This document discusses space management in mixed dentition. It defines different types of spacing in primary dentition and factors affecting the decision to maintain space. It also defines space maintainers and describes different classifications including fixed, removable, functional, and according to area of placement. Specific space maintainers are described like band and loop, lingual arch, and Nance appliance. Construction details and indications for different space maintainers are provided. Factors for ideal extraction of primary molars and situations where space maintenance may not be needed are outlined. Parental consent considerations are also mentioned.

1. Space management
2017-2018

2. 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

3. Growth of the dental arches
A) Maxilla B) Mandible

4. **Types of spacing between the primary dentition are
classified into:
i- Generalized spacing
ii- Primate spacing
iii- Lee way spacing

5. 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

6. 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.

7. SIGNS OF DIFFERENT TYPES OF DENTITION
Type of
dentition
Signs
Not crowded
( excess space )
Spacing between incisors
Space available<required
Not crowded
( just sufficient
space)
Normal contacts between incisors
Space available = required
Mild crowding Slight overlapping of incisors
Space available in arch up to 4mm less than
that required
Severe
crowding
Overlapping .rotation or displacement of incisors
Space available in arch over 4mm less than that
required

8. 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

9. 1- Nance analysis:
-Aim
Determine 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

10. -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.

11. 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

12. 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.

13. **Advantages:
1- can be completed in the mouth as well as on the casts .
2- may be used for both arches .

14. 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.

15. 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.

16. 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 mm
0.5 mm to values 23 mm & above

17. 6-Bishara and staely:
-This is the most recent and most universally used method

18. Space maintaining
decision

19. Factors affecting decision of space
maintaining
• Time elapsed since loss
of primary tooth

20. Factors affecting decision of space
maintaining
• chronological age Vs. dental age

21. Factors affecting decision of space
maintaining
• Amount of bone covering
the unerupted tooth

22. Factors affecting decision of space
maintaining
• Delayed eruption of
the permanent tooth

23. Factors affecting decision of space
maintaining
• Congenital absence of
permanent tooth

24. Factors affecting decision of space
maintaining
• Presentation of problems
to the parents

25. Space maintainer
Definition, requirement

26. 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.

27. 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

28. General requirements..
3. It should be esthetically pleasing in
case of ant teeth loss
4. prevent over-eruption of opposing
teeth.

29. General requirements..
5. It must permit maintenance of oral
hygiene.
6. It must not restrict normal growth
& development

30. Space maintainer
classification

31. 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

32. Fixed space maintainers
Advantages
1. Under control of dentist
2. Minimum fracture
3. More hygienic
Disadvantage
1. not restore function
2. Not restore ethetics
3. Needs good patient recall system

33. Band and loop

34. Crown and loop band

35. Crown with distal shoe extension

36. Passive lingual arch

37. Nance holding appliances

38. Trans palatal arch

39. Removable space maintainers
Advantages
1. Restore function
2. Aesthetically better
Disadvantage
1. Need cooperation
2. Easy breakage
3.less hygienic

40. Acrylic partial denture

41. According to Area
1- space maintainers for the 1st
primary molar area
1- Band and loop maintainer :
Fixed - passive - non functional
Most 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

42. Construction of band and loop
A) indirect
B) direct

43. 2- stainless steel crown and loop
maintainer
Indications
1- extensive caries in posterior abutment
2- vital pulp therapy in the posterior
abutment
N.B the loop may be cut off after eruption of
the successor leaving the crown to serve as a
restoration
Disadvantages:
Hard to make adjustements in the loop ,so
adapt band and loop ovet a cemented crown is
recommended

44. 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

49. I. Band & loop / Crown & loop
1. 1st 1ry molar prep. & crown is contoured
2. 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 poured
5. If the 2nd 1ry molar is planned for extraction but had not yet been removed , it’s
should be cut off the model
6. 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 crown
9. Sharping and smothing
10.Isolate and dry the tooth
11.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

50. 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

51. 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

52. • 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

53. Premature loss of posterior teeth: Multiple Teeth
•Following appliances
are indicated:
a)Transpalatal arch
b)Nance appliance
c)Lingual arch
d) Removable
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.

54. SM: Band and Loop
Indications
1. Loss of primary molar
prior/during period of
eruption of 1st perm M.
2. Anywhere in posterior
following 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

55. SM: Band and Loop
Advantages
1. Easy to construct.
2. Inexpensive.
3. Easily adjusted.
4. Allows eruption of
permanent tooth.
5. Non invasive.
6. Painless.

56. SM: Band and Loop
Disadvantages
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

57. SM: Band and Loop
Construction
• 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

58. SM: Lingual Arch
Indications
1. Premature loss of
primary posterior
teeth.
2. Base for aesthetic
restoration in loss
of anterior teeth.
3. Used as a base for
habit appliance.
QuickTime™ and a
TIFF (Uncompressed) decompressor
are needed to see this picture.

59. SM: Lingual Arch
Advantages Disadvantages
1. 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.

60. SM: Fixed Lingual Arch
Construction
• Band: Stainless steel
material 0.005
inches in thickness
(ortho bands)
• Lingual arch wire:
Stainless steel round
wire 0.036 inches in
thickness

61. SM: Nance Appliance
Maxillary arch: multiple tooth loss
Indications:
The same as for fixed lingual arch
Construction:
Bands: Stainless steel material 0.005 inches in thickness
Palatal wire: Stainless steel round wire 0.036 inches in thickness

62. Space maintenance for 1st permanent
molar:

63. 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

64. 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

65. 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

66. 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

67. 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.

68. 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.
QuickTime™ and a
TIFF ( Uncompressed) decompr essor
ar e neede d to see this picture.