During jaw movements, only the mandible moves. Movements by the jaw are left and right lateral excursion; forward protrusion; and retraction of the jaw called retrution. Protrusive movement incise the mandibular incisors to the maxillary incisors. This is achieved by translation of the condyle down the articular eminence of the TMJ without introducing any rotational movements in the jaw. Lateral excursive movements occur during chewing. The side at which chewing occur which move laterally is referred to as the working sides and the other as the balancing side. The working side condyle only performs rotational movements while the balancing side condyle performs translation. During functional chewing both condyles experience vertical and horizontal movement.
Non-adjustable articulators can open and close in a fixed horizontal axis. They have a fixed condylar path along which the condylar ball can be moved to simulate lateral and protrusive movements. The incisal guide pin is guided on a incisal plate on a fixed condylar angulation (like the one we use in class)
Semi-adjustable articulators have: adjustable condylar paths; adjustable lateral condylar paths; adjustable incisal guide tables; and adjustable inter condylar distance. Two kinds of semi adjustable articulators namely the arcon and non-arcon semi adjustable articulators are found.
Fully-adjustable articulators have various adjustable features capable of simulating all movements of the mandible. They can be set according the readings taken of the patients. They are very complex and are not commonly used.
the primary function of an articulator is to act as a patient in the absence of a patient. An articulator simulates the movements made by the patients TMJ, whilst in its rest position, during various excursive movements and even during movements made by the muscles of mastication, ligaments and other programmed movements.
an adjustable articulator only allows limited simulated adjustments in saggital and horizontal planes to replicate the recorded mandibular movements. a semi-adjustable articulator allows most mandibular excursions, it is considered as a Class III articulator. with regards to a fully adjustable articulator it is more advanced as mandibular jaw movement is viewed in a 3D perspective.
juan has made a good summary of the TMJ and articulators. (a) the non ajustible articulator can not simulated any TMJ movement. (b) semi-adjustble articulator simulates a few TMJ movements (c) Fully adjustble articulator simulates all the movement of the TMJ
Articulator - It is a mechanical instrument that represents the temporomandibular joints and jaw members, to which maxillary and mandibular casts may be attached to simulate some or all- mandibular movements.
Types of articulators
1-Simple hinge articulators. 2-Fixed or mean value condylar path articulators. 3-Adjustable condylar path articulators. a. Semi-adjustable condylar path articulators. b. Fully-adjustable condylar path articulators.
Simple Hinge Articulators - This type of articulators gives only opening and closing movements.
Mean Value Or Fixed Condylar Path articulators - Possible movements 1.Opening and closing. 2. Protrusive movement at a fixed horizontal condylar path angle.
Adjustable Condylar Path articulators A. Semi Adjustable Condylar Path Articulators - Possible movements 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. B. Fully adjustable articulators - They differ from the semi-adjustable articulators in that the lateral condylar path inclinations are adjusted according to records taken from the patient.
The non-adjustable articulator is very limited with regards to TMJ movement as it only allows vertical movement. The semi-adjustable articulator allows some of the TMJ movement, offering adjustable horizontable condylar paths, lateral condylar paths, incisal guided table and adjustable inter-condylar distances. With the fully-adjustable articulator, the TMJ movement of the patient can be mimicked very closely as it has curved condylar guides, immediate and progressive side-shifts, exact intercondylar width and an exact reproduction of the hinge axis.
Although the three types of articulators vary in function and movement, all of them are acceptable regarding on the type of work to be articulated
During jaw movements, only the mandible moves. Movements by the jaw are left and right lateral excursion; forward protrusion; and retraction of the jaw called retrution. Protrusive movement incise the mandibular incisors to the maxillary incisors. This is achieved by translation of the condyle down the articular eminence of the TMJ without introducing any rotational movements in the jaw. Lateral excursive movements occur during chewing. The side at which chewing occur which move laterally is referred to as the working sides and the other as the balancing side. The working side condyle only performs rotational movements while the balancing side condyle performs translation. During functional chewing both condyles experience vertical and horizontal movement.
ReplyDeleteNon-adjustable articulators can open and close in a fixed horizontal axis. They have a fixed condylar path along which the condylar ball can be moved to simulate lateral and protrusive movements. The incisal guide pin is guided on a incisal plate on a fixed condylar angulation (like the one we use in class)
Semi-adjustable articulators have: adjustable condylar paths; adjustable lateral condylar paths; adjustable incisal guide tables; and adjustable inter condylar distance. Two kinds of semi adjustable articulators namely the arcon and non-arcon semi adjustable articulators are found.
Fully-adjustable articulators have various adjustable features capable of simulating all movements of the mandible. They can be set according the readings taken of the patients. They are very complex and are not commonly used.
Correct
Deletethe primary function of an articulator is to act as a patient in the absence of a patient. An articulator simulates the movements made by the patients TMJ, whilst in its rest position, during various excursive movements and even during movements made by the muscles of mastication, ligaments and other programmed movements.
ReplyDeletean adjustable articulator only allows limited simulated adjustments in saggital and horizontal planes to replicate the recorded mandibular movements. a semi-adjustable articulator allows most mandibular excursions, it is considered as a Class III articulator. with regards to a fully adjustable articulator it is more advanced as mandibular jaw movement is viewed in a 3D perspective.
Good way of thinking of an articulator
Deletejuan has made a good summary of the TMJ and articulators.
ReplyDelete(a) the non ajustible articulator can not simulated any TMJ movement.
(b) semi-adjustble articulator simulates a few TMJ movements
(c) Fully adjustble articulator simulates all the movement of the TMJ
Articulator - It is a mechanical instrument that represents the temporomandibular joints and jaw members, to which maxillary and mandibular casts may be attached to simulate some or all- mandibular movements.
ReplyDeleteTypes of articulators
1-Simple hinge articulators.
2-Fixed or mean value condylar path articulators.
3-Adjustable condylar path articulators. a. Semi-adjustable condylar path articulators. b. Fully-adjustable condylar path articulators.
Simple Hinge Articulators - This type of articulators gives only opening and closing movements.
Mean Value Or Fixed Condylar Path articulators - Possible movements 1.Opening and closing. 2. Protrusive movement at a fixed horizontal condylar path angle.
Adjustable Condylar Path articulators
A. Semi Adjustable Condylar Path Articulators - Possible movements 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.
B. Fully adjustable articulators - They differ from the semi-adjustable articulators in that the lateral condylar path inclinations are adjusted according to records taken from the patient.
The non-adjustable articulator is very limited with regards to TMJ movement as it only allows vertical movement. The semi-adjustable articulator allows some of the TMJ movement, offering adjustable horizontable condylar paths, lateral condylar paths, incisal guided table and adjustable inter-condylar distances. With the fully-adjustable articulator, the TMJ movement of the patient can be mimicked very closely as it has curved condylar guides, immediate and progressive side-shifts, exact intercondylar width and an exact reproduction of the hinge axis.
ReplyDeleteAlthough the three types of articulators vary in function and movement, all of them are acceptable regarding on the type of work to be articulated