<ul><li>Open bites can occur in the anterior or posterior region and are called anterior open bite and posterior open bite.</li></li></ul><li>ANTERIOR OPEN BITE<br /><ul><li>Def. is the condition where there is no vertical overlap between the upper and lower anteriors. </li></li></ul><li><ul><li>Anterior open bites are esthetically unattractive particularly during speech when the tongue is pressed between the teeth and lips.</li></li></ul><li><ul><li>AOB can be classified as;
FEARTURES!<br />SKELETAL<br />DENTAL<br />Increased lower anterior facial height.<br />Decreased upper anterior facial height.<br />A steep mandibular plane angle.<br />Small mandibular body and ramus.<br />Proclined upper teeth.<br />The upper and lower anteriors fail to overlap each other.<br />The patient may have a narrow maxillary arch duo to lowered tongue posture duo to a habit.<br />
TREATMENT<br /><ul><li>REMOVAL OF THE CAUSE!</li></ul>Habits, by passive habit breaking appliance.<br />Habit breaker appliance can be either fixed or removable.<br />Persistence of all the causes will offer a sever limitation in the corrective procedures!! <br />
<ul><li>Myofunctional therapy!</li></ul>Functional appliance, e.g. head gear with chin cup for pt exhibiting a downward and backward rotation of the mandible with increased vertical growth (if treated during mixed dentition period).<br />
<ul><li> ORTHODONTIC THERAPY!</li></ul>Mild to moderate open bite can be successfully managed using fixed appliance with box elastics.<br />Elastic that is stretched to extend between the upper and lower anteriors.<br /> this brings extrusion of the upper and lower anteriors.<br />
Mechanical interference with eruption, either before or after the tooth emerges from the alveolar bone.
Failure of the eruptive mechanism of the tooth so that the expected amount of eruption does not occur.</li></li></ul><li>
NB.<br /><ul><li>Mechanical interference with eruption may be caused by ankylosis of the tooth to the alveolar bone, which can occur spontaneously or as a result of trauma, or by an obstacles in the path of the erupting tooth. </li></li></ul><li><ul><li>Such as supernumerary teeth and nonresorbing deciduous tooth roots or alveolar bone.
After the tooth emerges from the bone, pressure from soft tissue interposed between teeth (cheek, tongue, finger) can be an obstacle to eruption.
Infraocclusion by ankylosed teeth. </li></li></ul><li><ul><li>The second possible cause of eruption failure is a disturbance of eruption mechanism itself! Without any recognizable cause or disorder, which does not respond to orthodontic treatment.</li></li></ul><li>TREATMENT<br />
Remove the cause.<br />Lateral tongue spikes (to avoid tongue thrust).<br />Extrusion of the posteriors forcefully.<br />Infraocclusion by crowns to restore normal occlusal level.<br />
DENTAL DEEP BITE<br />This kind of deep bite is characterized by the absence of any skeletal complicating features that are seen in skeletal deep bites.<br />Dental deep bite occur duo to over-eruption of anteriors OR infra-occlusion of posterior. <br />
Deep bite duo to over-eruption of anteriors: is usually seen in class II malocclusion. The presence of an overjet allows the lower incisors to over-erupt, until they meet the palatal mucosa.<br />The pt hence exhibit an excessive curve of spee.<br />
Deep bite duo to infra-occlusion of molars : the presence of a large tongue posture or lateral tongue thrust may prevent the molars from erupting to their normal occlusal level.<br />It can also occur due to premature loss of posterior teeth.<br />
Lip relationship:<br /><ul><li>Pts with deep bite who </li></ul>exhibit a short lip or a gummy smile should be treated by intrusion of the anteriors.<br /><ul><li>In pts exhibiting normal upper lip with only 2-3 mm of maxillary incisal edge exposed, it is ideal to extrude the molars.</li></li></ul><li>TREATMENT<br />By removable, fixed or myofunctional appliance. <br />
Removable Hawley’s appliance + Adam’s clasps on the molars for retention. <br />Myofunctional activator desinged and trimmed to allow the extrusion. <br />Bionator can also be used.<br />