space management in deciduous teeth

Space management2017-2018

Problem??

loss of 1ry or permanent teeth loss of arch integrity loss of space & arch length circumference

Migration of 1ry &/or permanent teeth available space crowding in permanent dentition

Growth of the dental arches

A) Maxilla B) Mandible

**Types of spacing between the primary dentition are classified into:

i- Generalized spacing

ii- Primate spacing

iii- Lee way spacing

Generalized spacing• Anteriorly , sometimes posteriorly

primate spacing• Distal to mand. 1ry canines• Mesial to max. 1ry canines

Lee way spacing• For maxilla 0.9 unilaterally• For mandible 1.7 unilaterally

Types of spacing between the primary dentition

Arch Length (perimeter)is the distance between the mesial surface of 1st permanent molar on a side to the mesial surface of the 1st permanent

molar on the other side of the arch , over the contact points of the posterior teeth and incisal edges of the anterior teeth.

SIGNS OF DIFFERENT TYPES OF DENTITION

Type of dentition

Signs

Not crowded ( excess space)

Spacing between incisorsSpace available < required

Not crowded ( just sufficient space)

Normal contacts between incisorsSpace available = required

Mild crowding Slight overlapping of incisorsSpace available in arch up to 4mm less than that required

Severe crowding Overlapping .rotation or displacement of incisorsSpace available in arch over 4mm less than that required

1 -Nance analysis

2- Moyers mixed dentition analysis ( ballard wylie analysis )

3- Johnston and tanaka analysis

4 -Hixon & Oldfather

5 -Kaplan, Smith & Kenarkf

6 -Bishara & staely

Arch Length Analysis

1 -Nance analysis:

-AimDetermine whether the dental arch will accommodate the permanent teeth or not.

-Materials needed:* sharp divider* a set of periapical films * millimeter ruler* brass wire 0.026 inch* card of 3x5 cm for recording measures * a set of study models

-Procedure:1- X-ray films for the areas of unerupted canine & premolars.2- Study models for measurements.3- By means of sharp divider we measure:

- the individual mesio-distal width of the perament centrals & laterals from models- the individual mesio-distal width of the perament canine , 1st & 2nd premolars from x-rays- both measurements give the required space for accommodation of all permanent teeth anterior to 1st permanent molar.

4- By means of the brass wire we contour the arch on the model from mesial surface of 1st permanent molar on one side to that of the other side.

From the measurement of the arch length in mixed dentition we subtract:

Lower arch -3.4 mm ( 1.7mm x2 ) upper arch -1.8 mm ( 0.9mm x2 )

So this is the amount by which the arch length may be expected to decrease as a result of mesial drifting of the 1st permanent molar.

Compare between required space & available space:

Required = available arch length adequate Required > available crowding Required < available spacing

2-Moyers mixed dentition analysis: -The analysis is based on the theory that there is some type of harmony between the size of the incisors canines and premolar.- Predictographes: in which mandibular incisors chosen ( as

they erupt first ) , used to predict the size of upper as well as lower posterior teeth

- Measure mesio-distal width of each mandibular incisor separately then these measurements are added together , and by the means of predictographs we find the predicted size of permanent teeth more commonly in the 75% range.

**Advantages:

1 -can be completed in the mouth as well as on the casts.

2 -may be used for both arches.

3-Johntson and Tanaka analysis:

- Is a variation of Moyer’s analysis where the predictographs are not needed. * The sum of widths of mandibular permanent incisors is measured & divided by 2 ** for the lower arch add 10.5 mm to the result *** for the upper arch add 11 mm to the result **** The total is the estimated widths of canines & premolars- Then compare the tooth mass prediction with the total measured arch length to obtain inadequacies in arch length.

4 -Hixon & Oldfather: -They measured mesiodital widths of unererupted bicuspids on x-ray

film & then added to them size of lower permanent incisors from casts. -Result is termed “measured value” which is used to determine

“estimated value” from their prediction charts.

5 -Kaplan, Smith & Kenarkf: -They modified Hixon & Oldfather method by excluding lower

incisors. -To overcome Hixon-Oldfather overprediction they suggested

adding : 0.3 mm to value < 20 mm

0.4 mm to values 20-22 mm0.5 mm to values 23 mm & above

6-Bishara and staely:-This is the most recent and most universally used method

Space maintaining decision

Factors affecting decision of space maintaining

• Time elapsed since loss of primary tooth

Factors affecting decision of space maintaining

• chronological age Vs. dental age

Factors affecting decision of space maintaining

• Amount of bone covering the unerupted tooth

Factors affecting decision of space maintaining

• Delayed eruption of the permanent tooth

Factors affecting decision of space maintaining

• Congenital absence of permanent tooth

Factors affecting decision of space maintaining

• Presentation of problems to the parents

Space maintainer Definition, requirement

Definition* It is an artificial replacement for a prematurely lost primary tooth or teeth;

* It is main function is to preserve the space until the eruption of permanent teeth.

General requirements 1. It should maintain the entire

mesio-distal space created by a lost tooth.

2. It must restore the function as far as possible

General requirements ..3. It should be esthetically pleasing

in case of ant teeth loss

4. prevent over-eruption of opposing teeth.

General requirements ..

5. It must permit maintenance of oral hygiene.

6. It must not restrict normal growth & development

Space maintainer classification

Classification of space maintainers

According to means of retention:• fixed• removable

According to function• functional (Partial denture)• non-functional

According to force• active (space regainer)• passive

According to area

Fixed space maintainers

Advantages 1. Under control of dentist 2. Minimum fracture3. More hygienicDisadvantage 1. not restore function2. Not restore ethetics3. Needs good patient recall system

Band and loop

Crown and loop band

Crown with distal shoe extension

Passive lingual arch

Nance holding appliances

Trans palatal arch

Removable space maintainersAdvantages 1. Restore function2. Aesthetically betterDisadvantage 1. Need cooperation2. Easy breakage3.less hygienic

Acrylic partial denture

According to Area1- space maintainers for the 1st

primary molar area1 -Band and loop maintainer:

Fixed - passive - non functionalMost common SM to maintain space of a single tooth

.Advantages .Disadvantages*Ease of construction *not restore function

*low cost *not prevent over eruption *give room for erupting * cement dissolution..

caries Permanent tooth

Construction of band and loopA) indirectB) direct

2 -stainless steel crown and loop maintainer

Indications1 -extensive caries in posterior abutment

2 -vital pulp therapy in the posterior abutmentN.B the loop may be cut off after eruption of the successor leaving the crown to serve as a restorationDisadvantages:Hard to make adjustements in the loop ,so adapt band and loop ovet a cemented crown is recommended

S.M for 2nd 1ry molar

Eruption 1st perm. molar

Band & loop

Crown & loop

Loss of 2nd 1ry molar before eruption of the 1st perm. molar

Acrylic plate S.M

I. Band & loop / Crown & loop

1. 1st 1ry molar prep. & crown is contoured2. Alginate imp. Whlie the crown ( or band ) is put on the abutment tooth . 3. the crown ( or band ) removed from the tooth & placed in the imp.4. Stone is poured5. If the 2nd 1ry molar is planned for extraction but had not yet been removed , it’s

should be cut off the model6. Holes stimulate the position of the roots are made in the cast. 7. Loops contoured extending distally and into the holes .8. Free ends of the loops are soldered to the band or to the crown9. Sharping and smothing 10.Isolate and dry the tooth11.Cementation#N.B BEFORE cementation , x-ray is indicated while the S.M is in its position in the mouth to determine whether tissues extension is in the porper relationship with unerupted tooth or not

II. Acrylic plate S.M

1.1st perm. Molar not completely erupted , but a bulge marks its placed in the oral cavity .2. RPD plate constructed with its distal end mesial to the visible bulge of the 1st perm. molar

Premature loss of anterior teeth?• 1 Incisors: • no decrease in intracanine dimensions if loss after eruption

of canines

why?Long axis of anterior 1ry teeth is vertical to alveolar bone so, the anterior component of force is zero.

• Need SM?: Not necessary

• 2 Canines: • common loss due to ectopic eruption of permanent lateral incisors

• compromises arch length, possibly deepens bite, shift of dental midline toward side of loss

• -band and loop space maintainer is constructed and the 1st primary molar is used as abutment

• What about in case of 1ry upper canine

Premature loss of posterior teeth: Multiple Teeth

•Following appliances are

indicated:a) Transpalatal archb) Nance appliancec) Lingual arch

d) Removable

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SM: Band and LoopIndications

1. Loss of primary molarprior/during period of eruption of 1st perm M.

2. Anywhere in posteriorfollowing a time lapse b/w loss of tooth and eruption of its permanent successor.

3. Loss of 2 post teeth or bilateral situations

rarely used

SM: Band and LoopAdvantages1. Easy to construct.2. Inexpensive.3. Easily adjusted.

4. Allows eruption of permanent tooth.5. Non invasive.6. Painless.

SM: Band and LoopDisadvantages

1. Masticatory function.Not restored

2. Extrusion of opposing dentition.Not prevented

3. Normal distal mvmt of primary cuspids during eruption of perm lateral incisor

Not allowed if placed for the early loss of mand 1st primary molar

SM: Band and LoopConstruction• Band: stainless steel

material 0.005 inches in thickness

• Crib: portion of the wire spanning the edentulous space

• Loop: portion of the wire contacting the

abutting tooth 0.032 inches in diameter

SM: Lingual ArchIndications1. Premature loss of

primary posterior teeth.

2. Base for aesthetic restoration in loss of anterior teeth.

3. Used as a base for habit appliance.

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SM: Lingual ArchAdvantages Disadvantages1. Maintains est. arch form.

2. Allows eruption of perm teeth w/o interference.

3. Not easily displaced.

4. Ease of cleaning for proper OH.

5. Can be modified easily to serve in many situations.

6. Patient comfort.

1 .Does not prevent extrusion of opposing teeth.

2 .Not advisable to band teeth which are:•Hypoplastic•Hypocalcified•Highly prone to caries.

3 .Can promote decay in non-compliant patients.

SM: Fixed Lingual ArchConstruction

• Band: Stainless steel material 0.005 inches in thickness (ortho bands)

• Lingual arch wire: Stainless steel round wire 0.036 inches in thickness

SM: Nance Appliance Maxillary arch: multiple tooth lossIndications:The same as for fixed lingual archConstruction:

Bands: Stainless steel material 0.005 inches in thicknessPalatal wire: Stainless steel round wire 0.036 inches in thickness

Space maintenance for 1st permanent molar:

1 -after eruption of 2nd permanent molar:

• band and loop• Temporary modified bridge• move 2nd molar orthodontically to the 1st molar site if the 3rd molar will erupt in

normal position • Single implant

2 -befor eruption of 2nd permanent molar:• Distal shoe extension is made to guide the eruption of 2nd

permanent molar then replace by band and loop till time of fixed replacement

Ideal condition for extraction of 1st permenant molars

• Unerupted canines, premolars and 2nd molars are visible on a radiograph show no evidence of abnormality

• The occlusal relationship is class I• There is milde buccal segment crowding i.e. there is insufficient space for the

eruption of canine and premolars

A space maintainer may not be required if there is:

1 .Existence of cuspal interference.2 .Widely spaced primary dentition.

3 .If succeeding tooth is expected to erupt within 6 months.

4 .If present space is not adequate for the succeeding tooth.5 .The possibility of future orthodontic work.

6 .Where the opposing 6's are locked into a desirable and stable relationship

Suggested that succeeding tooth will most likely erupt within 6 months if:

1. 75% of the root is present on the succeeding tooth.2. Less than 1 mm of alveolar bone is covering succeeding tooth.

3. Destruction of the alveolar bone occurred when the primary tooth was lost.4. Mixed-dentition is in its later stages.

Prior to obtaining the consent, parents should be informed that:

1. Space maintainer requires monitoring.2. Patient must maintain adequate OH.3. Appliance may break, requiring repair or replacement.

4. Broken appliances are hazardous to the child and will be ineffective.5. Even properly maintained appliances may fail to preserve the space.

It is necessary to obtain parental awareness and understanding related to space maintenance.

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