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Rapid Prototyping as an Adjunct
for Autotransplantation of
Impacted Teeth in the Esthetic Zone
MEGHNA VANDEKAR, MDS
DHAVAL FADIA, MDS
NIKHILESH R. VAID, MDS
VIRAJ DOSHI, MDS
A
utotransplantation of teeth, introduced by
Slagsvold and Bjercke more than 40 years
ago,1 is a proven option either for substitution of
missing teeth or for replacement of avulsed and
traumatized teeth when the original donor teeth
are available.2 In cases of severely impacted teeth,
it can avoid the need for complex traction mechanics and the risks of side effects on adjacent teeth
while reducing overall treatment time.3 The procedure requires viable periodontal ligament cells
around the tooth to be transplanted. It is also technique-sensitive, necessitating proper preparation
of the recipient site, in the exact size and shape of
the donor tooth and root, to minimize the time the
donor tooth remains outside the oral cavity during
surgery.
Rapid prototyping of impacted donor teeth
can be a useful adjunct to autotransplantation in
these cases. A three-dimensional replica of the
impacted tooth is printed by stereolithography
Dr. Vandekar
Fig. 1 Cone-beam computed tomography of
maxillary section, showing impacted left central
incisor.
(STL) from a cone-beam computed tomography
(CBCT) scan to aid the surgeon in preparation of
the socket or recipient site. STL produces complex
3D physical models by solidifying one horizontal
layer at a time, with stepwise submergence along
the vertical axis.4 These 3D replicas can provide
significant advantages in terms of the accuracy of
diagnostics and treatment planning.
Dr. Fadia
Dr. Vaid
Dr. Doshi
Dr. Vandekar is a Professor and Chair, Dr. Fadia is a former resident, Dr. Vaid is a Professor, and Dr. Doshi is a former resident, Department of
Orthodontics, YMT Dental College and Hospital, Sector 4, Institutional Area, Kharghar, Navi Mumbai 410210, India. E-mail Dr. Vaid at orthonik@
gmail.com.
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© 2015 JCO, Inc.
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Rapid Prototyping as an Adjunct for Autotransplantation of Impacted Teeth
Fig. 2 Digital images of incisor in all three dimensions.
Procedure
After the area of concern is scanned by
CBCT, appropriate sections are obtained in the
form of Digital Imaging and Communications in
Medicine (DICOM) version 3 files (Fig. 1). These
files are then digitally extracted and converted to
a printable format using Anatomage InVivo* software version 4.3 (Fig. 2). The EnvisionTEC**
Perfactory Standard 3D printer (Fig. 3A) makes a
replica model from the STL files (Fig. 3B), using
either resin or starch.
Case Report
A 24-year-old male presented with a horizontally and palatally impacted upper left central
incisor, overretained deciduous central incisors,
and a mesiodens. Since the patient had reservations
about the length of treatment and the predictability of surgical traction, autotransplantation of the
tooth was planned. After leveling and alignment
of the maxillary arch using an .022" Victory Series
MBT*** preadjusted appliance (Fig. 4A), a rapid
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prototype was fabricated from a CBCT scan as
described above.
During the surgical procedure, the socket
was prepared (Fig. 4B) and the dimensions
checked with the printed replica tooth (Fig. 4C).
The impacted central incisor was then surgically
extracted, maintaining an intact periodontal ligament surface. The donor tooth was positioned into
its anatomical location (Fig. 4D). The transplanted tooth and the adjacent lateral incisor were
etched, an everSTICK† fiber splint was placed,
and flowable composite was laid and cured to fix
the splint, which was left in position for eight
weeks (Fig. 4E). Endodontic treatment was carried out during that period to prevent any chance
of infection, root resorption, or ankylosis. After
eight weeks of passive stabilization, orthodontic
*Anatomage Inc., San Jose, CA; www.anatomage.com.
**Registered trademark of EnvisionTEC, Gladbeck, Germany;
www.envisiontec.com.
***Trademark of 3M Unitek, Monrovia, CA; www.3Munitek.com.
†Registered trademark of GC India, Patancheru Mandal, Medak
District, Telangana, India; www.gcindiadental.com.
JCO/NOVEMBER 2015
Vandekar, Fadia, Vaid, and Doshi
Fig. 3 A. EnvisionTEC** Perfactory Standard 3D printer. B. Rapid-prototype tooth replica.
A
B
C
D
E
F
Fig. 4 24-year-old male patient with horizontally and palatally impacted upper left central incisor, over­
retained deciduous central incisors, and mesiodens. A. After seven months of leveling and alignment using .022" Victory Series MBT*** preadjusted appliance. B. Surgical socket preparation. C. Prototyped replica used to check socket dimensions. D. Placement of extracted incisor in anatomical position. E. Transplanted tooth and adjacent lateral incisor etched, and everSTICK† fiber splint placed. F. Alignment of autotransplanted central incisor after 12 months of treatment.
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Rapid Prototyping as an Adjunct for Autotransplantation of Impacted Teeth
A
B
Fig. 5 Patient after 14 (A) and 16 (B) months of treatment.
treatment was reinitiated to align the tooth within the arch (Figs. 4F). Four months of finishing
were required to obtain favorable esthetics and
function (Figs. 5,6). The overall treatment time
was 16 months.
Discussion
The challenge in treating patients with missing or impacted teeth is to achieve the best possible
esthetic and functional results while ensuring longterm stability.5 The most common treatment modality for unfavorably impacted teeth—surgical
extraction and prosthetic replacement or implant
placement6-8—has a questionable esthetic prognosis, especially in the anterior region where esthetic considerations are paramount.
In the case shown here, transplantation was
chosen because no other orthodontic treatment
option would bring the tooth into its normal anatomical position within the bone without the risk
of injury to the adjacent lateral incisor root. Longterm studies of autotransplantation have reported
a success rate of more than 90%.9-12 Today, with
the availability of rapid prototyping, a 3D replica
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tooth can be fabricated to improve site preparation, thus allowing more precise treatment planning and making the surgical procedure more
efficient.
Conclusion
Advantages of autotransplantation of impacted teeth in the esthetic zone include:
• The patient’s own natural tooth can be used in
its anatomical site, providing the best possible esthetic appearance.
• Because the transplanted tooth has a normal
periodontal membrane, it can be subjected to
orthodontic tooth movement.
• The transplanted tooth has the ability to erupt
in synchrony with adjacent teeth, to adapt to functional demands, and to establish a normal marginal gingival contour.6
• A transplanted tooth recovers its proprioceptive
function, so that the patient retains natural chewing sensation.13
• The risk of injury to adjacent teeth and the difficulty of root positioning associated with surgical
traction are eliminated.
JCO/NOVEMBER 2015
Vandekar, Fadia, Vaid, and Doshi
A
B
C
D
Fig. 6 Sequence of treatment (blue tooth represents rapid-prototyped model). A. After leveling and alignment. B. Socket preparation using prototyped replica. C. Extrusion mechanics after transplantation. D. Finishing stage with incisor in proper alignment.
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VOLUME XLIX NUMBER 11
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