
(11):5581.
5. Swennen Gwen. 3D Virtual Treatment Planning of Orthog-
nathic Surgery: a Step-by-Step Approach for Orthodontists and
Surgeons. Springer; 2016.
6. Adel Samar M, et al. Tip, torque rotations: how
accurately do digital superimposition software pack-
ages quantify tooth movement? Prog Orthodont. 2022;23
(1):1–10.
7. Ciocca L, Fantini M, De Crescenzio F, Persiani F, S R.
Computer-aided design and manufacturing construction
of a surgical template for craniofacial implant positioning
to support a definitive nasal prosthesis. Clin Oral Implants
Res. 2011;22:850–856.
8. Antony A, Chen W, Kolokythas A, Weimer K, Cohen MN.
Use of virtual surgery and stereolithography-guided
osteotomy for mandibular reconstruction with the free
fibula. Plast Reconstr Surg. 2011;128:1080–1084.
9. Murphy S, Atala A. 3D bioprinting of tissues and organs.
Nat Biotechnol. 2014;32:773–785.
10. Martelli N, Serrano C, Hvd B, Pineau J, Prognon P, Bor-
get I, et al. Advantages and disadvantages of 3-dimen-
sional printing in surgery: a systematic review. J Surg.
2016;159:1485–1500.
11. Rengier F, Mehndiratta A, von Tengg-Kobligk H, Zech-
mann CM, Unterhinninghofen R, Kauczor HU. 3D print-
ing based on imaging data: review of medical applications.
Int J Comput Assist Radiol Surg. 2010;5:335–341.
12. Chen H, et al. Comparison of three different types of
splints and templates for maxilla repositioning in bimaxil-
lary orthognathic surgery: a randomized controlled trial.
Int J Oral Maxillofac Surg. 2021;50(5):635–642.
13. Hanafy M, et al. Precision of orthognathic digital plan
transfer using patient-specific cutting guides and osteo-
synthesis versus mixed analogue digitally planned sur-
gery: a randomized controlled clinical trial. Int J Oral
Maxillofac Surg. 2020;49(1):62–68.
14. Van den Bempt Maxim, et al. Toward a higher accuracy
in orthognathic surgery by using intraoperative computer

navigation, 3D surgical guides, and/or customized osteo-
synthesis plates: a systematic review. J Cranio-Maxillofac
Surg. 2018;46(12):2108–2119.
15. Azaripour A, Weusmann J, Mahmoodi B, Peppas D, Ger-
hold-Ay A, Van Noorden CJ, Willershausen B. Braces ver-
sus InvisalignÒ
: gingival parameters and patients'
satisfaction during treatment: a cross-sectional study.
BMC Oral Health. 2015 Jun 24;15:69.
16. Kankam Hadyn, et al. Comparing outcomes in orthog-
nathic surgery using clear aligners versus conventional
ﬁxed appliances. J Craniofac Surg. 2019;30(5):1488–
1491.
17. Moshiri Mazyar. Considerations for Treatment of Patients
Undergoing Orthognathic Surgery Using Clear Aligners. AJO-
DO Clinical Companion; 2022.
18. Kankam Hadyn KN, et al. Segmental multiple-jaw surgery
without orthodontia: clear aligners alone. Plast Reconstruct
Surg. 2018;142(1):181–184.
19. Lee Kyungmin C. Postoperative stability in patients with
surgery-ﬁrst approach and clear aligners. J Oral Maxillofac
Surg. 2022;80(9):S68.
20. Chen Chen, et al. Accurate transfer of bimaxillary orthog-
nathic surgical plans using computer-aided intraoperative
navigation. Korean J Orthodont. 2021;51(5):321–328.
21. Han Jeong Joon, et al. Robot-assisted maxillary position-
ing in orthognathic surgery: a feasibility and accuracy
evaluation. J Clin Med. 2021;10(12):2596.
22. Burgner J, Toma M, Vieira V, Eggers G, Raczkowsky J,
Muhling J, Marmulla R, Worn H. System for robot
assisted orthognathic surgery. Int J Comput Assist Radiol
Surg. 2007;2:S419–S421.
23. Wang X, Song R, Liu X, Li Q, Cheng T, Xue Y. System
design for orthognathic aided robot. In: Proceedings of the
5th annual IEEE International Conference on Cyber Technology
in Automation, Control and Intelligent Systems. Shenyang,
China; 2015612–617. 6 10.

An-integrated-3D-driven-protocol-for-surgery-first.pdf

Recommended

Recommended

More Related Content

Similar to An-integrated-3D-driven-protocol-for-surgery-first.pdf

Similar to An-integrated-3D-driven-protocol-for-surgery-first.pdf (20)

Recently uploaded

Recently uploaded (20)

An-integrated-3D-driven-protocol-for-surgery-first.pdf