Class II division 1 malocclusion features and early intervention of growing maxillary excess .faculty of dentistry . Mansoura University.

1. Class II division 1 malocclusion:
features and early intervention of
growing maxillary excess
Supervisor . Dr Maher
Fouda
Prepared by Hawwa
Shoaib

2.  Prevalence of malocclusion of class 2
malocclusion.
Cephalometric finding.
Clinical findings.
Interception of growing class2 division 1
malocclusion.
OVERVIEW

3. Class 2 malocclusion comprises agroup of specific
skeletal. Dental and facial features. It is second in
frequency. Distribution and prevalence among Angle’s
malocclusion classes .
It is the most frequently encountered and treated
malocclusion in orthodontic practice

4. Class 2 malocclusion is a synonym with distal position of
the lower molar or mandible or protrusion of the maxilla
and maxillary teeth or a variable combination

5. Prevalence
The prevalence of Angle’s class 2 malocclusion varies
among population groups.. It is high among caucasians
and lowest among the primitive races..
Class 2 malocclusions are observed in a wide – spectrum
of presentation and severity …

6. Prevalence of class || malocclusion..

7. Clinical findings
• A distal step relationship 2nd deciduous molars is an
indication of a devoloping class 2 malocclusion during
the mixed dentition ..
Presentation during deciduous and early mixed
dentition..
Mixed dentition Permanent dentition

8. Occlusal and craniofacial characteristics from
deciduous to mixed dentition
• Distal terminal plane of second deciduous molars . Large
over jet and overbite .
• Narrow maxillary basal bone
• Poor or no spacing in the deciduous dentition
• Transverse discrepancy ( TD) between maxillary and
mandibular deciduous intermolar withs (2.8-1.1) mm
compared to nil among normal occlusal groups .
• Retruded mandible and shorter mandibular length ( Co-Pg)
on cephalometric examination
• The maxilla can also displaced forward in class || subjects
with or without difference in the mandible ..

9. Occlusal and craniofacial characteristics from
deciduous to mixed dentition
• It has been stated by Bishara et al that a distal step deciduous
molar relationship is never self - correcting in growing
children.
• Children with straight terminal plane may develop into a class |
molar or class || molar relationship influenced by the
mandibular growth pattern and adjustment of occlusion during
the late mixed dentition .that would in clinical sense .
• Infer that when we encounter a class|| distal molar relation
early in the mixed or permanent dentition.
• Some sort of interceptive measures may have to be undertaken
or planned because nature would not take care

10. • During transition from deciduous to mixed dentition ,the
craniofacial skeletal patteren shows an abnormal and
variable patteren of growth in class || children compared
to the control group of normal occlusion .
• The upper jaw becomes more prominent due to larger
increments of maxillary protrusion relative to stable basal
cranial structures .
• The mandible grows at a lesser pace than children with
normal occlusion.
• A more backward and downward inclination of the
mandibular body leading to a lesser decrease in the facial
angle is seen .

11. • All this is coupled with a narrow maxillary base in the
development of class || malocclusion .
• Other variations in class || subjects consist of contraction
of the maxilla at both the skeletal and dentoalveolar levels
and narrowing of the base of the nose.
• In general , the occlusal and skeletal features of class ||
malocclusion may remain stable or worsen to the stage of
mixed dentition . There are certainly no favourable
changes into a class | occlusion ..

12. Occlusal and craniofacial findings of class II
malocclusion during late mixed/permanent dentition stage
• A child with class II malocclusion presents with a
protrusive mid-face and/or a retrusive chin. They often
report with complaints of superior protrusion, front teeth
jutting out or showing too much.
.
Mid – face protrusive
Retrusive chin

13. This is often accompanied by a large overjet,
deep bite (open bite can be seen in some) and a
class II (distal) molar, premolar and canine
relationship.
.
Large over jet
Deep bite

14. These children have an aberrant pattern of
muscle activity of the facial musculature such as
a flaccid upper lip hyperactive mentalis and
lower lip trap under the procumbent upper
incisors.
Lower lip trap
under the
procumbent
upper incisors

15. The etiology may be attributed to mouth
breathing/prolonged thumb sucking which can be
elicited on carefully recording the history of the
patient….
THUMP SUCKINGMOUTH BREATHING

16. The underlying craniofacial pattern of class II children has
been extensively investigated. Most of the studies have
concentrated on angular, sagittal and vertical
measurements on lateral cephalograms. A few studies are
also available ontransverse dimensions using PA
cephalograms.
Cephalometric findings
PA. CEPHALOGRAMLAT. CEPHALOGRAM

17. A class II skeletal pattern may be associated with:
prognathic maxilla retrognathic mandible or combination
of these in varying severity…
Prognathic maxilla
Rertognathic mandible

18. McNamara5 observed two types of skeletal
combinationsin class II children. He found
mandibular retrusion thesingle most
characteristic feature which was attributed
toenvironmental factors such as :
abnormal muscle
function which
altered occlusal
interdigitations.

19. The skeletal maxillary protrusion was not the major finding.
But was rather neutral.
The 2nd was a combination of maxillary and mandibular
skeletal retrusion, often in association with altered mode of
respiration, i.e. mouth breathing.
These children with maxillary and mandibular retrusion
showed :
Greater vertical
development of the
face

20.  An excessive labial
proclination and forward
position of the maxillary
anterior teeth is a
common finding in class
IIdivision 1
malocclusion.
 The maxillary first
molar is more mesially
positioned ..
Class 2 division 1 , division 2 : the upper first molar mesially
positioned.

21. The anterior segment of maxilla is more
protrusive and superiorly positioned. Excessive
anterior cranial base length and enlarged frontal
and maxillary sinus may be a contributing factor in
the development of class IIdiv. 1 malocclusion.
The mandible and dentition were identical to those
of the controls in size, form and position..

22. Moyers et al6 (1980) have identified six
horizontal types of class II pattern which they
designated: A, B,C, D, E and F. They identified
five (1, 2, 3, 4, 5) vertical class II types ..

23. In brief, each case of class II malocclusion cannot
be placed in a single category or type, and it may
have a combination of sagittal, vertical and
transverse deviations of varying severity. Hence,
the treatment options may have to be considered
accordingly and should be chosen as a function of
disease entity. For type B and E, extraoral traction
to maxilla is suggested while for C, D and F
functional jaw orthopaedics is proposed….

28. Interception of developing class II malocclusion
Only limited orthodontic interventions are possible during
the deciduous dentition stage for the interception of
developing class II malocclusion…..
Orthodontic interventions in class II
malocclusion during deciduous dentition :

29. Maintenance of healthy primary dentition.
All efforts are directed
towards maintenance of the
healthy primary dentition
and thus integrity of arch
length. This is achieved
through education and
home care by all the
measures that minimize
occurrence of dental caries.
.

30. Restoration of carious teeth to their correct antero posterior
dimensions is absolutely essential especially proximal
carious lesions on deciduous molars.
The sole purpose is that permanent first molars should
occupy the space distal to 2nd deciduous molars and
should not prematurely migrate forward.
6E

31. Habits. Non-nutritive sucking habits such as prolonged
thumb and finger sucking are taken care of with appropriate
counselling and interceptive habit breaking appliance. A
child with recurrent throat infection, nasal blockages or
allergies should have ENT consultation to prevent mouth
breathing.
Mouth breathing ENT consultation

32. Orthodontic interventions in class II
malocclusion during mixed dentition..
1 - Cases involving essentially maxillary excess compared
to the mandible.
2 - Cases involving essentially mandibular retrusion .

33. Cases involving essentially maxillary excess compared to
the mandible. Involve guiding alveolar growth in class II
division 1 using headgear orthopaedic force.
Used in class 2 with open bite
cases to intrude molars
Used in class 2 with deep bite
cases to extrude molars

34. Kloehn (1953) was the earliest advocate of the use of
orthopaedic forces to change positions of teeth and so
influence the changes of the alveolar process in the maxilla.
During normal craniofacial and alveolar growth, alveolus
and teeth move forward and this can be intercepted. Thus
if the maxilla is restrained in class II patients, mandible will
follow its normal growth and reach to a normal relation with
the maxilla.

35. A cervical headgear with
a face bow is used to
restrain maxillary growth
and distalize the upper
dentition to
class I dentition.

36. Components of a face bow
Kloehn cervical facebow consists of an inner bow of 0.045"
diameter and an outer bow of 0.071" diameter. The inner
bow fits in the round headgear tube on the first molar
bands. Conventionally, a double buccal tube is welded and
soldered on to the maxillary first molar bands..
The inner face bow fits in the headgear tube on
first molar bands
Inner and outer facebow

37. the roundtube is housed as much gingival as permissible by
the15° (10°-20°) to the inner bow to prevent distal tipping
of the first molar crowns and prevent their extrusion
The inner bow is expanded, 8 to 10 mm larger than distance
between first molar tubes, and made parallel to the occlusal
plane.
The ends of inner bows are bent inwards to prevent the
rotation of the first molars in their position.

38. A force 350 gm is used from cervical gear to the outer bow.
The cervical headgear is recommended to be worn 12-14
hrs/day, in the evening and at night
It usually takes about 12 months to achieve class I molar
relation.
improvement in over jet. This phase of orthopaedic
correction is followed by full bonded fixed mechanotherapy

41. Age of treatment
Kloehn facebow can be used in suitable cases where
maxillary prognathism exists or mesial molar movement has
occurred. The facebow is indicated in early mixed dentition
when permanent maxillary first molars have erupted and can
be banded.

42. Filho et al8 recommended the onset of treatment
in the late mixed dentition or beginning of the permanent
dentition based on the belief that it often coincides with the
facial growth spurt. It may also have the advantage of
continuing the treatment with full-banded fixed appliance,
following completion of 12 months of the first phase.

43. cervical traction is continued during/or till the end of
activeclinical crown height. The purpose is to place it close
to centre of resistance of the first molar which is near the
trifurcation of the roots. The inner bow has stops against
molar tubes and are so adjusted that a space of 4-6 mm is
kept between the bow and incisors. The stops can be either
soldered or bent..

44. The outer face bow is extended to the tragus of the ear.
The rigid outer bow is maintained at an elevation of about
treatment to prevent relapse and enhance anchorage for
maxillary anterior retraction/overjet correction

46. Effect o f cervical headgear on dental/
craniofacial structures in sagittal, vertical and
transverse dimensions..
Following 12-18 months of treatment, there is a reduction
in maxillary protrusion, while mandible continues to
Grow normally. The distalizing effect on maxillary molars
causes them to erupt backward and downward, thus inhibit
loweringof the posterior region of the maxilla, while
anterior region continues to move downward.
.

47. There is a downward tipping
of palatal plane at the anterior nasal spine (ANS).
causes rotation of the palatal plane and slight increase in
SN-PP angle. The inferior descent or extrusion of upper
molars is essentially prevented by the forces of occlusion
from the masticatory muscles.

48. Transverse width of the maxilla improves from the
expanded inner bow, and allows an anterior displacement of
mandible and hence, improvement in the facial convexity.
The maxillary protrusion is reduced while sagittal position
of the mandible improves, which is measured as a reduction
in angle ANB. The improvement in craniofacial skeletal and
dental profile is sustained during the period of fixed
appliance therapy and post retention period.

49. Adverse effects
Unwanted side effects of Kloehn headgear can result from
the use of this method of treatment in high angle cases,
where molar extrusion and distal tipping may be significant.
This coupled with unfavourable growth of mandible and
clockwise rotation may bring about an undesirable outcome.
The success of the treatment is fully compliance dependent.
The appliance, if not worn correctly or in case of loose
molar band, breakage or welding failure of buccal tube(s),
may cause injury of various kinds and severity.

50. Long-term effects
The long-term effects of early headgear treatment on 8-year
follow-up have shown that headgear treatment shows a
significant reduction in number of extraction treatment as
compared to controls. The appliance inhibits the growth of
the maxilla and results in wider and longer arches. Its main
effect on maxilla is on the orientation of the maxillary plane.
The maxillary arch expansion achieved during early headgear
treatment results in a corresponding wide lower arch as an
adaptation to maxillary arch..
The arch expansion has been found to be maintained during
long-term follow-up

52. Summary
The forward growing maxilla can be intercepted during
mixed dentition utilising orthopaedic forces in right
direction and amount with Kloehn face bow
This modality of treatment was once very popular
especially in USA. The appliance is effective however
requires patient compliance..