The management of congenitally missing lateral incisors h rosenberg

The Management of
Congenitally Missing Lateral
Incisors

Dr. Harold Rosenberg
Humbertown Orthodontics
203-270 The Kingsway, Toronto
drhr@humbertownortho.com

Congenitally Missing Teeth
The interdisciplinary management of hypodontia: orthodontics.
Carter et al BDJ 2003; 194(7):361-366.

There are several issues that commonly arise in the orthodontic
management of patients with hypodontia:
1. Space management
2. Uprighting and aligning teeth
3. Management of deep overbite
4. Retention and stability

The decision on whether to open or close spaces depends upon:
1. The age of the patient
2. The severity of the hypodontia
3. The degree of inherent crowding

Congenitally Missing Mx Lateral
Incisors- Space Closure vs Prosthetic
Replacement

Replacement
The congenitally missing upper lateral incisor. A retrospective
study of orthodontic space closure versus restorative treatment.
Robertsson & Mohlin. EurJOrtho 2000;22:697-7100.

RESULTS: Orthodontic space closure produces
results that are well accepted by patients, does
not impair TMJ function, and encourages
periodontal health in comparison with
prosthetic replacements.

Replacement
The congenitally missing maxillary lateral incisor. Part 1: esthetic
judgement of treatment options. Armbruster PC, et al. World J of Ortho 2005;
6(4):369-75.

CONCLUSIONS: Including esthetics of the ﬁnished
result as an advantage or disadvantage for either
restoration or canine substitution of the lateral
incisors could be misleading to the patient because
judgment of esthetics of a smile can vary from one
person to another or from one dental professional to
another.


Managing Congenitally Missing Lateral Incisors. Parts I-III. Kokich
VO, Kinzer GA. J Esthet Restor Dent 17(1):5-10; 17(2):202-210;
17(4):202-210, 2005.


17(4):202-210, 2005.

Incisors
(20% of all conenitally missing teeth, third
most common)


17(4):202-210, 2005.

Incisors
most common)

Canine
Substitution


17(4):202-210, 2005.

Incisors
most common)

Canine Tooth
Substitution Supported
Restoration


17(4):202-210, 2005.

Incisors
most common)

Canine Single Tooth
Tooth
Substitution Implant
Supported
Restoration



17(4):202-210, 2005.



17(4):202-210, 2005.

Incisors



17(4):202-210, 2005.

Incisors

Canine
Substitution
?



17(4):202-210, 2005.

Incisors

Canine Tooth
Substitution Supported
? Restoration?



17(4):202-210, 2005.

Incisors

Canine Tooth Single Tooth
Substitution Supported Implant?
? Restoration?



17(4):202-210, 2005.

Incisors

Canine Tooth Single Tooth
Substitution Supported Implant?
? Restoration?
Appropriate option depends on the malocclusion, speciﬁc space
requirements, tooth-size relationship, and size and shape of the
canine.
The ideal treatment is the most conservative option that satisﬁes
individual esthetic and functional requirements.


Managing Congenitally Missing Lateral Incisors. Part I: Canine
Substitution. Kokich VO, Kinzer GA. J Esthet Restor Dent 17(2):

202-210, 2005.



202-210, 2005.

Incisors



202-210, 2005.

Incisors

Canine
Substitution
?


Managing Congenitally Missing Lateral Incisors. Part I: Canine Substitution. Kokich VO, Kinzer GA. J
Esthet Restor Dent 17(1):5-10, 2005.


Managing Congenitally Missing Lateral Incisors. Part I: Canine Substitution. Kokich VO, Kinzer GA. J

Canine Substitution- Dental & Facial Criteria

I. Malocclusion
Class II with no crowding in the Md arch Class II
molars, 1st PM in canine position
Class I with sufficient crowding requiring Md
extractions
•Design ﬁnal occlusal scheme so that lateral excursive
movements are in anterior group function.
•Evaluate anterior tooth size relationship  diagnostic
wax-up to assess how much reduction is required in the
maxillary arch to achieve proper OB & OJ


Managing Congenitally Missing Lateral Incisors. Part I: Canine Substitution.
Kokich VO, Kinzer GA. J Esthet Restor Dent 17(1):5-10, 2005.




II. Profile
•A balanced relatively straight profile is ideal
•A mildly convex profile may be acceptable



III. Canine Shape & Color
•With a wider crown and more convex labial surface, a
signiﬁcant amount of reduction is often required to
achieve a normal occlusion & acceptable esthetics.
•May result in dentin showing through and a need for
restorative intervention
•The color of the canine should match the central  if
bleaching of canine does not work than a veneer may be
indicated
•Crown width at the CEJ should be evaluated on a PA as
a narrow mesiodistal width produces a more esthetic
emergence proﬁle than one with a wide CEJ width.



Thus, the ideal lateral incisor substitute is a canine
that is:
•The same color as the central incisor
•Is narrow at the CEJ buccolingually and
mesiodistally
•Has a relatively ﬂat labial surface
•Has a narrow midcrown width buccolingually




IV. Lip Level
•Excessive gingiva-to-lip distance will reveal
•The gingival margin of the canine (should be
placed more incisal to the central incisor  may
require gingivectomy)
•Prominent canine root eminence



Canine Substitution- Treatment

•Brackets should be placed according to gingival margin
heights  brackets on canines placed at a distance from
the gingival margin that will erupt these teeth into the
appropriate lateral incisor vertical position.
•As canines erupt they may cause interferences and require
equilibration during orthodontic alignment.
•During ﬁnishing reshaping is required for optimal
esthetics
•A need for restorative treatment to re-create ideal lateral
incisor color and contour is often required (bleaching,
composite resin, porcelain veneer).
•Interdisciplinary treatment planning is necessary to
achieve optimal ﬁnal esthetics

Congenitally Missing
Teeth
Managing Congenitally Missing
Lateral Incisors. Part I: Canine
Substitution. Kokich VO, Kinzer GA. J


Congenitally Missing
Teeth
Managing Congenitally Missing
Lateral Incisors. Part I: Canine
Substitution. Kokich VO, Kinzer GA. J


A.Irregular gingival architecture
B.Incisor wear affects proper crown
width-to-length ratio
C.Ortho intrusion necessary to
facilitate restorative lengthening of
the central incisor
D.Provisional composite restorations
completed
E.Ortho extrusion of canines
F.Ideal length of canines as lateral
inicsors
G.Cuspal equilibration completed
H.Composite restoration of
mesioincisal corners


Managing Congenitally Missing Lateral Incisors. Part II: Tooth
supported restorations. Kokich VO, Kinzer GA. J Esthet Restor Dent

17(2):202-210, 2005.



17(2):202-210, 2005.
Incisors

Tooth
Supported
Restoration?



17(2):202-210, 2005.
Incisors

Tooth
Supported
Restoration?

A. Cantilevered Fixed
Partial Denture



17(2):202-210, 2005.
Incisors

Tooth
Supported
Restoration?

A. Cantilevered Fixed
Partial Denture
B. Resin-Bonded Fixed
Partial Denture



17(2):202-210, 2005.
Incisors

Tooth
Supported
Restoration?

A. Cantilevered Fixed C. Full-Coverage
Partial Denture Fixed Partial Denture
Partial Denture



17(2):202-210, 2005.
Incisors
The ideal treatment is the
most conservative (least
invasive) option that satisﬁes
individual esthetic and
Tooth
functional requirements.
Supported
Restoration?

A. Cantilevered Fixed C. Full-Coverage
Partial Denture Fixed Partial Denture
Partial Denture


Managing Congenitally Missing Lateral Incisors. Part II: Tooth Supported
Restorations. Kokich VO, Kinzer GA. J Esthet Restor Dent. 17(2):76-84,
2005.


2005.

How much space is necessary for the missing lateral
incisor?


2005.

incisor?
1. Golden proportion

• the perceived width of the anterior teeth as viewed
from the direct anterior should have a ratio of
1:0.618 with the tooth adjacent to it. (ex. If central
8mm lateral 5mm)
• Since proportion is derived from “perceived” size of
the teeth from the frontal view there is no relation
to the actual measured widths


2005.

incisor?
1. Golden proportion

• the perceived width of the anterior teeth as viewed
from the direct anterior should have a ratio of
1:0.618 with the tooth adjacent to it. (ex. If central
8mm lateral 5mm)
• Since proportion is derived from “perceived” size of
the teeth from the frontal view there is no relation
to the actual measured widths
2.
Contralateral lateral incisor
• Not suited for patients with missing or peg shaped
contralateral incisor.


2005.

36.6 mm
= 0.78
33.8 mm + X

X = 13 mm/2 = 6.5 mm for each lateral
incisor


2005.

incisor?
3. Bolton Analysis
• Sum of M-D widths of Mandibular anterior teeth/
Sum of M-D widths of Maxillary teeth = 0.78 when
an ideal occlusal relationship is achieved.
• Example: Sum of 6 Md anterior teeth is 36.5 mm,
Sum of 4 Mx anterior teeth is 33.8. To calculate
width of lateral incisor:
36.6 mm
= 0.78
33.8 mm + X

X = 13 mm/2 = 6.5 mm for each lateral
incisor


2005.

incisor?
4. Diagnostic wax-up.
• The most predictable guide for determining ideal
spacing
• The canines should be places in position that will
allow proper anterior disclusion, and the central
incisors incisors should be positioned to provide
optimal esthetics,
• Remaining space (usually b/w 5-7mm) used for the
lateral incisor.


2005.

A. Resin-Bonded Fixed Partial Denture “Maryland Bridge”-
Most Conservative
• Success rate varies widely from a 54% failure rate over
11 months to a 10% failure rate over 11 years, with
debonding the most common cause of failure (Williams et al J
Prosthet Dent 1989, 61:436-441; Priest Int J Prosthodont 1996;9:38-45).

• Speciﬁc criteria must be addressed to ensure optimal
esthetics and long-term predictability:
1. Position of abutment teeth
2. Mobility of abutment teeth
3. Thickness of abutment teeth Anne Arundel County, MD

4. Translucency of abutment teeth
5. Overall occlusion


2005.

A. Resin-Bonded Fixed Partial Denture-
1. Position of Abutment teeth
• Resin-bonded ﬁxed partial dentures placed in a deep
OB relationship have been shown to have a higher
incidence of failure (Creugers NH et al. J Dent Res
1992; 71:1822-1825).
• As the OB increases either the surface area available
for bonding the retainer must decrease or the tooth
must be prepared and the occlusion placed on the
retainer.
• Ideal anterior relationship = SHALLOW OVERBITE


2005.

A. Resin-Bonded Fixed Partial Denture- 1. Position of
Abutment teeth
• Occlusal forces on proclined incisors create a more tensile
type of force at the bond interface
• Wheras the same forces on teeth that are upright generate a
more shear type of force at the bond interface.
• An object loaded with a shear force can withstand 40% more
load prior to failure compared with the same object loaded
with a tensile force (theoretic physics principles)
Tensile Shear


Restorations. Kokich VO, Kinzer GA. J Esthet Restor Dent. 17(2):76-84, 2005.


Restorations. Kokich VO, Kinzer GA. J Esthet Restor Dent. 17(2):76-84, 2005.

2. Mobility of Abutment Teeth
• Mobility is a contraindication for resin-bonded ﬁxed
partial dentures owing to the stress that is placed on
the bond interface when the rigidity of the retainer
works to keep the abutment teeth from moving under
load.
• Although each tooth moves in the B-L direction they
have different vectors because of their position in the
arch.
• Generally, it is the least mobile of the two abutments
that debonds.


2005.

3,4. Thickness and translucency of abutment teeth
• When retainer extensions are carried too coronal, thin
teeth or teeth with a high degree of translucency in
the incisal 1/3 can appear grey due to show through
of the metal retainer.
• Coronal extension of retainer is also inﬂuenced by the
amount of overbite.

Greying of incisal less of an
issue with cerec maryland
bridges?


2005.

5. Occlusal Parafunction
• RBFPD contraindicated in patients with occlusal
parafunction.
The ideal Candidate for a RBFPD has:
• Non-mobile abutment teeth
• Moderately thick abutment teeth
• Have translucency localized in incisal 1/3
• No parafuntion
• Shallow Overbite
• Large interincisal angle (upright incisors)


2005.

B. Cantilevered Fixed Partial Denture –Second most
conservative
• Canine is an ideal abutment given its root length and
crown dimensions.
• Retention and resistance of a partial-coverage
preparation requires the use of pins, thus pulpal size
and location within the tooth must be evaluated.
• If the canine abutment requires a change in the facial
contour to enhance esthetics, a conventional full-
coverage preparation can be done to support the
cantilevered pontic.


2005.

B. Cantilevered Fixed Partial Denture –Second most
conservative
• The KEY to the long term success of the cantilevered
ﬁxed partial denture is managing the occlusion on the
pontic (Decock et al. 1996; Int J Prostho 9:331-340;
Hochman et al.1987; J Prosth Dent 58:542-545)
• Failure to remove all contacts in excursive movements
from the cantilever can lead to:
• loosening of the restoration
• Migration of the abutment
• Fracture


2005.

C. Conventional Full-Coverage Fixed Partial Denture- Least
Conservative
• Treatment of choice when replacing an existing ﬁxed
partial denture or when the adjacent teeth require
restoration for structural reasons.
• Added beneﬁt of being able to control the occlusion
and docclusal forces.
• Not the ideal treatment for replacement of
congenitally missing laterals in young patients.


2005.

Conservative
• Important to evaluate inclination and angulation of
teeth and have abutments aligned along a common
pathway.
• When looking at the patient’s teeth from a frontal
perspective, it is imperative that the long axis of the
central incisor and the labial surface of the canine are
parallel.


2005.

Conservative
• When evaluating at the patient’s teeth from a lateral
perspective, the long axis of the canine and the labial
surface of the central incisor must be parallel.


Managing Congenitally Missing Lateral Incisors. Part III: Single
Tooth Implants . Kokich VO, Kinzer GA. J Esthet Restor Dent 17(4):

202-210, 2005.



202-210, 2005.
Incisors

Single Tooth
Implant?



202-210, 2005.
Incisors
The ideal treatment is the
most conservative (least
invasive) option that satisﬁes
individual esthetic and
Single Tooth
functional requirements.
Implant?


Managing Congenitally Missing Lateral Incisors. Part III: Single Tooth
Implants. Kokich VO, Kinzer GA. J Esthet Restor Dent. 17(4):202-210, 2005.



Single Tooth Implants

Implant Site Development
• When the permanent canine is orthodontically
moved distally, an increased buccolingual
alveolar width is established and it remains
stable over time (Kokich 2004, Int J Oral
Maxillofac Surg 62:48-56.; Ostler MS 1994, J
Prosthet Dent 71:144-149.)
• If the crown of the permanent canine is apical to
the primary canine root, it may be necessary to
selectively extract the primary lateral incisor to
encourage the permanent canine to erupt
adjacent to the central incisor.




• To have adequate room for the development of the
papillae 1.5-2 mm of space is recommended between the
head of the implant and the adjacent teeth (i.e. if space is
7mm than a 3.75mm diameter implant can be placed)
• To place an implant the MINIMUM interradicular distance
is generally 5-5.5mm (small diameter implant with 0.75
mm of bone between the adjacent roots)




• To have adequate room for the development of the
papillae 1.5-2 mm of space is recommended between the
head of the implant and the adjacent teeth (i.e. if space is
7mm than a 3.75mm diameter implant can be placed)
• To place an implant the MINIMUM interradicular distance
is generally 5-5.5mm (small diameter implant with 0.75
mm of bone between the adjacent roots)

When space is opened the crowns of the
central incisor and canine are tipped apart;
however, the roots of these tooth do not
move as quickly.



• It is important to take a PA radiograph of the edentulous
are prior to removing orthodontic appliances to conﬁrm
the ideal root position and adequate spacing for future
implant placement (Spear 1997, Semin Orthod 3:45-72).




• In patients requiring proclination of the maxillary incisors
(Class III skeletal tendency) it may be impossible to
achieve acceptable interradicular spacing using
orthodontics even though the coronal spacing may be
ideal.
• As crowns are tipped labially their roots tend to converge
toward each other “wagon-wheel” effect.




• Because implants can not erupt, if an implant is placed
before a patient has completed facial growth signiﬁcant
occlusal, periodontal, and restorative problems may be
created.
• Best to monitor facial growth by evaluating serial cephs
taken 6 months to 1 year apart (superimpositions).

Missing Teeth

Replacement of missing teeth during and after orthodontic
treatment

Missing Teeth

treatment

Pontic tooth
attached to bracket

Missing Teeth

treatment

Removable retainer
with prosthetic
teeth

Pontic tooth
attached to bracket

Wire stops to prevent
loss of space should the
acrylic teeth become
detached

Missing Teeth

treatment

Removable retainer
with prosthetic
teeth

Pontic tooth
attached to bracket Essix Temporary
Bridge (http://www.oc-
Wire stops to prevent j.com/issue4/p0000033.htm)

loss of space should the
acrylic teeth become
detached

Missing Teeth

Retention and Maintenance of Space

Missing Teeth


Gold coated space
maintainer

Missing Teeth


Gold coated space
maintainer

Wire retained temporary
resin-bonded bridge

The management of congenitally missing lateral incisors h rosenberg

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