The document discusses open bite, a condition characterized by a lack of vertical overlap between maxillary and mandibular teeth, affecting speech, swallowing, and aesthetics. It outlines the types of open bite (anterior and posterior), their origins (dental or skeletal), etiological factors, clinical features, and treatment options for both. Treatments vary from orthodontic appliances to surgical interventions depending on the severity and type of open bite.

1. Vertical Plane Discrepancies
(Open Bite)
By : DR. Mohammed Almoosawi

2. OPEN BITE
 Difinition
 Lack of vertical overlap between maxillary and mandibular teeth in centric
occlusion is referred to as open bite. Open bite may be dental or skeletal in
origin. It can occur in anterior or posterior segment of the dental arches
and are called as anterior open bite and posterior open bite respectively.
Posterior open bite may be unilateral or bilateral.
 Anterior open bite is unesthetic and may pose difficulties during speech
and swallowing. Posterior open bite may affect mastication depending on
the severity

3. CLASSIFICATION OF OPEN BITE MALOCCLUSIONS
 Based on dental or skeletal components
 Dental
 Skeletal
 Based on location
 Anterior
 Posterior

5. ANTERIOR OPEN BITE
 Th e vertical overlap of permanent maxillary anteriors over the mandibular
anteriors in normal occlusion is referred to as “overbite,” which is ideally
about 2 mm. When there is no overlap of upper anterior over the lower
anterior, such a condition is known as “Anterior open bite.
 Anterior open bite may be of dental or skeletal origin.
 can be caused by a number of etiological factors such as
 1. HABITS
 2. Abnormally increased tongue size
 3. Abnormal growth pattern

6. Habits
 Thumb/Digit sucking habit: Abnormal pressure habits like thumb/digit
sucking cause forward placement of pre-maxilla, narrowing of the maxillary
arch and proclination of maxillary anterior thereby disturbing the normal
vertical relationship of anterior teeth.
 Anterior tongue thrusting habit: Habitual tongue thrusting causes
proclination and flaring of upper anterior, leading to anterior open bite.
 Mouth breathing: Mouth breathing habit due to any nasopharyngeal
obstruction may also cause prognathic premaxilla, proclined upper anterior
and thus anterior open bite.

7. Abnormally increased tongue size
 Abnormally increased tongue size can be
 Inherited
 Acquired
 Macroglossia ( large tongue ) caused due to hereditary or acquired factors
may also lead to anterior open bite by exerting pressure on the lingual
surfaces of upper anterior

8. Abnormal growth pattern
 Any abnormalities in the growth pattern of maxilla, mandible or both may
lead to anterior open bite:
 1. Counter-clockwise rotation of the maxilla.
 2. Clockwise rotation of the mandible
 3. Counter–clockwise rotation of the maxilla and clockwise rotation of the
mandible.
 4. Vertical maxillary excess.

9. Abnormal growth pattern

10. Clinical Features of Dental Anterior
Open Bite
 Open bite confined to anterior segment only.
 Maxillary anterior teeth proclination.
 Proclination of mandibular anterior teeth .
 Spacing may be present in maxillary and/or mandibul aranterior segments.
 Narrow maxillary arch.
 Fish-mouth appearance may be present.

11. Clinical Features of Dental Anterior
Open Bite

12. Clinical Features of Skeletal Anterior
Open Bite
 I. Extraoral Features of Skeletal Open Bite
 1. Lips
 a. Incompetent lips
 b. May show hyper tonicity
 c. May be averted
 2. Increased anterior facial height and decreased posterior facial height.
 3. Increased lower anterior facial height and decreased upper anterior facial height .
 4. A steep mandibular plane angle.
 5. Decreased nasolabial angle .
 6. Shallow mentolabial sulcus .
 7. Cephalometric examination may show
 a. Clockwise rotation of mandible and/or anticlockwise rotation of maxilla
 b. Vertical maxillary excess.
 c. Steep anterior cranial base.

13.  II. Intraoral features of skeletal open bite They are as listed below :
 1.Narrow maxillary arch
 2. Anterior or posterior open bite
 3. Excessive gingival display
 4. Decreased freeway space
Clinical Features of Skeletal Anterior
Open Bite

14. Clinical Features of Skeletal Anterior
Open Bite

15. RADIOGRAPHICAL Features of Skeletal Anterior
Open Bite

16. Treatment of Dental Anterior Open Bite
 1. Removal of the Cause

17.  2. Treatment of Anterior Open Bite using Fixed Orthodontic Appliance
 Open bites are more difficult to treat and are more unpredictable in their prognosis
than deep bites. Open bites are ideally treated by intrusion of posterior teeth,
thereby permitting counter clockwise rotation of the mandible. Extrusion of anterior
teeth represents a dental compensation and is achieved with box elastics or
extrusion arch wire.
 Mild to moderate dental anterior open bite can be successfully treated using fixed
orthodontic appliance with box elastics. The elastic is stretched in the form of a box
encircling all the four canine teeth . This causes extrusion of the anterior, thereby
closing the anterior open bite. However, this method is not advisable in skeletal
anterior open bite
Treatment of Dental Anterior Open Bite

19.  3. Myofunctional Orthodontic Appliances
 Skeletal anterior open bite can be successfully treated during growth
period using Franckel IV or modified activator. Posterior bite blocks
incorporated in these appliances cause intrusion of maxillary and
mandibular posterior teeth thereby improving the anterior open bite
Treatment of Dental Anterior Open Bite

20.  4. Orthopedic Appliance
 A chin cup with vertical pull head cap can be used for treating skeletal
anterior open bite, caused due to clockwise rotation of the mandible
during mixed dentition period.

22.  5. Surgical Correction
 Skeletal open bite in adults can be treated surgically after correction of the
habit by Le Fort I ostectomy of the maxilla.

24. POSTERIOR OPEN BITE
 Posterior open bite is characterized by the lack of contact between the
posteriors when the teeth are in centric occlusion. Posterior open bite can
be unilateral or bilateral.
 1. Unilateral posterior open bite: Occurrence of posterior open bite on one
side of the arch is referred as unilateral posterior open bite.
 2. Bilateral posterior open bite: Occurrence of posterior open bite on both
sides of dental arches is termed as bilateral posterior open bite

25. POSTERIOR OPEN BITE

26.  Etiological Factors Causing Posterior Open Bite
 1. Lateral tongue thrusting habit.
 2. Ankylosed/submerged posterior teeth fail to reach the occlusal plane
and thus may cause posterior open bite.
POSTERIOR OPEN BITE

27.  Treatment of Posterior Open Bite
 1. Removal of the Cause
 In most cases eventual closure of posterior open bite occurs followed with
cessation of the tongue thrusting habit.
 2. Treatment of Posterior Open Bite using Fixed Orthodontic Appliance
 Posterior open bite caused due to ankylosed/submerged teeth that can be
corrected by forced extrusion of the antagonistic teeth using fixed orthodontic
appliance , or by restoring the normal occlusal level using crowns on
submerged teeth.
 3. Treatment of Skeletal Open Bite Skeletal open bite
 In growing patients can be treated using functional appliance such as
bionator or Frankel appliance.
 A skeletal open bite in non-growing patients is best treated by orthognathic
surgery
POSTERIOR OPEN BITE

29. Retention after Open Bite
 Correction Excessive vertical growth and eruption of the posterior teeth
often continue until late in the teens or early twenties, so retention must also
continue till then. An appliance with posterior occlusal stops (posterior bite
plane), e.g. an open bite activator or bionator, can provide forces
opposing eruption of posterior teeth.

30. REFERENCE
 1. an introduction to orthodontics by Simon J. Littlewood and Loura Mitchell
fifth edition
 2. ORTHODONTICS Principles and Practice by Basavaraj Subhashchandra
Phulari second edition
 3. Baghdad university lectures