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Before
figure16a |
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Treatment of the different amelogenesis
imperfecta types depends on the specific AI type and the character
of the affected enamel. Treatments range from preventive care using
sealants and bonding for esthetics to extensive removable and fixed
prosthetic reconstruction. The treatment approach should ideally
be developed considering the specific AI type and underlying defect.
For example, while bonding may be very effective for restoring teeth
with hypoplastic types of AI, the forms with hypomineralization
and weak enamel (hypocalcification, hypomaturation) may not be amenable
to procedures relying on bonding to the enamel as the sole source
of retention. AI types with hypomineralized enamel are prone to
enamel fracturing and rapid wear making them poor candidates for
conservative restorative approaches or bonding procedures. Extreme
dental sensitivity to thermal, chemical, and mechanical stimuli,
commonly seen with hypocalcified and hypomaturation AI, may require
early treatment with full dental coverage so the individual can
masticate and perform appropriate oral hygiene procedures adequately.
Treatment in AI types with severely affected enamel will typically
require multiple phases to maintain form, function and esthetics
in the primary dentition (2-6 year olds), early mixed dentition
(6-11 year olds) and permanent dentition (11 and older). Initial
restorative care in severe forms of AI should begin in the early
primary dentition to prevent excessive sensitivity, protect the
dentition, and allow for maintenance of a functional occlusion.
Consideration must be given to the dental, esthetic, psychological,
skeletal, and functional factors when developing a treatment approach.
Correction of the diverse dental and skeletal manifestations associated
with the different AI types can require intervention from multiple
dental disciplines. For example, the general or pediatric dentist
may be involved with restorative therapies in the early primary
dentition and early mixed dentitions while complex restorative therapies
in the adolescent or adult will often be best accomplished by a
general dentist or prosthodontist. Although many malocclusions may
be managed by orthodontics alone, the severe skeletal open bites
often associated with AI may require both surgical and orthodontic
intervention. Active dental intervention of the complex AI patient
may, therefore, span several decades including both the primary
and permanent dentition and may involve numerous dental specialties.
Treatment
of Hypoplastic AI Types |
figure13a
figure13b |
| Therapy for the hypoplastic AI types
typically involves the use of bonding procedures to protect
the malformed teeth from caries and improve esthetics. Hypoplastic
teeth usually have reasonably well mineralized enamel, albeit
thin and/or pitted, making them suitable for restorative therapies
involving bonding to the enamel (Figure 13a and 13b). Composite
resin or porcelain veneers can be bonded to the anterior teeth
when the incisor shape, size and/or color requires modification.
Orthodontic therapy may be used to partially close the interdental
spaces (space between teeth) prior to restoration in those individuals
having small square shaped incisors (due to the thin enamel)
and interdental spacing that is too excessive to close with
restorative therapy alone. Individuals with hypoplastic AI often
can retain intracoronal restorations such as amalgams (silver
fillings) and composite resins (tooth colored fillings), however,
if the enamel is extremely thin and malformed the teeth can
require full dental coverage with crowns. |
Treatment
of Hypomaturation and Hypocalcified AI Types |
figure14
figure15a
figure15b
figure16a
figure16b |
| The hypomaturation and hypocalcified AI types
can be restored with conventional approaches if the enamel
is not severely involved. Bonded restorations may be successful
in some cases depending on the enamel mineral content and
strength. In hypocalcified and hypomaturation AI types where
the enamel is severely hypomineralized and of insufficient
strength to retain bonded or intracoronal restorations, full
coverage restorations should be placed. In cases of severely
hypomineralized enamel, stainless steel crowns are indicated
in the primary and early permanent dentitions.
Esthetic anterior restorations can be made using a variety
of techniques. Open face stainless steel crowns with composite
inserts (Figure 14) or composite crowns (Figure 15a and 15b)
that are retained both by mechanical undercuts and bonding
can greatly reduce tooth sensitivity and provide reasonable
esthetics. The dentist should not rely on retention from bonding
alone in those cases with very weak and poorly mineralized
enamel. Resin crowns can be placed on permanent incisors soon
after they begin to erupt during the mixed dentition (about
age 7 – 10 years). As the gingival margin becomes exposed
during continued tooth erupt the resins are easily modified
by adding resin to the gingival margin of the tooth.
Ultimately, porcelain fused to metal or other custom fabricated
crowns can be placed on the dentition. This may be delayed
until late adolescence or early adulthood when all the teeth
are present, the teeth are fully erupted, and the gingival
height around the teeth has stabilized. While costly, these
types of restorations can allow even severely affected dentitions
to be treated and achieve excellent function and esthetics.
The severely afftected individual shown in Figures 16a and
16b had AR Hypomaturation AI and was treated over several
years with stainless steel crowns, orthodontics, orthognathic
surgery and eventually porcelain fused to metal crowns to
achieve this excellent result. |
Treatment of Dental Malocclusions
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figure18
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Malocclusions can be managed using a variety of techniques
depending on the character and severity of the problem. The
prevalence of skeletal open bites ranges from about 25-35%
of people [16-19] with AI
(Figure 17). It appears to occur more commonly with the hypomaturation
and hypocalcified AI types [18].
It is variable in affected individuals even within the same
family having the same type of AI. The cause of skeletal open
bites in AI has been proposed to result secondarily to the
severe sensitivity and jaw posturing or due to affects of
the mutant gene in tissues other than the ameloblasts. The
reason skeletal open bite occurrs with an increased frequency
in people with AI compared with the general population remains
unknown.
Treatment of malocclusions will typically involve traditional
orthodontic treatment using “braces”. Braces are
most often placed using bonding. However, in AI cases where
all the teeth are covered with crowns, the orthodontic brackets
can still be placed using orthodontic bands. In severe cases
of skeletal open bite, orthognatic surgery (jaw surgery) can
be required to achieve a more optimal alignment of the jaws
and teeth [20, 21]. This treatment
is usually not performed until the child has completed growing
(late adolescence). The young lady in Figure 18 is seen before
and after orthognathic surgery showing the excellent result
that can be achieved using this procedure. |
Gingival Health Management in AI
Excessive calculus formation occurs in some AI types and is most
severe in the hypocalcified and hypomaturation types (see
Figure 16a). Calculus deposits may be extensive and grow to
such proportions on the anterior teeth so as to obscure the dentition
and produce tremendous soft tissue inflammation. The factors contributing
to the development of these calculus deposits can include a rough
enamel surface prone to deposits, altered salivary flow rate and/or
composition, decreased oral hygiene abilities due to dental sensitivity,
and altered oral microflora. Regardless of etiology these deposits
form very rapidly on some restorative materials, such as composite
or stainless steel, but appear to have a lower affinity for glazed
porcelain. Individuals with rapid calculus formation may require
more frequent recall appointments and professional scaling to control
these deposits and maintain gingival health. Dentifrices developed
to assist in controlling calculus formation could prove beneficial
in AI patients with excessive calculus formation although this has
not been clinically evaluated.
Prior to restorative treatment it is important to have optimal
gingival health. Gingivitis and bleeding gums makes placement of
bonded and esthetic restorations extremely difficult. Preventive
interventions, such as professional cleaning, the use of antimicrobial
oral rinses (e.g. chlorhexidene), and excellent oral hygiene, help
to achieve healthy soft tissue prior to and after restorative care.
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