Recording Jaw Relation

The separation of posterior teeth when anterior teeth touch in forward protrusion movement.

Remember: Christensen Ph. Is undesirable for denture fabrication.

• Maxillomandibuar relationship
• in which condole articulate with the thinnest portion of disk 
• with the complex in the anterior posterior position

The most posterior relation of the mandible to the maxillar from which lateral movement can be made

• Centric relation: condyle - glenoid fossa 
• Centric occlusion: upper teeth - lower teeth

Remember: CO can be either maximum intercuspation or not.

Freedom in centric is when patient have maximum intercuspation in both CR and some where near CR.

In a situation when CR is not precise (elderly, disable patient), freedom in centric is accommodated.

• repeatability
• able to arrange teeth in right position
• able to adjust condylar guidance right
• with hinge axis record able to get right relationship between maxillar and hinge axis

• Relationship between maxillar and hinge axis
• Arbitrary face-bow

Remember: kinematic face-bow is more precise but not practical when placing on edentulous.

Frankfort horizontal plane (infraorbital notch - Targus)

Remember: Camper’s is horizontal plane drawing from alar of nose to targus of ear

• Record at VD:
• adv. = ไม่เกิดการคลาดเคลื่อนเวลาทด pin เมื่อนำ bite ออก
• dis. = U/L oc rim อาจชนกันเวลา regist

• Remember: record befor reaching VD (ไม่ตัด oc rim)
• adv. = ไม่มีการชนของ oc rim
• dis. = เวลานำ bite ออก แล้วทด pin ลงมา มันจะคลาดเคลื่อน ถ้าไม่ได้ทำ hinge axis record

• Wax
• Zincoxide eugenol (best?)
• Silicine
• Impression plaster

• protrusion interocclusal record: condylar guidance angle
• lateral interocclusal record: Bennett angle or lateral side shift of the mandible)

• After try in oc. rim (before CR record), or
• After try in anterior teeth

Using Hanua formulae to calculate Bennett angle from condylar guidance angle.

L = (H/8) + 12

• L is Bennett angle 
• H is horizontal condylar guidance angle

• We use average angles:
• condylar guidance angle = 30 degree
• Bennett angle = 15 degree
• Incisal table = 0 degree

The interocclusal record need to be very thin!

• Easy to understand the movement
• Less error when using interocclusal record

• Remember: It represents real anatomy
• glenoid fossa - upper member
• condyle - lower member

• Multiple occlusal restoration (crowns)
• Need to restore at new VD

• Graphic record (dynamic jaw relation)
• Kinematic facebow

• Non-adjustable articulator is not accommodated with balanced occlusion
• Using with interocclusal record and facebow, semi-adjustable articulator (non arcon) is the most suitable for CD making.

Semi-adjustable (non arcon)

Remember: Hanua model H is not accommodated with lateral intrusion record. Bennett angle is calculated from condyle angle

• Incisal guidance angle
• Dentists will decide how steep the angle should be considering anterior esthetic and phonetic

Remember: the incisal guidance angle should be as low as possible so less steep cusp posterior teeth can be used.