1. Rapid Maxillary Expansion : An Update
Nalaka Jayaratne BDS, PhD
Resident in Orthodontics,
University of Connecticut School of Dental Medicine
USA

2. History
• First used in 1860
• By Emerson C. Angell (1822-1903)

3. History
• Walter Coffin – 1877

4. History
• Walter Coffin – 1877
• Not accepted by ortho
community

5. History
• Walter Coffin – 1877
• Not accepted by ortho
community
• Reintroduced in 1950’s by
Korkaus and Andrew Hass

6. Indications for RME
• Posterior crossbites
• Class III malocclusions
• Cleft palate patients with collapsed maxillary
arch
• Adjunct to facemask therapy

7. Types of
RME
Appliances
Removable Fixed
Tooth borne
lsaacson type Hyrax type
Tooth and
tissue borne
Derichsweiler
type
Hass type

8. Tooth borne
lsaacson type Hyrax type

9. Tooth borne
lsaacson type Hyrax type
Spring loaded screw-
Minne Expander

10. Tooth borne
lsaacson type Hyrax type
Spring loaded screw-
Minne Expander

11. Tooth and tissue borne
Derichsweiler type Hass type
Image Source: Bhalajhi SI. Orthodontics: At The Art and Science (5th Ed)

12. Tooth and tissue borne
Derichsweiler type Hass type
Wire tags
Image Source: Bhalajhi SI. Orthodontics: At The Art and Science (5th Ed)

13. Tooth and tissue borne
Derichsweiler type Hass type
Wire tags
Image Source: Bhalajhi SI. Orthodontics: At The Art and Science (5th Ed)

14. Tooth and tissue borne
Derichsweiler type Hass type
Wire tags Thick SS wire -
1.2mm
Image Source: Bhalajhi SI. Orthodontics: At The Art and Science (5th Ed)

15. RAPID MAXILLARY EXPANSION
1. What are the effects of RME on facial sutures
and bone?
2. How do RME affect the airway?
3. What are the dental changes caused by RME?

16. RAPID MAXILLARY EXPANSION
1. What are the effects of RME on
facial sutures and bone?
2. How do RME affect the airway?
3. What are the dental changes caused by RME?

17. Inclusion criteria
• Quantitative data on the immediate effect of RME assessed by CBCT or CT
Exclusion criteria
• Surgical treatment and/or surgery in combination with RME
• Papers on syndromic or medically compromised patients
Final article count: 10

18. Midpalatal Suture
Image Source: Bhalajhi SI. Orthodontics: At The Art and Science (3rd Ed)

19. Midpalatal Suture
• Triangular – 3 studies
• Parallel - 1 study
• Largely anteriorly in some individuals and largely posteriorly in others – 1 study
Image Source: Bhalajhi SI. Orthodontics: At The Art and Science (3rd Ed)

20. Mid-palatal suture: Mean expansion

21. Mid-palatal suture: Mean expansion
Posterior region

22. Mid-palatal suture: Mean expansion
Posterior region
= 1.6 -4.33 mm

23. Mid-palatal suture: Mean expansion
Posterior region
= 1.6 -4.33 mm
= 22%–53% screw expansion

24. Mid-palatal suture: Mean expansion
Posterior region
= 1.6 -4.33 mm
= 22%–53% screw expansion
Anterior region

25. Mid-palatal suture: Mean expansion
Posterior region
= 1.6 -4.33 mm
= 22%–53% screw expansion
Anterior region
= 1.52 to 4.33 mm

26. Mid-palatal suture: Mean expansion
Posterior region
= 1.6 -4.33 mm
= 22%–53% screw expansion
Anterior region
= 1.52 to 4.33 mm
= 20%–53% screw expansion

27. Mid-palatal suture: Mean expansion
Posterior region
= 1.6 -4.33 mm
= 22%–53% screw expansion
Anterior region
= 1.52 to 4.33 mm
= 20%–53% screw expansion
Mid-palatal suture opening = 20%–50% screw opening

28. Dentoalveolar Expansion
• Transverse dentoalveolar expansion>skeletal expansion

29. Dentoalveolar Expansion
• Transverse dentoalveolar expansion>skeletal expansion
• Alveolar bending30% of the total expansion

30. Dentoalveolar Expansion
• Transverse dentoalveolar expansion>skeletal expansion
• Alveolar bending30% of the total expansion
• Mean buccal tipping of the first molars ~ 7.50
Image Source: Bhalajhi SI. Orthodontics: At The Art and Science (5th Ed)

31. Profitt’s View
Image Source: Profitt WR. Contemporary Orthodontics (5th Ed)

32. Profitt’s View
Teeth cannot respond
suture is opened

33. • 20 patients (12.3 ± 1.9 years)

34. • 20 patients (12.3 ± 1.9 years)
• RME until the required amount of expansion was achieved
and the palatal cusp of the maxillary first molar
contacted the buccal cusp of the mandibular first
molar

35. • 20 patients (12.3 ± 1.9 years)
• RME until the required amount of expansion was achieved
and the palatal cusp of the maxillary first molar
contacted the buccal cusp of the mandibular first
molar
• Spiral CT scans
 Pre-RME (T1)
 Post-RME (T2)- immediately after the hyrax was removed (3 months)

37. What is the Center of Rotation during RME?

38. Frontomaxillary suture

39. Frontomaxillary suture

40. Frontomaxillary suture

41. Internasal suture

42. Midpalatal Suture

43. Results
Greatest increase in width

44. Results
Greatest increase in width
 Intermaxillary suture (1.7 ± 0.9 mm)

45. Results
Greatest increase in width
 Intermaxillary suture (1.7 ± 0.9 mm)
 Internasal suture (0.6 ± 0.3 mm)

46. Results
Greatest increase in width
 Intermaxillary suture (1.7 ± 0.9 mm)
 Internasal suture (0.6 ± 0.3 mm)
 Maxillonasal suture (0.4 ± 0.2 mm)

47. Results
Greatest increase in width
 Intermaxillary suture (1.7 ± 0.9 mm)
 Internasal suture (0.6 ± 0.3 mm)
 Maxillonasal suture (0.4 ± 0.2 mm)
Midpalatal suture
 At central incisor (1.6 ± 0.8 mm)
 At canine level (1.5 ± 0.8 mm)
 at first molar level (1.2 ± 0.6 mm)

48. Results
Greatest increase in width
 Intermaxillary suture (1.7 ± 0.9 mm)
 Internasal suture (0.6 ± 0.3 mm)
 Maxillonasal suture (0.4 ± 0.2 mm)
Midpalatal suture
 At central incisor (1.6 ± 0.8 mm)
 At canine level (1.5 ± 0.8 mm)
 at first molar level (1.2 ± 0.6 mm)
 No significant expansion of frontozygomatic, zygomaticomaxillary,
zygomaticotemporal, and pterygomaxillary sutures

49. Conclusions
• RME forces primarily affect the anterior sutures
(intermaxillary and maxillary frontal nasal interfaces)
compared with the posterior (zygomatic interface)
craniofacial structures

50. Conclusions
• RME forces primarily affect the anterior sutures
(intermaxillary and maxillary frontal nasal interfaces)
compared with the posterior (zygomatic interface)
craniofacial structures
• Cranial sutures respond differently to the external
orthopedic forces according to their anatomic location
and the degree of interdigitation

51. Conclusions
• RME forces primarily affect the anterior sutures
(intermaxillary and maxillary frontal nasal interfaces)
compared with the posterior (zygomatic interface)
craniofacial structures
• Cranial sutures respond differently to the external
orthopedic forces according to their anatomic location
and the degree of interdigitation
• Lack of significant opening of other craniofacial sutures
supports clinical findings of reduced effectiveness of
maxillary expansion and protraction facemasks in
adolescents

52. Effect on orbits

53. Effect on orbits

54. Effect on orbits

55. RAPID MAXILLARY EXPANSION
1. What are the effects of RME on facial sutures
and bone?
2. How does RME affect the airway?
3. What are the dental changes caused by RME?

56. RAPID MAXILLARY EXPANSION
1. What are the effects of RME on facial sutures
and bone?
2.How does RME affect the
airway?
3. What are the dental changes caused by RME?

60. Airway Measuring Devices
Rhinomanometry Acoustic Rhinometry

61. Airway Measuring Devices
Rhinomanometry Acoustic Rhinometry

64. RAPID MAXILLARY EXPANSION
1. What are the effects of RME on facial sutures
and bone?
2. How does RME affect the airway?
3. What are the dental changes caused by RME?

65. RAPID MAXILLARY EXPANSION
1. What are the effects of RME on facial sutures
and bone?
2. How does RME affect the airway?
3.What are the dental changes
caused by RME?

73. Majourau A, Nanda R.
Biomechanical basis of
vertical dimensional
control during rapid palatal
expansion therapy. AmJ
Orthod
Dentofacial Orthop
1994;106:322-328.
Buccal tipping of upper
molars & premolars
Palatal cusp move
downwards
Premature contact with
lower teeth
Clockwise rotation of
mandible
Majourau A, Nanda R. Biomechanical basis of vertical dimensional control
during rapid palatal expansion therapy. AJODO 1994;106:322-328.
Majourau A, Nanda R.
Biomechanical basis of
vertical dimensional
control during rapid palatal
expansion therapy. AmJ
Orthod
Dentofacial Orthop
1994;106:322-328.
Majourau A, Nanda R.
Biomechanical basis of
vertical dimensional
control during rapid palatal
expansion therapy. AmJ
Orthod
Dentofacial Orthop
1994;106:322-328.

74. Majourau A, Nanda R.
Biomechanical basis of
vertical dimensional
control during rapid palatal
expansion therapy. AmJ
Orthod
Dentofacial Orthop
1994;106:322-328.
Buccal tipping of upper
molars & premolars
Palatal cusp move
downwards
Premature contact with
lower teeth
Clockwise rotation of
mandible
Majourau A, Nanda R. Biomechanical basis of vertical dimensional control
during rapid palatal expansion therapy. AJODO 1994;106:322-328.
Majourau A, Nanda R.
Biomechanical basis of
vertical dimensional
control during rapid palatal
expansion therapy. AmJ
Orthod
Dentofacial Orthop
1994;106:322-328.

75. Majourau A, Nanda R.
Biomechanical basis of
vertical dimensional
control during rapid palatal
expansion therapy. AmJ
Orthod
Dentofacial Orthop
1994;106:322-328.
Buccal tipping of upper
molars & premolars
Palatal cusp move
downwards
Premature contact with
lower teeth
Clockwise rotation of
mandible
Majourau A, Nanda R. Biomechanical basis of vertical dimensional control
during rapid palatal expansion therapy. AJODO 1994;106:322-328.

76. Buccal tipping of upper
molars & premolars
Palatal cusp move
downwards
Premature contact with
lower teeth
Clockwise rotation of
mandible
Image Source: Nanda RS, Tosun Y. Biomechanics in Orthodontics: Principles and Practice

81. Take-home messages

82. Take-home messages
• Mid palatal suture opening is commonly
triangular but it can be parallel

83. Take-home messages
• Mid palatal suture opening is commonly triangular
but it can be parallel
• Mid-palatal suture opening = 20%–50% screw
opening

84. Take-home messages
• Mid palatal suture opening is commonly triangular
but it can be parallel
• Mid-palatal suture opening = 20%–50% screw
opening
• RME primarily affect the anterior sutures than
posterior sutures

85. Take-home messages
• Mid palatal suture opening is commonly triangular
but it can be parallel
• Mid-palatal suture opening = 20%–50% screw
opening
• RME primarily affect the anterior sutures than
posterior sutures
• RME can improve nasal breathing

86. Take-home messages
• Mid palatal suture opening is commonly triangular
but it can be parallel
• Mid-palatal suture opening = 20%–50% screw
opening
• RME primarily affect the anterior sutures than
posterior sutures
• RME can improve nasal breathing
• Vertical changes due to RME are small and transient

87. Thank You