Reconstruction of a facial defect is a complex modality either surgically or prosthetically, depending on the site, size, etiology, severity, age, and the patient’s expectation. The loss of an auricle, in the presence of an auditory canal, affects hearing, because the auricle gathers sound and directs it into the canal. Surgical reconstruction is preferable but prosthetic approach may be necessary in some circumstances such as the presence of complex or large defects, requirement of the recurrence control, local or general contraindications of surgery, damaged neighboring tissues due to the radiotherapy, general poor health, failed reconstructive attempts previously made, refusal of the surgery by the patient, high esthetic demands, the desire for a quick recovery and palliatively operated patients. Nowadays, craniofacial implants are used to support and retain such prostheses. Studies have shown successful retention and stability of auricular prostheses anchored to the temporal bone with titanium implants.

1. Implant Retained Auricular
Prostheses
Meryem Gu¨ lce Subas¸ı , Gamze Alnıac¸ık, Abdullah Kalaycı , Serhan Akman,
Ercan Durmus; J Indian Prosthodont Soc (Dec 2014) 14(Suppl. 1):S196–S201’
Nishu Priya
2nd-year PGT
Journal club

2. Introduction
2
Reconstruction of a facial defect is a complex modality either surgically or
prosthetically, depending on the site, size, etiology, severity, age, and the
patient’s expectation. The loss of an auricle, in the presence of an auditory
canal, affects hearing, because the auricle gathers sound and directs it into
the canal.
Surgical reconstruction is preferable but prosthetic approach may be necessary in
some circumstances such as the presence of complex or large defects, requirement of
the recurrence control, local or general contraindications of surgery, damaged
neighboring tissues due to the radiotherapy, general poor health, failed
reconstructive attempts previously made, refusal of the surgery by the patient, high
esthetic demands, the desire for a quick recovery and palliatively operated patients.
Nowadays, craniofacial implants are used to support and retain such prostheses.
Studies have shown successful retention and stability of auricular prostheses
anchored to the temporal bone with titanium implants.

3. Fabrication
The traditional method of fabricating an auricular prosthesis usually involves:
3
making
impressions
sculpting a wax
pattern of the
proposed ear
prosthesis
investing in a 3-
piece mold
packing and
curing silicone
hand painting of
the silicone
prosthesis

4. Retention
Adhesives
● Medical adhesives are more often classified according to their use;
double-sided tape, glue, sprayers, pastes, and liquid systems are
classified according to the silicone substrate.
● Double-sided tape is the most highly preferred type of adhesive due
to its ease of application, easy removal, and renewability.
● Facial prostheses are often used in adhesive systems such as acrylic
resins, silicone adhesives, and pressure sensitive tapes.
● Adhesives and solvents may adversely affect the physical and optical
properties of the maxillofacial elastomers
● They do not provide sufficient adhesion against gravity, sweating, and
tissue movement.
4

5. Implant
● Implant retention is currently considered as the gold standard in prosthetic
reconstruction of these structures.
● Bone thickness in the temporal and supraorbital regions, suitable places for implant
placement, ranges between 2.5 and 6 mm; hence, extraoral implants were designed to be
3–4 mm long and 5 mm in diameter, unlike intraoral implants.
5
Extraoral implants have wing
extensions and holes to provide
mechanical stability and retention.
Originally, craniofacial implants were introduced by Nobel Pharma, then transferred to Nobel
Biocare, Göteburg in the Swedish market.

6. Implant systems used in extraoral prostheses
Bar systems
● In bar systems, there is a bar that connects the implants to each other and a retentive
lock that sits in this bar.
● The bars used in these systems are gold alloys and are about 2 mm in diameter.
● To hold the clips in the prosthesis, an acrylic plate is prepared. Leaving a distance of about
1.5 mm between the bar and the tissue is important to allow for the easy cleansing of this
area.
6

7. Magnetic systems
● Magnet systems consist of individual implant supports that do not require superstructure
preparation and are not interconnected.
● These systems are used in the retention of a facial prosthesis, in regions with high muscle
activity adjacent to the prosthesis; in cases where the ability to use the hand is
inadequate, the bone is thin, the bone.
7

8. Implant retained auricular prosthesis
● The location of the implants in the temporal region is very important for the aesthetics of
auricular prosthesis. Implants should be placed at the anti-helix level because retention systems
must remain within the limits of the auricular prosthesis.
● In the literature, some researchers have recommended that 2 implants are enough for auricular
function, because the episthesis is not heavy. (Wazen et al., 1999).
8
Auricular prosthesis retained on ball shaped
retentive caps of two implants
Auricular prosthesis retained on ball shaped
retentive caps of three implants

9. ● The choices of retentive mechanisms to be applied on the implants depend on the
patient, the number of the implants and the flexibility of the episthesis. The
conventional retention techniques involve magnetic or clip retention provided by
golden bars and ball clip or magnet retentive cap systems
9
Retention provided by
golden bars Retention
provided by ball
clips
Retention provided by
magnet retentive caps

10. ● Magnets can be used with at least 3 bone-connected implants. In cases with three implants, a
cantilever extension of the bars could be planned. If four bone connected implants were used,
there is no need for a cantilever extension of the bars.
● Episthesis connected on bars between four implants by ball shaped caps are also used.
10
Bars connected to magnets
used with 3 bone-connected
implants
a cantilever extension
of the bars
no need for a cantilever
extension of the bars

11. ● Magnets offered the advantages of easier fabrication, shortened appointments, and
access for peri-abutment hygiene procedures. Magnets also could maintain a longer, more
predictable level of retention than clips, which tended to loosen in a shorter period of
time.
● However, bar and clip systems were advantageous biomechanically in that they effectively
splinted the implant sites together, and these systems could offer stronger immediate
retention. (Sencimen et al., 2008, Wright et al., 2008)
11

12. Planning
● The diagnostic step is an important point that must
be clearly defined in construction of an auricular
prosthesis.
● CT of the temporal bone and clinical photographs of
the patient should be obtained preoperatively to
plan the placement and appropriate size of the
implants and to evaluate the thickness and spaces
of mastoid cortical bone in order to preserve the
duramater. (Ciocca et al., 2009)
12
The arrows show the distances from the mastoid
region to the adjacent anatomical structures such
as external auditory canal, duramater and the

13. ● A new approach to the diagnosis of bone available for craniofacial implant positioning
based on Computer-aided design and manufacturing (CAD–CAM) system was described by
Ciocca et al. (Ciocca et al., 2009)
● A mirrored volume of the healthy ear was rapidly prototyped for a clinical trial in an
appropriate position relative to the patient’s face.
13

14. Radiotherapy
● In cases with aetiology of cancer, the surgeon should be aware of the risk of osseointegration
failures and such patients who have undergone irradiation should be treated with caution.
(Gumieiro et al, 2009)
● Basically, the adverse biological changes that occur when osseous tissues are exposed to ionizing
radiation results from alterations in the cellular components of bone, involving significant
reductions in the numbers of viable osteoblasts and osteocytes, as well as the development of
areas of fatty degeneration within the bone marrow spaces. In addition, regional ischemia could
also be seen as results of the blood vessels undergo progressive endarteritis, hyalinization and
fibrosis.
● As a conclusion, radiotherapy is not a contraindication for the use of osseointegrated implants in
the maxillofacial region, but the loss of implants is higher in irradiated sites than in nonirradiated
sites. (Gumieiro et al, 2009)
14

15. Surgical technique
● It has been suggested that the mastoid region as a recipient site could offer the best results in
implant retained auricular epistheses. Wright et al have stated that, the mastoid region in
nonirradiated patients has provided a high degree of predictable individual implant survival. (Wright
et al., 2008)
● First, during the facial observations, verify the distance between the outer canthus and the tragus, as
well as whether the angle of the naso-auditory meatus line is symmetrical in relation to the bipupillar
line.
● The location of the epithesis would be considered in such a way that the epithesis appears
symmetrical in relation to the unaffected ear in both its placement and form.
15

16. ● the method of Tjellström et al. suggested a method
that considers a safe implant site to be the site where
the following is taken into consideration: the reference
axis is set based on the straight line that connects the
outer canthus and the tragus in the 3:00 to 9:00
direction of a clock, and a straight line that
perpendicularly crosses the previous line centering the
external auditory canal in the 0:00 to 6:00 direction
also: if the right side is the affected side, the 7:30 to
8:30 and the 10:00 to 11:00 directions along with the
location would form an antihelix.
● As the antihelix is located approximately 20 mm from
the external auditory canal, during the operation,
there will be a total of two implants: one implant in
the 7:30 to 8:30 direction and the other in the 10:00
to 11:00 direction at a distance of approximately 20
mm away from the external auditory canal.
16
Safety area for implant placement described by Tjellström

17. 17

18. ● After marking the implant sites with surgical
pen, a curved incision is used in the skin over
the mastoid process approximately 30 mm
posterior to the opening of the expected
position of the external auditory canal.
● Skin and subcutaneous tissue are reflected
until the periost was seen. Then the periost is
incised and bone surface is exposed. The
implants placed are inserted at the sites that
were marked with surgical pen parallel to each
other under minimum trauma to prevent heat
injury to the surrounding bone and to ensure
a stable osseointegration. (Sencimen et al.,
2008)
18

19. ● After forming the initial pilot hole, a round-tipped probe should be used to check the
bottom of the drill hole for bone-like hardness. Once it is verified that the hole does not
extend to the inside of the cranium, the width of the hole could be increased. Once the final
drilling is completed, the bottom of the hole should be checked with a probe once again.
19
Implantation surgery: Primary surgery

20. Implant Fenestration Surgery :Secondary Surgery
● The secondary surgery for implant fenestration is performed three to four months
after the initial surgery.
● The cover screw is exposed, and the healing abutment is attached.
20

21. Prosthetic procedure
● At the end of the recommended period of 3-4 months for osteointegration, the recovery screws are
removed and titanium bone graft retentive anchors or bars are placed.
21
● loosening of abutment
● loosening of prosthetic bar screws
● broken bar or extensions
● broken or lost clips
● loss of clip retention
● Loss of magnet retention
● fractured acrylic resin substructure
● loss of bonding between substructure and silicone
● deposits on tissue surface of the prosthesis
● tear or rupture of the prosthesis
Complications

22. 22
Conclusion
Osseointegrated titanium implants may provide patients with a safe and reliable method
for anchoring auricular prostheses that enables restoration of their normal appearance
and offer an improvement in their quality of life. The use of osseointegrated prostheses
should be considered to be a simple and viable alternative to surgical reconstruction
and as a gold standard in the management of individuals with massive auricular
defects.

23. Multimaterial 3D printing of a
definitive silicone auricular
prosthesis: An improved technique
(J Prosthet Dent 2020)

24. • Additive manufacturing continuously advances the field of maxillofacial rehabilitation.
In the past decade, various additive manufacturing approaches have been described to
produce facial prostheses, either directly or indirectly.
• Since early 2010, the additive manufacturing of silicone structures has become
possible.
• Clinical trials have demonstrated the direct silicone printing of a custom nasal
prosthesis, which, however, was considered as an interim solution because of poor
marginal adaptation.
• Recently printable rubber-like flexible materials have enabled the manufacturing of a
nasal prosthesis and an ear model.
• However, these materials are not genuine silicones, and their biocompatibility has not
been established.
24
Introduction

25. TECHNIQUE
1. Scan the patient with a stationery 3D photogrammetry system to obtain an image of
the whole face; then, with an intraoral scanner (IOS) (TRIOS; 3Shape), render the
anatomy of the intact ear and capture the position of the retention magnets (X-line and
T-line; steco-systemtechnik GmbH & Co KG) on the defect side.
Implant position transfer with intraoral scanner. A, Virtual image of 2 X-line and 1 T-line (steco-system-technik GmbH & Co KG)
abutments
obtained by intraoral scanner. B, Matching of corresponding abutments in STL file format with their scans. C, STL files of prosthesis
magnets put in presaved position on top of corresponding abutment. STL, standard tessellation language.

26. 26
A, Extensive 3D image consisting of matched facial scan obtained by 3D photogrammetry, scans of intact ear and defect
obtained by IOS; aligned IOS scan of intact ear mirrored on defect side and adjusted for shape and position. B, C, Virtual
design of prosthesis bulk and retention bar inside; tissue fitting surface adjusted by subtracting face scan from prosthesis
design with Boolean-out function. IOS, intraoral scanner.

27. 27
A, Virtual design of retention bar and negative form over it for further manufacturing process. B, Printed cast with
prosthesis magnets put on top of abutments and printed negative form for formation process. C, Retention bar in
negative mold, manufactured from autopolymerizing resin.

28. 28
Definitive design of auricular prosthesis divided into 3
parts. A, Concha (blue e 40 A Shore) and lobe (green e
20 A Shore). B, Bulk (lila e 60 A Shore hardness).

29. 29
A, Directly printed silicone prosthesis without postprocessing.
B, Ground with polishing paper. C, Sealed with conventional silicone material only on areas not reached by
polishing instrument. D, Individualized by extrinsic coloring and with aligned frontal margin.

30. 30
Printed and individualized silicone prosthesis on
printed cast of defect for further adjustment of frontal
margin by adding conventional silicone material.
The finished prosthesis had adequate
marginal adaptation and fitted well to the
patient’s facial anatomy. The patient was
satisfied with the soft ear lobe, as she had
had the same feature on her previous
conventionally fabricated prosthesis. The
patient was pleased with the treatment
outcome in terms of general esthetics and
appreciated that the prosthesis design was
copied from her intact ear. The patient also
liked the color in general but requested
more yellow in the painting scheme.

31. 31
A, Intact ear. B, Individualized and adjusted printed silicone prosthesis with acceptable marginal adaptation

32. 32

33. 33
The virtual design and integration of retention elements has become possible since the
manufacturers provided the STL files of their products (abutments, magnets, copings) with a
proper virtual orientation. In the present example, an IOS was used to capture the implant
position and to scan the intact ear anatomy with numerous undercuts. The prosthesis
magnets fitted well on the implants, but this was not challenging because of the plain
geometry of the X-line magnets.
Although the constructed prosthesis was considered definitive, the esthetic outcome was
poorer than that of conventional processing. The printed prosthesis was devoid of skin
structure, which was impossible to apply because of the limited printing resolution. The
grinding with abrasive paper did not alter the prosthesis shape but made the surface even
smoother. As the present technique did not use a clinical evaluation appointment, a
functional impression to reflect facial mimics was not performed. Furthermore, as multicolor
printing in a medical-grade silicone is not feasible, no intrinsic coloring could be applied,
which compromised the esthetics.
However, because of the mirror-imaging technique, a digital workflow allows for an excellent
size, shape, and position match of the prosthesis to the contralateral side.
Discussion

34. ● The outcome of auricular defect rehabilitation by means of a directly printed silicone
prosthesis in various Shore hardness grades is presented.
● The application of additional silicone on the prosthesis frontal ridge helped achieve a more
precise marginal fit and a smooth transition to the adjacent tissues.
● The virtual integration of retention elements on the CAD stage aided a more predictable
rehabilitation outcome and is the next step on the way to a fully digital workflow.
● Further technical advancements in the printing hardware are needed to enable multicolor
printing with greater resolution in order to minimize the number of analog steps.
Summary

35. Prosthetic rehabilitation of
unilateral congenital microtia
with an implant-retained
auricular prosthesis – a case
report
Journal of the Irish Dental Association | Feb/March 2022: Vol
68 (1)

36. Case report
36
● A 24-year-old male with unilateral microtia of the left ear presented to the Dublin Dental
University Hospital with an existing implant-retained auricular prosthesis.
● The patient was unhappy with this prosthesis, as it had become poorly retentive, noticeably
discoloured, and displayed poor adaptation to the underlying tissues.
● The patient had undergone surgery 14 years previously for removal of auricular remnants at
the defect site and placement of two craniofacial implants in the temporal bone.

37. 37
• His current auricular prosthesis was fabricated in the immediate
aftermath of this surgical procedure.

38. ● Removal of the prosthesis revealed a cast
gold dolder bar screwed to two standard
abutments splinting the implant fixtures.
● Two gold rider clips were set in an acrylic sleeve
embedded in the silicone prosthesis as the interface
between the prosthesis and the implant bar.
● On removal of the gold bar, granular tissue and
erythema of the peri-implant soft tissues was evident,
particularly surrounding the superior implant
abutment
38

39. • The superior abutment displayed some mobility and, on removal, it was noted that the abutment
was not fully seated on the implant fixture. The stability of both implant fixtures was assessed,
and no movement was evident.
• Both abutments were reattached, ensuring that they were fully seated on their respective
implants. When reattaching the implant bar, the single screw test was employed to assess its
passivity of fit on the implant abutments and revealed a misfit of the superstructure.
• The mobility displayed by the superior implant abutment was attributed to torque generated by
the ill-fitting bar.
39
The single screw test revealed that the cast gold bar was not
seating passively on the implant abutments.

40. Clinical and laboratory procedures
With the patient sitting in an upright position and looking directly
ahead, transfer of following landmarks from the unaffected ear to
the corresponding location on the defect side:
● the superior margin of the tragus;
● the junction of the lobe with the side of the face;
● the junction of the anterior aspect of the helix with the side
of the face; and,
● a line indicating the vertical angulation of the ear
40

41. ● Two open tray impression copings were splinted with
resin to stabilise them within the impression before a
polyether impression material was applied over the
defect site.
41
● A layer of thick gauze was then adapted over the
polyether material before it set to provide retention
for an impression plaster backing, added to support
the impression and minimise distortion.
● An alginate impression of the contralateral ear was
also made for reference when carving the prosthetic
pattern in wax.

42. ● With the aid of the orientation marks and the stone cast of the contralateral ear, a model of the
left ear was shaped in modelling wax.
42

43. ● 3D scans of the implant model and wax pattern were made , and CAD software was used to design a
fixture-level implant bar to fit within the confines of the wax pattern, with 3mm clearance from the
skin surface.
● CAD/CAM technology made it possible to cantilever the bar from the inferior implant so that the
retentive clips could be ideally positioned beneath the antihelix of the prosthesis, providing maximum
stability and resistance to dislodgement. 43

44. ● The finalised digital design was manufactured in titanium using computer numerical
control (CNC) milling technology.
44
3D scans of the implant model and wax pattern were obtained and CAD/CAM technology was used to produce a
milled titanium superstructure

45. ● The milled titanium bar was assessed for fit on
the master cast before three gold rider clips
were fixed to the bar and a clear acrylic
housing to retain the clips was processed in
self-cure acrylic resin.
45
The wax pattern was then modified to
incorporate the acrylic clip assembly

46. ● The new titanium bar and wax pattern were tried on the patient and assessed for
shape, orientation and fit.
46

47. ● Required adjustments to the wax pattern
were made chair side before it was
invested in a three-part mould with type III
dental stone.
47

48. ● At the next clinical appointment, a two-part vinyl addition silicone was mixed on a
glass pallet with intrinsic pigments and coloured flocking to produce multiple
coloured swatches, replicating the skin tones of the surrounding tissues and the
patient’s unaffected ear.
48

49. ● A thin coat of primer was applied to the outer surface of the acrylic clip assembly
before the various silicone swatches were packed into their respective positions
within the mould and cured in an oven to the manufacturer’s specifications.
49
The cured silicone prosthesis was processed to incorporate the acrylic clip assembly.

50. 50
● The prosthesis was tried on the patient to
assess the fit before excess silicone was
trimmed from the edges as appropriate.
Extrinsic stains were applied and sealed with a
silicone sealant.

51. Discussion
During the treatment planning process, a number of options were considered for the rehabilitation
of this case.
● Fabrication of a new auricular prosthesis to attach to the existing implant bar was ruled out
once it was determined that the cast gold bar did not seat passively on the implant
abutments.
● Dispensing of the bar and clip interface in favour of magnetic connections was also
considered.
● It is reported, however, that bar-clip attachment provides better retention than magnetic
systems for auricular prostheses.
● In addition, placement of three implants in a non-linear alignment is recommended to achieve
optimum retention for magnetically retained auricular prostheses, whereas two implants are
considered sufficient for bar-clip retention systems.
51

52. ● Considering the patient’s age, active lifestyle and the presence of only two craniofacial
implants, it was decided that the most appropriate available treatment option was the
fabrication of a new, passively fitting implant bar to retain, support and stabilise a new
silicone auricular prosthesis.
● CAD/CAM fabrication technologies were employed in the design and manufacture of the
new implant bar as they are less labour intensive and allow for more versatility in relation
to the bar design when compared with traditional casting techniques.
52

53. 53
Conclusion
CAD/CAM technology is now routinely used in the fabrication of dental
restorations;however, there is a gap in the literature regarding the use of milled
titanium substructures for use with implant-retained maxillofacial
prostheses.
Further technical advancements in the printing hardware are needed to enable a
multicolor printing with greater resolution in order to minimize the number of
analog steps.

54. References
1. Meryem Gu¨ lce Subas¸ı , Gamze Alnıac¸ık, Abdullah Kalaycı , Serhan
Akman, Ercan Durmus; J Indian Prosthodont Soc (Dec 2014)
14(Suppl. 1):S196–S201
2. Auricular Osseointegrated Implant Treatment: Basic Technique and
Application of Computer Technology; Appl. Sci. 2020, 10, 4922;
doi:10.3390/app10144922
3. Multimaterial 3D printing of a definitive silicone auricular prosthesis:
An improved technique; J Prosthet Dent 2020
4. Prosthetic rehabilitation of unilateral congenital microtia with an
implant-retained auricular prosthesis – a case report; Journal of the
Irish Dental Association | Feb/March 2022: Vol 68 (1)