Tooth Bone vs Tissue Bone MSE Does it matter? Beom Kim
Reasons for Bone borne expansion
· Opening mid-palatal suture in adults
· Success OVERALL 74-90%
o Study of success rates of palatal suture opening depending on age Oliveiera 2021
§ 15-19 82%
§ 20-29 82%
§ 30-37 20%
Challenge – older male patients
Conventional RME in adults – risks
· Periodontal problems
· Severe tipping
· Root resorption
Types of skeletal Anchorage Maxillary Expansion SAME
1. Hybrid – TAD and attachment to teeth
2. Bone bourne – no contact with teeth
Which is better
· Stress of dentition with both types Finite analysis Lee 2014
· BB significant less stress on the buccal plate, however hybrid stress on buccal plate Seong 2018
· Comparison of RME, hybrid and BB Oh 2019
o Suture opening at ANS: greater with hybrid 4.5mm, BB 2.8mm, RMA 1.2
o Molar expansion: Greater with yybrid 6.3mm, RME 5.1, bb 3.5
o Molar tipping: Greater with RME 4 degrees, Hybrid and BB 2 degrees
· BB Vs RME Lin 2015
o Skeletal expansion: BB 1mm more than RME
o Molar tipping: BB less tipping 3 degrees
· 4 banded RME Vs 2 band hybrid appliance Toklu 2015
o Molar expansion: No difference
o Bone bending at 6s
§ 3 degrees = no difference RME Vs hybrid
o Molar tipping = no difference
o 1st premolar tipping = RME 2.5 degrees Vs 0.5 hybrid
· Hybrid Vs RME Jai 2021
o Skeletal opening: Greater with hybrid (3.8mm Vs 2.3mm)
o Molar expansion: No difference (RME 7mm Vs 6.3mm hybrid)
o Molar tipping: Hybrid less tipping (6.7 degrees Vs 3.8)
· BB Vs RME Celank-Koca 2019
o Molar expansion: No difference (4.2 RME Vs 4.5 BB)
o Sutural opening: BB greater (3.1 BB Vs 1.1 RME)
· Arruda / Kim study BB Vs Hybrid
o Expansion dental Vs Skeletal = 40%
Overall changes
· RME Jai 2021
o Expansion dental = 7mm (6-6)
o Skeletal changes 2.2mm (6-6)
§ Ratio skeletal:dental = 31%
o Tipping 5-6 degrees of molars
· Hybrid Moon 2020
o Expansion dental 5mm
o Skeletal expansion 2.45
§ Ratio skeletal: dental 50% (OTHER studies 28%)
o Tipping 2.4 degrees
· BB Lin 2015
o Expansion 3.4mm
o Skeletal 1.87mm
§ Ratio skeletal:dental 54%
o Tipping 1.15
Difference in changes possibly due to number of TADs, technique
Systematic review BB Vs RME Crusi 2019
· Conclusion
o No difference in dental expansion
o BB greater skeletal expansion = 2mm greater (6-6 level)
o Hybrid = less tipping than RME
Clinical questions to ask when expanding
What is the purpose of expansion?
· Correct crossbite OR expand midface
End point of expansion?
· Molar correction
· Achieving skeletal expansion = for 2mm require 5mm dental expansion
Limitations = studies based on younger patients
Adult patients with MSE Kangvonkit
· Skeletal expansion 4.6mm
· Soft tissue changes
o Alar base increased 2mm
o
Issues with skeletal expansion
· Different vertical heights of TADs = asymmetric expansion
· 30% of skeletal expansion = asymmetric Kim 2019
o Issue is up to 2mm of vertical discrepancy also occurs = Cant
How to manage cases
· Normal molar angle + thin alveolar bone
o BB – maximise skeletal changes
· Normal molar angle + normal bone
o Hybrid / BB
· Tipped molars
o BB
· Palatally tipped molars
o RME, hybrid, BB
Does it matter
· Younger patients = probably not
· Adult patients = consider skeletal anchorage
