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151]

Invited Review Article

3D modeling, custom implants and its future

perspectives in craniofacial surgery
Access this article online
Website:
Jayanthi Parthasarathy
www.amsjournal.com Department of Engineering, Director Engineering MedCAD Inc. Dallas TX 75226, USA
DOI:
10.4103/2231-0746.133065 Address for correspondence:
Quick Response Code:
Dr. Jayanthi Parthasarathy, 1372 Todd Dr, Plano, TX 75023, USA.
E‑mail: jayanthip7@hotmail.com

ABSTRACT

Custom implants for the reconstruction of craniofacial defects have gained importance due to better performance over their
generic counterparts. This is due to the precise adaptation to the region of implantation, reduced surgical times and better
cosmesis. Application of 3D modeling in craniofacial surgery is changing the way surgeons are planning surgeries and graphic
designers are designing custom implants. Advances in manufacturing processes and ushering of additive manufacturing for
direct production of implants has eliminated the constraints of shape, size and internal structure and mechanical properties
making it possible for the fabrication of implants that conform to the physical and mechanical requirements of the region of
implantation. This article will review recent trends in 3D modeling and custom implants in craniofacial reconstruction.

Keywords: 3D modeling, implants, additive manufacturing, craniofacial surgery, porous titanium, PEEK implants, electron
beam melting, patient specific implants, custom implants, CAD CAM surgery, CAD CAM implants

INTRODUCTION anatomical shapes that is hard to achieve intraoperatively by

carving harvested bone from the donor site. Hence it would
Reconstruction of the craniofacial skeleton is extremely be very useful for the surgeon to be aided by standard practice
challenging even to the most experienced surgeon. Some of and proven methods in engineering wherein, the design and
the critical factors that contribute to the complexity include performance of the reconstructed implants/prosthesis can be
anatomy, presence of vital structures adjacent to the affected predicted with accuracy and precision.
part, uniqueness of each defect and chances of infection. In
any craniofacial reconstruction whether secondary to trauma,
Surgeons have adapted to enhanced visualization techniques for
ablative tumor resection, infection and congenital/developmental
close to two decades and even today this is an advancing field.
deformities, restoration of aesthetics and function is the primary
Advantages of virtual reality can be totally beneficial only when
goal and calls for precise pre‑surgical planning and execution
transferred to the clinical scenario, i.e., the operatory to achieve
of the plan. Auto grafts are the gold standard for craniofacial
skeletal reconstruction. However their use is limited by the expected results. Development of computer assisted design (CAD)
availability of suitable donor site especially for large defects, and computer assisted manufacturing (CAM) systems that adapt to
additional expensive surgeries, tissue harvesting problems, donor the surgeons needs has resulted in a gamut of the armamentarium
site morbidity with an additional patient discomfort, chances of for computer assisted surgery. Such systems specifically focus on
infection at both the recipient and donor sites, increased surgical enhanced visualization tools – 3D modeling or better termed
time, resorption of the graft requiring secondary surgeries and the as virtual reality and gives the surgeon the ability for precise
need for additionally skilled surgical team, which has led to the preoperative planning and perform virtual osteotomies resections
search of alloplastic material that would be suitable without the and design patient specific implants preoperatively. These virtual
inherent problems.[1‑6] Craniofacial defects also have complex models can be imported into an intraoperative navigation system

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for precise placement of bone segments, implants and hardware. The DICOM data is then processed using software as MIMICS,
Advances in manufacturing technology and material science has Biobuild, 3D Doctor to name some to create a 3D model of
led to the possibility of turning such virtual model or design into the anatomy depicting the defect. The 3D model file is then
reality as physical replica models, surgical guides or cutting jigs imported into design software which could be either a haptic
or splints for intraoperative use and patient specific implants. based environment as Freeform® Geomagic or CAD based one
as 3 Matic™ from materialize to create the final implant design.
The success and longevity of implants depend upon factors The implant is then manufactured by machining a block of
like material characteristics, design of the implant and the material (subtractive manufacturing) or by adding material layer
surgeon’s skill. Advances in image processing and manufacturing by layer and fusion of the layers (additive manufacturing).
technologies have made it possible for the surgeons to have hand
held models for a tactile perception of the defect. The next level The process of 3D modeling and custom implants is continuously
of automation has brought in fabrication of custom designed evolving with advancements in the design and manufacturing
implants as the best option for reconstruction of craniofacial worlds. This article will review the recent literature on 3D
defects. Custom implants for the reconstruction of craniofacial Modeling and recent advances in custom implants in cranial,
defects have recently gained importance due to their better skull base, zygomatic orbital, midface, mandible reconstruction,
performance over their generic counterparts. This is attributed to, orthognathic surgery and treatment of the syndromized patient
the precise adaptation to the region of implantation, that reduces more specifically in relation to application of CAD/CAM
surgical times, in turn leading to lesser chances for infection, faster technologies craniofacial reconstruction with respect to various
recovery and better cosmesis in craniofacial surgery.[7‑9] materials and also include the author’s 15 years’ experience in
3D modeling and design and manufacturing of custom implants
Enhancements in recent years have been in the area of and discuss future perspectives. A systematic search on National
design, materials and manufacturing process for craniofacial Library of Medicine (PubMed/Medlinehttp://www.ncbi.nlm.
implants. Use of the haptic device introduced a decade nih.gov/pubmed) for related articles with search criteria as 3D
ago, and 3D visualization has given the graphic designer modeling, custom craniofacial implants, orbital implants, CAD/
the capability to design these implants more aesthetically CAM craniofacial applications and computer assisted craniofacial
enhancing the cosmetic outcome of custom implants. surgery was performed. Articles related to 3D modeling, custom/
Availability of multitude materials as, autologous bone flaps, patient specific implants in craniofacial surgery using various
titanium, polymethylmethacrylate (PMMA), bioceramics as materials were chosen for review.
hydroxyapatite (HA), polyethylene, biodegradable polymers that
have been used for craniofacial reconstruction give the surgeon CAD/CAM in cranioplasty
many options to choose from. Recent introduction of direct Cranioplasty is the procedure of choice for treating cranial defects
digital manufacturing technologies that enable the fabrication of commonly caused by trauma, tumor removal or decompressive
porous implants with lattice and solid structures in one go from craniotomies. The main goal of cranioplasty is to protect the
patient specific data has opened up a new horizon for the next brain and alleviate psychological affliction caused by the defect
generation of craniofacial implants. and enhance social performance of the patients. Hence the ideal
cranial implant material would fit the cranial defect and achieve
CAD/CAM systems have enabled us the ability to design complete closure, be, radiolucent – for postoperative imaging,
and manufacture custom implants at an acceptable cost in resistant to infections, strong to biomechanical processes, easy to
a reasonable time. Additive manufacturing technologies as shape, not expensive and ready to use. The following paragraphs
stereolithography (SLA), polyjet, fused deposition modeling; highlight the advantages of 3D modeling and custom implant
3D printing, selective laser melting (SLM), selective laser manufacturing in cranioplasty that allows the surgeon to use the
sintering (SLS) and electron beam melting (EBM) lend themselves material of his choice.
to manufacturing of complex anatomic parts without any barriers
of design constraints including lattice structures. SLS, SLM and Titanium
EBM use biocompatible implantable materials as titanium, Titanium has been a material of choice for cranioplasty due to its
Ti6Al4V, chrome cobalt and polyetheretherketone  (PEEK) and biocompatibility, strength to weight ratio and osseo integrative
facilitate the direct production of implants with engineered property. Titanium in various forms as sheets, mesh have been
properties that match properties of the tissues at the region of in use for sometime more recently with the advent of EBM or
implantation. Surgeons can now have access to the facilities direct metal laser sintering (DMLS) 3D printed cranial implants
service providers. has come into vogue.

THE PROCESS FLOW Titanium mesh reconstruction is a popular method among the
surgeons due to the ability to use the preformed mesh as a
The complete process flow for CAD/CAM generated implants is template for resection. However, the strength of a thin dynamic
shown in Figure 1 and is described briefly below. mesh that can be molded intraoperatively at times requires to be
enhanced with PMMA.
The process generally known as reverse engineering in
the engineering world starts with acquiring computed In recent years the model of the cranium with the defect is
tomography (CT)/magnetic resonance imaging 2D image data as fabricated using 3D printing technologies and used as a replica
digital imaging and communications in medicine (DICOM) files. or template of the actual region of interest depicting the precise

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Figure 1: Process flow for design and manufacture of computer assisted design/computer assisted manufacturing generated implants

defect. A secondary processing method as forming is used to

produce the actual implant.[6,10] This process delivers a well‑fitting
prosthesis and is very useful in treating large cranial defects
with advantages of reduced, operating time, healing time and
hospitalization period, eventually leading to reduced cost to the
patient. However, the process involves fabrication of the rapid
prototyping (RP) model at an additional cost and time. Figure 2
shows a large titanium mesh cranioplasty implant and the same
being fitted in surgery.
a b
The technology was used to assess the temporalis thickness and Figure 2: (a) Titanium mesh implant fitted to the cranium model,
include in the design of the implant for achieving best cosmetic (b) Intraoperative fixation of implant
results and prevent the “hourglass facial deformity.”[11]
In the very recent past ushering ushering of metal additive
A long‑term  (6‑12  years) evaluation of CAD/CAM titanium in manufacturing EBM and DMLS has introduced the direct
cranioplasty of 26  patients with large cranial defects on a fabrication of the implant without the need for the template. This
visual analog scale showed that none of the implants required next gen implants will aim to confirm to the normalized shape
removal, and all patients would have chosen cranioplasty of the part it replaces, with mechanical properties being close to
again and had stated improvement in their life‑style. However that of the region of implantation preventing stress shielding in
the authors observed sub optimal follow‑up imaging in four load bearing regions, porous for bone ingrowth, have repeatable
patients with meningioma. The authors concluded titanium properties.[14‑24]
to be material of choice for secondary reconstruction of large
cranial defects resulting from decompressive craniectomies As mentioned earlier, a 3D digital model of the cranium is
following trauma or infarction.[12] PMMA would be the choice generated from the CT data. The virtual model is then used to
for primary reconstruction when monitoring with postoperative create the implant design either by mirroring from the contralateral
imaging is needed. The technology has also been used as a side or by generating curves based on the anatomical region with
one‑step procedure for resection and reconstruction of skull base CAD based/haptic devices. The implant model is then sent to the
meningioma wherein, the authors used the preformed titanium EBM machine from ARCAM AB® or DMLS from electro optical
plate as a template for resecting the cranium.[13] systems (EOS) GmbH EOS. The software then creates layers of 2D

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images that are sent to the machine for solidification of the part
from a bed of Ti6AlV4 powder layer by layer that finally creates
an implant ready for implantation. EBM and DMLS technologies
alleviate the need for a skull model or a secondary process to
create a custom implant. Figure 3 shows a patient specific porous
titanium implant made using EBM and the same fitting to the
model and intraoperative fixation of the implant.

PMMA, bioceramics and other polymers a

CAD/CAM technology has been used successfully to make PMMA
implants as well. 3D models of cranial implants were designed
from CT scan DICOM data and 3D printing technology is used
to produce mold templates of the proposed implant, which
was then used intraoperatively to quickly make the implant in
the operatory.[25] Similarly, CT scan data was used to create an
implant digital model and RP to produce silicon molds which b c
were then used for creating patient specific cranial implant.[26] The Figure 3: (a) Patient specific porous titanium implant made using electron
authors concluded that custom‑made implants for cranioplasty beam melting, (b) Implant fitting to the cranium model, (c) Intraoperative
showed a significant improvement in morphology especially fixation of implant
for repairing large and complex‑shaped cranial defects. The
authors further concluded technique may be useful for the bone
reconstruction of other sites as well. Custom implants from
polypropylene and polyester were made using a computerized
numerical control (CNC) milled 3D model of the skull generated
from CT scan data.[27] Stereolithographic or 3D printed models of
skull defects generated from CT scan can be used as templates
to fabricate porous bioceramic Hydroxy Apatite implants.
60 patients received these implants and were followed‑up for
2  years.[28] Similar implants were designed in CAD with and
manufactured using the SLA photo polymerization process. The
material used was a combination of resin and HA powder. The
final implant seen in Figure  4 had surface porosity for tissue
ingrowth.[29]

PEEK cranial implants

PEEK custom cranial implants are being used more in the current Figure 4: Porous resin and hydroxyapatite implant manufactured by
times.[30,31] PEEK is a highly strong engineering thermoplastic, stereolithography
which retains its chemical and mechanical properties even at
high temperatures. The material has high biocompatibility and
biostability maintaining its physical and chemical characteristics
on long‑term exposure to body fluids. The modulus of elasticity
of PEEK is similar to that of cortical bone, preventing any stress
shielding making it a better choice over metallic implants
that have high modulus of elasticity. PEEK is also radiolucent
facilitating postoperative imaging procedures. Implants can be
designed to replace exact anatomy even in bulky regions as the a
material is very light. The material can be repeatedly sterilized by
common methods as autoclave, gamma or ethylene oxide. PEEK
lends itself to machining of complex organic shapes very well.
PEEK implants can be fixated to the adjacent bone with standard
screws and plates of surgeons’ choice. All the above mentioned
characteristics have made PEEK the sought after material for
cranial implants by manufacturers and surgeons in the recent
past. In general, PEEK implants are made from a block of extruded
b c
material using a CNC machining. Figure 5a‑c shows images of
machined PEEK implant and the same being fixed to the cranium Figure 5: (a) Machined polyetheretherketone implant, (b) Intraoperative
fixation to the cranium, (c) Postoperative X-ray imaging
in surgery and postoperative X‑ray imaging. PEEK implants can be
used in non‑load bearing regions of the craniofacial skeleton. PEEK
can also be sintered to produce implants similar to the machined CAD/CAM in mandible reconstruction
PEEK.[32] CAD designed PEEK custom implants have been used The ultimate goal of mandibular reconstruction is to restore speech,
to correct cranial, frontal, malar and mandibular defects.[33,34] masticatory function and facial form. Current reconstruction

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procedures combine mandible reconstruction plate fixation and region and the vasculature in the donor region. The part to
use of micro vascular flaps. be resected is then determined and the part to be harvested is
designed accordingly. Resection and harvesting guides are then
Virtual pre bending of mandible recon plates designed taking the surgical needs like access to the operative site
Intraoperative bending of plates can be time consuming. and vasculature reconstruction. The guide is then produced with
Bending reconstruction plates depends on the complexity of 3D printing methods using a biocompatible material approved
resection and surgeon’s skill. Bending the plates on the 3D for the purpose that can be used in surgery for resection of the
models fabricated using additive manufacturing technologies recipient site and harvesting the flap from the donor site. The
prior to the surgery reduces operating times. Some authors[35] guide is a 3D printed part and is generated in accordance to the
have found saving of an average of 0.4 hr while others[36] in a resection/harvesting postoperative plan of the craniofacial skeletal
study of 30 patients reported a 1.4 hrs reduction of operating structures and the donor site. The postoperative plan mandible
times. Ideal positioning of mandibular segments, time saving model is used to adapt the recon plate. The surgeon then uses the
by no intraoperative repeated bending and adapting of plates, guide on the harvested fibula and precisely cuts the segments for
use of the original surface of the cortical bone as a template for reconstruction. The surgical planning is performed planned over
adapting the recon plate, facilitating the preoperative surgical the internet and teleconsultations gives access to technology and
simulation and restoration of centric occlusion of the patient expertise of surgeons all over the globe even in remote locations.
were some of the benefits of virtual surgical planning and
construction.[37,38] In a study, wherein five oral and maxilla Virtual surgical planning with 3D models using preoperative CT
facial surgeons adapted a standard 10‑hole Compact UniLock data enables the use of the outer surface contour of the un operated
2.4‑mm large plates (Synthes) on stereolithographic models and mandible as a reference for positioning the plate if there is no
virtual bending was done by importing and bending polygonal expansion of the buccal plates. Cutting guides can be very precisely
model of the same plate into standard CAD/CAM software, the designed and made with biocompatible materials for intraoperative
author found statistically significant better adaptation of the use for tumor resection as well as harvesting of fibula segments.
virtual model compared with the physical model which favors Fibula segments harvested using such jigs is found to be repositioned
manufacturing of patient specific pre bent plates.[39] The above in the mandible very precisely with minimal adjustments if necessary
studies concur with the previous observation of preoperative and are very useful in extensive mandible reconstructions where the
bending of plates may result in lesser bending stresses and may maxillary mandible relation is completely lost in all 3 directions.
reduce the chances of postoperative plate breakage reported.[40] A mathematical algorithm to derive an optimal position for bone
Computer aided planning simulated the surgical resection and grafting from the iliac crest for reconstruction of large mandible
laser sintered model derived from the plan and CT data for pre resection defects had also been made for teleconsultations of experts
bending the reconstruction plate has been successfully used by between Vienna and Switzerland and established the possibility of
some authors [Figure 6].[41] using the technology on a global basis.[42]

Virtual surgical planning for mandible reconstruction and micro The world’s first additive manufactured full mandible was
vascular bone tissue grafting implanted in a patient by Dr. Jules Poukens and his team in
Micro vascular bone tissue grafting for mid facial and mandible Belgium is seen in [Figure 8].[43]
reconstruction has improved over years and gives the surgeon
a new outlook in reconstruction of large craniofacial defects. Reducing operating time is one of the key prognostic factors
Placement of dental implants on the revascularized grafts has in free flap surgery. In addition, reduced blood loss, chances
made the procedure very attractive to surgeons and patients of postoperative infection[44] and perioperative cost are some
as well. However the large variety of donor sites, shape and other benefits of virtual surgical planning and cutting guides.[45]
complexity of the facial skeleton, harvesting the exact shape, A new protocol for mandible for design and manufacture of
precise positioning of the grafts are some of the pertinent problems custom cutting guides for complete ablative tumor resection of
that make traditional planning methods challenging even for the the mandible including the condyles has been described.[46] The
experienced surgeon. Added to the complexity many procedures surgical device consisted of two components a cutting guide and
involve a combination of custom implants and micro vascular a titanium reconstructive bone plate and was designed as a patient
osteocutaneous flaps for best results. Computer assisted planning specific device from the patients CT scan data. The cutting guides
techniques and guides generated out of the process go a long way assisted precisely to transfer the virtually planned osteotomies
in assisting the surgeon in achieving facial symmetry, preventing to the surgical scenario. The bone plate was designed using the
dystopia and implant based dental rehabilitation comfortably with patient’s anatomical data including the condyles. The authors
reduced operating time and lesser chances for repeat surgeries. found a reduction of operating time.
For mid facial reconstruction custom implants would be the
preferred method and for the mandible the traditional recon Restoration of masticatory function is very dependent on the basal
plates can be used. bone position and relationship of the maxilla and mandible. To
achieve a good anatomic contour and optimal placement of the
Process flow for virtual surgical planning and manufacturing of flap for prosthetic rehabilitation the need for precise computer
the guides is shown in Figure 7 a-e. The process starts with 3D assisted planning, pre and postoperative simulation 3D models
reconstruction of both the donor (fibula, scapula etc as the case cannot be over emphasized. The use of stereolithographic models
may be) and recipient site maxilla/mandible. Virtual 3D models for planning complex maxilla and mandibular reconstruction and
are generated depicting the pathological region in the recipient generation of surgical guides has been emphasized.

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Patient specific dental implants for atrophic bone according to extension of the pathology.[49] The authors further
In atrophic mandible standard diameter root form implants also state there is no single flap procedure that can provide a
are a challenge and bone reconstructive surgery may not be solution for larger Class III defects. Smaller defects involving
the treatment of choice due to patient acceptance or other only the alveolar ridge can be corrected using ridge form plates
contraindications. In a 2 year study of five patients with severe and bone grafting, but larger defects require a combination of
posterior atrophy of mandible custom designed blade implants procedures as osteocutaneous flaps and patient specific implants
made using CAD/CAM technologies manufactured using RP that makes it more difficult to visualize the outcome. In order to
technology – SLS were successfully placed. Subsequently, achieve the best cosmetic and functional outcome some critical
prosthesis was also constructed successfully and no rejection, considerations for treatment of larger defects of the midface
infection or failure of the treatment was seen.[47] This opens‑up include soft‑tissue reconstruction, establishment of connection
a whole new concept for dental implant design and prosthetic between the residual alveolar bone and the zygomatic buttress,
reconstruction. orbito‑zygomatic complex reconstruction and alveolar ridge

Construction of arch forms or space holders for grafts

3D printed model can be used to adapt arch forms or titanium
space holders for bone grafts to be held in position until
integration with the host bone takes place.[48] 3D models are
reconstructed from the CT scan data. The defective region is
ascertained and a surgical resection is planned. An ideal arch
form is then constructed considering the shape and position of
implants to achieve a good occlusion. A 3D printed model is then
fabricated that forms a template for adapting the titanium mesh
which will be used as the space holder. Figures 9 and 10 show a
3D reconstruction of a maxilla and mandible and the arch form
reconstruction that was used as a space holder.

Midface reconstruction
Midface reconstruction after extensive ablative tumor resection
often, extends to the regions from the orbit to the alveolar bone,
involves the nasal bone medially and may be unilateral and Figure 6: Virtual surgical planning and manufacturing of the guides for
bilateral. The defects themselves have been classified as Class I‑IV mandible reconstruction

a b c

d e

g
Figure 7: (a-e) Process plan for virtual surgical planning for fibula reconstruction of mandible (f) Fibula guide fitting to fibula bone model and (g) post
op reconstructed mandible bone mode

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reconstruction for dental implant placement. Computer assisted optimized location for the graft that would satisfy the design of
3D modeling and virtual surgical planning can give the surgeon the alveolar reconstruction was determined with virtual surgical
a better understanding of the anatomy, osteotomies of the donor planning. The authors mention osteomyocutaneous flap and the
and recipient sites and planning of patient specific implants help titanium implant design were separated by virtue of the outlines.
precise placement of the bone graft in an optimum position The titanium implant supporting the midfacial region was then
for dental rehabilitation. Reconstruction of the orbital wall by fabricated. The titanium implant and the flap were fixated to the
mirroring data from the normal side has been described by basal bone using traditional plates and screws. The scapula flap
several authors.[50‑53] A methodology for computer assisted surgical was then positioned in the predetermined optimum location for
planning and custom titanium plates and mesh for midfacial placement of dental implants. The dental implants were then
reconstruction. 3D printed models have been used as a template placed later as a secondary procedure. Manufacturing the implants
to presurgically adapt a titanium mesh or plate to precisely fit the and designing the scapula flap is a major part of the process and
defects of the orbital wall a procedure that helps to reduce surgical the complete success depends on placing the implant and the graft
time.[54,55] Stereolithographic models fabricated from patient’s in the predetermined 3dimensional location. Precise placement
CT have been used to reshape a sheet of titanium for creating can be achieved with intraoperative navigational systems. The
patient specific implants for orbital floor reconstruction.[56] CAD
titanium implant in this case replaced the zygomatic bone and
design for the implant was derived from the CT scan data and
arch and the orbital walls in a close to original shape [Figure 11].[59]
orbital implants were machined in bio ceramic glass material
(Bioverit II).[57] A similar design process was used and an implant
Maxillo mandibular impressions were taken with trial dentures
was made from external hexagon compound an artificial bone like
material approved by Food and Drug Administration of China.[58] A and articulated to arrive at a precise dental implant placement
combination of CT scan data, virtual surgical planning and custom to achieve correct occlusion and guides for fibula resection and
titanium implants and micro vascular flap reconstruction was used dental implant placement was constructed. The guides were
for treatment of an extensive maxillary resection extending from used for fibula resection and placement of dental implants.
the orbital floor to the alveolus. Dental implant placement was Postoperative stable functional occlusion and good aesthetics were
also determined in the virtual surgical planning. The defective achieved. The authors concluded “the incorporation of CAD‑CAM
region was imaged and data from the contralateral side was technologies to this field has enabled the refinement of both the
mirrored with reference to the mid sagittal plane for correction surgical and prosthetic phases through a holistic 3D evaluation
of the defect. The scapula was used as the donor site and an of the target defect, simulation of the surgical reconstruction and
prosthetic rehabilitation and effective transfer of the preoperative
plan to the operating room.” The authors further, impact on clinical
outcome and ultimately patients’ quality‑of‑life should favor the
implementation and further development of this technology
despite the additional cost [Figure 12].[60]

Corrective surgery and implant combined procedures

In some cases, a combination of custom implants and other
corrective surgical procedures as fixation of salvageable large chunks
of fractured bone as in blown out midfacial fractures are performed
to restore the facial structure. Figure 13 shows correction of a blown
out maxillary fracture by repositioning and fixation of some of the
large bone pieces and a PEEK custom implant. A bigger implant was
made and modified in surgery as per requirements. This allowed the
surgeon to use autologous bone to the maximum possible extent and
limit the use of alloplastic material to the minimal extent required.
The ease of modification of the implant intraoperatively allows the
Figure 8: 3D printed titanium mandible implant surgeon to make the final decision in surgery.

Figure 9: 3D reconstruction of a mandible tumor and arch form reconstruction for adaptation of titanium mesh as graft space holder

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Figure 10: 3D reconstruction of a maxillary bone and arch form

reconstruction for adaptation of titanium mesh as graft space holder
Figure 11: Maxillary defect reconstruction and the use of a titanium mesh
as a temporary space holder for the graft[59]

a b

a b

c
Figure 12: (a and b) Midface reconstruction plan with fibula graft,
(c) Dental implants placement in the fibula flap c
Figure 13: (a) Reconstructed blown out maxillary fracture, (b) Repositioning
Similarly orthognathic surgery can be used to reposition the and fixation of some of the large bone segments, (c) Intraoperative fixation
maxilla/mandible and structural differences between the right of polyetheretherketone implant
and left sides can be corrected using custom implants made of
PEEK or silicone material. morphometric data derived from computer generated 3D models
has been reported.[61] Four patients with TCS in the ages of
Craniofacial reconstruction of the syndromic patient 6, 10, 14 and 20 were chosen for tomodensitometric studies.
The syndromic patient exhibits multiple distinctive facial 40 controls who underwent CT scan for reasons unrelated to facial
characteristics as hypertelorism, frontal bossing, midfacial hypo/ skeleton were chosen. In total 8 TCS and 80 control orbital and
hyperplasia, malar and zygomatic region abnormalities and zygomatic volumes were derived for comparison. Ideal zygoma for
micrognathia to name a few. 3D modeling and custom implants the patient was then chosen by computer simulation. Cutting guides
would be very helpful to the surgeon in reconstruction of such generated from the simulation were used for resection of bone
multiple abnormalities that co‑exist specifically due to the fact that graft and fabricated by RP. Positioning guides made by a similar
multiple surgeries have to be performed over time and combination method was used for placement of the bone graft or the alloplastic
of bone grafts from regions of the body and patient specific implants implant. The authors concluded that the process established a stable
would be required to restore near normal esthetics and functions in reproducible methodology for zygomatic reconstruction in TCS.
a growing individual. Surgical guides for resection and templates As a next step the authors evaluated soft tissue morphometrics and
are very useful tools for the reconstructive surgeon. Establishment found the variation between normal and patients affected by TCS
of morphometric data for the hard and soft‑tissues of various regions and found the results to be very useful in analyzing the deficient
of the face like the zygomatic arch, nose, malar, mandible angle, regions and quantifying the extent of reconstruction.[62]
symphysis and contour and pre surgical simulation can go a long
way in precise designing of the template and guides for resection. Future perspectives
Two directional advancements are slated to happen as the next
Successful reconstruction of the hypo plastic zygomatic and steps. Design of the implants themselves are dictated by the
orbital region in treacher collins syndrome (TCS) using normative anatomy, improvements in better fixation methods will be seen.

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Advances in virtual reality and 3D image based reconstruction 2. Schlickewei  W, Schlickewei  C. The use of bone substitutes in the
will lead to faster data processing reducing processing times treatment of bone defects‑The clinical view and history. Macromol Symp
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closer to natural tissues. There is no one material that can provide a
Engineers; 2008.
complete solution. The future is regenerative medicine that allows 15. Parthasarathy J, Starly B, Raman S. Computer aided bio‑modeling and
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ACKNOWLEDGMENTS 20. Li X, Feng YF, Wang CT, Li GC, Lei W, Zhang ZY, et al. Evaluation of
biological properties of electron beam melted Ti6Al4V implant with
The author gratefully acknowledges the support given by Nancy Hairston biomimetic coating in vitro and in vivo. PLoS One 2012;7:e52049.
President Med CAD Dallas, USA in the preparation of this article. The 21. Abdelaal  OA, Darwish  SM. Review of rapid prototyping techniques
author also acknowledges Prof. Raman and Prof. Starly, University for tissue engineering scaffolds fabrication. Adv Structured Mater
of Oklahoma School of Industrial Engineering and Prof. Jebaraj and 2013;29:33‑54.
Dr. Gowri, College of Engineering Guindy, Chennai India for the 22. Palmquist A, Snis A, Emanuelsson L, Browne M, Thomsen P. Long‑term
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modeling and RP during her Doctoral and Master’s program respectively. free‑form‑fabricated solid and porous titanium alloy: Experimental
studies in sheep. J Biomater Appl 2013;27:1003‑16.
23. Sallica‑Leva E, Jardini AL, Fogagnolo JB. Microstructure and mechanical
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of head and neck defects. Int J Oral Maxillofac Surg 2009;38:666‑70. Source of Support: Nil, Conflict of Interest: None declared.
45. Macario  A, Vitez  TS, Dunn  B, McDonald  T. Where are the costs in

18 Annals of Maxillofacial Surgery | January - June 2014 | Volume 4 | Issue 1