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Revise, Review & Update: What is the newly investigated effect of Rapid Maxillary Expansion?

Revise & Review


Rapid maxillary expansion (RME) is not a new concept; it was first described and used, 150 years ago, on a 14-year old female patient, utilising heavy forces to correct a transverse maxillary arch discrepancy (McQuiellen, 1860).

Biomechanics of RME

The theoretical principle behind substantial force application of RME is to disarticulate the circum-maxillary suture with resultant orthopaedic expansion before teeth respond. (Provatidis et al., 2008, Chaconas and Caputo, 1982).

Claimed clinical applications

1. Correction of 4-6mm of unilateral or bilateral crossbite

2. Mild space provision to provide relief of mild crowding (Adkins et al., 1990)

3. Interceptive treatment of palatally impacted canines (Armi et al., 2011, Sigler et al., 2011)

4. To enhance maxillary protraction (Limited evidence) (Vaughn et al., 2005)

5. Improvement of nasal airflow in patients suffering from nasal obstruction (Limited evidence) (McDonald, 1995)

6. Improvement of hearing (Limited evidence) (Laptook, 1981) (Gray, 1975)

7. Assisting in the control of Nocturnal Enuresis (NE) (Limited evidence) (Schütz-Fransson and Kurol, 2008)

8. Treating patients suffering from headaches (Limited evidence) (Farronato et al., 2008)

Design of Rapid Maxillary Expanding Appliances

A. Based on the method of appliance support

1. Teeth-Borne Expanders

· Banded RME Appliances

· Bonded RME Appliances

2. Bone-Borne Expanders

3. Hybrid (Teeth-Bone-Borne Expanders)

4. Others

B. Based on the design of the appliance

1. Derichsweiler appliance.

2. Hyrax appliance.

3. Isaacson appliance.

4. Others

Isaacson appliance

Haas appliance

Derichsweiler appliance

Hyrax appliance.

Metal cap bonded RME

Acrylic cap bonded RME

Potential problems encountered with RME

1. Pain and soreness during the active phase of expansion though in 98% of cases treated with RME, the pain generally occurs during the first 6 turns and diminishes thereafter (Needleman et al., 2000).

2. Short-term, gingival tissue irritation and inflammation (Sardessai and Fernandesh, 2004)

3. Sometime, bone dehiscence and root resorption of the anchor teeth (Barber and Sims, 1981)

4. Rarely, transient pulpal changes (Greenbaum and Zachrisson, 1982)

5. Very rarely, dizziness, epistaxis, temporary diplopia or even compression of the oculomotor nerve (Lanigan and Mintz, 2002)

6. Negative impact on on oral health-related quality of life during the active phase (unanswered question)


A recent RCT published by AJODO in October 2021 answered the last issue. The study was undertaken by Dr Pithon and team from Brazil.

This study included 80 participants aged 8-10 years with transverse maxillary deficiency who were randomly assigned to 2 groups (n = 40 each): a group treated with RPE using hyrax-type appliances and a nontreated control group.

Self-perceived oral health–related quality of life (OHRQOL) of the recruited children were assessed before RPE, during RPE, at the end of RPE, and 1 month after the appliance removal.

In summary, RME temporarily worsening of OHRQOL but things improve after transverse correction and appliance removal.

If you are interested in refreshing your knowledge about RME, please read my review paper that I published 5 years ago though it is slightly outdated.

What do you think?



ADKINS, M. D., NANDA, R. S. & CURRIER, G. F. 1990. Arch perimeter changes on rapid palatal expansion. American Journal of Orthodontics and Dentofacial Orthopedics, 97, 194-199.

ARMI, P., COZZA, P. & BACCETTI, T. 2011. Effect of RME and headgear treatment on the eruption of palatally displaced canines: a randomized clinical study. The Angle Orthodontist, 81, 370-374.

BARBER, A. F. & SIMS, M. 1981. Rapid maxillary expansion and external root resorption in man: a scanning electron microscope study. American journal of orthodontics, 79, 630-652.

CHACONAS, S. J. & CAPUTO, A. A. 1982. Observation of orthopedic force distribution produced by maxillary orthodontic appliances. American journal of orthodontics, 82, 492-501.

FARRONATO, G., MASPERO, C., RUSSO, E., PERITI, G. & FARRONATO, D. 2008. Headache and Transverse Maxillary Discrepancy. Journal of Clinical Pediatric Dentistry, 33, 67-74.

GRAY, L. P. 1975. Results of 310 cases of rapid maxillary expansion selected for medical reasons. J Laryngol Otol, 89, 601-614.

GREENBAUM, K. R. & ZACHRISSON, B. U. 1982. The effect of palatal expansion therapy on the periodontal supporting tissues. American Journal of Orthodontics, 81, 12-21.

LANIGAN, D. T. & MINTZ, S. M. 2002. Complications of surgically assisted rapid palatal expansion: review of the literature and report of a case. Journal of oral and maxillofacial surgery, 60, 104-110.

LAPTOOK, T. 1981. Conductive hearing loss and rapid maxillary expansion: Report of a case. American journal of orthodontics, 80, 325-331.

MCDONALD, J. 1995. Airway problems in children--can the orthodontist help? Annals of the Academy of Medicine, Singapore, 24, 158-162.

MCQUIELLEN, J. 1860. Review of the dental literature and art: Seperation of of the superior maxilla in the correction of irregularity of teeth. Dental Cosmos, 2, p. 170-173., .

NEEDLEMAN, H. L., HOANG, C., ALLRED, E., HERTZBERG, J. & BERDE, C. 2000. Reports of pain by children undergoing rapid palatal expansion. Pediatric Dentistry, 22, 221-226.

PROVATIDIS, C., GEORGIOPOULOS, B., KOTINAS, A. & MCDONALD, J. 2008. Evaluation of craniofacial effects during rapid maxillary expansion through combined in vivo/in vitro and finite element studies. The European Journal of Orthodontics, 30, 437-448.

SARDESSAI, G. & FERNANDESH, A. S. 2004. Gingival necrosis in relation to palatal expansion appliance: an unwanted sequelae. Journal of Clinical Pediatric Dentistry, 28, 43-45.

SCHÜTZ-FRANSSON, U. & KUROL, J. 2008. Rapid maxillary expansion effects on nocturnal enuresis in children: A follow-up study. The Angle Orthodontist, 78, 201-208.

SIGLER, L. M., BACCETTI, T. & MCNAMARA JR, J. A. 2011. Effect of rapid maxillary expansion and transpalatal arch treatment associated with deciduous canine extraction on the eruption of palatally displaced canines: a 2-center prospective study. American Journal of Orthodontics and Dentofacial Orthopedics, 139, e235-e244.

VAUGHN, G. A., MASON, B., MOON, H.-B. & TURLEY, P. K. 2005. The effects of maxillary protraction therapy with or without rapid palatal expansion: a prospective, randomized clinical trial. American journal of orthodontics and dentofacial orthopedics, 128, 299-309.

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