Treatment planning for maxillary surgical procedures

Treatment planning for
Maxillary surgical procedures.
www.indiandentalacademy.com

• For patients whose orthodontic
problems are so severe that neither
growth modification nor camouflage
offers a solution ,surgical realignment
of the jaws or repositioning of
dentoalveolar segment is the only
possible treatment.

• Dramatic progress in recent years
has made it possible for
combined treatment to correct
many severe problems that
simply were untreatable a few
years ago

History of orthognathic surgical procedures.
• Surgical treatment for mandibular prognathism
began early in the 20th
century.
• Trauner & obwegeser (1959)introduced sagittal
split ramus osteotomy marked the modern era in
orthognathic surgery.
–Bell, Epker & wolford introduced LeFort I
downfracture technique that allowed repositioning of
maxilla in all 3 planes of spaces.

• 1980s progress in maxillofacial surgery made it possible
to reposition either or both jaws.
• 1990s, rigid internal fixation greatly improved patient
comfort by making immobilization of the jaws
unnecessary.
• Combined surgical orthodontic treatment can now be
planned for patients with a severe dentofacial problem of
any type

Envelope of discrepancy
• It graphically illustrates the current concepts of how
much change can be produced by various treatments.
• The inner circle showing the amount change in all 3
planes of space that could be produced by orthodontic
tooth movement alone.
• The middle circle –orthodontic tooth movement
combined with growth modification in a growing child.
• The outer circle – orthognathic surgery.

Envelope of discrepancy

Evolution of maxillary surgical procedures
• The downfracture osteotomy technique for maxillary
surgery originated with cheever (1864).
• 1921,German surgeon, Herman wassmund attempted
maxillary osteotomy.
• 1934 Auxhausen did a surgery for the correction of open
bite deformity.
• Before 1965 dentofacial deformity was treated by
mandibular surgery alone.
• LeFort I osteotomy with maxillary down fracture allows
the surgeon to move maxilla in all 3 planes of space.www.indiandentalacademy.com

Anatomy of maxilla.
• Maxilla consists of a body and four
processes
1. Zygomatic process.
2. Palatine process.
3. Frontal process.
4. Alveolar process.

Psychosocial considerations in orthognathic
surgery
• The negative effect on psychic and social
well being from dentofacial disfigurement
is why most patients seek orthodontic
treatment.
• Psychological support and counseling are
important for the patients.

Contemporary surgical procedures
• Widening - RPE
• Set back
• Maxillary advancement
• impaction

Indications for surgery.
• Severe skeletal discrepancy or extremely severe
dento alveolar problem.
• Adult patient / younger patient with extremely
severe or progressive deformity.
• Good general health status.

Cephalometric findings
• Bruce n. Epker & Leward c.Fish have chosen 6
skeletal measurements
• Facial axis angle.(90+/-3).decreased
value=recessive chin.
• Facial depth angle=angle formed by the
intersection of the anatomic frankfort plane &
nasion- pogonion line.(89+/-3).decreased
value =recessive chin.

• Mandibular plane angle.(24+/-4degrees)
( low angle /high angle)
• Facial convexity=distance between point A &
N-PO line.(1+/-2mm)
• Maxillary length :mandibular length = ratio
measured from condylon – point A & from
condylon to gnathion.

Four basic varieties of long
face.
• Vertical maxillary
excess & vertical chin
excess

• A low maxilla &
vertical chin excess.

• The maxillary occlusal
plane is tilted
producing an anterior
open bite & vertical
chin excess.

• A short upper lip
simulates vertical
maxillary excess
which may be
exaggerated by
vertical chin excess

Face bow transfer.

•To take a face bow registration, the bite-fork is sandwiched
within four layers of well-softened pink card wax and the
teeth are closed in centric relation.
• When the face bow is attached, the condyle is assumed to
be 12-16mm infront of the tragus,where it should be
marked on the skin to help to locate the ear pieces.
•The orbital pin & condylar points establish the frankfort
•plane.A separate wax squash bite in centric relation is also
taken. www.indiandentalacademy.com

•Anatomically trimmed working & study models.
•The face-bow is mounted on the articulator & the upper
model carefully seated on the bite fork wax impression.
note that the orbital margin pin is adjusted to the level of
the mounting assembly disk.
•The model is then fixed with plaster of paris.
•The face bow has been removed & the lower model is
carefully related to the upper one with the squash bite in
centric relation

Marked models,the interrupted lines are proposed osteotomy
sites & the hatched area indicates planned bone removal

Surgically assisted rapid palatal
expansion.(S.A.R.P.E)
• Technique used in adult patients in whom
mid palatal suture does not open up with
mere orthopedic force.
• The surgeries generally employed are,
In mid palatal snyostosis –suture fuses
prematurely.
In mid palatal interlocking.
in circum maxillary rigidity.

History of S.A.R.P.E.
• STARTED WITH KOLE (1959) ADVOCATED
SELECTIVE DENTO ALVEOLAR OSTEOTOMIES TO
SECTION THE CORTICAL BONE.
• 1969 CONVERSE SUGGESTED BOTH LABIAL
&PALATAL CORTICAL OSTEOTOMIES.
• 1975,LINES ADVOCATED OSTEOTOMIES FOR
ADULT RPE CASES.
• 1976 BELL & EPKER RECOMMENDED THE SAME .
• 1980 JACOBS USED LATERAL
MAXILLARY,PTERYGOMAXILLARY & PALATAL
OSTAOTOMIES TO ACHIEVE THE SAME.

ADVANTAGES OF S.A.R.P.E.
• MORE OF SKELETAL THAN DENTAL
EXPANSION.
• BETTER STABILITY.
• LESS GINGIVAL PROBLEMS.
• IMPROVED DENTOFACIAL ESTHETICS.

INTRA ALVEOLAR CORTICOTOMY
(AJO APRIL 1986)
• IF THE DIASTEMAS ARE LARGE
ASSOCIATED WITH PROCLINATION OF
MAXILLARY ANTERIORS & LIP
INCOMPETENCE THIS PROCEDURE IS
PERFORMED.

LIMITATIONS
• POSSIBILITY OF NON VITALITY OF THE
TEETH.
• DIFFICULTY IN POSITIONIG THE SEGMENTS
AS DESIRED.
• AVASCULAR NECROSIS OF OSTEOTOMY
SEGMENTS.
• POSSIBILITY OF ROOT DAMAGE.

DISADVANTAGE OF ORTHODONTIC
THERAPY IN THESE CASES
• LESS BONE SUPPORT FOR THE
ROOTS.
• HIGH INCIDENCE OF RELAPSE.
• PROLONGED TREATMENT TIME.
• SOCIO ECONOMIC FACTORS.

ANTERIOR MAXILLARY
OSTEOTOMY
• EMPLOYED PRIMARILY TO REPOSITION
THE ANTERIOR DENTO OSSEOUS SEGMENT
POSTERIORLY.AISO CAN MOVE IT
SUPERIORLY OR INFERIORLY.
• HELPS IN THE REDUCTION OF OVER JET
OR ANTERIOR OPEN BITE.

LeFort I OSTEOTOMY
• INCISION HIGH ON THE ZYGOMATIC-
MAXILLARY BUTTRESS OF THE ANTERIOR
MAXILLA ACROSS THE MID LINE TO END
ON THE OPPOSITE BUTTRESS.
• THE WHOLE DENTOALVEOLAR CAN MOVE
IN ANY DIRECTION.
(FORWARD,BACKWARD,SUPERIORLY &
INFERIORLY)

Superior repositioning of maxilla.

Advancement of maxillawww.indiandentalacademy.com

POSTERIOR MAXILLARY
OSTEOTOMY
INDICATIONS:-
• TO ALTER TRANSVERSE POSITION OF THE
POSTERIOR MAXILLA.
• TO SUPERIOLY POSITION SUPRAERUPTED
POSTERIOR SEGMENT.
• TO INFERIORLY REPOSITION A POSTERIOR
MAXILLARY SEGMENT TO CLOSE A POSTERIOR
OPEN BITE.
• TO MOVE A POSTERIOR SEGMENT FORWARD TO
CLOSE AN EDENTULOUS SPACE.

POSTERIOR CORTICOTOMY.
(JCO/MAY 2001-CHUNG et al)
• CORTICOTOMY MAKES IT POSSIBLE TO
MOVE TEETH FASTER WITHOUT THE
PRIMARY RESISTANCE ENCOUNTERED IN
THE CORTICAL BONE.
• CAN BE USED IN THE TREATMENT OF
ANKYLOSED TEETH,TEETH SURROUNDED
BY NARROW CORTICAL BONE,SIGNIFICANT
ARCH LENGTH DISCREPANCIES &
TRANSVERSELY CONSTRICTED MAXILLA.

• Corticotomy is 1st carried out on the palatal side
& 2 weeks later on the buccal side.
• Horizontal bone cut is made 2 mm above the
apices of the teeth to be moved.
• A connecting vertical cut begins 2-3mm above
the interdental alveolar margin between canine
&1st premolar & extends through the interdental
bone to 2mm above the apices.
• Horizontal cut is extended to the maxillary
tuberosity.
• The depth of the bone cut should be limited to
the cortical bone.

Timing & sequencing of surgical
treatment.
• Early vs later surgery.
early jaw surgery has little inhibitory effect on
further growth.so surgery should be delayed until
growth is completed.
• Early surgery & excess growth.
correction of excessive growth must be delayed
until the late teens.
• Early surgery & growth deficiency:
major indication for orthognathic surgery before
puberty is a restriction caused by restriction of
growth.

Surgical & orthodontic phases of
treatment.
successful management of combined surgical &
orthodontic treatment requires the integration
of
1. pre surgical orthodontic phase.
2. surgical phase.
3. post surgical orthodontic phase.
Dental compensations are removed before
surgery & the teeth are properly located in
relationship to the individual skeletal
component. www.indiandentalacademy.com

Appliance systems.
• Fixed orthodontic appliance is used to stabilize
the teeth & basal bone at the time of the surgery
and during healing.
• Rectangular wires are used for strength &
stability.
• Ceramic brackets are not indicated due to the
brittleness of ceramic material makes them
susceptible to fracture.

Pre surgical orthodontics
• Main aim is to position the teeth in the arches
,so that the dental arches become
compatible,facilitating their proper placement
during surgery.
• Main tooth movements commonly required
include intrusion,levelling,derotation,closure of
spaces,correction of anterior / posterior
crossbites &co-ordination of the arches.

Goals of pre-surgical treatment.
• The objective of pre-surgical treatment is to
prepare the patient for surgery.
• Placing the teeth relative to their own supporting
bone without concern for the dental occlusion at
this stage.
• Time period is less than one year.

Steps in orthodontic preparation.
• Main steps in pre-surgical orthodontics are-
Align the arches / arch segments & make them
compatible.
To establish the antero posterior and vertical position of
the incisors. so that the teeth will not interfere with
placing the jaws in desired position.
`

Leveling the mandibular arch.
• Accentuated curve of spee can be corrected
by two methods
1. Intrusion of incisors.
2. Extrusion of premolars
based on the desired final face height.
Face is short & distance from lower incisal
edge of the chin is normal leveling by extrusion
of posterior teeth is indicated.

• If the incisors are elongated & face height is
normal / excessive they must be intruded to
prevent problems in controlling face height at
surgery.

• Establishment of incisor position and space
closure.
The anteroposterior position of the incisors determines
where the mandible will be placed relative to the maxilla
at surgery & hence is a critical element in planning
treatment.
This is a major factor in planning anchorage in the
closure of extraction sites.

Stabilizing archwires
• Stabilizing archwires should be placed at least 4
weeks before surgery so that they will be
passive when impressions are taken for surgical
splint.
• These should be full slot edgewise wires ie.
17 x 25 s.s in 18-slot.
21x 25 s.s in 22-slot.

Patient management at surgery
• Final surgical planning :
1. After pre-surgical orthodontics pre-surgical
records should obtain. (panoramic & lateral
cephalometric films,periapical films of
interdental osteotomy sites & dental casts )
2. Cast should be mounted on a semiadjustable
articulator if maxillary surgery is planned.
3. To avoid distortion,impressions are best made
with the stabilizing arch wires removed.

Splints & stabilization
• Interocclusal wafer splint made from the casts
as repositioned by model surgery are commonly
used.
• The splint is made with autopolymerizing acrylic
and cured in a pressure pot to prevent distortion.
• Should be more than 2 mm thick at thinnest
point where the teeth are separated minimally.
• Should be trimmed on the buccal surfaces to
allow good oral hygiene & permit visual
verifications of proper seating at the time of
surgery www.indiandentalacademy.com

Surgical phase.
• The orthodontist is generally present in the
operating room along with the surgeon to
assist in fixation of the inter occlusal wafer
&for varifying occlusal relationship.

• Maxillary osteotomies require overnight
hospitalization & 2 jaw surgery require 1 –2
days hospitalization.
• Soft diet for the 1st
week after surgery.
• 6-8 weeks after surgery should be back to
normal diet.
• After 1st
week mild jaw exercises are
indicated.
• Wire fixation, immobilization for 4-6 weeks.www.indiandentalacademy.com

Post surgical orthodontics.
• This phase usually start after 6 weeks.
• The occluded wafer is first removed &the
ligature fixation wires replaced with
elastics slowly re-initiating the mandibular
function .
• Heavy stabilizing wires are removed and
round or rectangular braided wires are
placed to facilitate settling.

• Box elastics,short up & down elastics are
used to achieve maximum inter cuspation.
• Evidence of skeletal relapse tendency
should be monitored closely.
• Periodic check up should be done.

Post-surgical stability
• The hierarchy of stability, based on UNC data
base
• Maxilla up, mandible forward,chin any direction
= very stable.
• Maxilla forward ,maxilla asymmetry = stable.
• Maxilla up + mandible forward, maxilla forward
+mandible back,mandible asymmetry = stable
with rigid fixation.
• Mandible back, maxilla down,maxillary
expansion =relapse are more.

principles that influence post
surgical stability
1. Stability is greatest when soft tissues are
relaxed during surgery & least when they
are stretched.
2. Neuromuscular adaptation is an
essential requirement for stability.

conclusion
• So it is an adjunct to orthodontia to treat
the patients better.

Treatment planning for maxillary surgical procedures

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