Download rapid maxillary expansion assisted with mini

RAPID MAXILLARY EXPANSION ASSISTED WITH MINI-SCREWS AND A
MODIFIED HAAS EXPANDER IN A PROGNATHIC PATIENT – CASE REPORT
Dominguez, P; Díez-Cascón, M, Ustrell, JM.
AIM -The objective of this case report was to achieve a rapid maxillary expansion
in a 16-year-old female. Assisted with mini-screws and bone-borne expander,
correcting the severe transversal maxillary discrepancy and minimizing dental side
effects, avoiding in the future a surgical assisted rapid palatal expansion (SARPE).
Diagnosis:
MATERIAL AND METHODS - Based in a CBCT scan, four orthodontic miniimplants (Jeil, JA model) with a 2-mm collar diameter and a 10-mm length were
placed in the palate between the roots of canines and first premolars, and second
premolars and first molars. A precise silicone impression was taken. The expander
consisted in a modified HAAS with only an acrylic plate and 4 insertion holes for
the mini-implants. The insertion sites were adjusted for a correct fitting and then
filled with hybrid composite for fixation. The activation protocol was two times per
day (morning and evening) and changed to one time per day once the maxillary
suture was open. One month prior to the expander´s placement, conventional 022
brackets (MBT prescription) were placed in the lower teeth to correct the lingual
tipping.
16 years old
Concave profile
Severe Maxillary Constriction
Retrusive Maxilla
Protrusive and Asymmetric Mandible
Angle Class III
Anterior open bite
Mild dental crowding
Inferior Lingual tipping
RESULTS - Following the activation protocol of two times per day, an occlusal x-ray was taken within two weeks
and the maxillary suture was open. Activation was changed to one time per day during 3,5 months while following
a lower Niti wire sequence of 016, 16x22 and 19x25. There was a slight overcorrection of the maxillary expansion
due to possible relapse. The patient´s facial esthetics (middle and lower third) and smile was highly improved with
the transversal correction.
CONCLUSION - The skeletal anchorage achieved with mini implants allows severe transversal corrections with
rapid maxillary expansion in patients after their growth peak, where a conventional expansion is harder or
impossible to achieve. Also minimizes dental side effects and prevents a two-stage orthognathic surgery, avoiding
a surgical assisted rapid palatal expansion (SARPE).
BIBLIOGRAPHY
.Lisson, J.A.: Anatomical guidelines for miniscrew insertion: Palatal sites, J. Clin. Orthod. 45:165-173, 2011.
.Lee KJ, Park YC, Park JY, Hwang WS. Miniscrew-assisted nonsurgical palatal expansion before orthognathic surgery for a patient
with severe mandibular prognathism. Am J Orthod Dentofacial Orthop 2010;137:830-9
.Vanarsdall RL, Blasi I, Evans M, Kocian P.: Rapid Maxillary Expansion with skeletal anchorage vs bonded tooth/tissue born
expanders: a case report comparison utilizing CBCT. RMO Clinical Review 2012, page 18- 22.