Diagnosis & management of anterior open bite.

1. Anterior open bite of mixed dentition
(Diagnosis & Management)
Introduction(1) Anterior open bite is defined as no contact and vertical overlap between the
maxillary and the mandible incisors. The incidence of anterior open bite ranges from 1.5% to
11% and varies between races and with dental age. The complexity of anterior open bite is
attributed to combination of skeletal, dental, soft tissue, and habitual factors.. However, there is a
tendency toward relapse after conventional or surgical orthodontic treatment.
Etiology of anterior open bite(2)The etiology of anterior open bite is multifactorial:
Habits
i. Prolonged thumb-sucking habit is one of the chief etiological factors of open bite.
ii. Tongue thrusting is also implicated for some cases of open bite.
Skeletal : An overgrowth or undergrowth of one or more alveolar segments. posterior open bites
there is undergrowth of the posterior alveolar segment.
a) Increased anterior and decreased posterior facial height.
b) Vertical growth pattern or backward rotation or clock wise rotation of the of the lower jaw.
c) Anticolock wise rotation of the maxillary base.
Dental: When there is only dental and dentoalveolar involvement, there is predominance of
environmental causes such as thumb or dummy sucking habits, mouth breathing, and tongue or
lip thrusting in addition to some local factors such as tooth ankylosis and eruption disturbances
that result from over eruption of the anterior teeth.
Features of open bite
Features of skeletal anterior open bite: The anterior skeletal open bite is called Apertognathia.:
a. The patient often has a long and narrow face with marked convex profile.
b. The patient may have a short upper lip with excessive maxillary incisor exposure.
c. Increase lower anterior facial height and decreased upper anterior facial height.
d. Small mandibular body and ramus.
e. Divergent jaw bases as well as other horizontal cephalometric planes.
Features of dental anterior open bite :
a. Proclined upper anterior fail to overlap each other resulting in a mild open bite.
b. The patient may have a narrow maxillary arch due to lowered tongue posture due to a
habit.
c. There may be spacing between the upper and lower anteriors.

2. Diagnosis : Diagnosis should include a thorough case history pointing to critical examination
towards the presence of any etiological factors like habits. Hereditary content it present should
be noted. The cephalometric analysis will differentiate a dental from a skeletal component.
Management: The treatment for open bite problems ranges from observation or simple habit
control procedures to complex surgical procedures . (3)
The CDABO group defined early treatment as that initiated during the primary or the mixed
dentition stage to enhance dental and skeletal development before the eruption of the permanent
dentition. (4)
treatment should begin when the patients are 7 to 8 years of age, as soon as they are mature
enough to cooperate during treatment. Treatment techniques can be categorized as follows:
Habit therapy : Inyoung children, the treatment consists of controlling the habit. A habit
device can be incorporated into the maxillary expansion appliance to correct both the transverse
(maxillary constriction) and vertical problems . Appliances such as tongue cribs have been used
to treat anterior open bites by redirecting an anteriorly positioned tongue.(3)
Appliance therapy :
Posterior bite blocks: Posterior bite blocks impede posterior teeth eruption and their design
has been continuously modified. They can be made of wire or plastic to fit between the maxillary
and mandibular teeth, or they can be spring-loaded or fitted with magnets. It helps control
eruption and permits an upward and forward autorotation of the mandible.
Vertical chin cup: The vertical chin cup, together with fixed appliances, has been used to
manage anterior open bite in growing patients. In an investigation of 4-bicuspid extraction
followed by application of a vertical-pull chin cup for an average of 9 months and then fixed
appliance therapy, the mandibular plane angle decreased by an average of 4 degree and all open
bites closed
High-pull headgear: high-pull headgear reduces the vertical eruption of upper molars. Such a
change in the dentoalveolus minimizes clockwise rotation and, in some cases, results in
counterclockwise rotation of the mandible. the use of acrylic splints combined with high-pull
headgear among patients with Class II division 1 malocclusion and maxillary dentoalveolar
protrusion resulted in a superior and distal displacement of the maxilla, reduction in the SNA
angle, clockwise rotation of the palatal plane, and relative intrusion of the upper molars .

3. Vertical holding appliance: is a modified transpalatal arch. The VHA uses tongue pressure
to reduce the vertical dentoalveolar development of maxillary permanent first molars .
Fränkel IV regulator:its acting as an exercise device and leading to postural balance between
the forward and backward rotating muscles.
Use of elastics: Fixed appliance treatment with the use of vertical elastics is a common method
of correcting open bites. One of these techniques is the multiloop edgewise archwire (MEAW)
technique .
Extractions: Extraction of the first premolars has been accepted by many clinicians in the
management of skeletal open bite due to the draw-bridge effect of reducing the inclination of
both upper and lower incisors to increase overbite. Alternatively, molars can be extracted, to
supposedly remove the wedge that opened the bite.
Camouflage treatment of anterior open bite: Some mild cases of open bite can be
corrected by fixed appliances that cause dental movements while the skeletal profile and
characteristics are kept unchanged. (5)
Surgical management: One method of surgical correction is to extract second and/or third
molars. Severe skeletal open bites in patients who are not growing are often treated by combined
orthodonticsurgical approach. Superior repositioning of the maxilla via total or segmental
maxillary osteotomies, Superior repositioning of the maxilla is one of the most stable
orthognathic surgical procedures.(3)
Stability of open bite correction: Retention of closed anterior open bite is a major problem.
One reason is that vertical growth and eruption of posterior teeth may continue until the late
teenage years or early twenties, with vertical growth of the maxilla being the last stage of
maturation . Studies indicates that the relapse rate is about 40%. Clinicians attempt to retain the
corrected open bite for growing patients by applying a vertical chin cup or high-pull headgear to
the upper molars in conjunction with a standard removable retainer. An orthodontic appliance
with bite blocks between the posterior teeth, such as an open bite activator or a bionator, can also
be used. (5)
Prepared by :
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Reham Altayepmustafa : 1002012055 TasneemmohammedTawfeeq: 100 20 12189
Noor Abdulrahman : 100 20 120 52 Rana Hamid: 100 20 120 65
Rolla Mira: 110 20 121 66 Layala Daghistany: 100 20 121 40