Articulator PDF

ARTICULATORS Dr. YARA KAMMOUN Lect u rer, D e p a r tme nt O f P ro s t hod ontics. A A S TM T ARTICULATORS -Definitions. -Functions. -Uses. -Advantages. -Basic components. -Requirements: -Minimal. -Additional. -Classification.  ARTICULATION The place of union or junction...

ARTICULATORS Dr. YARA KAMMOUN Lect u rer, D e p a r tme nt O f P ro s t hod ontics. A A S TM T ARTICULATORS -Definitions. -Functions. -Uses. -Advantages. -Basic components. -Requirements: -Minimal. -Additional. -Classification.  ARTICULATION The place of union or junction between two or more bones of the skeleton.  ARTICULATION In dentistry, the static and dynamic contact relationship between the occlusal surfaces of the teeth during function.  ARTICULATOR A mechanical instrument that represents the temporomandibular joints (TMJ) and jaws, to which maxillary and mandibular casts may be attached to simulate some or all mandibular movements.  MOUNTING The laboratory procedure of attaching the maxillary and or the mandibular cast to an articulator. Functions: 1. Act 2. Stimulate 3. Mounting 4. Arrangement 5. Fabrication  Uses: 1. To diagnose the state of occlusion in both the natural and artificial dentition. 2. To plan the dental procedures based on the relationship between opposing natural and artificial teeth. 3. To aid in the fabrication of dental restorations and prosthodontics replacements. 4. To correct and modify completed restorations. 5. To arrange artificial teeth. Advantages: 1. Properly mounted casts allow the operator t o visualize e the patient’s occlusion, especially from the lingual view. 2. Patient cooperation is not a factor when using an articulator. 3. The patient’s saliva, tongue and cheeks are not a factor to deal with. 4. Reduced chair time. 5. Stable base for denture base instead of resiliency of denture bearing mucosa which makes it easier to refine occlusion. ADVANTAGES Basic components of articulator:  Requirements (Minimal requirements) Maintain correct vertical and horizontal relations. Casts easily removed and attached. Incisal guide pin with a positive stop. Open and close. Construction rigid, accurate, non-corrosive metal. Moving parts resist wear, move freely. Not too bulky , or heavy. Requirements: (Additional requirements) 1. The articulator should accept a facebow transfer  Requirements: (Additional requirements) 2. The condylar guides should allow right lateral, left lateral and protrusive movement. 3. The sagittal and horizontal condylar guides should be adjustable. Classification: 1- According to condylar position: Arcon non arcon 2- According to condylar path adjustment:  CONDYLAR PATH lateral condylar path Protrusive condylar path  CLASS I ARTICULATOR NON-ADJUSTABLE ARTICULATOR (Simple holding instrument) Plaster slab articulator Simple hinge articulator CLASS I ARTICULATOR Plaster slab articulator CLASS I ARTICULATOR Simple hinge articulator (plane line)  CLASS I ARTICULATOR Accept a single inter-occlusal record “centric relation”. Vertical motion may or may not be possible. Minimal articulator requirements hardly achieved.  CLASS II ARTICULATOR Mean value articulator Fixed condylar path Accept a single inter-occlusal record “centric relation”. Hinge movements and lateral movements are possible. All basic articulator requirements are achieved. CLASS II ARTICULATOR  CLASS II ARTICULATOR On average, the distance between the 2 condyles and the tip of the mandibular central incisors is 10 cm making an equilateral triangle known as Bonewill triangle.  CLASS II ARTICULATOR A 4 inch equilateral triangle bounded by lines connecting the contact points of the mandibular central incisor’s incisal edge (or the mid-line of the mandibular residual ridge) to each condyle (usually its mid point) and from one condyle to the other.  CLASS II ARTICULATOR The angle between Bonewill’s triangle and the occlusal plane averages around 15°- 20°, This angle is known as Balkwill angle. 15 CLASS II ARTICULATOR  CLASS III ARTICULATOR Adjustable condylar path Semi-adjustable Fully adjustable articulators articulators  A- semi-adjustable articulators: Accept a single inter-occlusal record “centric relation”. Accepts protrusive eccentric records. Accepts Facebow transfer. Can be arcon type or non-arcon type. Adjustable incisal guidance.  A- semi-adjustable articulators: Opening and closing. Protrusive movement to an angle recorded from the patient. Lateral movement to an angle calculated from the Hanau’s formula: L=H/8+12. Where; L = the lateral condylar path H = the horizontal condylar path angle which is recorded from the patient.  A- semi-adjustable articulators: Fixed intercondylar distance. Can not accept a lateral eccentric record, the lateral condylar angle is determined by Hanau’s formula; L = H/8 + 12 Where; L = the lateral condylar path H = the horizontal condylar path angle which is recorded from the patient.  B- Fully adjustable articulators: All features of Semi-adjustable articulators. Adjustable intercondylar distance. Can accept lateral eccentric record from the patient’s mouth.  B- Fully adjustable articulators: Complex „Designed to duplicate TMJ features They differ from the semi-adjustable articulators in that the lateral condylar path inclinations are adjusted according to records taken from the patient.  FACEBOW Definition: “A caliper like instrument used to record the spatial relationship of the maxillary arch to some anatomic reference point or points and then transfer this relationship to an articulator”  FACEBOW Significance: 1-It is essential for the articulator to simulate mandibular movements as close as possible to the patient’s actual movements. 2-It determines the distance and orientation of the occlusal plane from the terminal hinge axis.  FACEBOW Indications: 1- Extensive restorations including posterior teeth and full arch restorations. 2- In cases of complete dentures where bilateral balanced occlusion is the choice of occlusal scheme. 3-When fully anatomic teeth are used for restorations. 4- In cases where vertical dimension may be adjusted by 1-2mm. 5-Used with interocclusal records in cases where occlusal interference is present in natural or artificial dentition.  FACEBOW Types: These types of Facebow locate the average location of the hinge axis, which yields and error within 2 mm of the true location. There are 2 types: 1- Arbitary: a)Fascia b)Earbow 2-Kinemetic. FACEBOW  FACEBOW 1- Arbitrary facebow: a:Fascia type Parts of arbitrary facebow:  FACEBOW 1-Arbitrary facebow. a:Fascia type: The condylar rod is placed on the line between the outer canthus of the eye to the top of the tragus of the ear, 11-13mm in front of the external auditory meatus.  FACEBOW 1:Arbitrary facebow. B:Earbow -Condylar Rod: Earbow (The condylar rod is placed inside the ear).  FACEBOW 2-Kinematic facebow -These types of facebows exactly locates the location of the terminal hinge axis. -It is attached to the mandible, and as the mandible opens and closes, the consular styli move in an arc, their position is adjusted until they exhibit pure rotation.. Cadiax compact 2  Cadiax compact is a computerized axiography, a new technology to record the transverse hinge axis and the horizontal condylar inclination HCI and Bennett angle. Helme R , Ali A, Abdulla H ,Mohammed M. L. Evaluation of the effects of fixedpartial denture on the Temporomandibular joint dysfunction by using Cadiax compact 2. J Bagh College Dentistry Vol. 23(1), 2011