This document discusses open bite, including its definition, classification, causes, and management. Open bite is classified as anterior, posterior, dental/simple, or skeletal/complex. Causes include hereditary factors, environmental factors like mouth breathing, thumb sucking, and trauma. Management depends on the patient's age and involves things like habit control, growth modulation, functional appliances with bite blocks, and sometimes orthognathic surgery. High pull headgear is discussed as a way to control vertical growth.

1. Zainab Haji
Roll # 12
Dept of Orthodontics

2. 
Definition

Classification

Causes

Management

3. 
Malocclusion in vertical plane.

A deviation in the vertical relationship of the
maxillary and mandibular dental
arches characterized by a definite lack of
contact between opposing segments of
teeth.” (Daniel Subtelny, 1964).

“Localized absence of occlusion while the
remaining teeth are in occlusion” (Moyer’s).

4. 
According to location:
Anterior OB.
Posterior OB.

According to cause:
Dental or simple OB.
Skeletal or complex OB.

5. 
Anterior OB:
“Absence of contact between the maxillary
and mandibular incisors at centric relation (Worms 1971).”
Absence of vertical overlap of incisors.

Posterior OB:
“Lack of contact between the posterior teeth
when the teeth are in centric occlusion.”

Dental (Simple) OB:
When the basal skeleton is normal and
the open bite is confined to the teeth and alveolar processes.

Skeletal OB:
Results from skeletal dysplasia, so severe that
the alveolar processes cannot cope to maintain occlusal stops.

6. Dental openbite
 1) Heredity
Secondary to class III malocclussion.

7. 2) Environmental

8. change in mode of respiration
,lowers the mandible and the
tongue
 supra-eruption of posterior
teeth
 downward and backward
rotation of mandible
 increased facial (ant) height.

Factors that cause mouth
breathing Enlarged adenoids or tonsils.
 naso-pharyngeal deformities.
 Enlarged turbinates.
 Allergic rhinitis, nasal
polyps, etc.

9. Normal upto 4-5 years
- Inadequate development of the
anterior alveolar process.
 - Incomplete eruption of the incisor
teeth


Accommodation of thumb
Lowered positioning of mandible
Alteration in vertical equilibrium
Excessive eruption of posterior teeth

10. 




defined as placement of the
tongue tip forward between
the incisors during
swallowing”.
Transitional
Displaced incisors
Trauma
Failure of eruption

11. Excessive tipping of the
buccal segments.
Elongation of lingual cusp
Premature contacts
Open Bite
Distalization:
Expansion
treatment:
as a consequence of orthodontic
therapy
Distalization of 6 l 6
Distal tipping
Elongation of mesial cusps
OpenBite (Great concern in
vertical grower)

12. Jaw rotation during
growth.
 The palatal plane
rotates downward
posteriorly.
 Mandible shows
backward rotation
with an increased in
MPA

13. Diagnosis:



Extraoral
Intraoral
Cephalogram
Treatment:

Deciduous dentition

Mixed dentiton:
-habit control
-growth modulation

15. 







Gaining confidence of the
patient
Education to the patient
Reminder Therapy
Reward Therapy
Restriction Therapy:
Appliance :
Vestibular screen.
Tongue crib

16. Bluegrass appliance

17. 
Only if associated with long face syndrome.
I. HIGH PULL HEADGEAR TO THE MOLARS:
 Maintains the vertical position of the maxilla.
 Inhibits eruption of the maxillary posterior teeth..
 Duration
:
14 hours, putting the headgear right after dinner
and wearing it until next morning.
 Force
:
350 – 450 gm / side (12 – 16 ounces).
 Drawback
:
It does not control the eruption of other teeth.
II. HIGH PULL HEADGEAR TO A MAXILLARY SPLINT:
 acrylic splint to which a face bow and HP headgear is attached.
 appears to have substantial maxillary skeletal and dental effect with
good vertical control.
 Unfortunately, this appliance allows mandibular posterior teeth to erupt
freely, and if this occurs, there may be neither redirection of growth for
favorable upward and forward mandibular rotation.

19. III. FUNCTIONAL APPLIANCES WITH BITE BLOCKS :
The retraction force of headgear is replaced by the
somewhat lesser “headgear effect” of the functional
appliance with posterior bite block
Purpose:

To inhibit eruption of posterior teeth and vertical
descent of the maxilla.

When the mandibular is held in this position by the
appliance, the stretch of soft tissues (including but not
limited to the muscles) exerts a vertical intrusive force in
the posterior teeth.

In children with AOB the anterior teeth are allowed
to erupt, which reduces the OB.

As this allows the mandible to position
forward, horizontal growth of mandible can be
encouraged.

20. IV. HP HEADGEAR TO A FUNCTIONAL APPLIANCE
WITH BITE BLOCKS:
 Most effective approach in OB classII.
HP headgear:
 Increases the control of maxillary growth.
 Allows the force to be delivered to the whole maxilla
 Improves retention appliance.
 Produces force direction near the estimated center of
resistance of the maxilla.
 The headgear tube – is incorporated in premolar
regions.
 Force = 250 – 500 /side

22. High pull headgear to a maxillary
molars



High pull headgear to maxillary
splint
Functional appliance with bite blocks

High pull headgear to a functional
appliance with bite blocks

23. 

Surgical Orthodontics is a term that refers to
surgical procedures carried out as an adjunct
to or in conjunction with orthodontic
treatment.
Orthognathic surgery is a surgical procedure
carried out along with orthodontic therapy to
correct dento-facial deformities or severe
orofacial disproportion involving the
maxilla, the mandible or both in combination.

24. 
I. MAXILLARY SURGERY:
 LeeForte I down fracture of maxilla, or.
 Segmental maxillary osteotomy, and
 Combination.

II. MANDIBULAR SURGERY:
1. BSSO (BILATERAL SAGITTAL SPLIT OSTEOTOMY)
2. INVERTED ‘L’ OSTEOTOMY OF RAMUS WITH RIF:
III. SUPERIOR REPOSITIONING OF THE CHIN BY A
MANDIBULAR LOWER BORDER OSTEOTOMY

26. (AOB NOT RELATED TO LONG FACE):
 There are 2 major possibilities:
1-Deficient eruption of maxillary incisor:
*LeForte 1 osteotomy with or without
anterior and posterior components.
*Maxillary anterior segmental osteotomy.

27. 2-AOB due to deficient eruption of mandibular
incisors +excessive eruption of posterior
teeth:
*anterior subapical osteotomy
*total submandibular sub-apical osteotomy

28. 





Worms F.W, Meskin L.H, Isaacson R.J., Open bite. AJO
1971; 59:589-95.
Klein: The Thumb sucking habit: Meaningful or Empty.
AJO 1971.
Bishara.
Clinical Biomechanics, Seminar Orthodontics; March
2001, Vol 7. No.1.
Carano A., Machita W. A rapid molar intruder for `Noncompliances treatment’ . JCO 2002 March; 8: 137-142.
Iscan M.N. Akkaya Sevil and Koralp E. The effects of the
spring - loaded posterior bite-block on the maxillo-facial
morphology. Eur J Orthod 1992; 14:54-60.