3. Overbite
Definition:
overbite defined as “the overlapping of the upper anterior teeth
over the lowers in the vertical plane”.
“the amount and percentage of overlap of the lower incisors by
the upper incisors” .
ideal overbite ranges from 5-25% overlap.
5-25% normal (yellow),
25-40% increased (orange)
>40% excessive (red)
Ranges of overbite.
4. The maxillary dental
arch being LARGER
than the mandibular
arch allows the
maxillary anteriors to
overlap the
mandibular anteriors.
Thus some degree of
vertical overlapping
(overbite) is a normal
feature of human
dentition.
5. However, some patients present with excessive overbite.
Such a condition where there is an excessive
vertical overlapping of the mandibular
anteriors by the maxillary anteriors is called
deep bite.
front upper incisor and
canine teeth project over
the lower.
• Also called vertical
overlap.
6. Deep bite is one of the most common malocclusion seen in
children as well as adults that can occur along with other
associated malocclusions.
مؤذ
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It is said to be one of the most deleterious malocclusion
when considered from the viewpoint
of the future health of the
masticatory apparatus and
the dental units.
7. Prevalence
The prevalence of severe deep bite varies between racial groups
twice as common in Caucasian Americans
compared to African Americans and Hispanics
3-4 mm
5-7 mm
> 7 mm
8. Tow types of deep verbite:
• an incisor relationship • an incisor relationship in which
in which the lower the lower incisors contact the
incisors fail to occlude palatal surface of upper incisors
with either the upper or the palatal tissue when the
incisors or the mucosa teeth are in centric occlusion
of the palate when the (results in trauma of the
teeth are occluded mucosa palatal to maxillary
Incomplete incisors.
overbite Complete overbite
11. If not treated, deep bites can result in:
TRAUMA to the palatal mucosa
- behind the upper incisors or
- to the labial gingiva of the lower incisors
This can result in
Painful soft tissue and periodontal defects
overbites greater than 40% as excessive,
compromising the periodontal tissues
and acting as a co-contributing factor in
the aetiology of TMD.
12. Excessive ATTRITION of anterior teeth,
especially lower incisors, is often associated with a deep anterior overbite and bruxism
13. Aetiology and Diagnosis
Aetiology of Deep bites:
Environmental Genetic
Play a role in the development of deep bites.
14. CLASSIFICATION & Aetiology:
A) Developmental deep bite B) Acquired Deep Bite
1) Skeletal deep bite 1) Lateral Tongue Thrust
- horizontal growth pattern 2) Early loss of Deciduous Teeth
2) Dento alveolar deep bite 3) Wearing of Occlusal Surface
- supra erupted incisors
- infra eruption of molars
15. Skeletal deep bite
Usually of
Caused by:
genetic origin
- Upward & - Downward &
forward rotation of forward inclination
the mandible of the maxilla
16. Caused by: Skeletal deep bite
- Upward & forward rotation of the mandible
- Downward & forward inclination of the maxilla
- Combination
17. - Characterized by the presence of the following features:
Patients exhibit a
horizontal growth The anterior facial
height is reduced
pattern.
parallel horizontal
A reduced inter-
planes (mandibular
occlusal clearance
plane, F.H. plane, S.N.
(freeway space).
plane
18. Skeletal Deep Bites:
Also described as brachyfacial or hypodivergent facial pattern
skeletal deep bites exhibit characteristics including
- Reduced lower anterior face height,
- Reduced mandibular plane angle and
- Reduced gonial angle.
19. Skeletal Deep Bites:
Also described as brachyfacial or hypodivergent facial pattern
skeletal deep bites exhibit characteristics including
- Reduced lower anterior face height,
- Reduced mandibular plane angle and
- Reduced gonial angle.
22. Skeletal Deep Bites:
Cephalometrically :
Acute cranial base angle
reduced Jarabak ratio
(proportion of posterior
face height to anterior face
height)
reduced Y-axis
increased ramal length
forward growth rotation of the mandible
Deep bites are often associated
with Class II malocclusions
23. Dental deep bite
Characterized by
the absence of any skeletal complicating
features which are seen in skeletal deep bites.
- - Occurs due to:
a. Over-eruption of anteriors
or
b. Infra-occlusion of molars.
• Tooth loss can contribute to an occlusal
imbalance resulting in lingual collapse of
the anterior teeth and a deepening of the
anterior bite Deep bites are commonly
associated with an excessive Curve of Spee
24. Deep bites due to over-eruption of anteriors:
Usually seen in
Class II Excessive curve
malocclusion of Spee
Molars are
fully erupted
overjet the lower incisors
allows over-erupt
until they meet the palatal mucosa Normal inter-occlusal clearance
25. - Deep bites due to infra-occlusion of molars:
Characterized by:
- Occur due to:
1) Infra-occlusion of molars
2) Lateral tongue posture or lateral Large inter- The presence
tongue thrust (prevent the molars occlusal of partially
clearance erupted molars
from erupting to their normal
occlusal level)
3) Premature loss of posterior teeth
Reduced crown length
26.
27. Soft Tissue Deep Bites:
Deep bites are often associated with Class II malocclusions
Hypodivergent (short) facial patterns tend to have: -
- stronger mandibular elevator musculature and
- high mentalis activity
- a deep mento-labial fold and
- everted lower lip.
28. Diagnosis
It is important to assess the patient facially, skeletally and
dentally to ensure correct diagnosis of the vertical dimension
29. - The routine diagnostic aids:
Identification of the aetiology of the deep bite
will allow formulation of appropriate
treatment mechanics.
30. Successful treatment requires:
Careful analysis of the several possible
contributing factors and this warrants a
detailed clinical and cephalometric
examination.
31. Tow modalities to correct deep bite:
- Intrusion of the - Extrusion of the
anterior teeth or posterior teeth
32. DIAGNOSTIC CONSIDERATIONS IN MANAGEMENT OF DEEP BITE
1)Soft tissue considerations
2)Dental considerations :
3)Skeletal considerations :
33. 1)Soft tissue considerations
a)Interlabialgap :
2 to 3 mm is normal.
If interlabial gap is EXCESSIVE, molar
EXTRUSION should be AVOIDED.
b)Smile line :
In case of GUMMY SMILE , INTRUSION
of maxillary incisors should be done.
c)Lip length :
In cases of SHORT UPPER LIP,
INTRUSION should be carried out.
34. 2)Dental considerations :
Incisor INTRUSION is ideal to treat
deep bite in cases of SUPRAERUPTION
and GUMMY SMILE.
It maintains the vertical dimension.
Upto 4 mm
of incisor intrusion can be
achieved.
35. 3)Skeletal considerations :
In case of decreased lower anterior face height ,
EXTRUSION of molars is acceptable but it should
be attempted only in growing children.
If the same is
attempted in adults,
the stability of the
result will be
questionable.
In patients with increased
face height, INTRUSION of
anteriors should be
considered.
36. Factors to be considered in treatment of deep bite
- Decision whether to intrude the anteriors or extrude the
molars depend on certain factors include:
(a)lip relationship
(b) vertical facial relationship
(c) inter-occlusal space
37. Lip relationship
INTRUSION of the anteriors.
- Patients with a shorter upper lip or a
gummy smile should be treated by
EXTRUDE the molars.
- Patients exhibiting
normal upper lip with
only 2 – 3 mm of
maxillary incisal edge
exposed, it is deal to
38. Vertical facial relationship
EXTRUSION of one or more posterior teeth
- usually results in downward & backward
rotation of the mandible (increase anterior facial
height).
-This can be a benefit in treating
skeletal deep bites with excessive
horizontal growth & upward
rotation of the mandible
39. - The average inter-occlusal space is 2-4 mm in the
Inter-occlusal space
premolar region.
- Increase inter-occlusal space is an
indication that molars are not fully erupted
(treated by EXTRUSION of posterior teeth).
- The presence of normal inter-occlusal
space is an indication for INTRUSION of
incisors rather than extrusion of molars.
- Reduction of normal inter-occlusal space by extrusion
of molars can result in fatigue of the muscles of
mastication which get stretched & predispose to
relapse.
41. Orthodontic treatment mechanics to correct a deep bite must be specific for:
- the TYPE of deep bite and
- ETIOLOGICAL FACTORS identified in the diagnosis for each individual patient
- The amount of GROWTH remaining also affects treatment decisions and modalities.
Deep bite corrections achieved during periods of active growth have been
found to be more stable than those in adult patients
42. Treatment modalities include:
1. Intrusion of upper and or lower incisors
2. Extrusion of upper and or lower posterior teeth
3. A combination of anterior intrusion and posterior extrusion
4. Proclination of incisors
5. Adult surgery
43. 1. Intrusion of upper and or lower incisors
•1) Relative intrusion:
It is achieved by preventing eruption of •2) Absolute intrusion:
the incisors while growth provides There is pure intrusion of the incisors
vertical space into which the posterior without extrusion of the posterior
teeth erupt. teeth.
J-Hook headgear
Anterior bite plate
Bypass and segmental mechanics
Twin-Blocks
Particularly with the assistance Implants
of mandibular growth
44. Methods of relative intrusion include
- Anterior Bite Plates contacting the anterior
dentition while allowing posterior eruption
- Twin-Blocks, where differential molar eruption
can occur by trimming the posterior blocks.
- Ant Bite Turbos
45. Anterior bite plate :
This disoccludes the posterior teeth and
hence causes their extrusion
It can be used in growing patients.
Stability of bite opening by
extrusion will be
questionable in adults
especially those who have
brachycephalic and
horizontal growth pattern
48. RELATIVE INTRUSION:
A)Reverse curve of Spee :
It mainly causes extrusion of the
posterior teeth. However there may be
undesirable changes in the axial
inclinations of the buccal teeth and
flaring of the incisors.
49. B)Anchor bend:
These bends are incorporated in the archwire, just mesial to the first
molars and are used in conjunction with Cl II elastics.
50. Absolute intrusion :
- involves moving the dentition deeper into bone and
- can be used in both adolescent treatment and adult orthodontic
treatment where there is no growth
Methods of relative intrusion include
) J-Hook headgear
) Bypass and segmental mechanics
) Temporary skeletal anchorage
(Micro Implants)
51. J-Hook headgear:
J-Hook headgear can also be used for
J-Hook Headgear
intrusion of the anterior segment and it
produces absolute intrusion
52. Bypass and segmental mechanics
The bypass arch is a continuous
arch wire that bypasses the
premolars (and often canines) to
maintain light forces by lengthening
the span between molars and
incisors
53. Micro Implants : Temporary skeletal anchorage
Today, en masse intrusion of all
anterior teeth is possible using
temporary skeletal anchorage
without relying on traditional,
compliance dependent extra-oral
appliances, or less predictable
segmental intrusion mechanics.
Implants can be used for true intrusion of anteriors or a combination of intrusion
and retraction depending upon the site of implant placement and direction of
force delivery.
54. 2. Extrusion of upper and or lower posterior teeth
Active extrusion of the posterior teeth results in:
an increase in lower anterior face height
generally associated with a downward and backward rotation of
the mandible. achieve posterior extrusion.
56. 3. A combination of anterior intrusion and posterior extrusion
Commonly used this can be achieved by :
- placing anterior brackets more incisally and posterior brackets more gingivally or by-
- using reverse-curve archwires..
58. 5. Adult surgery
In severe adult skeletal deep bite cases,
ORTHOGNATHIC SURGERY is an option to increase the efficiency of
orthodontic mechanics, improve facial aesthetics and enhance long-
term stability
59. Surgical options include:
mandibular advancement, maxillary surgery and
sub-apical osteotomy.
mandibular advancement Anterior segmental osteotomies
61. The successful treatment of deep bite correction
depends on
- an elaborate clinical examination,
- thorough cephalometric analysis,
- judicious treatment planning among the various
available options and by
- using appropriate mechanotherapy followed by
- a proper retention protocol.
62. Mechanics for overbite reduction
The following mechanisms are available for overbite
reduction
- removable acrylic anterior bite planes
- fixed anterior bite planes
metal e.g. bite turbo
composite bite buttons
- high-pull headgear to incisors
- archwire curves of Spee
- archwires with step-down T loops
- sectional archwires
- class 2 elastics
- segmental surgery
63. Deep bites can be treated using:
Removable appliances
Myofunctional appliances
Fixed appliances
64. REMOVABLE APPLIANCES
- The anterior bite plane is a modified Hawley’s appliance with
a flat ledge of acrylic behind the upper incisors.
- The anterior bite plane consist of
1) Adam’s clasps on the molars (help in retaining the
appliance)
2) A labial bow (counter any forward movement of
incisors)
3) Base plate with anterior bite plane (1.5 – 2 mm)
- As the posterior teeth erupt the height
of the bite plane is gradually increased.
70. Myofunctional appliances
- Activator:
can be used to treat deep bites diagnosed to
be due to infraocclusion of molars &
trimmed to allow the extrusion of these
teeth.
- Bionator can be used for a
similar purpose.
71. Fixed appliances
1) Use of anchorage bends:
given in the arch wire mesial to the
molar tubes (the anterior part of the
arch wire lies gingival to bracket slot)
2) Use of archwires with reverse curve of Spee.
72. 3) Use of utility arches:
Utility arches are arch wires that are
bent in such a way that they bypass the
buccal segment & are engaged on the
incisors (activated by giving a V bend in
the buccal segment of the wire.
73. The stability of deep bite correction has been a challenge to the orthodontist.
In most of the cases it REQUIRES:
a prolonged RETENTION protocol
usually constitutes use of a removable appliance
with a potential biteplane incorporated on to it.
