View
262
Download
2
Category
Preview:
Citation preview
8/13/2019 Space Maintainer Primary Dentition Final
1/46
Space maintenance in theprimary dentition
Dr. Ola M Omar
Professor of Pediatric Dentistry,Taibah University/ Cairo University
8/13/2019 Space Maintainer Primary Dentition Final
2/46
Lecture outline General considerations
Appliance therapy
Band and loop
Lingual arch
Distal shoe Removable appliances
8/13/2019 Space Maintainer Primary Dentition Final
3/46
Characteristics of normal occlusion in the
primary dentition:At 3y years Spacing between primary teeth
A- Incisor spacing
B- Primate space
C- Spacing between primary molars
Molar relationship
A- Flush terminal planeB- Mesial step
C- Distal step
Normal overbite
8/13/2019 Space Maintainer Primary Dentition Final
4/46
Primate spaceMesial step
Good spacing
8/13/2019 Space Maintainer Primary Dentition Final
5/46
THE THREE TYPES OF TERMINAL PLANES
FLUSH PLANE MESIAL STEP DISTAL STEP
8/13/2019 Space Maintainer Primary Dentition Final
6/46
The premature loss of a primary tooth has adeleterious effect on the occlusion. Proper
management of space problems in theprimary and mixed dentition stages canprevent unnecessary loss in the arch length.
8/13/2019 Space Maintainer Primary Dentition Final
7/46
Effect of premature loss Why is the tooth maintained in its
correct position in the dental arch?
8/13/2019 Space Maintainer Primary Dentition Final
8/46
The rate and extent of mesial or distal drift isinfluenced by the degree of crowding in the
dental arch, the primary tooth extracted andthe age of the patient.
In general the earlier the primary tooth isextracted the greater the opportunity of
drifting of teeth.
8/13/2019 Space Maintainer Primary Dentition Final
9/46
Anterior tooth loss Loss of anterior teeth is due to caries or
trauma
Drifting of anterior teeth and space loss isminimal.
Loss of canine is rare
Reasons for replacement of primary incisors:Space maintenance, function, speech,esthetics.
8/13/2019 Space Maintainer Primary Dentition Final
10/46
Posterior tooth loss Loss of inter-proximal contact as a result of
caries causes space loss
If the first primary molar is lost during activeeruption of first permanent molar, a strongforward force will be exerted on the secondprimary molar which tips into the space
required for the eruption of the firstpremolar.
Premature loss of second primary molar leadsto mesial drifting of first permanent molar
and impaction of second premolar.
8/13/2019 Space Maintainer Primary Dentition Final
11/46
Space maintenance
Process of maintaining space previouslyoccupied by a tooth or several teeth.
8/13/2019 Space Maintainer Primary Dentition Final
12/46
Definition of space maintainer
Appliances used to maintain space created by
premature loss of primary teeth till eruption of
permanent successor or Extraction of
permanent teeth till construction of fixed
replacement
8/13/2019 Space Maintainer Primary Dentition Final
13/46
Requirements of space maintainer
Easy construction & placement
Hygienic , Durable
Prevent abnormal tooth position Maintains mesio-distal and vertical
dimensions of the space.
Does not interfere with tooth eruption.
Does not interfere with natural growth.
Provides esthetics in case of anteriortooth loss.
8/13/2019 Space Maintainer Primary Dentition Final
14/46
Indications for space maintainers(factors affecting placement)
1. Time elapsed since loss
2. Dental Developmental Age
( chronological age?)
3. Amount of bone ( 4-5 monthsto move through 1 mm bone)
4. Degree of root development( if started accelerate eruption)
8/13/2019 Space Maintainer Primary Dentition Final
15/46
5. Sequence oferuption
6. Delayederuption
7. Congenital
absence
If D lost and 2erupting
If E lost and 7erupting before 5
8/13/2019 Space Maintainer Primary Dentition Final
16/46
8/13/2019 Space Maintainer Primary Dentition Final
17/46
Space maintainers for missingprimary molars
Band and Loop space maintainer
Indications
Advantages
Disadvantages
Construction
8/13/2019 Space Maintainer Primary Dentition Final
18/46
Band and loop space maintainer
Indications:
In case of unilateral single tooth loss;
usually the first primary molar or thesecond primary molar after the eruptionof first permanent molar.
Bilateral loss of a primary molar beforethe eruption of permanent incisors
The band is adapted on the tooth distal
to the space.
8/13/2019 Space Maintainer Primary Dentition Final
19/46
Advantages:
Easy to construct.
Inexpensive.
Gives room for erupting permanent teeth.
Does not need patient compliance.
Can be used for very young patients.
Disadvantages:
Does not restore masticatory function.
Does not prevent over eruption of opposing
teeth.
8/13/2019 Space Maintainer Primary Dentition Final
20/46
8/13/2019 Space Maintainer Primary Dentition Final
21/46
5- Adapt a stainless steel wire of 0.7 mm into aloop to fit the band and alveolar ridge. Thelop should paralel edentulous ridge 1 mm off
gingival tissues and contact the distalsurface of the adjacent tooth at the contactpoint. The BL dimension 8 mm to allowpermanent tooth eruption freely.
6- Solder the loop to the band on the stonemodel.
7- Smooth and polish the appliance.
8/13/2019 Space Maintainer Primary Dentition Final
22/46
8- Fit and adjust appliance if necessary.
9- Cement the appliance onto dry clean
abutment with zinc phosphate or glassionomer.
10- Recall every 6 months
The appliance should be constructed andfitted as soon as possible afterextraction.
8/13/2019 Space Maintainer Primary Dentition Final
23/46
Band and Loop space maintainer
8/13/2019 Space Maintainer Primary Dentition Final
24/46
Construction
0.7 mm wire
8/13/2019 Space Maintainer Primary Dentition Final
25/46
8/13/2019 Space Maintainer Primary Dentition Final
26/46
Modifications of band and loop
Bonded spacemaintainer
Construction:Contoured wire bonded with composite.Disadvantage:
1. Breaks easily due to shear forces of occlusion2. Very difficult to adjust
8/13/2019 Space Maintainer Primary Dentition Final
27/46
Modifications of band and loop
Crown and loop appliance
Disadvantage:Failure of the solder and wire break cannot be repaired intra-
orally and necessitates new crown.Alternative :If the abutment tooth requires stainless steel crown it ispreferred to adjust a band and loop space maintainer that fitsthe crown.
8/13/2019 Space Maintainer Primary Dentition Final
28/46
Variations of band and loop
8/13/2019 Space Maintainer Primary Dentition Final
29/46
Distal shoe space maintainer
If the second primary molar is lost beforeeruption of the first permanent molar.
The space maintainer to be used shouldguide the first permanent molar into itsnormal position such as crown or bandmaintainer with distal shoe extension or
intragingival extension. The first primary molar distal to the space is
used as the abutment tooth.
8/13/2019 Space Maintainer Primary Dentition Final
30/46
Contruction
1- Select a band.
2- An alginate impression is taken.
3- If the second primary molar is planned for extractionbut has not yet been removed, it should be cut offthe prepared model. A hole that simulates theposition of the position of the distal root of theextracted tooth is drilled in the model.
4- If the second primary molar has been removedpreviously, the position of the tissue extension maybe determined with dividers and a bite-wingradiograph.
8/13/2019 Space Maintainer Primary Dentition Final
31/46
5- The tissue bearing loop is contoured with awire extending distally then downwards into
the prepared opening on the model (forminga v-shaped extension). The free ends of theloop are soldered to the band.
6- The band and loop appliance is removed
from the model and the v of the tissueextension is filled in and soldered with piecesof gold.
8/13/2019 Space Maintainer Primary Dentition Final
32/46
7- If the second primary molar has previously beenextracted and the extraction site has healed, a knifeedge is formed at the apex of the V-shaped extensionso that it can be forced through the anesthetized
area of the ridge.
8- If it is delivered at the time of extraction, the intra-gingival extension is just polished but not sharpened.
9- Before cementation of the maintainer, a radiograph
of the appliance should be taken to determinewhether the tissue extension is in proper relationshipwith the un-erupted first permanent molar.
8/13/2019 Space Maintainer Primary Dentition Final
33/46
If the first permanent molar un-eruptedDistal shoe space maintainer
8/13/2019 Space Maintainer Primary Dentition Final
34/46
8/13/2019 Space Maintainer Primary Dentition Final
35/46
Disadvantages of distal shoe
Cantilever design therefore fragile
Does not restore occlusal function
Complete epithelialization does notoccur so contra-indicated in medicallycompromised children.
8/13/2019 Space Maintainer Primary Dentition Final
36/46
Lingual arch
It is a bilateral fixed space maintainerindicated in case of multiple teeth loss.
Constructed if the lower permanent incisorsare erupted. In case of presence of primaryincisors a bilateral band and loop is indicated.
Maxillary lingual arch can be used in the
primary dentition.
8/13/2019 Space Maintainer Primary Dentition Final
37/46
There are two types of lingual arch:
Nance
Transpalatal arch
8/13/2019 Space Maintainer Primary Dentition Final
38/46
Transpalatal arch
Bands are adapted to the maxillary firstpermanent molar and wire traverses the
palate without touching it will besoldered to the bands.
Hygenic
Can allow mesial tipping of abutment
8/13/2019 Space Maintainer Primary Dentition Final
39/46
Transpalatal arch
8/13/2019 Space Maintainer Primary Dentition Final
40/46
8/13/2019 Space Maintainer Primary Dentition Final
41/46
Nance appliance
8/13/2019 Space Maintainer Primary Dentition Final
42/46
Removable appliances
Removable partial denture:
Indicated in case more than one tooth are
lost. Stainless steel wire clasps are difficult to
contour for the canines as they do not havelarge undercut.
Stainless steel wire rests for the molars onthe opposite side aid in retention.
Needs compliance thus recommended only in
case of cooperative children.
8/13/2019 Space Maintainer Primary Dentition Final
43/46
Advantages:
It can be easily adjusted to allow for the eruption of teeth.
It restores normal masticatory function and esthetics.
Prevents abnormal speech and tongue habits.Disadvantages:
It is easily broken from a child.
If the appliance is removed from the mouth even for few days,changes in the denture base will occur and drifting of teeth
may make it impossible for the child to replace the applianceunless extensive adjustment has to be done by the dentist.
There is a possibility of the development of new cariouslesions unless proper cleaning of the teeth and denture isperformed.
8/13/2019 Space Maintainer Primary Dentition Final
44/46
Space maintenance for multipleloss of posterior mandibular teeth
8/13/2019 Space Maintainer Primary Dentition Final
45/46
Modified fixed partial denture
8/13/2019 Space Maintainer Primary Dentition Final
46/46
(Pinkham, Ch. 25 page 423-430)
Recommended