The document discusses the anatomy and function of the ear, diseases that can affect the ear, and treatments for hearing loss. It covers the three main parts of the ear - outer, middle, and inner ear. It describes how sound is transmitted through the ear and processed in the cochlea. The document focuses on different prosthetic devices and implants that can be used to reconstruct parts of the middle ear or restore hearing loss, such as partial or total ossicular replacement prostheses. It also discusses cochlear implants for inner ear deafness.

1. Namitha Chandran
MSc biopolymer science
No:10

2.  The ear is the organ of hearing and, in
mammals, balance.
 It transmit and transduce sound to the brain
through the parts of the ear.

 the ear having three parts—the outer ear,
middle ear and the inner ear.

4.  The ear may be affected by disease,
including infection and traumatic damage.
 Diseases of the ear may lead to hearing loss,
tinnitus and balance disorders such as
vertigo.
 many of these conditions may also be
affected by damage to the brain or neural
pathways leading from the ear.

5.  The replacement of a damaged or diseased
external ear is done principally for cosmetic
reason, it is considered a maxillofacial
reconstruction.
 In middle ear, conduction of sound depends
on the ossicular chain of small bones .
 The use of implants can restore the
conductive hearing loss associated with
partial or complete impairment of the
ossicles.

6.  Porous polyethylene total ossicular
replacement implant is used to obtain a firm
fixation of the implant by tissue in growth.
 The tilt top implant is designed to retard
tissue in growth into section of the shaft,
which may diminish sound conduction.

7. Teflon piston is the most
commonly employed
prosthesis in stapes
surgery.
Titanium pistons are
relatively the new
development in the
evolution of stapes
prosthesis.

8. Titanium and ceramic Titanium

9. When the incus is eroded, broken
or absent, the ossicular chain is
reconstructed with an incus
replacement prosthesis.

10.  When both the incus and malleus are eroded
or absent, the ossicular chain is
reconstructed with a partial ossicular
replacement prosthesis (PORP).
 A piece of cartilage is removed from the
tragus and inserted between the prosthesis
and the inner surface of the drum to
minimize rejection.

11. Teflon
Titanium Titanium

12.  When the incus and arch of the stapes are
eroded, or when the malleus, incus and arch
of the stapes are absent, the ossicular chain
is reconstructed with a total ossicular
replacement prosthesis (TORP).

13. As one of the first adjustable
titanium prosthesis to offer a
titanium shaft combined with
a hydroxylapatite (HA) head.
The addition of the titanium
malleus arm is a favorite
among the proponents for
saving and using the malleus.
an integrated footplate shoe
for improved stability in
malleus to footplate hearing
restoration for conductive
hearing loss.

14.  Cochlea is a fluid filled spiral structure
 In which sound of different frequency
excited nerve endings linked to the brain.
 Deafness due to disease of inner ear has
been treated with cochlear implants.
 In cochlear implants sound waves are
collected, amplified, and processed before
the signal are conducted to cochlear nerve
endings.
 There are more than 30000 nerve fibres in
each ear.

16.  In implant designs, one typically used only 20
or so stimulating conductors, made mostly of
platinum and other noble metal alloys.
 Cochlear implants have electrodes that
stimulate the cochlear nerve cells.
 The electrodes are insulated individually and
connected to nerve endings.
 The electrodes are made up of noble metals
and there alloys, which would have the most
corrosion resistance, least tissue reaction ,
and threshold potential elevation.

18.  The electrical impulse can also be
transmitted directly by means of a
percutaneous device (PD).
 Most widely used is the LTI pyrolytic carbon
coated graphite substrate similar to heart
valve disc.
 Usally ends of electrode are embedded in the
PD, and another connector is attached to
minimize stress on PD.

20.  maxillofacial surgery specializes in treating
many diseases, injuries and defects in the
head, neck, face, jaws and the hard and soft
tissues of the maxillofacial (jaws and face)
region.
 In countries such as the UK, Australia and
most of Europe, it is recognized as a dual
degree in medicine and dentistry is
compulsory for surgeons.

21.  A considerable number of procedure in facial
plastic surgery involves the use of either
biological or synthetic materials.
 Biomaterials are used to correct defects in
the face, recontour the nose, lips, chin and
forehead.

22.  Intraoral - mostly functional
 Mandible
 Maxilla
 Extraoral - cosmetic ◦
 Ear
 Nose
 Orbit

23. 1. Color and texture should be matched with
that of patients
2. It should be mechanically and chemically
stable
3. It should be easily fabricated

24.  For maxilla, mandibular, and facial bone
defects, metallic materials are used.
 Metals-Tantalum, titanium, Co-Cr alloys, etc.
 Polymers-Polyvinyl chloride and acetate
copolymers, PMMA , Silicone,Dacron, Teflon,
Polyurethane
 For soft tissues like gum and chin, polymers
are used.
 Polymers- silicone rubber,
polymethylmethacrylate.

25.  Collagen is used in an injectable form to
remove depressions and wrinkles and marks of
acne scars.
 It required continues maintenance due to the
limited life of the implant.
 The use of injectable siloxanes, which
polymerizes in situ has been partially
successful in correcting facial deformation.
 Silastic is widely used in the area of face
including the chin and cheek.
 It is available as a gel filled implants for
augmentation of soft areas and in rubber forms
for areas of the face that is stiffer.

26.  Augmentation of other areas of face
including malaria(cheek), submalar(below
the cheek), forehead has been reported with
Silastic.
 Porous Teflon composites with carbon fibers
are used for augmentation of alveolar ridge,
cheek, chin, forehead, for reconstruction of
mandible, middle ear, orbital floor and
temples.
 The use of polyethylene implants for
correction of frontal, orbital rim, and
external ear defects has been reported.

27.  Acrylic cement widely used for fitting the
implant into the desired space.
 Acrylic and solid implants have been used for
chin and forehead augmentation.
 Mesh materials derived from Vicryl(polyglycolic
acid, polylactic acid copolymer),
supramide(polyamide) and
Mersilene(polyethylene terephthalate) are
used for site requiring augmentation where
small or contour defects exist.
 Mesh products are used for chin augmentation,
mandible angel, forehead and jawline
reconstituting.

28. •Stainless steel
Y Shape Plate
Maxillofacial
Implant
Z Shape Plate
Maxillofacial Implant
• Titanium

29. Y Shaped Nose
Plates
• Steel
H Shape Nose Plates
• Titanium

30. Maxillofacial Screw
Material used-Titanium

31. Thank you