MANAGING THE ARCH
CIRCUMFERENCE
Diagnosis and Treatment
Planning
Introduction
• Managing the arch circumference is a
formidable task.
• Decisions are frequently tentative.
• Learning goal is not sophistication; but
basic, foundational knowledge.
• Build on knowledge through electives, postdoctoral education, and practice experience.
Arch Circumference
The distance from the
distal of the second
primary molar (or
mesial surface of the
first permanent molar)
on one side of the arch
to that same surface on
the opposite side of
the arch.
Arch Circumference
It is the space which
during the primary
dentition is occupied
by the 10 primary
teeth, and the space
that will be available
for the eruption of the
10 succendaneous
teeth.
Arch Circumference
• Arch circumference is relatively
unaffected by growth.
• It increases slightly with the
more anterior (procumbent)
positioning of the permanent
incisors on their eruption, but it
decreases as a result of the
mesial migration of the first
permanent molars during the
canine-premolar transition.
(“leeway space”)
Two Goals. . .
in managing the arch circumference
 1.
The arch circumference’s integrity is
maintained in order that the child’s
inherent potential to erupt the
succedaneous teeth in normal arch
alignment is realized.
 2. The succedaneous teeth are assisted in
erupting into as normal an arch alignment
as possible within the constraints of the
size of the arches and the size of the tooth
mass.
Two Problems . . .
in managing the arch circumference
 1. Available
arch circumference may be lost
as a result of pathology, and
 2. A discrepancy
may exist between the size
of the succedaenous teeth and the amount of
arch circumference available.
Physiologic Forces
A tooth is maintained in its correct
relationship by the action of several forces.
An alteration in these forces can alter the
relationship among the teeth.
The Problem of Pathologic
Loss of Arch Circumference
Physiologic Forces
Of primary concern is
the mesial migration
of the first permanent
molar; any mesial
movement, by
definition, reduces
arch circumference.
Primary Causes of Loss of Arch
Circumference
• Extraction of posterior primary teeth due to
pulpal pathology.
• Interproximal caries
Premature Loss of Primary
Tooth (Extraction)
Proximal Caries
Additional Causes of Loss of
Arch Circumference
• Ankylosis of primary tooth
• Ectopic eruption of the first permanent
molar
Anklyosis
Ankylosis
An aberration in the eruption of
teeth in which the continuity of
the periodontal ligament becomes
compromised, with fusion of the
cementum and bone at one or
more locations. Results in the
tooth being “submerged”
relative to the occlusal plane.
Adjacent teeth may tip into
space, resulting in loss of arch
circumference.
Ectopic Eruption
Ectopic Eruption
Eruption of first permanent
molar into the root of the
second primary molar.
Prevalence 2-3% Generally selfcorrecting, but can cause loss of
second primary molar if not
corrected, with first permanent
molar positioning itself
anteriorly, with resultant loss of
arch circumference.
The Problem of Inadequate
Arch Circumference
Inadequate Arch
Circumference
• It is frequently the case that a practitioner
preserves the integrity of the arch circumference
and yet a malocclusion develops due to a basic
discrepancy between the size of the succedaneous
teeth (mesial-distal width) and the amount of arch
circumference available for their eruption.
• This is frequently stated as a “tooth size/arch
circumference discrepancy.”
• Plainly stated, the child’s “teeth are too big for the
size of the jaws.”
Inadequate Arch
Circumference
• The first manifestation of this problem is
when the first succedaneous teeth erupt, the
mandibular permanent incisors.
• They may be crowded, rotated, blocked out,
or in their eruption cause the exfoliation of
one or both of the primary canines; this is
referred to as ectoptic eruption of the lateral
insisor(s).
Ectopic Eruption of Lateral
Incisor
Management of the arch
circumference includes the
management of the inadequacy of its
circumference relative to the size of
the succedaneous tooth mass.
DIAGNOSTIC
CONSIDERATIONS
In Managing the Arch
Circumference
Diagnostic Data Base
• Diagnosis and treatment can be complex,
especially in the mixed dentition.
• A valid data base must be gathered in a systematic
manner.
• Data Base:
– Case History
– Oral Examination
– Radiographic survey
and in the mixed dentition
– Diagnostic Casts and a Space Analysis
Questions To Be Answered
From The Data Base
1. What is the patient’s profile?
2. Has there been premature loss of teeth
and/or does it appear that teeth present
will have to be extracted prematurely?
3. What is the occlusal development?
4. Is there a discrepancy between the
available arch circumference and the size
of the permanent succedaneous teeth?
What is the patient’s profile?
• Important in determining facial growth
patterns
• Can be determined in a preliminary (nondefinitive) manner, that is, without the
exposure of a cephalogram, by clinically
relating the bony aspects of the maxilla and
mandible to one another and the cranial
base
What is the patient’s profile?
This evaluation is accomplished by:
• palpating the basal bone above the roots of
the maxillary incisors -- Point A on a
cephalogram;
• palpating the basal bone below th roots of
the mandibular incisors -- Point B on a
cephalogram;
• palpating the nasal bone -- Nasion on a
cephalogram.
Profile Landmarks
What is the patient’s profile?
• Ideally, the bony landmarks should be in a
direct line relationship with one another, an
orthognathic profile.
• A (developing) skeletal Class II is
characterized by a retrognathic mandible.
• A (developing) skeletal Class III is
characterized by a prognathic mandible.
Orthognathic Profile
1. Cranium
2. Maxilla
3. Maxillary Dentition
4. Mandibular Dentition
5. Mandible
Orthognathic Profile
Retrognathic Profile
Prognathic Profile
Viewing Profile
What is the patient’s profile?
• In the mixed dentition, children with a developing
retrognathia or prognathia should be referred to a
specialist for consultation in the context of the generalist
managing the arch circumference, as management of the
arch circumference exists in the context of a larger skeletal
problem. However, it is generally always advisable to
maintain the integrity of the arch circumference, even in
the context of an overarching skeletal problem.
• Space management by the generalist alone is most
appropriate and successful in the patient with an
orthognathic profile.
Has there been premature loss of
primary teeth and/or does it appear that
primary teeth present will have to be
prematurely extracted?
• Which teeth? Arch circumference loss is greater with
second primary molars that with first primary molars.
• Has there already been loss of arch
circumference? If not, management man involve
simple maintenance of available space. In instances where
you remove a tooth and all other factors indicate a need for
space maintenance, the appliance should be placed
immediately. Watchful waiting for space closure
following extraction is never indicated!
Premature Loss?
• If space loss has already occurred:
– What is the magnitude of the loss? If it proves
to be necessary to regain lost arch
circumference, different appliances are used
depending on the magnitude of the loss.
– Is there still adequate space remaining to
permit eruption of the succcedaneous tooth? If
so, regaining lost arch circumference may be
unnecessary.
Premature Loss?
• Is it possible that additional arch circumference
could be lost? Space closure following extraction of
primary molars is generally related to the position and
eruption of the first permanent molar. In the late mixed
dentition it may be more related to the position and
eruption of the second permanent molar. Because of this,
space loss may be immediate or delayed. However, it is
generally found that significant amounts of space loss will
occur within the first six months following extraction.
Additional increments of loss may occur at periods
associated with the eruption of the permanent molars.
Premature Loss?
• Is the succedaneous tooth present? The congenital
absence of the succedaneous tooth (or teeth) may affect
your decision of how to manage the available arch
circumference. The second premolars are common
congenitally missing teeth. An evaluation of the presence
or absence of this tooth is an important consideration. The
second premolar is also highly variable in the initiation of
its calcification. Formation can begin as late as 8 years of
age, so be wary of jumping to conclusions.
Premature Loss?
• When can the eruption of the succedaneous
tooth be expected? The chronologic age of the patient
is not as important as the developmental age. Average
eruption dates must not influence decision regarding the
construction of a space maintainer; there is too much
variation in the time of eruption of teeth. Gron found that
the premolar teeth erupt when approximately 3/4 of the
root is developed, regardless of the child’s chronologic
age. Another factor in predicting tooth emergence is the
amount of bone overlying the permanent tooth. Again,
Gron found that the eruption of the permanent successor is
accelerated if that permanent tooth had penetrated from the
bone prior to the extraction of the primary tooth.
Eruption of the tooth may be retarded if there is still
considerable bone overlying the succedaneous tooth.
Frequently primary molars are extracted due to chronic
pulpal pathology. This pulpal infection may have resulted
in considerable resorption of the alveloar bone overlying
the succedaneous tooth. In this situation, emergence of the
tooth is accelerated. In some instance the tooth may erupt
with a minimum of root development. Generally, early
extraction of primary molars, before age 9, will retard
eruption of the premolars, and late extraction, after age 9,
will accelerate their eruption.
What is the status of occlusal
development?
• Have the first permanent molars erupted and are
they in occlusion?
After their eruption there is considerable dissipation of the
strong mesial vector of force that has been active until this
time; this affects treatment planning decisions. For
example, after the eruption of the first permanent molar it
is generally not necessary to place a space maintenance
device when premature loss of the first primary molar
occurs. However, in the mandible, there can be distal
drifting of the primary canine, which can permit a shift in
the midline.
What is the status of occlusal
development?
• Are the mandibular permanent incisors erupted?
The eruption of the mandibular incisors provides an initial
impression as to whether a significant discrepancy exists
between the size of the succedaneous teeth and the
available arch circumference; this is due to the “incisor
liability.” After the eruption of the mandibular incisors it
is also possible to perform a space analysis, a basic
diagnostic aid in managing the arch circumference in the
mixed dentition. Once the mandibular incisors have
erupted, and there is any question regarding the adequacy
of the arch circumference, space analysis is indicated
before placing any space management appliance.
What is the status of occlusal
development?
• What is the molar relationship, canine
relationship, overbite, and overjet? These
evaluations help to support or reject the presence of dentoskeletal malocclusions that would require the supervision
of a specialist. The presence of a Class I or end to end
molar, relationship; Class I canine relationship and with an
overbite and overjet of 2-3mm supports a preliminary
evaluation of an orthognathic skeletal relationship. This
evaluation is foundational to managing the arch
circumference for a general practitioner of dentistry.
Is there a discrepancy between the
available arch circumference and the
size of the permanent succcedaneous
teeth?
• This determination is made by performing a space analysis.
• Arch circumference is adequate when sufficient space
exists around the arch, from one first permanent molar to
the contralateral one to accommodate the succedaneous
teeth without crowding (broken contacts and rotations),
and without excessive protrusion of the teeth and alveloar
process. Absent such the arch circumference is inadequate.
Is arch circumference adequate?
• To determine adequacy:
– the amount of space available for the succedaneous
teeth is measure on diagnostic casts.
– The erupted permanent teeth are measured and the size
of the unerupted permanent teeth predicted from a
prediction table. This provides the total amount of
succedaneous tooth mass to be accommodated in the
arches.
– A comparison of these two figures permits an
assessment of the overall adequacy or inadequacy of
the arch.
TREATMENT
ALTERNATIVES
In Managing the Arch
Circumference
Four Alternatives
• MAINTAIN SPACE
– By means of appliance therapy provide for the maintenance of the
arch circumference present at the time of examination.
• REGAIN SPACE
– By means of active appliance therapy attempt to regain arch
circumference (space) which was at one time available but has now
been lost for whatever reason
• CREATE SPACE
– By a more sophisticated application of knowledge of the
developing occlusion and/or by application of biomechanically
active appliance therapy increase the amount of space available for
the teeth as they erupt and possibly increase overall arch
circumference.
• ELIMINATE SPACE
– Through extraction of permanent teeth with the subsequent closure
of excess space, resolve sever discrepancies between tooth size and
arch circumference.
TREATMENT DECISIONS
For Space Management in the
Primary Dentition
Treatment Planning
Primary Dentition
• Decision making regarding space management is not as
challenging in the primary dentition as it becomes later in
the mixed dentition.
• This is due to a meager data base.
• At this stage of development it is difficult to ascertain the
existence of a tooth size/arch circumference discrepancy,
and generally dento-skeletal malocclusions are not
identifiable at this time.
• Because of these diagnostic constraints, maintenance or
preservation of the available space is accomplished should
a primary tooth be lost prematurely.
Treatment Planning
Primary Dentition
• It must be emphasized that space
maintenance in the primary dentition may
well not be definitive treatment.
• Significant alteration in treatment rationale
and appliance therapy may be necessary
after entering the period of the mixed
dentition when more information is
available to add to the data base.
Parental Understanding
• It is critically important to inform the parents of
the lack of definitiveness of a space maintenance
protocol in the primary dentition.
• Many parents develop the erroneous idea that a
space maintainer placed during the preschool
years precludes the development of a
malocclusion in later years.
• When practitioner and parent are both aware of the
purpose or objective to be achieved by the
placement of an appliance, misunderstandings can
be avoided.
Treatment Planning
Primary Dentition
As a general rule, loss of a primary molar
during the period of the primary dentition
requires the placement of a space
maintainer in all instances.
Treatment Planning
Primary Dentition
• Unfortunately, a not insignificant number of general
practitioners are guilty of extracting primary teeth and not
advising the parents of the imperative of space
maintenance to preserve the arch circumference.
• This is an ethical issue; for in failing to provide for space
maintenance when arch circumference will be reduced is
doing harm to the patient.
• Of course, a practitioner cannot force a parent to pursue
space maintenance, however failure to inform, educate,
and attempt to persuade must be considered a moral
failing; such is below the standard of care for the
profession.
Treatment Planning
Primary Dentition
Three appliances are used to maintain the
available arch circumference in the primary
dentition:
– Band and loop
– Intra- alveolar or distal shoe
– Removable acrylic appliance
Band and Loop Space
Maintainer
Band and Loop
• The band and loop is used to maintain
space subsequent to the loss of the first
primary molar.
• The band is attached to the second primary
molar and the loop extends to the distal of
the primary canine.
• This effectively reserves the space that is
available for the eruption of the first
premolar.
Band and Loop
• After the child enters the mixed dentition and more
diagnostic information becomes available (specifically, the
results of a space analysis) the decision to maintain the
space must be reevaluated.
• If it is determined at that time that the space should be
maintained the band and loop can continue to function.
• It can be removed when the eruption of the first premolar
has begun, or when it is determined that no space loss
would occur if it were removed, for example, after the
complete eruption and intercuspation of the first permanent
molar.
Intra-Alveolar
(Distal Shoe)
Intra-Alveolar
(Distal Shoe)
• The intra-alveolar or distal shoe space maintainer is indicated
following premature loss of the second primary molar and prior to the
eruption of the first permanent molar.
• The abutment tooth is the first primary molar with a wire extending
distally to the mesial aspect of the unerupted molar and extending
gingivally to contact the mesial surface of the permanent molar.
• The gingival extension provides a surface along which the first
permanent molar can erupt.
• Subsequent to the eruption of the molar at age 6, an alternative
appliance (lingual arch) must be placed.
• Employment of a distal shoe dictates the employment of 2 appliances
to maintain space until the eruption of the second premolar, at age
10-12.
Removable Acrylic Space
Maintainer
Removable Acrylic Appliance
• A removable acrylic appliance is required
should multiple posterior teeth be lost in
one quadrant.
• Extraction of both the first and second
primary molars in one arch would prevent
the utilization of either a band and loop or a
distal shoe.
Removable Acrylic Appliance
• Unless absolutely dictated by the
circumstances, removable acrylic
appliances should not be utilized for three
reasons:
– their success is too dependent on the child’s
cooperation and compliance.
– their ability to maintain the space for which
they were designed is sometimes questionable,
– children tend to break and/or lose them.
Treatment Planning
Primary Dentition
• In cases where there is bilateral loss of a single tooth it is
preferable to fabricate and place two unilateral appliances
than to place one bilateral one.
• For example, a lingual arch placed on the second primary
molars would interfere with the eruption of the permanent
incisors.
• Additionally, there is some growth in arch width with the
eruption of the permanent incisors, and no appliance
should be placed that would restrict this.
Treatment Planning
Primary Dentition
• The need to place a space maintainer in the
anterior part of the arch during the primary
dentition is an area of some uncertainty and
controversy.
• There is a question as to whether there is actual
loss of arch circumference or merely shifting of
the anterior teeth in the available space.
• It can be stated that premature loss of anterior
teeth does not pose as great a problem as loss of
primary posterior teeth.
Treatment Planning
Primary Dentition
• It has been argued that if the anterior tooth is lost
before the permanent teeth have developed their
mesio-distal width so as to maintain the arch
dimension, space closure and actual loss of arch
circumference may occur.
• This would be the case in primary incisors loss
before age 3.
• The presence of spacing among the anterior
incisors is a further consideration; if spacing is
present, there is little chance that space loss will
occur with the removal of teeth.
Treatment Planning
Primary Dentition
• Should anterior space maintenance be necessary,
the anterior fixed esthetic appliance best suits the
design requirements.
• This appliance may also be used in situations were
space loss is not considered a problem but where
the parents are concerned about esthetics.
• It may also be employed when the practitioner is
concerned that multiple missing anterior teeth may
contribute to the development of a deleterious oral
habit.
Fixed Anterior Esthetic
Appliance
TREATMENT
DECISION MAKING
For Managing Space Problems in
the Mixed Dentition
Treatment Planning
Mixed Dentition
• Treatment decision making during the
mixed dentition is more complex.
• Primary dentition - basically a decision to
maintain space
• Mixed dentition - decision is to maintain,
regain, create, or eliminate space.
Learning Objective
Mixed Dentition
• To enable the student dentist to conceptualize the broad
issues of space management, and to understand, in at least
a preliminary manner, the strategies of space regaining,
creating, and eliminating in the mixed dentition.
• Detailed discussions of active appliance therapy and the
role of the generalist with the specialist, will be a
component of the orthodontics curriculum.
• Space maintaining and regaining generally fall under the
purview of the generalist, whereas creation and
elimination of space are typically accomplished in
consultation with a specialist.
BASIC PREREQUISITES FOR
MANAGING ARCH CIRCUMFERENCE
IN THE MIXED DENTITION
• Profile is orthognathic
• Relationship between the maxillary and mandibular
dentitions is normal as evidenced by molar relationship,
canine relationship, overbite, and overjet
This does not mean that the various management
procedures to be discussed are not, or should not be
utilized, only that absent the above prerequisites, there
is likely an underlying malocclusion that simple
management of the arch circumference in one plane of
space one not resolve. Referral to a specialist competent
to treat the case comprehensively is indicated.
Maintaining Arch
Circumference
Indications:
(Mixed Dentition)
• premature loss of the second primary molar
• premature loss of the first primary molar, but only if the first permanent
molars are not in a Class I relationship
• succedaneous tooth present and it appears it eruption will be delayed.
• no loss of arch circumference has occurred
• adequate arch circumference exists for the eruption of the succedaneous teeth
as determined by a space analysis
• Profile is orthognathic
• Relationship between maxillary and mandibular dentitions is normal as
evidenced by molar relationship, canine relationship, overbite and overjet.
• Space maintenance may be indicated even if some of the indications are
not met. However, consultation with a specialist would be indicated as
additional, more complex treatment, may be required.
Maintaining Arch
Circumference
(Mixed Dentition)
Appliances Utilized:
• Mandibular Arch - Lingual Arch
• Maxillary Arch - Palatal Arch
Lingual Arch
Lingual Arch
Nance (Palatal) Arch
Nance (Palatal) Arch
Maintaining Arch
Circumference
(Mixed Dentition)
• The utilization of these “full arch” appliances emphasizes the concept
of maintaining the integrity of the arch circumference rather than
individual tooth spaces.
• Single tooth appliances, such as a band and loop, are generally not
appropriate in the mixed dentition due to the eruption sequence of
teeth.
• For example, a band and loop extending from the first permanent
molar to the first primary molar would lose its anterior abutment, the
first primary molar, prior to the eruption of the succedaneous tooth, the
second premolar. The mesial component of force with the erupting
second molar could force the first permanent molar forward reducing
arch circumference and compromising the space for the second
premolar.
Regaining Arch Circumference
Mixed Dentition
Indications:
• Unilateral or bilateral missing second primary molars with mesial
tipping of the first permanent molar
• Succedaneous tooth is present
• Space analysis indicates adequate arch circumference exist for
succedaneous teeth with the exception of the localized inadequacy in
the quadrant(s) where the regaining is planned.
• Localized inadequacy is less than 4 mm
• Profile is orthognathic
• Relationship between maxillary and mandibular dentitions is normal as
evidenced by molar relationship, canine relationship, overbite and
overjet.
• Space regaining may be indicated even if some of the above
criteria are not met. However, consultation with a specialist would
be indicated, as more complex treatment may be required.
Regaining Arch Circumference
Mixed Dentition
• Regaining arch circumference is not
particularly complex and the prognosis is
good.
• The objective is simply to regain arch
circumference that has been lost; for
example, by distalizing first permanent
molar(s) that have migrated mesially
subsequent to the premature loss of
posterior primary teeth.
Regaining Arch Circumference
Mixed Dentition
Appliances used:
Amount to be gained
Mandible
Maxilla
0-2 mm
helical spring
loop lingual arch
split saddle
helical spring
headgear
jackscrew
2-4 mm
sling shot
split saddle
lip bumper
split saddle
headgear
jackscrew
Loop Lingual Arch
Loop Lingual Arch
Head Gear
Jackscrew Appliance
Jackscrew Appliance
Helical Spring Appliance
Helical Spring Appliance
Slingshot Appliance
Split Saddle Appliance
Creating Arch Circumference
Mixed Dentition
Two Definitions:
1. Increasing the arch circumference by moving the
first permanent molars distally and/or advancing
the incisors labially. Limited by the extent can be
accomplished without having a deleterious effect
on the periodontium of the incisors, on the profile,
or on the eruption of the second permanent molar
.
Creating Arch Circumference
Mixed Dentition
2. Also refers to selectively stripping enamel from
the primary teeth and/or selectively removing
primary teeth to allow a more favorable eruption
path for the permanent tooth. This is variously
called “space supervision or eruption guidance.”
This type of guidance can often prevent rotated
incisors, blocked out canines, and cross-bite
positions of the premolars. It does not create
additional arch circumference per se, but it
does provide for additional space in an area
where such is required at a given point in time.
Creating Arch Circumference
Mixed Dentition
Indications:
• Crowding of the permanent incisors; or early loss of the
primary canine unilaterally or canines bilaterally, as a
result of ectopic eruption of the lateral incisors
• Space analysis that demonstrates a moderate generalized
tooth size/arch circumference discrepancy of 4 mm or less
in the arch.
Creating Arch Circumference
Mixed Dentition
• Typical appliance therapy might consist of using a headgear in the
maxillary arch to distalize the first permanent molars, and a loop
lingual arch in the mandibular to advance the incisors.
• If the discrepancy is small, 1-2 mm, it may be possible to provide
additional space in the anterior region to permit favorable alignment of
the permanent incisors by selective stripping of the primary canines
and/or sequential extraction without employing active appliance
therapy. The option for ‘creating space’ in this manner is due to the
existence of the leeway space; essentially borrowing space from the
posterior for the anterior. Another way of saying it is using the leeway
space to overcome incisor liability.
Leeway Space
Nota Bene
Remember that the
majority of the leeway
space is ‘housed’ in the
primary second
molar/second premolar
differential.
Creating Arch Circumference
Mixed Dentition
Typical space creation protocol:
• Removal of primary canines to allow for the alignment of the
permanent incisors. One of the incisors may have been lost due to
ectopic eruption of the lateral inciosr. Should this have occurred,
extraction of the contra-lateral canine should be accomplished to
preserve the midlines.
• Placement of a lingual arch. Failure to place a lingual arch will result
in the incisors positioning themselves lingually. This will close the
canine space and shorten the arch circumference.
• Removal of first primary molar and stripping of mesial surface of
second primary molar. This is accomplished when it appears the canine
cannot erupt normally; thus allowing the canine to erupt distally.
• Removal of second primary molar when the first premolar is erupting
to allow room for its eruption.
• Removal of the lingual arch after eruption of the second premolar.
Lingual Arch
Creating Arch Circumference
Mixed Dentition
This protocol is employed when the first
permanent molars are in a Class I molar
relationship. If the first permanent molars
are in an end to end relationship, then the
maxillary molars may be distalized in order
to create additional space in the maxilla,
and a Class I molar relationship.
Eliminating Arch
Circumference
Mixed Dentition
• If the arch discrepancy is large, 4 mm/quadrant
(8mm/arch), it is unlikely adequate arch circumference
can be created by the aforementioned methods, or even
potentially by functional appliance therapy or multibanded therapy. Therefore, it is often necessary to extract
permanent teeth, usually four premolars, to allow the
remaining teeth to achieve a normal occlusion. This course
of therapy should only be taking in consultation with a
specialist or referral to one.
• Space elimination is also referred to as serial extraction.
Eliminating Arch
Circumference
Mixed Dentition
Space elimination would be considered, in consultation
with an specialist, when the following criteria are met:
– Arch circumference discrepancy of at least
4 mm/quadrant, as determined by space analysis
– Profile is orthognathic
– Relationship between maxillary and mandibular
dentitions is normal as evidenced by molar relationship,
canine relationship, overbite and overjet.
Eliminating Arch
Circumference
Mixed Dentition
The following protocol is one generally followed, in consultation with a
specialist; there are alternatives depending on a variety of conditions
and objectives:
– Extract of mandibular first primary molar when 1/3 of root of the
mandibular first premolar is formed.
– Extract maxillary first primary molar when mandibular first
premolar emerges
– Extract mandibular first premolar when it has erupted to the
approximate height of its clinical crown. It is unwise to extract it
earlier because its eruption forms alveolar bone at the site where
the canine will eventually move.
– Extract the maxillary first premolar when it is fully erupted.
COMMUNICATION SPACE
MANAGEMENT TO THE PARENT
As with any procedure or protocol with children, it is
imperative that the parent understand the goal(s) of
treatment, treatment alternatives, advantages or benefits
versus disadvantages or risks; prognosis and the financial
investment required. These are also the elements of an
informed consent, which the parent must provide for the
minor child. This information should be discussed
interactively with the parent(s), but also documented in
written form, such as in the Parent’s Notes, as previously
discussed.
COMMUNICATION SPACE MANAGEMENT
TO THE PARENT
As we will primarily be providing space maintenance therapy in pediatric
dentistry, the following are statements appropriate for the Parent’s Notes:

“There is enough space for all the way the permanent teeth and the
manner in which the teeth meet is acceptable. The space maintainer be
placed will probably be the only appliance required.”

“There are additional problems with the way the teeth and jaws relate,
and the space maintainer alone will not resolve the problem. It will
maintain space, but further, more definitive treatment will be required
later.”

“The space maintainer being placed will need to be replaced with a
different type of space maintainer when the permanent incisors and first
molars have erupted.”

“A slight amount of space loss has already occurred, and the space
maintainer will prevent the problem from worsening.”

“A space analysis cannot be done yet, and the space maintainer will be
placed until this can be accomplished at about age 7; only then can a
more definitive diagnosis be established.”