Maxillary skeletal expansion using MARPE: Akram Alhuwaizi
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Join me for a summary of Akram Alhuwaizi’s lecture on MARPE – Miniscrew assisted rapid palatal expansion. This summary explores MARPE from a clinical aspect, assessing the advantages and disadvantages, followed by a case discussion of success and failure, a discussion of MSE and lessons learned for designing MARPE.
The full lecture is available on Akram’s youtube channel:
Maxillary Skeletal Expansion using MARPE from A to Z (Updated) – YouTube
Introduction
Purpose of expansion
· Correction of crossbite
· Creating space
· Pre myofunctional treatment
· Widening smiles
Methods available
· Removable appliance
· Quad Helix
· Rapid Maxillary Expander RME
· Surgically assisted Rapid Palatal Expansion SARPE
Expansion methods
Ideal features of expansion appliances are to achieve bodily movement, minimal compliance required from the patient, applicable to a range of ages and straightforward for patients
MARPE experience
Case 1
· Attended Peter Ngan lecture Arab conference
· Surgical case requiring expansion – 2019
· 4 palatal TADs
· FAILIURE – TADs moved, one got embedded into the palatal tissue, no significant expansion occurred
Cause of failure
Hyrax position:
· Too posterior = near to Pterygo palatine suture and the zygomatic buttress which causes more resistance to the expansion
· No guiding arms, greatert risk of dental movements but they help in seating of the appliance
· Lack of guiding arm allowed rotation of the device by failure of only one TAD.
TADs
· Length: Short: Ideally bi-cortical engagement to avoid bending and increase retention
Appliance design
· There was a play between the TAD and the device
· Lab fabricated loops, not precision fit
Case 2
Design
· Used 2 TADs 2mm D/12mm L
· Guiding arms to the 1st molars
· Hyrax more anterior
· Good fit abutment / screw and expander
· Longer screws – bicortical engagement
· Younger patient and female
o Successful palatal expansion
MARPE Vs MSE
Prof Moon Maxillary Skeletal expander (MSE)
· Difference in posterior expansion
o MSE:
§ Posterior position of expander
§ Expand at the pterygo palatine suture = more horizontal expansion
§ Requires more force to overcome resistance
§ Precision fit required between TAD and the MSE.
§ Longer TADs.
§ TADS are in the vault of the palate not on the lateral walls
· Outcome with MSE
· Less pyramidal expansion in the anterior region
· Anterior and posterior Maxillary expansion
MSE design Shwan Elias
· 8,10,12mm / most commonly used is the 8mm one
· MSE 1
o Same hyrax screw
o Issue = key bends under higher forces
o Activation:
§ Late teens: 0.2mm/ day = 1 turn
§ Older: 0.4-0.6mm/day = 2-3 turns
§ After diastema 0.2mm/day = 1 turn
· MSE 2 (Biomaterial Korea)
o Uses wrench / it is hexagonal screw = 6 turns for 1mm
o Advantage = expansion is slower than MSE1
o Flexible arms – instead of the rigid arms
§ Decrease the dental effect and increase the skeletal effect
o Activation:
§ Late teens: 0.27mm/day = 2 turns
§ Older: 0.5-0.8mm/day = 4-6 turns
§ After diastema 0.27mm/day = 2 turns
Issues with MSE
· Large force application can cause TADs to fail
· Narrow and high palate = difficult to place the TADs for bicortical engagement.
Method of production
· Procedure
o Wire soldering with close contact to vault of palate, and 2 mm clearance of arms ofr the palatal mucasa for hygiene
o TAD insertion: screw half way for efficiency, followed by ratchet / screw driver for second half of insertion – to have tactile feedback to ensure cortical engagment
o End point: patient feel tingling sensation through nasal mucosa
Conventional RME / MSE 1 – 0.25mm per activation
· 2-3 x activation = 0.5-0.75mm
Hexagonal RME / MSE2 – 0.13mm per activation
· 4-6 activations = 0.5-0.8mm
· MSE 1
o Same hyrax screw
o Issue = key bends under higher forces
o Activation:
§ Late teens: 0.2mm/ day = 1 turn
§ Older: 0.4-0.6mm/day = 2-3 turns
§ After diastema 0.2mm/day = 1 turn
· MSE 2 (Biomaterial Korea)
o Uses wrench / it is hexagonal screw = 6 turns for 1mm
o Advantage = expansion is slower than MSE1
o Flexible arms – instead of the rigid arms
§ Decrease the dental effect and increase the skeletal effect
o Activation:
§ Late teens: 0.27mm/day = 2 turns
§ Older: 0.5-0.8mm/day = 4-6 turns
§ After diastema 0.27mm/day = 2 turns
Contributions
Content: Abdallah Sharafeldin
Edited and produced: Farooq Ahmed
