Dr. Kokich's Guide to Finishing in Orthodontics

Vincent G. Kokich, Sr.
Doctor Kokich is a Professor in the Department of
Orthodontics at the University of Washington in
Seattle. He also maintains a private orthodontic
practice in Washington.
He has published 18 book chapters, 67 scientific
articles, and 48 review articles.
He is on the editorial board of most of the reputed
international journals
www.indiandentalacademy.com

• Dr. Kokich has also presented several
distinguished lectures including The
Salzmann and The Mershon Lectures for
the American Association of Orthodontists.
• Dr. Kokich has been elected to
Fellowship in both the American College
of Dentists and the Royal College of
Surgeons of England.
• He has served as President of the
American Board of Orthodontics.

INTRODUCTION
• Ideal finishing
• Optimum finishing
• Check list for finishing
1. Series of nine occlusal factors
2. Periodontal factors
3. Esthetic factors

The ABO Objective Grading System for scoring
dental casts and panoramic radiographs
contains eight criteria:
• Alignment
• Marginal ridges
• Buccolingual inclination
• Occlusal relationships
• Occlusal contacts
• Overjet
• Root angulation
• Interproximal contacts
• Overbite

ALIGNMENT
• Alignment is usually a fundamental
objective of any orthodontic treatment
plan.
• Therefore, it seems reasonable that any
assessment of the quality of orthodontic
results must contain an assessment of
tooth alignment.

• In the anterior region, the incisal edges and
lingual surfaces of the maxillary anterior teeth
and the incisal edges and labial-incisal surfaces
of the mandibular anterior teeth were chosen as
the guide to assess anterior alignment.
• These are not only the functioning areas of
these teeth, but they also affect esthetics if they
are not arranged in proper relationship.

In the maxillary and
mandibular anterior regions,
proper alignment is
characterized by coordination
of alignment of the incisal
edges and lingual incisal
surfaces of the maxillary
incisors and canines and the
incisal edges and labial
incisal surfaces of the
mandibular incisors and
canines

• In the maxillary posterior region, the mesiodistal
central groove of the premolars and molars is
used to assess adequacy of alignment.
• The central grooves (mesiodistal) should all be in
the same plane or alignment

• In the mandibular arch, the buccal cusps
of the premolars and molars are used to
assess proper alignment.
• The mesiobuccal and distobuccal cusps of
the molars and premolars should be in the
same mesiodistal alignment.

• These areas were chosen because they
represent easily identifiable points on the
teeth, and represent the functioning areas
of the posterior teeth.

A, 1 mm in width and measures discrepancies in alignment,
overjet, occlusal contact, interproximal contact, and occlusal
relationships;B, steps measure 1 mm in height and are used
to determine discrepancies in mandibular posterior
buccolingual inclination; C, steps measure 1 mm in height and
are used to determine discrepancies in marginal ridges;
D, steps measure 1 mm in height and are used to determine
discrepancies in maxillary posterior buccolingual inclination.

• If all teeth are in alignment or within 0.5
mm of proper alignment, no points are
subtracted from the candidate’s score.
• If the mesial or distal alignment at any of
the contact points is 0.5 mm to 1 mm
deviated from proper alignment, 1 point
shall be subtracted for the tooth that is out
of alignment.

• If adjacent teeth are out of alignment, then
1 point should be subtracted for each
tooth.
• If the discrepancy in alignment of a tooth
at the contact point is greater than 1 mm,
then 2 points shall be subtracted for that
tooth .
• No more than 2 points shall be subtracted
for any tooth.

• The most commonly malaligned teeth
were the maxillary and mandibular lateral
incisors and second molars.

• Dr Kokich uses standard edgewise
brackets – bends in archwire
• Convinces the patient that he needs 2 -3
months more to do a good job
• Pre Adjusted Edgewise Appliances

• Canine substitution in case of missing upper
lateral incisors
problem solution
gingival levels extrude canines

problem solution
cusp tip hangs equilibrate cusp tip
thicker edge equilibrate lingual surface
Finally equilibrate lingual cusp of first premolar

Finishing to class II

Finishing to class III

Marginal ridges

Definition of marginal ridges
• Are those rounded borders of enamel that form
the mesial & distal margins of the occlusal
surfaces of premolars and molars and the
mesial & distal margins of the lingual surfaces
of the incisors & canines.
(Wheeler’s: Dental Anatomy, Physiology &
Occlusion)

canine premolar

Marginal ridges
• The second of the occlusal factors assessed by the
American Board of Orthodontics (ABO) for scoring
dental casts
• In the non-worn, non-restored & non-periodontally
involved adolescent dentition, marginal ridges are
good guides for proper vertical relationships
• Marginal ridge will be considered as the most
occlusal point that is within 1 mm of the contact at
the occlusal surface of the adjacent teeth
• The marginal ridges of adjacent posterior teeth,in
both maxillary & mandibular arches, should be at the
same level or within 0.5 mm of the same level

Scoring criteria
If adjacent marginal ridges deviate
a) 0.5 to 1mm- 1 point shall be
subtracted
b) >1mm – 2 points shall be subtracted
The total number of deductions shall be
subtracted from 32 to give the score for
marginal ridges.

Marginal ridges at the same level
All fossae at the same level
All cusps at the same level
All CEJ at the same level on radiograph
CEJ to bone at 2 mm
All bone flat b/n adjacent teeth at same height

Where are the problem areas ?
• Between first & second molars in upper arch
• Between first molar & second molars in the lower
arch
When do we need to modify ?
• When dealing with grossly restored, abraded or
periodontally compromised teeth.
- In such instances marginal ridges are not good guides
for posterior vertical tooth position.
- We should rely on bone levels between teeth to
determine correct vertical position of adjacent teeth.www.indiandentalacademy.com

• Don’t only look at the clinical crown in such
cases as tooth anatomy is questionable
“When bonding adult periodontally
compromised cases, don’t always believe the
obvious- don’t look only at the teeth, look for
bone in radiograph”
N.B : To upright tipped teeth, the attachments
must be placed perpendicular to the long axis
of the teeth & not parallel with the abraded
occlusal surface

Steps
• Place ideal brackets first
• Measure the bone level difference using
bitewing radiograph from CEJ on the ideal
tooth to the bone level using calipers
• Determine long axis of the root and draw it on
the radiograph
• Place the bracket (tube) orienting to this line
• Later on equilibrate occlusion if necessary

1mm in height & measures discrepancies in marginal ridges

• Reliability of the grading system is insured
through the use of a precise measuring
instrument.
• In a day to day practice, orthodontists may use
this scoring system at anytime in their career
to determine if they are producing “Board
quality” results.

The occlusal relationship is used to assess the relative
anteroposterior position of the maxillary and mandibular
posterior teeth.
The most verifiable method of scoring this criteria is to
use Angle’s relationship.
Occlusal relationships

If the occlusion has been finished in an
Angle Class I relationship :
Ideally, the maxillary canine cusp tip should align with or within 1
mm of the embrasure or contact between the mandibular canine
and adjacent premolar.
The buccal cusps of the maxillary premolars should align with or
be within 1 mm of the interproximal contacts between the
mandibular premolars and first
molar.
The mesiobuccal cusps of the maxillary molars should align with
the buccal grooves of the mandibular molars.www.indiandentalacademy.com

In a Class II situation, the buccal cusp of the maxillary first molar
should align with the embrasure or interproximal contact between
the mandibular second premolar and first molar. The buccal cusp
of the maxillary second molar should align with the embrasure or
interproximal contact between the mandibular first and second
molars.

If the final occlusion is finished in a Class
III relationship, the buccal cusp of the
maxillary second premolar should align
with the buccal groove of the mandibular
first molar.

Buccolingual Inclination
Assessed by using a flat surface that is extended between
the occlusal surfaces of the right and left posterior teeth.

In the mandibular arch, straight edge should contact the buccal
cusps of contralateral molars. The lingual cusps should be within 1
mm of the surface of the straight edge.

In the maxillary arch, the straight edge should contact the lingual cusps
of the maxillary molars and premolars.The buccal cusps should be
within 1 mm of the surface of the straight edge.

• Position the teeth to facilitate restorative
treatment :
Resin Bonded Bridges.
Conventional Anterior Bridges.
Anterior Inclination

• If the maxillary central incisors are upright
or oriented vertically to the mandibular
arch, then the occlusal forces during
incisor contact will be directed vertically
through the root of the tooth.
• This is Ideal :
– The resin bonded framework will have better
shear strength
– The retention of the resin bonded bridge will
be enhanced.
Resin Bonded bridges

• If the maxillary central incisors are
proclined, the occlusal forces on the
maxillary central incisors will be directed
labially.
• This will be unsuccessful :
– The metal connector of the resin bonded
framework could get dislodged.
– Higher tendency for bond failure.
Resin Bonded bridges

The abutments for a conventional bridge must be positioned
appropriately, so the crown preparations of the two abutments
will have parallel walls to permit seating of the soldered
bridge.
Conventional bridges

OVERBITE
• How much of overbite should be left….
General answer would be 2-4mm
• Over bite should be individualized rather
than generalized.
• The purpose of overbite is to permit the
anterior teeth to function or incise food in
protrusive jaw position ,while the posterior
teeth are out of occlusal contact.

• Amount of overbite is actually determined
by the length of the premolars and
canines, which is sufficient to disocclude
posterior teeth.
• Shallow cusps and long cusps
• Overbite should be checked in protrusive
function

How it affects in restorative dentistry
• During the placement of a resin-bonded
anterior bridge
• Study by Boyer D in 1993 shown that
89%-----1yr
83%-----2yr
72%-----3yr survival rates

• Retention of an anterior resin-bonded
bridge is partially determined by the size
of the bonded metal connector on the
lingual surface of incisors.
• Incisors should be upright so that there
will be shear force , and overjet should be
decreased

OVERJET
• According to ABO guidelines it should be
zero, or in other words, the upper and
lower anterior teeth should contact, when
the posterior teeth are brought into
occlusion.

• It is used to assess the relative transverse
relationship of the posterior teeth &
anteroposterior relationship of the anterior
teeth.
• In the posterior region, the mandibular
buccal cusps and maxillary lingual cusps
are used to determine proper position
within fossae of the opposing arch.

How it affects in restorative dentistry
• Example in a case with missing central
incisor teeth
• Retention modality is to give essix
retainer after debonding, then give begg
retainer with riding pontic for 6 months
,finally to restore with bridge

• Next is in patient who has significant tooth
abrasion or erosion of labial surfaces of
the mandibular incisors or lingual
surfaces of the maxillary anterior teeth.
• As they wear , they usually erupt to
maintain contact with opposing arch.

• In this situation answer is to intrude the
anterior teeth because here overjet is a
vertical problem.
• In case of abraded teeth to create
sufficient overjet slenderize the lower
anteriors and use Class III elastics or
intrude the extruded teeth.

Occlusal Contacts
The adequacy of tooth interdigitation –by
cusps and fossae of molars and premolars
The buccal cusps of mandibular molars
and premolars and lingual cusps of
maxillary molars and premolars should
contact the fossae or marginal ridges of
opposite arches.

Occlusal Contacts

Occlusal Contacts
 The exceptions
1. Lingual cusps of maxillary first premolars
because of the lack of adequate occlusal
table
2. Distolingual cusps of maxillary first and
second molars if the cusps are diminutive in
size

Interarch Relationships
1. The mesiobuccal cusp of the permanent
maxillary first molar occludes in the
groove between mesial and middle
buccal cusps of the permanent
mandibular first molar.

1. The distal marginal ridge of the maxillary
first molar occludes with the mesial
marginal ridge of the mandibular second
molar.

3. The mesiolingual cusp of the maxillary
first molar occludes in the central fossa
of the mandibular first molar.

4. The buccal cusps of the maxillary
premolars have a cusp-embrassure
relationship with the mandibular
premolars.

5. The lingual cusps of the maxillary
premolars have a cusp fossa
relationship with the mandibular
premolars.

6. The maxillary canine has a cusp-
embrassure relationship with the
mandibular canine and first premolar.
The tip of its cusp is slightly mesial to
the embrassure.

7. The maxillary incisors overlap the
mandibular incisors and the midlines of
the arches match.

• When two maxillary premolars are
extracted and the patient is finished in an
Angle class II molar relation, then the
maxillary first molar must be rotated
mesiopalatally.

• In finished Angle class III molar relation
the maxillary second premolar must be
moved buccally.

However, in situations where posterior
teeth have worn significantly and have to
be restored with full crowns, then it is not
advantageous to establish contact at the
end of orthodontic treatment.
In such cases the attrited and overerupted
tooth can be intruded thus creating open
contact between this tooth and the
opposing arch.

This eliminates the need for the restorative
dentist to reduce the occlusal surface of
the attrited tooth.
This will result in adequate length of the
axial walls of the tooth preparation and
enhance the retention of the restoration.

After the attrited molar has been intruded,
it must be held in position with a
provisional crown or a composite build-up
of the occlusal surface, until final
restoration.

Bone level
In adolescents the orthodontist should
align the incisal edges of anterior teeth
and marginal ridges of posteriors.
In adult patients the incisal edges and
marginal ridges are not reasonable
guides.

Bone level
If the patient has horizontal bone loss in
maxillary or mandibular anterior regions, it
is best to align the bone levels and then
equilibrate the incisal edges.
This establishes the correct incisal edge
position, occlusion and crown to root
relationships.

Root Angulation
Root Angulation is used to assess how well
the roots of the teeth are positioned in relation
to one another.www.indiandentalacademy.com

• Orthodontic treatment may have adverse
treatment effects on gingival and
periodontal tissues.
• It may hasten or promote periodontal
breakdown later in life.

• Adequate space between the teeth at the
level of crestal bone is necessary for the
gingival health.
• Malposed or rotated teeth may be
predisposed to more rapid break down of
the perodontium when roots are in close
proximity.

• Close proximity of the roots result in a thin
interproximal septum (Prichard, Kessler,
Klassman, Hatasaka).
• The root angulation is studied at the
finishing stage by the orthodontist by using
OPG.

In theory, if roots of adjacent teeth are
perpendicular to occlusal plane, and
parallel with one another, then there will
be sufficient bone present between their
roots.

• It is assumed that more interproximal
bone will provide greater resistance to
periodontal bone loss.
• This prevents the patient from developing
periodontal disease at later time.

Issues concerning root angulation
• Precision of OPG in determing root
angulation
• Close proximity of roots :does it cause
long term detrimental effects?

• Artun, J Osterberg & Kokich VG (1986)
concluded that close proximity did not
produce detrimental effects in their
sample.
• Results from this study showed that
anterior teeth are not predisposed to more
rapid breakdown when roots are in close
proximity.

• But their sample were young patients not
susceptible to periodontal diseases.

– However they
concluded that close
root proximity after
orthothodontic treatment
will cause problems in
certain restorative
patients.

If the patients have to go for full crown
or veneers, it is difficult to obtain
adequate impression of the gingival
margins for the tooth preparation.
–The placement of the retraction cord is
difficult.

–In single tooth implant
cases it is very important to
create adequate room for the
implant placement.

Conclusion
The checklist for finishing a case also includes
1. Periodontal factors
Root angulation
Bone level
2. Esthetic factors
Crown width
Gingival levels
Gingival form

Crown width
Crown widths of anterior
teeth may not be matching
proportionately, especially
upper lateral incisors.
To restore such teeth, the
space has to be distributed
properly. This is more
important when the
discrepancy is unilateral.

Crown width
Space can be distributed
using compressed coil
springs within a few
weeks.
The position of
microdonts like peg
laterals has to be
determined in all the
three planes before
bonding.

Gingival level
Four characteristics
contributing to ideal
gingival form:
1. Gingival levels of centrals
2. Gingival levels of
centrals, laterals and
canines
3. Contour of the margins
4. Interdental papillae

Gingival level
In case of discrepancies it has
to be corrected
orthodontically or
surgically evaluating four
criteria:
1. Lip line during smile
2. Sulcus depth
3. Gingival level of centrals
and laterals
4. Abrasion of incisal edges

Gingival form
Presence of a papilla between
teeth is a key esthetic
factor.
Black triangles (open gingival
embrassures) are
unaesthetic and difficult
to correct periodontally.
They are caused by:
1. Tooth shape
2. Root angulation
3. Periodontal bone loss

Gingival form
The tooth contact and the
papilla should be in 1:1
ratio.
The clinician should
evaluate whether the
problem is due to papilla or
tooth contact.
When the disproportion is
due to improper angulation
or shape of the crown, it is
corrected by altering the
same.

Dr. Kokich is of the opinion that a perfect
finished case does not exist in reality.
As orthodontists have started treating more
and more adult cases, it is necessary to have an
interdisciplinary approach.
Through this approach, we can modify our
objectives for patients with periodontal disease
or with gross occlusal restoration.

So, for every case it is necessary
to establish a problem list
to establish treatment objectives
to achieve treatment objectives

The treatment objectives can be idealistic or realistic.
He is of the opinion that we should try to achieve
realistic objectives.
Economically Occlusally
Realistic objectives
Periodontally Restoratively

Where is the data that proves that class-I molar
relation is better than class-II?
No study since more than 100 years of
orthodontic history!!!

‘Success’ is when you achieve your objectives.
‘Compromise’ is when you don’t achieve your
objectives.
Finishing the case to good occlusion is a
continual challenge and also the key objective
we all stand by as ‘orthodontists’.

In the race to perfection there is no finish line !!

Dr. Kokich's Guide to Finishing in Orthodontics

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Dr. Kokich's Guide to Finishing in Orthodontics