Chums Bezana - Theory #2

Provide a full description of the position, extension and angle of the inclined plane of the mandibular acrylic block with reference to treating or correcting a deep overbite condition.
Twin Blocks are simple bite-blocks that effectively modify the occlusal inclined plane using upper and lower bite blocks which engage on occlusal inclined planes.. Wearing bite-blocks is rather like wearing dentures and patients can eat comfortably with the appliances in place. The upper and lower bite blocks engaged mesial to the 1st permanent molar at 90° to the occlusal plane, when the mandible postured forward. This positioned the incisors edge-to-edge with 2 mm vertical separation to hold the incisors out of occlusion. The patient had to make a positive effort to posture the mandible forward to occlude the bite blocks inprotrusive bite.The inclined plane on the lower bite-block is angled from the mesial surface of the second pre-molar or second deciduous molar at 70° to the occlusal plane. This places the leading edge of the inclined plane on the upper appliance mesial to the lower first permanent molar, thus keeping a provision for the unhindered eruption of the lower 1st permanent molar. Mesially, the lower bite block extends up to the canine region with a flat occlusal surface.Twin Block appliance acrylic extends to cover the incisal edges of lower incisors. This helps to avoid tipping of the lower incisors and improve in retention. Torquing springs were used to control position of the upper incisors.