ANTERIOR OPEN BITE ETIOLOGY AND MANAGEMENT

1. Anterior open bite aetiology and its
management
DR MAMOON
SARDAR BEGUM DENTAL COLLEGE

2. Contents
 Definition
 Etioiology of AOB
 MANAGEMENT

3. What is AOB?
 Defined as “ there is no vertical overlap of the incisors when
the buccal segment teeth are in occlusion
(laura Mitchell)

4. open bite
 Based on location
>anterior open bite
>posterior open bite
 Based on etiology
>skeletol
>dental
anterior open bite
posterior open bite

5. features of OB
DENTAL OPEN BITE
 Proclined maxillary and/or
mandibular incisors.
 Spacing between maxillary and/or
mandibular anteriors
 Narrow maxillary arch is a possibility
Extraoral features:
 No unusual features.
SKELETAL OPEN BITE
 Increased lower facial height
 A steep mandibular plane angle
 Vertical maxillary excess
 Pt may have short upper lips with
excessive maxillary incisor exposure
 Steep palatal plane and increased
percentage lower facial height
 Excess eruption of the maxillary
posterior teeth
 Downward and backward rotation of
the mandible
 Lip incompetence

7. Aetiology
 Both environmental and inherited factors are implicated in the etiology of
Anterior open bite..factors include
 Skeletal factors
 Habits
 Softtissue Pattern
 Localized failure of development
 Mouth breathing

8. aetiology
 Skeletol factors:
indivuals with tendency to vertical rather than horizontal facial growth
exhbit increases skeletol proportion
 when lowerface height increased Inc interocclusal
distance b/w maxilla & Mandible ,the labial segment
teeth able to compensate for this to a limited extentent by further eruption
…
when interocclusal distance exceeds this compensatory ability =>
ANTERIOR OPEN BITE WIL OCCUR AND worsened by downward and
backward facial growth

9. Patient with increased vertical skeletal
proportions and an
anterior open bite.

10. Lateral cephalometric radiograph of a patient with a
marked
Class II division 1 malocclusion on a Class II skeletal
pattern with increased vertical skeletal proportions

11. aetilogy
 Habits:
The effects of a habit depend upon its duration and intensity
Habits include digit sucking habit is likely to be the cause of Anterior open bite
If a persistant digit sucking habit continues into mixed and permanent
dentition result an Anterior open bite and cross bite due to
 Restriction of development of incisors
 Consrtiction of the upper arch is believed to be caused by cheek pressure
which predisposes to post CROSS bite

12. Note the anterior open bite and the unilateral posterior crossbite

13. Aetiology
 Lips and tongue habits:
Dentists and speech therapists often attribute open bite malocclusion to
abnormal tongue function
i.e tongue thrusting

14. Patient with an anterior open bite which was believed to be due to an tongue thrust. Both upper and lower
incisors were proclined. The patient did not have a digit-sucking habit.

15. Aetiology
 Airway obstruction:
Open-mouth posture adopted by individuals
who habitually mouth breathe, either
 due to nasal obstruction or habit results in overdevelopment of the
buccal segment teeth
 This leads to an increase in the height of the lower third of the face and
consequently a greater incidence of anterior open bite

16. aetiology

17. Management of AOB
 SEVERAL POSSIBLE APPROACHES:
REMOVAL OF THE CAUSE:
Open bite that have been diagnosed due to habit such as thumb
sucking,tongue thrusting, requires interception(in early age)
Treatment may involve
 Habit awareness
 Positive reinforcement
 Chemical a version
 Hand wraps
 Proper swallowing technique
 Habit breaking appliances(fixed type crib)etc
when the habit is prolonged beyond pubertal growth spurt the open bite
will not correct

18. Habit breaking Appliance

19. A patient aged 10 years with a
dummy-sucking habit
4 months after habit stopped.At presentation

20.  Growth modification
skeletol anterior open bite can be treated during the growth period using
functional appliance OR MODIFIED ACTIVATOR(these appliance incorporate bite
block i.e intrusive action on posterior teeth
Also preventing a downward and backward rotation of the mandible…
patient exhibiting a downward and backward rotation of the mandible with
increased vertical growth,
benefit from therapy using vertical pull headgear if treated during mixed
dentition period

21. Growth modification
 AOB with sk class 2 benefit from twin block appliance with highpull
headgear to correct the anterioroposterior discrepancy and whil
controlling the vertical dimension
After the functional phase, fi xed appliances are then used to complete arch
alignment,

22. A B
Intra-oral view of a van Beek appliance extra-oral view showing the high-pull
headgear

23. c d
lateral cephalometric radiograph of the
patient prior to treatment
AFTER
lateral cephalometric radiograph of the same patient 1
year later

24. Fixed appliances
 Successful reduction of AOB has been achieved using fixed
appliance mechanics that tip the molars teeth distally. This can be
achieved using multi-loop archwires or continuous ’rocking-horse‘ archwires
in conjunction with anterior vertical elastics.
The rationale is that as the molars tip distally the posterior vertical dimensions
reduce and the vertical elastics bring the incisors together as this happens.

25. The introduction of skeletal anchorage devices has also expanded
the envelope in terms of the severity of AOB that can be treated
non-surgically .A greater degree of molar intrusion can
be achieved utilizing bone anchorage either with screws or plates

27. surgical
 Superior repositioning of the maxilla, via total or segmental maxillary
osteotomies, is indicated in skeletal open bite patients with excess vertical
maxillary growth
 Maxillary impaction allows forward and upward rotation of the mandible,
thereforedecreasing the lower face height and eliminating anterior open
bite