GLossary Flashcards
Angle classification
The Angle classification of malocclusion is often used to describe the antero-posterior relationship of upper and lower teeth. Ie Class 1- mesiobuccal cusp of the upper first permanent molar occludes with the mesiobuccal groove of the lower first permanent molar. Class 2- anteriorly placed. Class 3- posteriorly placed
Anterior guidance
Contact of maxillary incisors and mandibular incisors to guide mandible downward to create disarticulation of the posterior teeth. Edge to edge on the incisors
Articulating paper
Carbon paper; placed between the upper and lower teeth to mark contact when teeth occlude
Articulation
The contact that exists between teeth while the mandible is moving
Articulator
Mechanical device used in dentistry to which casts of the maxillary (upper) and mandibular (lower) teeth are fixed, reproducing recorded positions of the mandible in relation to the maxilla
Axial alignment
Teeth are inclined in both mesiodistal and buccolingual directions. The degree of inclination varies from tooth to tooth. In general, each tooth is placed at an angle that best withstands the lines of forces brought against it during function
Balancing side
The opposite side to the working side is called the non-working side or balancing side. (in lateral movements on mandible, it’s the direction of movement)
Bennett angle
The angle traced by the non-working side condyle in relation to the sagittal plane
Bennett movement
The working condyle shows a small lateral shift called the Bennett movement. The bodily lateral shift is about 15 mm
Border movement diagram
Movement of the mandible limited by anatomical structure view in a plane
Border movements
The maximum jaw openings that can be done in one direction. The retruded opening path and the opening path from maximum protrusion to maximum opening are all border movements
Bruxism
Grinding or clenching of teeth that is not part of normal function of chewing ie parafunctional activity that may occur when awake or asleep
Buccal segments
All of the premolar and molar teeth in a given quadrant
Canine guidance
Occlusion in which occlusal contacts of the cuspids cause contacts of posterior and anterior teeth to separate in excursive mandibular movements
Centric occlusion
AKA Intercuspal position
Centric relation
The mandibular jaw position in which the head of the condyle is situated as far anterior and superior as it possibly can within the mandibular fossa/glenoid fossa.
Centric stops
The opposing cuspal/fossae contacts that maintain the occlusal vertical dimension between the opposing arches. The stable points of contact between occluded maxillary and mandibular teeth.
Chewing cycle
3d record of Mn movement when chewing The chewing cycle consists of an opening and crushing phase. The opening phase begins from the intercuspal position, with an opening movement gradually approaching the food colus side, although there may be slight deviation to the non- food side initially. The opening is usually about 18mm. The crushing phase involves jaw deviation to the food side with the pressure and velocity of movements depending on the size, shape and hardness of the food. There may be a slide into intercuspal position. The cycle of opening and crushing usually lasts one second approx
Condylar guidance
The mechanical device on an articulator; intended to produce guidance in articulator movement similar to that produced by the paths of the condyles in the temporomandibular joints.
Contralateral
Relating to or denoting the side of the body opposite to that on which a particular structure or condition occurs
Cross-bite
An occlusal irregularity where a tooth has a more buccal or lingual position than its corresponding antagonist tooth in the upper or lower
Curve of Spee
When viewed from the lateral aspect (opposite the first molars), the cusps and incisal edges of the teeth tend to follow a curve, where the mandibular arch conforms to curved planes that appear concave, and the maxillary arch conforms to convex planes
Cusp
A peak on the crown of a tooth making up a divisional part of the occlusal surface.
Cusp angle
The angle made by the slopes of a cusp with the plane that passes through the tip of the cusp and is perpendicular to a line bisecting the cusp, measured mesiodistally or buccolingually
Cusp interference
The condition of tooth contacts that diverts the mandible from a normal path of closure to centric jaw relation or causes a denture to slide or rotate on its basal seat
Diastema
A space between adjacent teeth in the same jaw.
Disclusion
A separation of the teeth when the jaw is slightly opened; Especially, a separation of posterior teeth when the lower jaw moves forward, as a natural result of the alignment of the anterior teeth
Edge-to-edge
An occlusion in which the anterior teeth of both jaws meet along their incisal edges when the teeth are in centric occlusion
Embrasures
The V-shaped areas related to the contact areas, ie the areas that diverge from the areas of contact. There are four embrasures at each interproximal region; labial, lingual, occlusal and gingival. When viewed from the occlusal, the lingual embrasures tend to be larger than the labial in the anterior region, but are more equal in size in the posterior region
Envelope of motion
The border paths enclose a total movement space or envelope of motion (see border paths diagram)
Facebow
Devices that relate a patients maxillary arch to the intercondylar axis and the point orbitale (the lowest point on the infraorbital margin) and enable these relationships to be transferred to an articulator where they can be reproduced
Freeway space
Interocclusal distance
Group function
The simultaneous contact of opposing teeth in a segment or group
Guidance
A plane of measurement during dynamic occlusion, looking at the contact points while the mandible is moving
Guiding cusps
The lingual cusps of the lower posterior teeth and buccal cusps of the upper posterior teeth. These cusps occlude outside the opposing occlusal table
Intercuspal occlusion (IO)
The occlusion where there is maximum contact between the opposing occlusal surface
Intercuspal position (IP)
The position of the mandible when the teeth are in the intercuspal occlusion/ maximum contact; therefore it is determined by the teeth.
Interincisal angle
The angle between the incisors from the proximal view. The interincisal angle is generally about 130ᵒ- 135ᵒ and is important for aesthetics, allowing gliding contact between incisors in protrusion and for phonetics (speech
Interocclusal distance (IOD)
The space between the intercuspal and rest positions is called the freeway space or IOD. Usually about 2-4mm
Interproximal contacts
The point of contact between two adjacent teeth in the same arch.
Ipsilateral
Belonging to or occurring on the same side of the body.
Masticatory musculature
Muscles of Mastication:
the masseter: elevation (closing of mouth) and protraction
the temporalis: elevation and retraction
the medial pterygoid: elevates, closes jaw, helps lateral P in moving jaw side to side
the lateral pterygoid: depresses mandible, protrude mandible, side to side movement.
Maximum hinge opening
The most a jaw can be opened (about 20mm of incisal separation).
Maximum lateral excursion
The most the mandible can shift to the side
Mesial drift
The attachement changes due to continual turnover of periodontal ligament, occlusal forces on teeth and changing positions of teeth, allow teeth to move forward (mesially) in the jaw.
Monson’s curve
See Wilsons curve
Myofascial pain dysfunction syndrome (MPD)
A syndrome characterized by chronic pain caused by multiple trigger points and fascial constrictions. Characteristic features of a myofascial trigger point include: focal point tenderness, reproduction of pain upon trigger point palpation, hardening of the muscle upon trigger point palpation, pseudo-weakness of the involved muscle,referred pain, and limited range of motion following approximately 5 seconds of sustained trigger point pressure.
Neutral zone
That space in the oral cavity where the forces exerted by the musculature of the tongue are equal and balanced with the forces exerted by the buccinator muscle of the cheek laterally and the orbicularis oris muscle anteriorly
Nociceptors
A receptor of a sensory neuron (nerve cell) that responds to potentially damaging stimuli by sending signals to the spinal cord and brain.
Long centric
Therapeutic modality used in modern dentistry and occlusal adjustment in all patients showing differences in strong and weak closure of the lower jaw starting from the position of physiological rest.
Occlusal analysis
An examination of the occlusion in which the interocclusal relations of mounted casts are evaluated
Occlusal curvatures
The curve of the dentition in which the occlusal surfaces lie, when viewed in the frontal and sagittal planes
Occlusal stability
The equalization of contacts that prevents tooth movement after closure
Occlusal table
The portion of the occlusal surfaces of posterior teeth that lies within the perimeter of the cusp tips and marginal ridges; the functional portion(s) of the occlusal surface(s) of a posterior tooth (teeth)
Occlusal vertical dimension (OVD)
The height of the face when the mandible is in intercuspal position.
Occlusion
The study of tooth contacts, both stationary and mobile, both functional and parafunctional, of the tissues that provide these functions, of disturbances that can affect tissues, and of the treatment procedures devised to restore them.
Open bite
Lack of occlusion of the front teeth when the jaw is closed normally.
Overbite
Distance that the maxillary anterior teeth overlap the mandibular teeth in a vertical plane.
Overeruption
The physiological movement of a tooth lacking an opposing partner in the dental occlusion. Because of the lack of opposing force and the natural eruptive potential of the tooth there is a tendency for the tooth to erupt out of the line of the occlusion.
Overjet
Distance that the maxillary anterior teeth are positioned anteriorly or posteriorly (reverse overjet) to the mandibular anterior teeth ie distance between anterior maxillary and mandibular teeth in a horizontal plane.
Parafunction
(aka wrong or irregular function) refers to the non-functional contact between teeth during habits such as clenching, tapping, grinding, holding pencils, etc.
Proprioceptors
Sensory receptors that are located in the periodontal ligament, muscles of mastication and TMJ that convey information about movements and positions of the mandible.
Proclined
Tipped foward. Usually referring to anterior teeth
Rest position
(AKA postural position or endogenous postural position). Not determined by teeth and is maintained by substained contraction of temporalis muscle acting to counteract the effect of gravity.
Rest vertical dimension (RVD)
The vertical dimension of the face with the jaws in rest relation; decrease in rest vertical dimension may or may not accompany a decrease in occlusal vertical dimension.
Retroclined
Tipped backwards. Usually referring to anterior teeth
Retruded hinge axis
From the retruded contact position, the jaws can be opened until incisal separation is about 20 mm.
Retruded relation
The contact between teeth in retruded positions of the mandible.
Retrusion
The shifting of the mandible posteriorly .
Scissors bite
A bite in which the outer side of the lower incisors touches the inner side of the upper incisors.
Supporting cusps
The buccal cusps of the lower posterior teeth and the lingual cusps of the upper posterior teeth. (due to the overjet relationship between the maxillary and mandibular posterior teeth, they occlude wholly within the opposing occlusal table)
Vertical dimension
The superior-inferior relationship of the maxilla and the mandible when the teeth are situated in maximum intercuspation.
Wilson’s curve
An occlusal curve that is concave for the mandible in the posterior region, when viewed from the coronal plane
Working side
In lateral movements to the side to which the mandible moves is called the working side, and the condyle on this side is called the working (side) condyle..
