This document discusses occlusion, dentition development, malocclusion classification, and methods for maxillomandibular fixation (MMF). It describes how teeth erupt and are replaced during development. Malocclusion is classified using Angle's classification as Class I, II, or III based on molar relationships. Standard MMF methods include arch bars, Ivy loops, ligatures, and splints. Advanced methods use screws, plates, and miniplates for bone-supported fixation. Proper placement of these devices is outlined.

1. Occlusion and MMF
Dr Shubhanshu Gaurav
KEMH , MUMBAI

2. Occlusion
• Definition - Contact relationship between upper (maxillary) and lower
mandibular teeth when they approach each other during chewing or
at rest.
• Malocclusion – there is deflection or malalignment of normal relation
of the teeth to the other teeth in the same arch or to in the teeth of
opposing arch

3. DENTITION
• The deciduous teeth begin to erupt at 5 to 6 months of
age , lower central incisors are first to be noted
• By the age of 20 to 24 months, the child has a total of
20 teeth, 10 in the upper and 10 in the lower dental
arch
• This complement of teeth is known as the deciduous,
or temporary, dentition
• At the age of 6 years, in addition to the temporary
dentition, the first permanent or 6-year molars erupt
behind the second deciduous molars
• At the age of 6 years, the maxillary and mandibular
central incisor teeth are replaced by the permanent
incisors

4. • At the age of 9 years, the permanent lateral incisors erupted
• At the age of 10 to 11 years, the deciduous molar teeth are replaced by the permanent
premolar teeth
• At the age of 12 to 13 years, the second permanent molar teeth come into position; the
deciduous canine teeth are lost and replaced by the permanent canine teeth
• At the age of 14 years, all the deciduous teeth usually have been exfoliated and replaced
by the permanent teeth
• The first and second permanent molars, in all quadrants, are present. The third molars
(wisdom) may be missing, partially erupted, impacted, or totally unerupted in some but
erupt in most persons after the age of 16 years.

5. • When all of the
permanent teeth have
erupted, the adult has 32
permanent teeth, 8 in
each quadrant. The teeth
are numbered as follows:
the maxillary dental arch,
right to left, 1 to 16; the
mandibular dental arch,
left to right, 17 to 32

7. DBCR, Distobuccal cusp ridge;
DBDG, distobuccal developmental groove;
DCR, distal cusp ridge;
DTF, distal triangular fossa (shaded area);
DLCR, distolingual cusp ridge;
LDG, lingual developmental groove;
MLCR, mesiolingual cusp ridge;
MTF, mesial triangular fossa (shaded area);
SG, a supplemental groove;
MBCR, mesiobuccal cusp ridge;
MBDG, mesiobuccal developmental groove

8. Angle
Classification
(1890) of
Malocclusion
• A class I (neutral) occlusion
is one in which the mesial
buccal cusp of the upper first
molar occludes with the
mesial buccal groove of the
mandibular first molar.

9. Class II - The mesiobuccal cusp of
the maxillary first molar occluding anterior
to the buccal groove of the mandibular first
molar , the retrusive or undeveloped jaw is
termed class II malocclusion (distoclusion )
Class III - The mesiobuccal cusp of
the maxillary first molar occluding
posterior to the buccal groove of
the mandibular first molar, IT IS
protruding or jetting type of jaw is known as
class III malocclusion (mesial occlusion)

10. Occlusal plane - When teeth erupt to meet each other, they form
the occlusal plane
The anteroposterior curve of the occlusal
plane is called the curve of Spee
An occlusal curve also exists in the transverse
plane, called the curve of Wilson

11. • Centric relation
• Centric relation is a position
determined by maximal contraction of
the muscles of the jaw.
• It is considered a stable, reproducible
position that relates bone to bone
through the temporomandibular joint.
• It does not depend on interdigitation of
the teeth
• Centric occlusion
• Centric occlusion is a position
determined by the way the teeth fit
best together with the greatest amount
of interdigitation.
• It is related to tooth occlusion and not
muscle or bone

12. Overlap relationship
(2-4 mm)
Overbite is the amount of vertical
overlap measured between the
upper and lower incisal edges
when the teeth are in occlusion
Overjet is the horizontal overlap
measured from the labial surface
of the lower incisor to the labial
surface of the upper incisor,
parallel to the occlusal plane,
when the teeth are in occlusion

13. • There are abnormalities of occlusal relationship in a lateral direction, which are referred to as
crossbite or laterognathism
• Open bite or absence of occlusal contact in any area should be noted. An open bite may occur
laterally, anteriorly, or anterolaterally and may be unilateral or bilateral.

14. Various methods of MMF
Standard MMF methods are:
• Arch bars
• Ivy loops
• Ernst ligatures
• Acrylic splints
• Bone supported devices including intermaxillary fixation (IMF) screws,
hanger plates, and inter-arch miniplates
OLD fixation methods such as Gilmer wiring, Stout wiring, and
Kazanjian buttons

15. MAXILLARY ANAETHESIA BLOCKS

16. Nerve Anaesthetized
Inferior Alveolar nerve
Lingual
Buccal
incisive

17. ARCH BAR TRAY

18. PENCIL WIRE
TWISTER

19. GILMER METHOD
• The simplest way to establish intermaxillary fixation is
by the Gilmer method, first described in 1887
• The technique is simple and effective but has the
disadvantage that the mouth cannot be opened for
inspection of the fracture site without removal of the
wire fixation.
• The method consists of passing wire ligatures around
the necks of the available teeth and twisting them in a
clockwise direction until the wire is tightened around
each tooth.
• After an adequate number of wires have been placed
on the upper and lower teeth, the teeth are brought
into occlusion and the wires are twisted, one upper to
one lower wire.

20. Eyelet Method

21. • The eyelet method of intermaxillary fixation has the advantage that the
jaws may be opened for inspection by removal of only the intermaxillary
ligatures.
• This method consists of twisting a 20-cm length of 24-gauge or 26-gauge
wire around an instrument to establish a loop.
• Both ends of the wire are passed through the interproximal space from the
outer surface. One end of the wire is passed around the anterior tooth, the
other around the posterior tooth. One end of the wire be passed through
the loop.
• The eyelet should project in the upper jaw above and in the lower jaw
below the horizontal twists to prevent the ends from impinging on each
other.
• After the establishment of sufficient number of eyelets, the teeth are
brought into occlusion, and ligatures are passed in "loop" fashion between
one upper and one lower eyelet.
• The inter-jaw wires are twisted tightly to provide intermaxillary fixation.

22. Arch Bar Method
A. Selection of an appropriate length and contouring of the Erich
arch bar.
B Trimming the bar to length as established by measurements of
the patient.
C The posterior edges of the bar should be bent to conform to the
contour of the posterior maxillary arch and dentition to prevent soft
tissue injury.
D&E. Wires are passed above and below the arch bar and tightened
so as not to obstruct the lug. It is important to make sure that these
wires have been tightly applied by checking whether any vertical
movement of the arch bar is possible at the site of the wire loop.
The bar may be grasped with a clamp and movement attempted.
F - intermaxillary fixation may be established by either wires or
elastics. Elastics apply a constant force and, if light, permit some
movement of the jaws. Wires are stable, permit no movement, and
do not constantly apply undesirable forces to the dentition as
elastics do.
G. Elastic forces tend to displace (rotate) the dentition.

25. Supplementary fixation of arch bars
It is necessary in partially edentulous jaws. Teeth
may be missing because of previous extraction
or injury and may be insufficient in numbers to
secure the arch bar adequately.
A. Support in the maxillary anterior region may
be obtained by passing additional wires through
small drill holes at the piriform aperture or by
use of a screw in this area, passing the wire
around the screw. Additional wires may be
placed through the piriform aperture at the
nasal spine, around the zygomatic arches, or to
drill holes placed in the inferior orbital rims.
B. The approach to the piriform margin is
through a small vertical incision in the labial
vestibule of the upper lip.

26. Circum-mandibular wiring

27. Orthodontic bands and brackets

28. Ernst ligature

30. Acrylic splints
• Acrylic splints provide precise dental
alignment during healing and are
specifically useful in complicated
fractures, such as those mandible
fractures with combined alveolar
fractures.
• Splints prevent alveolar segment fracture
rotation and telescoping of the fragments,
and they may also be designed to provide
an occlusal "stop" to compensate for
missing sections of teeth.
• An acrylic splint is occasionally placed to
facilitate dental occlusal alignment before
plate and screw fixation of a fracture is
employed, and then it is removed after
fixation.

31. Use of IMF screws and plates for
maxillomandibular immobilization
.

32. • Correct screw locations
• Various IMF screw placement
patterns exist and are dictated by
fracture location and the patient's
dentition.
• The insertion point is limited by the
position of the:
• inferior alveolar nerve
• infraorbital nerve
• tooth roots

33. Screw placement

34. Maxillomandibular fixation is performed with 0.4 mm wires. Before
tightening the wires, the correct occlusion to be established.
X PATTERN

35. Hanger plates

37. Matrix wave plates

38. REFRENCES
• https://www.nysora.com/regional-anesthesia-for-specific-surgical-
procedures/head-and-neck/maxillofacial/oral-maxillofacial-regional-
anesthesia/
• Revisiting the Pencil Wire Twister: An Instrument par excellence
• https://surgeryreference.aofoundation.org/cmf/basic-
technique/maxillomandibular-fixation-mmf-bone-supported-devices
• MATHES TEXTBOOK VOL 2

39. Thanks