Metallurgy & fixation methods

1. M O D E R A T O R –
D R . R A J A S E K H A R G .
P R E S E N T E D B Y -
D R . S H E E T A L K A P S E

2. 
 Introduction
 Metallurgy
 Evolution of fixation methods
 Various methods of fixation
 Principles of rigid internal fixation
 Conclusion
 References
Contents

3. 
 Maxillofacial injuries are most commonly involved in all type of body
injuries.
 Most of the maxillofacial fractures require open reduction and internal
fixation by using miniaturized metallic hardware.
 Therefore it is necessary to have the knowledge of these metals, their
properties & their effect on biological tissues.
Introduction

4.  Since 40 yrs - repair and reconstruction of craniofacial and upper
extremity skeletal injuries, and as an adjunct to oral and craniofacial
prosthetic rehabilitation.
 The biocompatibility of metal implants is primarily determined by their
surface properties and corrosion resistance.
 After implantation, an oxide layer quickly forms on the metal’s surface
that determines its resistance to corrosion and the amount of leaching of
metals or oxides into the adjacent tissues.
 The combination of corrosion and metal ion release may cause pain and
localized tissue reactions around the implant, necessitating its removal.
 Stainless steel, Vitallium, Titanium and Gold

5. METALS, SURFACES AND TISSUE
INTERACTIONS
 62.5% iron
 18% chromium
 14% nickel
 2.5% molybdenum
 minor elemental
316 L iron-base alloy
Allergic reactions to nickel 3–15%
Titanium alloys
 Ti grades 1–4
 Ti-6Al-7Nb alloy
 Ti-15Mo alloy
(α & β)

6. FIXATION DEVICE BLOOD
BLOOD PROTEINS COVERING
THE FIXATION DEVICE
(matrix for platelets and other cells)
PLATELET
DEGRANULATION
INFLAMMATION
(cytokines & growth factors)
HEMATOMA
FORMATION
Proliferation
Remodelling

7.  Surface layer of chromium oxide
 Have a higher corrosion potential, have a greater
amount of metal ion release, and are more likely to
require secondary removal.
 Nickel - allergic reactions in 3 – 15 % cases
 62.5% iron
 18% chromium
 14% nickel
 2.5% molybdenum
 minor elemental
316 L iron-base alloy

8.  Introduced in the 1930s.
 Cobalt-chromium alloy that has strength
comparable to that of stainless steel.
 It also forms a chromium oxide surface layer, it is
much more highly resistant to corrosion than
stainless steel due to the higher concentration of
chromium in the alloy.
 Radiographic imaging and artifact scatter - lost
favor for most craniofacial indications
 65% cobalt
 30% chromium
 5% molybdenum
 other substances

9.  Pure material - titanium allergy, toxicity or
tumorigenesis.
 An alloy - Ti-6a-4v: 6% aluminum an 4%
vanadium), which improve the strength
 Titanium oxide surface layer (5-6 nm) - very
adherent and highly resistant to corrosion, and
even if the oxide layer is damaged, it reforms in
milliseconds.
 Low density - minimal x-ray attenuation (40%
less), no artifact on CT or magnetic resonance
images.
Titanium alloys
 Ti grades 1–4
 Ti-6Al-7Nb alloy
 Ti-15Mo alloy (α & β)

10. • The density of Ti is about 57% of SS density. This decrease in density equates to
a weight reduction of approximately 50% when comparing materials of similar
volumes.
• The modulus of elasticity for Ti is about 55% of SS, and for an equivalent cross-
sectional area, the stiffness of a Ti implant is 55% of an SS implant.

11.  Does not develop a layer of oxide
 Lack of strength
 It has one surgical use as an upper eyelid implant for the treatment of
acquired ptosis in facial nerve palsies
 Weights between 0.6 and 1.6 g

12. Biodegradable materials
Water and CO2
In the future, maxillofacial fracture
fixation may utilize biodegradable
bone adhesives and composites in
lieu of the traditional titanium
plate/screw systems. The adhesives
currently under study are in the
cyanoacrylate polymer family,
namely, butyl-2-cyanoacrylate.

13. History of development of fracture management modalities
1650 BC Egytion Papyrus Wiring of mandible
460 BC Hippocrates Direct approximation and bridle wiring
1492 Concept of MMF
1846 Buck & Kinlock Use of wire ligature for fixation
1881 Gilmer Placed two heavy rods on either side of fracture
1888 Schede Used solid steel plate across the fracture, held by 4 screws
1917 Cole
Used silver plates and screws on each side of fracture and
tied silver wire to plats on both sides of plates to immobilize
the fracture
1934 Vorschutz Percutaneous two long screw held in position by POP
Evolution of fixation
methods

14. DEVELOPMENT OF INTERNAL RIGID FIXATION
1886 Hansmann Retrievable bone plates
Sherman Vanadium steel bone plates
1932 Key Compression of bone segments for tuberculous knee arthrocentesis
Egger 1st true compression plates
1945 Christiansen Tantalum plate in mandibular fracture
1956 Bagby 1st self compression plate (sliding hole principle)
1960s Mittlmeir & Luhr Improvement in mandibular compression plates
1970s Brons & Boeriing Lag screw in OMFS
1977 Luhr 1st to use compression plates in mandibular fractures
1977 Spiessel Used AO/ASIF principle for mandibular fractures
AO/ASIF DCP
1973 Schmoker & Spiessel EDCP
1973
Michelete, Deymes &
Dessus
Miniplates
1975 Champy Principles of fixation of fractures with Monocortical screws
1989 Bos Resorbable plates and screws

15. 
 In this phase the fractured fragments (after reduction) are fixed, in
their normal anatomical relationship to prevent displacement and
achieve proper approximation.
 “Any form of fixation applied to the bone that is strong enough to
prevent the mobility of bony fragments during active use of skeletal
structure during healing phase.”
Various methods of
fixation

16. • Direct skeletal fixation – Consists of:
i) External direct skeletal fixation, where the device is
outside the tissues, but inserted into the bone
percutaneously . In external direct fixation, bone clamps
or pin fixation are used.
ii) Internal direct skeletal fixation – by devices which are
totally enclosed within the tissues and uniting the bone
ends by direct approximation.It is carried out with
transosseous or intraosseous wiring or using bone
plating system.

17. • Indirect skeletal fixation:
 Here, the control of bone fragments is done via the
denture bearing area.
 By means of arch bars and IML or Gunning splint, if
the patient is edentulous.
 It can be extraoral or intraoral method.

18. Methods of immobilization
The methods of immobilization can be summarized as follows:
1. Osteosynthesis without intermaxillary fixation:
(A) non-compression small plates
(B) compression plates
(C) miniplates
(D) lag screws
(E) resorbable plates and screws
2. Intermaxillary fixation:
(A) bonded brackets
(B) dental wiring
(I) direct
(II) eyelet
(C) arch bars
(D) cap splints
3. Intermaxillary fixation with
osteosynthesis:
(A) transosseous wiring
(B) circumferential wiring
(C) external pin fixation
(D) bone clamps
(E) transfixation with kirschner wires

19. Closed Reduction & Fixation
Techniques
• Gilmer method
• Essig’s wiring
• Risdon’s wiring
• Col. Stout’s multiloop wiring
• Ivy loops/ eyelet method
• Arch bars – Erich arch bars
• Intermaxillary fixation screws
• Acrylic Splints

20. Gilmer’s Direct Wiring method

21. Risdon’s wiring
Essig’s wiring

22. Col. Stout method (continuous or multiple loop wiring)
Described by Col. Stout in 1943

23. Interdental Eyelet Wiring
(Ivy Loop Method)

24. Williams modification of eyelet wiring

25. The application of clove hitch to one long standing tooth

26. New Simplified Technique for Intermaxillary
Fixation by Loop-Designed Wire
Ajay Verma • Sunil Yadav • Vikas Dhupar

27. Closed method
Orthodontic brackets

28. Arch Bar Fixation
Many types of prefabricated arch bars are available. But
the most popular one and commonly used are-
1) Erich arch bar; 2) Jelenko; 3) German silver bars.

31. Intermaxillary fixation screws

32. Custom made splints
• The splints can be constructed using acrylic material or
cast metal.
• Indications:
– When the wiring of the teeth will not provide adequate
fixation.
– When both the jaws are edentulous.
– In case of growing children, where mixed dentition is
present and number of firm teeth for anchorage are
not adequate.
Acrylic splints:
• Lateral compression splint
• Gunning splint

33. Multiple studies show clinical bone union (no
mobility, no pain, reduced on films)
in 4 weeks in adults and 2 weeks in children
Juniper et al. J Oral Surg 1973;36Juniper 36
Amaratunga NA. J Oral Maxillofac Surg 1987;45Amaratunga 45

34. Closed method
cap splint

35. Closed method
Gunning splint

36. Circum-mandibular wiring
of Gunning- type splint

37. External Pin Fixation
• Technique of fracture repair by using transcutaneous
pins threaded into the lateral surface of the mandible.
• External fixation systems utilise the principle of
craniomaxillary or craniomandibular fixation in order to
immobilise facial fractures.
• Fractures of the midfacial,
occlusal or mandibular units
are suspended from an intact
and rigid cranial unit.

38. Indications:
• Comminuted mandible fractures with/without
displacement
• Avulsive gunshot wounds
• Edentulous mandible fractures
• Can be used on patients that are poor candidate
for open reduction and closed reduction (may
increase likelihood of follow-up)

39. Joe Hall Morris appliance
The pin segments are then connected together with an
acrylic bar, metal framework, or graphite rods.

40. • Box frames consist of 4 threaded bone pins screwed
transcutaneously into the lateral supraorbital rims
above and the body of the mandible below.
• The pins are then linked by 2 vertical and 2 horizontal
bars via universal clamps.
• Combinations of pins and bars can be used to build
custom external fixation devices to support and control
virtually any facial bone fracture.

42. Disadvantages
• Involves closed fracture reduction, usually guided by
clinical observation of the occlusion and facial form thus,
there is a significant margin for error.
• External frames are cumbersome, unaesthetic, poorly
tolerated and prone to accidental dislodgement.

43. TRANSOSSEOUS WIRING
• Provides Non rigid fixation.
• Use of wire for direct skeletal fixation.
• Keeps the fragments in an exact anatomical alignment,
but must rely on other forms of fixation to maintain
stability (splints, IMF).
• Low cost, fast to perform, must rely on patient
compliance as does closed reduction techniques .

46. Hayton – Williams Method

47. Internal fixation in cases of midface fractures
1. DIRECT OSTEOSYNTHESIS
a. Transosseous wiring at fracture sites
i. High level (frontozygomatic and frontonasal)
ii. Mid level (orbital rim zygomatic buttress)
iii. Low level (alveolarjmidpalatal)
b. Miniplates
c. Transfixation with Kirschner wire or Stemmann pin
1. Transfacial
ii. Zygomatic-septal
2. SUSPENSION WIRES TO MANDIBLE
a. Frontal--central or lateral
b. Circumzygomatic
c. Zygomatic
d. Infra-orbital
e. Pyriform aperture
3. SUPPORT
a. Antral pack
b. Antral balloon

48. External fixation
1. CRANIOMANDIBULAR
a. 'Box-frame'
b. 'Halo-frame'
c. Plaster-of-Paris headcap
2. CRANIOMAXILLARY
a. Supra-orbital pins
b. Zygomatic pins
c. Halo-frame
3. SUSPENSION BY CHEEK WIRES FROM HALO-FRAME OR HEADCAP

49. Type Use
Frontal
a) central
b) lateral
Le Fort III and II (Mandible unstable)
Le Fort III and II (Mandible stable)
Circumzygomatic Le Fort II and I
Zygomatic Le Fort I
Infra-orbital Le Fort I
Piriform aperture Le Fort I
Transnasal ‘Gunning-type' splint
Peralveolar ‘Gunning-type' splint

50. l. Frontal suspension
a) Lateral

51. Central

52. Circumzygomatic suspension

55. • Zygomatic suspension
• Guerman 1975

56. Infraorbital suspension

57. Piriform aperture suspension

58. Circumpalatal suspension
• This method was described and illustrated by Bowerman &
Conroy (1981) to facilitate retention of a surgical splint
following maxillectomy.
• The technique provides an extremely useful and simple means
of fixing an upper ‘Gunning-type' splint to the maxilla.
• It has proved in use to provide superior retention and stability
for the splint and hence less discomfort for the patient during
the period of jaw fixation when compared with retention of
such a splint by peralveolar or circumzygomatic wires.

59. Peralveolar suspension
• The 'Gunning-type' splint is
placed in situ and the position
of the holes located in the
palatal aspect of the splint are
marked on the underlying
palatal mucosa with Bonney's
Blue.
• peralveolar awl, or introducer
of the Kelsey-Fry type, is then
directed through the mucosa
in the canine region and
driven through the alveolus
from high up in the buccal
sulcus.

60. External skeletal fixation
• The primary indication for external skeletal fixation of the mid-face
is the presence of antero-posterior instability of the facial
skeleton.
• This situation is classically seen when the mid-face fracture is
associated with concomitant bilateral condylar fractures of the
mandible.
• Stabilisation of this type of facial fracture usually requires open
reduction and direct transosseous wiring at critical fracture sites,
combined with the application of some form of rigid anterior
external skeletal fixation appliance.

61. • There are four methods of external skeletal fixation
1. Plaster of Paris head cap
2. Halo frame (various designs)
3. Box frame
4. Levant frame

62. Plaster of Paris head cap with metal frames

63. Royal Berkshire Hospital pattern
Halo frame

64. Box Frame Fixation

65. Levant frame

66. • The requirements of such an appliance are:
1. Rigidity under the stresses of tension and torsion
2. Lightness and minimal bulk
3. Simplicity of design and manufacture
4. Simplicity in application
5. Ease of maintenance and hygiene
6. Location to permit urgent neurosurgical procedures
7. Location to free the patient's visual field
8. Provision to support additional appliances to- control associated fractures
9. The ability to maintain the position of the maxilla in the absence of
intermaxillary fixation

67. BONE PLATE OSTEOSYNTHESIS
The direct internal fixation of the fractured fragments can be
carried out by bone plate osteosynthesis method.
It either totally eliminates the need of IMF or minimizes the
period of IMF.
Two types:
1. Rigid fixation
2. Semi- rigid fixation

68. Rigid
Lag screws
Compression
plates (DCP /
EDCP)
Reconstruction
plates
Semi- rigid
Miniplates
Intraosseous
wiring
ELLIS
FUNCTIONALLY
STABLE FIXATION

69. 
Biomechanics of
facial skeleton

71. Mandible : plate fixation is
determined by line of stress
distribution – functional
osteosynthesis
Maxilla : plate fixation is
determined by line of fracture –
adaption osteosynthesis

72. Load bearing osteosynthesis
• Locking reconstruction plate – bears 100%
functional force at fracture site.
• Indicated in atrophic/ edentulous/ comminuted/
defect fractures

73. Load sharing Osteosynthesis
• Functionally adequate / semi rigid fixation
• Ideally bone assumes most functional loads
• Champy Miniplate fixation along lines of ideal
osteosynthesis.
• Works with principles of biomechanics of
mandible.

74. Tension Band Principle

75. Dynamic compression plates
A plate using the gliding-hole
principle to compress the
fragments.

76. The center screw (N3) traverses the
fracture using a lag technique and
using the passive or neutral position
in the plate

77. Eccentric
Dynamic
Compression
Plates

78. Advantages:
• Rigid fixation
• Thicker hardware
Disadvantages:
• Technique sensitive- plates must be adapted
properly or malalignment can occur
• More expensive than miniplates
• Bicortical screws

79. NON-COMPRESSION
OSTEOSYNTHESIS
1. Non-activated compression plates
2. Locking plates
3. Reconstruction plates
4. THORP

80. Reconstruction Plates
• Useful in comminuted fractures, defect fractures and
infected fractures.
• It is also useful in the case of severely displaced angle
fracture.
• Reconstruction plate absorbs all functional loads and
permits early mobilization.
• Consist of plates that utilize screws greater than 2mm in
diameter (2.3, 2.4, 2.7, 3.0).

82. Advantages:
• Rigid fixation with load-bearing properties
• Low infection rates in the literature, especially in the
mandibular angle region
• Can be used for edentulous and comminuted fractures
Disadvantages:
• Expensive
• Requires larger surgical opening
• Can be palpated by patient if in body or symphysis
region

83. SCREWS

84. Locking Plates

85. Miniplate Osteosynthesis
• Non-compression monocortical screw system
• Developed in France by Michelet in 1973 and made
clinically popular by Champy in 1975.
• Therapeutic principle:
Fixation by stability:
Stability is achieved by a perfect anatomic reduction and
intrafragmentary approximation without compression.

86. Champy’s Ideal
Osteosynthesis Lines
• By placing the plates at the most
biomechanically favourable site to neutralize
the tension forces causing fracture distraction,
one can minimize plate thickness, with the
consequent advantage of increased
malleability.

87. Advantages:
• Small and easily adapted plates
• Monocortical application
• Intraoral approach
• Functional stability
• Biomechanically favorable

88. Lag Screws
• Utilizes screws that create a compression of the fracture
segments by only engaging the screw threads in the
remote segment and screw head in the near cortex.
• Utilizes 2-3 screws to overcome rotational forces.
• Specially indicated in oblique fracture of the mandible.

92. Advantages:
• Low cost, less equipment
• Faster technique than plating
• Rigid fixation
Disadvantages:
• Screw must be placed perpendicular to fracture;
technique sensitive

93. 3-D Miniplates

94. Resorbable Plates
• Constructed using Polylactic
acid or Polyglycolic acid.
• Resorbable plates do not have
to be removed.
• The plates used will resorb
over a period ranging from 2 to
4 years.

95. 
 It has been demonstrated that absolute rigid fixation is not necessary for
successful healing.
 In fact it has been shown that the additional plates necessary to establish
absolute rigidity may actually increase the complication rate.
 The rapid increase in bioresorbable technology has led to the introduction of
many successful resorbable plating systems that do not meet the criteria for
rigid fixation, and some of the plating manufacturers are even introducing
semi rigid fixation that is intentionally designed to allow minor post fixation
manipulation.
 Current clinical techniques using titanium or resorbable plating systems may
not meet the definition of rigid fixation yet are capable of providing clinically
adequate fracture stability. Ellis has used the term "functionally stable
fixation"
Conclusion

96. 
1. Fonseca Raymond J, Walker Robert V, Barber H Dexter, Powers, Michael P,
Frost David E. oral and maxillofacial trauma. China: Saunders; 2013.
2. AOCMF principles of internal fixations of craniomaxillofacial skeleton,
trauma & orthognathic surgery.
3. Rowe NL, William JL. Maxillofacial injuries. 1st ed. India ISBN 978-81-312-
1840—2 2009.
4. MAXILLOFACIAL SURGERY VOL – 1 PETER WARD BOOTH
References