Intra-oral device for mandibular adjustment

An intra-oral device for mandibular adjustment, comprising:

• an upper splint configured to adapt to an upper jaw of a patient and a lower splint configured to adapt to a lower jaw of said patient;
• at least one follower and at least one contact surface on which the follower contacts;
• wherein the upper splint and lower splint interact with each other through the follower and the contact surface;
• and wherein the lower jaw is placeable in different positions with respect to the upper jaw;
• wherein the contact surface is defined by a curve according to the equation:
• X=X1+X2+X3+X4;
• Y=Y1+Y2+Y3+Y4;
• wherein:
• X1=xat·(1−t)3;
• X2=3·xi1·t·(1−t)2;
• X3=3·xi2·t2·(1−t);
• X4=xbl·t3;
• Y1=yat·(1−t)3;
• Y2=3·yi1·t·(1−t)2;
• Y3=3·yi2·t2·(1−t);
• Y4=Ybl·t3;
• wherein:
• xbl=xICR+Ll·cos(θ4);
• ybl=yICR+Ll·sin(θ4);
• al=(xal,yal)=known input datum;
• wherein:
• Ll=√{square root over ((xal−xICR)2+(yal−yICR)2)};
• xICR=Xal+Lciri·cos(θi′);
• yICR=yai+Lciri·sin(θi′);
• θ4=θ3+α;
• wherein:
• L
• c
• ⁢
• i
• ⁢
• r
• ⁢
• i
• =
• l
• i
• sin
• ⁡
• (
• α
• 2
• )
• θ
• i
• ′
• =
• θ
• i
• -
• 9
• ⁢
• 0
• +
• α
• 2
• θ
• 3
• =
• arc
• ⁢
• tan
• ⁡
• (
• y
• ICR
• -
• y
• a
• ⁢
• l
• x
• ICR
• -
• x
• al
• )
• wherein:
• li=known lineal distance measured to the middle point of the straight line ai-bi;
• θi=known angle that forms the straight line ai-bi;
• wherein:
• θ
• i
• =
• tan
• -
• 1
• ⁡
• (
• y
• b
• ⁢
• i
• -
• y
• a
• ⁢
• i
• x
• b
• ⁢
• i
• -
• x
• a
• ⁢
• i
• )
• α=angle of rotation of the jaw;
• wherein:
• α=θ1−θ1′;
• wherein:
• xai+MDi·cos(θ1)=xbi+xbc+s·cos(β);
• yai+MDi·sin(θ1)=ybi+ybc+s·sin(β);
• θ1 and s are obtained;
• wherein:
• ai=(xai,yai)=known input datum;
• bi=(xbi,ybi)=known input datum;
• bc=(xbc,ydbc)=known datum;
• MDi=mandibular distance known;
• β=known angle;
• wherein:
• the variable “t” is delimited between 0 and 1;
• the coordinates “xal”, “yal” define an initial point “al” of the contact surface corresponding to a known initial position of the follower when the mouth of the patient is closed;
• the coordinates “xbl”, “ybl” define a final point “bl” of the contact surface which corresponds to a final position of the follower with the patient's mouth open;
• the variables “xi1”, “xi2” have a value delimited between the coordinates “xal” and “xbl”;
• and the variables “yi1”, “yi2” have a value delimited between the coordinates “yal” and “ybl”;
• “ICR” is a point corresponding to an instantaneous centre of rotation of the lower jaw;
• “Ll” is the distance between the point “ICR” and the initial point “al” of the contact surface;
• “Lciri” is the distance between the point “ICR” and a position “ai” of a point of the lower incisors of the lower jaw with the mouth closed;
• the angle “θ4” comprises a delimited angular space between a plane parallel to the plane of occlusion with the mouth of the patient closed, and a direction passing through the point “ICR” and the final point “bl” of the contact surface;
• the angle “θ3” comprises a delimited angular space between a plane parallel to the plane of occlusion with the mouth of the patient closed, and a direction passing through the point “ICR” and the initial point “al” of the contact surface;
• the angle “θ′i” comprises an angular space delimited between the plane of occlusion with the mouth of the patient closed and a direction passing through the point “ICR” and the position “ai” of the point of the lower incisors of the lower jaw with the mouth of the patient closed;
• the angle “θi” comprises an angular space delimited between the plane of occlusion with the mouth of the patient closed, and a direction passing through position “ai” of the point of the lower incisors of the lower jaw with the mouth closed and through a position “bi” of the point of the lower incisors of the lower jaw when the mouth of the patient is open;
• the angle “α” comprises an angular space delimited between a first direction passing through the position “ai” of the point of the lower incisors of the lower jaw and an initial point “ac” of the condyle with the mouth of the patient closed, and a second direction passing through said point “ac” and a final point “bc” of the condyle with the mouth of the patient open;
• wherein the angle “α” is an angular amplitude corresponding to the rotation of the lower jaw when the point of the lower incisors passes from the position “ai” to the position “bi”;
• the angle “β” comprises a delimited angular space between a plane parallel to the plane of occlusion with the mouth of the patient closed, and a direction passing through the initial point “ac” of the condyle with the mouth closed and through the final point “bc” of the condyle with the mouth open;
• the “s” distance is a distance delimited between the initial point “ac” of the condyle with the mouth closed and the final point “bc” of the condyle with the patient's mouth open;
• and
• “MDi” is the distance between the centre of the condyle and the point of the lower incisors of the lower jaw.