FEARTURES! SKELETAL DENTAL Increased lower anterior facial height. Decreased upper anterior facial height. A steep mandibular plane angle. Small mandibular body and ramus. Proclined upper teeth. The upper and lower anteriors fail to overlap each other. The patient may have a narrow maxillary arch duo to lowered tongue posture duo to a habit.
REMOVAL OF THE CAUSE!
Habits, by passive habit breaking appliance. Habit breaker appliance can be either fixed or removable. Persistence of all the causes will offer a sever limitation in the corrective procedures!!
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).
Mild to moderate open bite can be successfully managed using fixed appliance with box elastics. Elastic that is stretched to extend between the upper and lower anteriors. this brings extrusion of the upper and lower anteriors.
Skeletal open bites in adults are best treated by surgical procedure involving the maxilla and the mandible.
POSTERIOR OPEN BITE DEF. is a condition characterized by lack of contact between the posteriors when the teeth are in centric occlusion.
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.
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.
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.
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.
Remove the cause. Lateral tongue spikes (to avoid tongue thrust). Extrusion of the posteriors forcefully. Infraocclusion by crowns to restore normal occlusal level.
DEEP BITE DEF.
Vertical overlap of the upper and lower anteriors.
One third – one half coverage is normal, greater will be increased, thus termed overbite.
This overlapping of the mandibular teeth occurs both the horizontal as well as vertical direction. The horizontal overjet The vertical overbite
Overbite can be :
Deep bite can be broadly classified into : Skeletal dental
SKELETAL DEEP BITE Genetic origin. Caused by upward and forward rotation of the mandible, which can be worsen by a downward and forward inclination of the maxilla!!!
SKELETAL DEEP BITE Features: Pt exhibit horizontal growth pattern The anterior facial height is reduced A reduced inter-occlusal clearance (freeway space)
DENTAL DEEP BITE This kind of deep bite is characterized by the absence of any skeletal complicating features that are seen in skeletal deep bites. Dental deep bite occur duo to over-eruption of anteriors OR infra-occlusion of posterior.
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. The pt hence exhibit an excessive curve of spee.
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. It can also occur due to premature loss of posterior teeth.
Pts with deep bite who
exhibit a short lip or a gummy smile should be treated by intrusion of the anteriors.
In pts exhibiting normal upper lip with only 2-3 mm of maxillary incisal edge exposed, it is ideal to extrude the molars.
TREATMENT By removable, fixed or myofunctional appliance.
Removable Hawley’s appliance + Adam’s clasps on the molars for retention. Myofunctional activator desinged and trimmed to allow the extrusion. Bionator can also be used.
Fixed to intrude the anteriors.
Fixed anterior bite plane can be use in conjunction withthe fixed appliance.