PDO315 Space Maintenance

Page 2: Patient Assessment

• Starting point for working with patients in need of space maintenance.

Page 3: Essential Concepts to Master

• Understanding space maintenance requires knowledge of:

  • Permanent teeth counting (1-32)

  • Primary teeth counting (A-T)

  • Typical eruption patterns of primary teeth

  • Typical eruption patterns of permanent teeth

  • Counting teeth in mixed dentition

Page 4: Counting Permanent Teeth

• Sequence for counting permanent dentition:

  • 8, 9, 7, 10, 6, 11, 5, 12, X, 4, 13, 3, 14, 2, 15, 1, 16

  • 32, 17, 31, 18, 30, 19, X, 29, 20, I, 28, 21, 27, 22, 26, 25, 24, 23

Page 5: Counting Primary Teeth

• Sequence for counting primary dentition:

  • E, F, D, G, C, H, B, I, A, T, K, I, S, L, R, M, P, N

  • Note: Focus on crowns of D's and E's during assessments.

Page 6: Eruption Timing and Sequence of Primary Teeth

• Primary tooth eruption:

  • Begins around 6 months; complete by 36 months (variable)

  • Mandibular central incisors erupt first, maxillary second molars last

  • Sequence in both arches: A-B-D-C-E (incisors, molars, canines)

  • Occlusion typically established by 36 months with little change prior to permanent dentition eruption.

  • Permanent teeth eruption sequence:

    • Maxillary: 6-1-2-4-5-3-7-8

    • Mandibular: 6-1-2-3-4-5-7-8

Page 7: AAPD Eruption Chart

• Primary Dentition:

  • Central Incisors: 4th fetal month, calcified 18-24 months, erupt 6-10, exfoliate 7-8 years

  • Lateral incisors: same timing with different eruption completion

  • Canines: 4th fetal month, calcified 30-39 months, eruption at 16-20 months

  • Primary first molars follow a similar timeline.

• Permanent Dentition:

  • Central and lateral incisors: calcified 3-4 months, erupt 7-10 (max) and 6-7 (man)

  • Canines start between 4-5 months, erupt between 11-15 years.

Page 8: Mixed Dentition Assessment

• Utilizing panoramic images to group teeth effectively for easier assessment in mixed dentition.

Page 9: Primary Dentition Arch Space Concept

• 2/3 of primary dentition generally exhibits spacing.

• Primate spaces: mesial to upper canines and distal to lower canines.

• Leeway space: refers to the greater length between primary canines and molars compared to their permanent counterparts.

  • Measurements: Maxillary: 1mm, Mandibular: 2mm per quadrant.

Page 10: Eruption and Occlusion of Primary Dentition

• Spacing characteristics in primary dentition:

  • Primate spaces are common regardless of spacing type (Baume I and II).

Page 11: Leeway Spaces

• Leeway spaces vary in size by arch:

  • Maxillary: 1mm per quadrant

  • Mandibular: 2mm per quadrant.

Page 12: Mixed Dentition Occlusion: Molar Transition

• Factors affecting transition:

  1. Primary molar relationship

  2. Primary spacing (early mesial shift)

  3. Leeway space (late mesial shift)

  4. Differential growth of maxilla and mandible.

Page 13: Early Mesial Shift

• Process of closing interdental spacing before permanent molars erupt, influenced by primary molar eruption paths. Occurs around 4 years of age.

Page 14: Late Mesial Shift

• Refers to the mesial shift of permanent first molars into leeway space after exfoliation of second primary molars.

• Contributes to Class I molar relationship in permanent dentition, especially in the mandibular arch.

Page 15: Primary Incisors

• Space loss generally unlikely if primary canines are erupted and occluded (around 20 months).

• Options include pedi-partial/Hollywood bridge or partial denture for cosmetic reasons, though not commonly needed.

Page 16: General Concepts of Space Maintenance

• Concerns regarding early loss of primary canines include preventing arch collapse and maintaining midline symmetry.

• Options include:

  • Lingual arch with spur

  • Extraction and bilateral space maintainer.

Page 17: Primary Molars

• Space maintenance typically unnecessary if permanent premolar cusp tips are at the pulp chamber level.

Page 18: Primary First Molars

• Space maintenance is usually required if the first molar is lost before the permanent one erupts.

• Band & Loop is the most common space maintainer used for these cases.

Page 19: Primary First Molars (continued)

• Space maintenance discussions continued with emphasis on common solutions.

Page 20: Primary Second Molars

• Space maintenance is required regardless of timing regarding loss.

• Distal Shoe recommended if the first permanent molar is not yet erupted.

Page 21: Primary Second Molars (continued)

• Further exploration of space maintenance techniques.

Page 22: Ectopic Eruption of Permanent First Molars

• Up to 3% of the population may experience this condition.

• Monitor for self-correction; can require intervention if no progress observed.

• Treatment options:

  • Distalization of first molar

  • Extraction of primary molar with traditional space maintainer.

Page 23: Ectopic Eruption (continued)

• Further detailing the implications and interventions needed for ectopic eruptions.

Page 24: Appliances for Ectopic Eruption

• Common appliances:

  • Halterman Appliance

  • Brass ligature wire

  • Arkansas spring

  • Orthodontic separating elastics.

Page 25: Unilateral Space Maintenance Concepts

• Utilization of applicable codes for restoring missing teeth, methods include:

  • Traditional (lab fabricated)

  • Chairside methods.

• Advantages & disadvantages discussed.

Page 26: Chairside Preparation for Unilateral Space Maintenance

• Step-by-step guide for creating a unilateral space maintainer chairside versus in a laboratory.

Page 27: Bilateral Space Maintenance Concepts

• Ideal when permanent first molars are in occlusion.

• Advantages include maintaining arch perimeter and success dependent on oral hygiene.

Page 28: Bilateral Space Maintenance Appliances

• Common types:

  • Transpalatal Arch

  • Nance Arch

  • Lower Lingual Holding Arch (LLHA).

Page 29: Bilateral Space Maintenance: Preparation

• Detailed process for fabricating bilateral space maintenance appliances, including securing bands and adding components.

Page 30: Important Concepts for Space Maintenance

• Recap of vital aspects:

  • Overview of unilateral versus bilateral options.

  • Importance of hygiene and monitoring.

  • Passive nature of appliances; no orthodontic forces exerted.

Page 31: Conclusion

• Final remarks summary overview relaying critical takeaways.