This document discusses the importance of treatment timing in orthodontics. It summarizes decades of research on when is the optimal time to treat different malocclusions based on a patient's growth and development. Key findings include: - Treatment for mandibular deficiencies works best when it coincides with the peak growth period of the mandible. - Early treatment of Class II problems can reduce the need for later treatment but may require more retention. - Treatment in the permanent dentition appears to be more stable than in the mixed dentition. - Fixed appliances provide more efficient treatment than removable appliances. - Growth modification is still possible even in young adults using appliances like Herbst or chin cups.

1. Fourth dimension in
Orthodontics

2. Introduction
• First discussed about the importance of treatment
timing
• Why treatment timing is important ?
• Varying in total growth potential of bones
• Various sizes of bones among individuals
• If growth modification is considered then timing is
more important
Brodie AG. The fourth dimension in orthodontia. The Angle Orthodontist. 1954
Jan;24(1):15-30.

3. Moyers Symposium
• Various studies and RCT were discussed about the
treatment timing in orthodontics
• It was held in 2001 and more contributions given
by Dr.W. Proffit and James A.McNamara,Jr
Treatment timing : orthodontics in four dimensions / volume editors,
James A. McNamara, Jr., Katherine A. Kelly 2002

4. Tick-Tock
• Treatment timing discussion for more than 100
years
• Early vs Late treatment timings
• Kiyak 1998 – the average treatment timing
• 12-18yrs – 44%
• 8-11 yrs – 26%
• Adults – 20%
• 6-8yrs – 10%
Treatment timing : orthodontics in four dimensions / volume editors,James A. McNamara, Jr.,
Katherine A. Kelly 2002

5. • Tiziano Baccetti and Lorenzo Franchi first reviewed the
literature on studies of treatment timing.
• They noted that Class II treatment for mandibular
deficiencies is most effective when it includes the peak in
mandibular growth.
Franchi L, Baccetti T, McNamara JA Jr. Mandibular growth as related to cervical vertebral maturation
and body height. Am J Orthod Dentofacial Orthop 2000;118:335-340.

6. • Baccetti and Franchi note that the features of an “ideal” biologic indicator of
skeletal maturity would:
• The cervical vertebral maturation method proved the best, allowing the
prediction of the pubertal growth spurt in statural height and mandibular
growth for 93.5% of a tested North American sample (Franchi et al., 2000).
(1) Be effective in
detecting the peak of
mandibular growth in a
majority of individuals
(2) Minimize the need
for added X-ray
exposure
(3) Have ease in
recording, i.e., a
minimal number of
observations
(4) Be easy to interpret
without error
(5) Anticipate the
occurrence of the peak
of growth.
Franchi L, Baccetti T, McNamara JA Jr. Mandibular growth as related to cervical vertebral maturation and body height. Am J Orthod
Dentofacial Orthop 2000;118:335-340.

7. the question is not early vs. late, mixed vs. permanent
dentition, younger vs. older
the best timing for treatment of mandibular deficiency is
when the mandible is growing at its peak velocity.
This approach makes treatment timing a biologically-
based decision, unlike chronological age and/or dental
maturational status.
Franchi L, Baccetti T, McNamara JA Jr. Mandibular growth as related to cervical vertebral maturation and body height. Am J Orthod
Dentofacial Orthop 2000;118:335-340.

8. • Studies carried out at the University of Giessen subdivided a group of
204 Class II, division 1 patients into three “stages,”
• early mixed
• late mixed
• permanent dentitions.
• Four different appliance approaches were compared:
functional
combination
of functional
and fixed
Herbst
multibracket
fixed
appliances.
Proffit WR. The evolution of orthodontics to a data-based specialty. Am J Orthod Dentofacial Orthop 2000;117:545–
547.

9. While Pancherz noted - Treatment In the permanent dentition appears to Be more
efficient for Class II therapy than In the mixed dentition.
The Herbst and multi bracket systems were - more efficient
Pancherz's report Of successful Class II orthodontic/orthopedic treatment In young
adults.
His findings resulted In the following recommendations for treatment timing regarding
Class II, division 1 treatment:
(1) Growth modification can Be completed for children, adolescents, post adolescents,
and young adults
(2) Camouflage treatment Or oral surgery Is required for older adults

10. TREATMENT TIMING:
EFFECTIVENESS AND EFFICIENCY - Proffit
• Effectiveness - defined as how well it works
• Effective treatment produces large average improvement, and a
high percentage of the patients have an excellent outcome.
• Efficiency - defined as how much benefit the patient receives
relative to the costs and risks of treatment.

11. PRINCIPLES OF TREATMENT THAT AFFECT TIMING
• Growth modification is desirable.
• The ideal way to correct a jaw discrepancy Is to guide growth
1. At the time treatment starts, there has To be enough remaining Growth
in the desired plane Of space.
2.Growth must have declined to slow adult level before treatment or else
chances of recurrence is high
• If you start too late, growth modification is not effective.
• But if you start too soon, treatment takes too long and is not efficient.

12. Transverse growth – completed by time of adolescent
growth spurt begins for other two dimensions
Sagittal growth declines at sexual maturity attained
Vertical growth – till late teens
Different treatment timing for different planes of space

13. • Lowery, 1982 - 50–50 chance that tooth eruption will coincide with jaw
growth well enough to determine treatment timing from the dentition
• Slow dental development relative to skeletal growth – reason for second
stage of treatment after permanent teeth erupts

14. THE ADOLESCENT GROWTH SPURT. THE “GOLD STANDARD” FOR
ORTHODONTIC TIMING
• Begin in late mixed dentition or early permanent
dentition
• Depending on skeletal growth
• Treatment ends with growth spurts - retention
problems are minimised

15. Indications of later treatment
• Means delaying treatment after adolescent growth
spurt
• Mainly indicated to minimise the relapse after
growth spurt ends
• Eg : Class III with mandibular prognathism and
anterior open bite

16. Indications for early treatment
Class 1 crowding /
Protrusion
Approach by expansion
of arches without
protrusion – unesthetic
and unstable
Extraction – flattening
the profile – unesthetic

17. Serial extraction
• Dale et al 2000
• Difficult to determine the prognosis
• Long time follow up needed for efficiency
• It prevents the severing of malocclusion
• efficient in reducing the phase 2 treatment time
Dale JG. Serial extraction—nobody does that anymore. Am J Orthod Dentofacial Orthop
2000;117:564–566.

18. Early treatment Class II problems
• slightly greater reduction in ANB than later
treatment - Tulloch et al 1998
• Preadolescent treatment is not effective than later
treatment
• But considered based on
Special concerns of
the patient – social
problems
Skeletal
maturation ahead
of dental
maturation
An exceptionally
severe problem
Short / Long face problems – deep
bite and trauma to palate , often
respond well to functional appliance

19. Early treatment Class III problems
Maxillary deficiency – 1970 – Delaire succeeded in correcting
maxillary deficiency
Face mask therapy effective up to the onset of adolescence
Mandibular rotations improves ANB angle but maxillary change is
the primary goal
Early treatment enhances the effectiveness of face mask therapy in
maxillary deficiency
Franchi et al , Baccetti et al 1998 – changes in position of maxilla at
age 8yrs or younger

20. • Expansion of mid palatal suture is not needed in
early treatment
Mandibular Prognathism
• Chin cups- growth redirection rather than growth
restriction (Yoshida et al 1999)
• very early chin cup helps in restriction
(Droschl 1990)
Baccetti T, McGill JS, Franchi L, McNamara JA Jr. Skeletal effects Of Early Treatment Of Class
III malocclusion. Am J Orthod Dentofacial Orthop 1998; 113:333–343.

21. Efficiency of Class II therapy in relation to
timing and modality
• Beckwith et al., 1999; Berg, 1990; Birkeland Et al., 1997; Shia, 1986; Vaden and
Kidser, 1996
• Controversies in the treatment outcome and stability
• Early Vs late treatment
• One phase vs two phase
• Removable vs fixed
• Growth modifications vs orthodontics and surgery
• Extraction vs non extraction

22. Treatment efficiency in relation to timing and
modality of treatment – Von Breman
• 204 class II div 1 patients – university of Giessen
• Three groups
• Early mixed dentition
• Late mixed dentition
• Permanent dentition
• Four treatment options
Functional
Functional +
fixed appliance
Herbst
Fixed
appliance
therapy

23. Findings

25. Findings
• Fixed appliance treatment (19-24 months) duration
is shorter than removable appliance (38-49
months)
• Pancherz (1994) – treatment in permanent
dentition showed more stable results than in mixed
dentition
• Fixed appliances was more efficient

26. A new concept for Class II therapy
• Paulsen et al 1999 – histologically –zones of
unmineralized growth cartilage and
undifferentiated mesenchyme in adult mandibular
condyle
• Hinton and McNamara (1984) – condylar growth
can be stimulated and glenoid fossa remodelled
• Yatani et al 1991 – adult TMJ is capable of
remodelling
• Ruf and Pancherz 2000 – with Herbst – mandibular
skeletal changes about 25%

27. Herbst appliance
changes in
young adult
Pancherz 2000

30. Findings
Class II in permanent dentition with fixed appliance – more
effective
Shorter duration of treatment timing
Herbst appliance after pubertal peak of growth – more stable
than the mixed dentition ie before pubertal peak of growth
Skeletal tissue adaptation is possible even in young aduts

31. Federally funded Class II RCT – T.Wheeler
• University of Florida 1990 - 20months
• University of North Carolina 1989 - 15months
• Class II molar on both sides
• Overjet >7mm

32. Early phase 1 treatment –
positive effect
class II correction alone
not a criteria for early
treatment
other factors to be
considered
early treatment needs
more retention and longer
phase2 treatment
Tulloch CJF, Phillips C, Proffit WR. Early vs. late treatment of Class II malocclusion: Preliminary results from the UNC clinical trial. JA McNamara, Jr.,
ed., Orthodontic treatment: outcome and effectiveness, Craniofacial Growth Series Vol 30. Ann Arbor: Center for Human Growth and Development,
University of Michigan, 113–138, 1995

33. Two UK based Multicenter RCT- Kevin O’Brien
First study – sample between 8-10 years treated
with twin block and control
Second study – 11-14 years treated with herbst or
twin block and phase 2 fixed appliance therapy
Keeling SD, Wheeler TT, King GJ, Garvan CW, Cohen DA, Cabassa S,McGorray SP, Taylor MG. Anteroposterior skeletal and
dental changes following early ClassII treatment with bionators and headgear. Am J Orthod Dentofacial Orthop 1998; 113:40–50.

34. • Previously
• Jacobsson 1967 – treated with Anderson activator –
concluded that no effect on mandibular growth
only maxillary restriction
• Ghafari 1998 – concluded that frankel appliance
was effective in more forward position of mandible

35. Early treatment study
• Pts from 14 hospitals included in this study
• Treated with twin block appliance
• Instructed to wear full time
• Data collection at the start of treatment and after
fifteen months
• Cephalometric analysis as per Tulloch et al 1997

36. Results
Keeling SD, Wheeler TT, King GJ, Garvan CW, Cohen DA, Cabassa S,McGorray SP, Taylor MG. Anteroposterior skeletal and
dental changes following early ClassII treatment with bionators and headgear. Am J Orthod Dentofacial Orthop 1998; 113:40–50.

37. • Psychological effects – showed happiness and
satisfaction in early treatment

38. Findings
• Successful reduction of overjet
• 27% of skeletal change
• Roughly 2mm of skeletal change was seen
• More of dentoalveloar changes as like as Tulloch et
al 1998

39. Later treatment study
• The aim of the study to find the effectiveness of
removable and herbst appliance
• Overjet >7mm
• Late transitional dentition with second premolars
erupted
• Two groups
Twin block
group n=110
Herbst
appliance
group n=105

40. Findings
Twin block – 24 months duration
Herbst – 20 months duration
Both pahse 1 and phase 2

41. Findings
• No significant difference in the outcome between
twin block and herbst
• early treatment improved self perception
• Early treatment with twin block corrects the
prominent incisors
Keeling SD, Wheeler TT, King GJ, Garvan CW, Cohen DA, Cabassa S,McGorray SP, Taylor MG. Anteroposterior skeletal and
dental changes following early ClassII treatment with bionators and headgear. Am J Orthod Dentofacial Orthop 1998; 113:40–50.

42. Treatment effects of the twin block
appliance – M.Mills

43. Study samples
• Mean age – 9years
• The mean treatment time was 14months
• Class II molar on both sides
• Mixed dentition
• ANB >5°
• Mandibular retrognathism
Mills CM, McCulloch KJ. Post-treatment changes after successful correction of Class II malocclusion with
the Twin Block appliance. Am J Orthod Dentofacial Orthop 2000;118:24–33.

44. R
e
s
u
l
t
s
Adequate retention is needed for better stability of skeletal
correction along with phase 2 treatment

45. Effects of early activator treatment –
Christopher J Lux
• Study Sample
• male pt with skeletal classII with increased overjet
• Mean age – 9.5 years
• Treated with activator
• Post treatment cephs after 2years
Lux CJ, Rübel J, Starke J, Conradt C, Stellzig A, Komposch G. Effects of early
activator treatment in patients with Class II malocclusion evaluated by thin-plate spline
analysis. Angle Orthod 2001;71:120–126.

46. Lux CJ, Rübel J, Starke J, Conradt C, Stellzig A, Komposch G. Effects of early activator
treatment in patients with Class II malocclusion evaluated by thin-plate spline analysis. Angle
Orthod 2001;71:120–126.

47. Timing for anterior crossbite and class III
malocclusion – Patrick K Turley
• Gianelly 1995 – correction of class III as soon as it is
identified
• Early treatment is indicated
• To avoid gingival recession – Harrison 1991
• Reduce the chance of TMJ dysfunction – Muto et al 1998
• To avoid worsening of growth pattern – MacDonald
1999
• Potential for greater orthopedic change - Torres (2000)
• Elimination of functional shift of mandible – Kerr 1988

48. Timing of anterior crossbite treatment
• Whether it is skeletal or dental ?
• Combination of facial and cephalometric is a
reliable method in primary dentition
• Bishara 2000 – anterior crossbite with 3mm of
mesial step – skeletal origin
• <3mm mesial step with lower spacing and upper
retroclination – dental origin

49. Diagnosis of skeletal class III malocclusion
• Tsai (2001) children with crossbite in primary
dentition are skeltal origin
• Smaller anterior cranial base and maxillary
retrusion

50. Nartallo –Turley (1998 ) significant change in
maxillary advancement of 3.3mm
SNA change of 2.35 degrees
Mandibular clockwise rotation

51. Merwin et al 1997 – concluded that similar skeletal response
was seen in either early 5-8years or late mixed dentition
period 9-12 years
Baccetti et al (1998) – early treatment group – 6years – for
17months of treatment
Late group 10years – 10months of treatment
Concluded that younger group showed greater advancement
with upward and forward direction of condyle

52. • Kapust et al (1998) with three groups
• 4-7years
• 7-10 years
• 10-14 years
the maxillary advancement was higher in the
youngest age group
Resulted that earlier treatment produces more
favourable outcome
But 10-14 group also showed significant change
in the maxillary advancement

53. Earlier treatment increases the overall treatment duration
Overcorrection is recommended
Successful Facemask therapy doesn’t change the class III
pattern of maxilla
Orthopedic correction may needed during phase 2
treatment also

54. How to find the right timing ??

55. Maturational indices for the identification of optimal
treatment timing
• Proffit 2002 – time plays a crucial role in dictating
the rules of final morphological and dimensional
result
• Optimal timing – most favourable results with least
biological damage
• Baccetti et al 2000
Pubertal growth peak – reliable maturational index
for functional orthopedics - With more skeletal
changes and least dentoalveolar changes

56. Various indices
• Pubertal growth spurt – Nanda (1955)
• Increase in body height – Nanda (1955)
• Hand and wrist radiographic method – Hagg and
taranger (1980)
• Dental development and eruption – Hellman 1923
• Menarche and voice changes – Tanner 1962
• Cervical vertebral maturation – Lamparski 1972

57. Increase in body height – Nanda (1955)
• The adolescent peak in body height coincides with or is
slightly before the peak in mandibular growth (Nanda,
1955; Bambha, 1961; Hunter, 1966, Björk and Skieller,
1972; Tofani, 1972).
• The method does not require X-ray exposure.
• need of repeated measurements with a standardized
technique.
• At least three consecutive recordings are needed to
construct an individual growth curve in order to
determine whether the subject is in the accelerative
phase of the pubertal growth spurt.

58. Hand and wrist radiographic method
• A. Tofani (1972) moderate correlations between the onset of fusion of
the distal phalanges of the fingers and the peak in mandibular growth.
• According to Hägg and Taranger (1980a), the stage MP3-FG occurred in
90% of subjects, either in the year preceding, or at the peak of body
height.
• The stage MP3–G (the sides of the epiphysis have thickened and also
capped the meta physis, forming a sharp edge distally at one or both
sides)
• took place in 90% of the subjects either during the year after the peak in
body height.

59. • B. Additional X-ray exposure is needed for this
method.
• C. The recording of the different stages is relatively
easy.
• D. The reproducibility for the recorded data is
about 95% among expert examiners (Hägg and
Taranger, 1980a).
• E. The peak in body height has not been reached
if the stage MP3 F (the epiphysis of the middle
phalanx of the third finger is as wide as Its
metaphysis)
• the skeletal maturation of The hand and wrist are
related to increases In body height, without an
extensive evaluation of the peak In mandibular
growth.

61. Cervical vertebral maturation
• Franchi et al 2000 – 94% north americans stage 3
and 4 coincides with pubertal peak in both
mandibular growth and body height
• The peak is not attained in the initial stages of cvmi
staging
• 6 stages in original CVMI (Lamparski 1972 , Franchi
et al 2000)

63. Innovation to CVM method
• C2,C3,C4 taken into consideration
• 6 stages
• Presence of concavity at lower borders
• Shape of body of C3 and C4
 Trapezoid
 rectangular horizontal
 squared
 rectangular vertical

66. CVMI I
• Lower borders are
flat
• C3 and C4
trapezoidal
• Peak in mandibular
growth will occur
not earlier than 2
year after this
stage

67. CVMI II
• Concavity in C2
• C3 and C4 trapezoidal
• Peak in mandibular
growth will occur not
earlier than 1 year
after this stage

68. CVMI III
• Concavity at lower
borders C2 and C3
• C3 and C4 trapezoidal
or rectangular
horizontal
• Peak in mandibular
growth will occur
within one year after
this stage

69. CVMI IV
• Concavity in C2 C3 C4
• C3 and C4 –
rectangular
horizontal
• Peak in mandibular
growth has occurred
within one or two
years before this
stage

70. CVMI V
• Concavities
• C3 and C4 square in
shape
• Peak in mandibular
growth – has ended at
least one year before
this stage

71. CVMI VI
• Concavities are
evident
• C3 and C4 –
rectangular vertical
• Peak in growth ended
at least 2years before
this stage

72. CVMI II – ideal time for mandibular
retrognathism
Age ranges at CVMI II was about 4years
7years to 11years – females
9years to 14 years – males

73. Rajagopal R, Kansal S. A comparison of modified MP3 stages and the cervical
vertebrae as growth indicators. Journal of clinical orthodontics: JCO. 2002 Jul
1;36(7):398-406.

74. MP3-F stage: Start of the curve of pubertal
growth spurt
• Features observed by Hagg and Taranger:
• 1. Epiphysis is as wide as metaphysis.
• 2. Ends of epiphysis are tapered and rounded.
• 3. Metaphysis shows no undulation.
• 4. Radiolucent gap (representing cartilageous
epiphyseal growth plate) between epiphysis
and metaphysis is wide.
CVMI-1: Initiation stage of cervical vertebrae2
• 1. C2, C3, and C4 inferior vertebral body
borders are flat.
• 2. Superior vertebral borders are tapered from
posterior to anterior (wedge shape).
• 3. 80-100% of pubertal growth remains.

75. MP3-FG stage: Acceleration of the curve of pubertal
growth spurt
• Features observed by Hagg and Taranger:
• 1. Epiphysis is as wide as metaphysis.
• 2. Distinct medial and/or lateral border of epiphysis
forms line of demarcation at right angle to distal
border.
• 3. Metaphysis begins to show slight undulation.
• 4. Radiolucent gap between metaphysis and
epiphysis is wide.
CVMI-2: Acceleration stage of cervical vertebrae
• 1. Concavities are developing in lower borders of
C2 and C3.
• 2. Lower border of C4 vertebral body is flat.
• 3. C3 and C4 are more rectangular in shape.
• 4. 65-85% of pubertal growth remains.

76. • MP3-G stage: Maximum point of pubertal growth spurt
• Features observed by Hagg and Taranger:
• 1. Sides of epiphysis have thickened and cap its
metaphysis, forming sharp distal edge on one or both
sides
• 2. Marked undulations in metaphysis give it “Cupid’s
bow” appearance.
• 3. Radiolucent gap between epiphysis and metaphysis is
moderate.
CVMI-3: Transition stage of cervical vertebrae
• 1. Distinct concavities are seen in lower borders of C2
and C3.
• 2. Concavity is developing in lower border of C4.
• 3. C3 and C4 are rectangular in shape.
• 4. 25-65% of pubertal growth remains.

77. • MP3-H stage: Deceleration of the curve of pubertal
growth spurt
• Features observed by Hagg and Taranger:
• 1. Fusion of epiphysis and metaphysis begins.
• 2. One or both sides of epiphysis form obtuse angle
to distal border.
• 3. Epiphysis is beginning to narrow.
• 4. Slight convexity is seen under central part of
metaphysis.
• 5. Typical “Cupid’s bow” appearance of metaphysis
is absent, but slight undulation is distinctly present.
• 6. Radiolucent gap between epiphysis and
metaphysis is narrower.
• CVMI-4: Deceleration stage of cervical vertebrae
• 1. Distinct concavities are seen in lower borders of
C2, C3, and C4.
• 2. C3 and C4 are nearly square in shape.
• 3. 10-25% of pubertal growth remains.

78. • MP3-HI stage: Maturation of the curve of pubertal
growth spurt
• 1. Superior surface of epiphysis shows smooth
concavity.
• 2. Metaphysis shows smooth, convex surface, almost
fitting into reciprocal concavity of epiphysis.
• 3. No undulation is present in metaphysis.
• 4. Radiolucent gap between epiphysis and metaphysis is
insignificant.
• CVMI-5: Maturation stage of cervical vertebrae
• 1. Accentuated concavities of C2, C3, and C4 inferior
vertebral body borders are observed.
• 2. C3 and C4 are square in shape.
• 3. 5-10% of pubertal growth remains.

79. • MP3-I stage: End of pubertal growth spurt
• Features observed by Hagg and Taranger:
• 1. Fusion of epiphysis and metaphysis complete.
• 2. No radiolucent gap exists between metaphysis
and epiphysis.
• 3. Dense, radiopaque epiphyseal line form integral
part of proximal portion of middle phalanx.
• CVMI-6: Completion stage of cervical vertebrae
• 1. Deep concavities are present in C2, C3, and C4
inferior vertebral body borders.
• 2. C3 and C4 are greater in height than in width.
• 3. Pubertal growth is complete.

81. Gu Y, McNamara Jr JA. Mandibular growth changes and cervical vertebral maturation: a
cephalometric implant study. The Angle Orthodontist. 2007 Nov;77(6):947-53.

82. • The peak increase in mandibular length, along with greatest bone
apposition at condylion, was observed during the interval CS3–CS4.
• Mandibular remodeling and condylar rotation continue over a relatively
long period of time, even after the peak in mandibular growth had
occurred.

83. Ball G, Woodside D, Tompson B, Hunter WS, Posluns J. Relationship between cervical vertebral maturation and
mandibular growth. American Journal of Orthodontics and Dentofacial Orthopedics. 2011 May 1;139(5):e455-61.

84. The length of time to progress from the PPM to the PMdG velocity is an average of
2.2 years.
The most frequent stage at which PMdG velocity occurs is CS 4.
The greatest amount of mandibular growth occurs during CS 4.

85. • Group I (CVMI Stage 1 to 2) (n=5): Significant amount (65-100%) of
adolescent growth expected.
• Group II (CVMI Stage 3 to 4) (n=29): Moderate amount (10-65%) of
adolescent growth expected.
• Group III (CVMI Stage 5 to 6) (n=14): Small amount (≤10%) of adolescent
growth expected.

86. • Optimum timing for
myofunctional therapy of
Class II malocclusion is
during or slightly after the
pubertal growth spurt.
• From the point of view of
occlusal development, this
period correlates in most
patients with the late mixed
or early permanent dentition.

87. Conclusion
• The first time you see is the best time to treat
• There are many studies to justify the effectiveness
of orthodontic treatment at various ages
• Early treatment needs more treatment duration for
better stability and the outcome is more favourable
than later treatment but later treatment doesn’t
showed much differences in the outcome
• Start early plan well for longer treatment duration
• Start late execute well with shorter duration

88. References
• Tulloch JF, Proffit WR, Phillips C: Outcomes in a 2-phase randomized
clinical trial of early Class II treatment. Am J Orthod Dentofacial Orthop
125:657-667, 2004
• Keeling SD, Wheeler TT, King GJ, et al: Anteroposterior skeletal and
dental changes after early Class II treatment with bionators and
headgear. Am J Orthod Dentofacial Orthop 113:40-50, 1998
• Franchi L, Baccetti T, McNamara JA Jr. Mandibular growth as related to
cervical vertebral maturation and body height. Am J Orthod Dentofacial
Orthop 2000;118:335-340.
• Tulloch JFC, Phillips C, Koch G, Proffit WR. The effect of early
intervention on skeletal pattern in Class II malocclusion: a randomized
clinical trial.Am J Orthod Dentofacial Orthop 1997b; 111:391–400.
• Pancherz H, Hägg U. Dentofacial orthopedics in relation To somatic
maturation: an analysis of 70 consecutive cases treated with the Herbst
appliance.Am J Orthod 1985;88:273-287.

89. • Taranger J, Hägg U. Timing and duration of adolescent growth. Acta
OdontScand 1980:38:57-67.
• Keeling SD, Garvan CW, King GJ, Wheeler TT, McGorray SP.
Temporomandibular disorders after early ClassII treatment with bionators
and headgears: Results from a randomized controlled trial. Seminars
Orthod 1995; 1:149-165.
• Tulloch JFC, Phillips C, Koch G, Proffit WR. The effect of early
intervention on skeletal pattern in Class II malocclusion: A randomized
clinical trial.Am J Orthod Dentofacial Orthop 1997;111:391–400.