Maxillary skeletal expansion using MARPE: Akram Alhuwaizi

Maxillary skeletal expansion using MARPE: Akram Al-Huwaizi Join me for a summary of Akram Al-Huwaizi’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, greatest 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