Dental Occlusion

Cards · 52

Centric Relation (CR)

Maxillomandibular relationship where condyles articulate with the thinnest avascular portion of their discs in the anterosuperior position against the articular eminences, independent of tooth contact.

Centric Occlusion (CO)

The occlusion of opposing teeth when the mandible is in centric relation; may or may not coincide with maximum intercuspation.

Maximum Intercuspation (MIP)

The complete intercuspation of opposing teeth independent of condylar position; also termed intercuspal position (ICP).

CR-MIP Slide

The translational movement of the mandible from centric relation to maximum intercuspation, typically 1 to 2 mm anterosuperiorly in most healthy individuals.

Angle Class I Malocclusion (Neutroclusion)

Mesiobuccal cusp of maxillary first molar aligns with the buccal groove of mandibular first molar, but with crowding, rotations, or other irregularities.

Angle Class II Malocclusion (Distoclusion)

Mesiobuccal cusp of maxillary first molar occludes anterior to the buccal groove of the mandibular first molar.

Angle Class II, Division 1

Class II molar relationship with proclined maxillary incisors, resulting in excessive overjet.

Angle Class II, Division 2

Class II molar relationship with retroclined maxillary central incisors, labially flared lateral incisors, and deep overbite.

Angle Class III Malocclusion (Mesioclusion)

Mesiobuccal cusp of maxillary first molar occludes posterior to the buccal groove of the mandibular first molar.

Canine Guidance (Canine-Protected Occlusion)

Mutual protection where maxillary and mandibular canines contact during lateral excursions, disoccluding all posterior teeth on both sides.

Group Function Occlusion

Multiple teeth on the working side contact simultaneously during lateral mandibular movement, distributing lateral loads.

Mutually Protected Occlusion

Posterior teeth prevent excessive load on anterior teeth in MIP; anterior teeth disocclude posterior teeth during excursive movements.

Working Side

The side of the dental arch toward which the mandible moves during lateral excursion.

Non-Working Side (Balancing Side)

The side of the dental arch opposite to the direction of mandibular lateral movement.

Overjet

The horizontal overlap of the incisal edge of maxillary central incisors over the labial surface of mandibular incisors, normally 2 to 4 mm.

Overbite

The vertical overlap of maxillary central incisors over mandibular central incisors, normally 2 to 4 mm or roughly 30 to 50 percent coverage.

Open Bite

Lack of vertical overlap between opposing incisors or posterior teeth when opposing teeth are in full occlusion.

Deep Bite

Excessive vertical overlap of maxillary incisors over mandibular incisors, often exceeding 50 percent.

Crossbite (Anterior)

Maxillary anterior teeth occlude lingual to mandibular anterior teeth.

Crossbite (Posterior)

Maxillary posterior teeth occlude lingual to mandibular posterior teeth, or mandibular posterior teeth occlude buccal to normal.

Curve of Spee

Anteroposterior curvature of the occlusal surfaces, beginning at canine tips, following buccal cusps of posterior teeth to the condyle.

Curve of Wilson

Mediolateral curve of the occlusal plane across buccal and lingual cusp tips of contralateral posterior teeth in the frontal view.

Sphere of Monson

A theoretical combination of the curves of Spee and Wilson forming a sphere of 4-inch radius centered in the glabella.

Supporting Cusps (Centric Cusps)

Cusps that maintain vertical dimension: palatal cusps of maxillary posterior teeth and buccal cusps of mandibular posterior teeth.

Guiding Cusps (Non-Centric Cusps)

Cusps that guide excursions and shear food: buccal cusps of maxillary posterior teeth and lingual cusps of mandibular posterior teeth.

Articular Eminence

Anterior boundary of the mandibular fossa on the temporal bone down which the condylar head translates during opening.

Articular Disc (TMJ)

Biconcave fibrocartilaginous structure between condylar head and temporal bone, absorbing load and guiding joint movement.

Mandibular Condyle

Posterior superior projection of mandibular ramus that articulates with the glenoid fossa via the articular disc.

Posselt's Envelope of Motion

The 3D boundary representing the extreme range of mandibular movement in sagittal, horizontal, and frontal planes.

Rest Position of the Mandible (Physiologic Rest)

Postural position of mandible maintained by resting muscle tonus when head is upright and teeth are apart.

Freeway Space (Interocclusal Rest Space)

Vertical gap between occlusal surfaces of teeth when mandible is in rest position, typically 2 to 4 mm.

Vertical Dimension of Occlusion (VDO)

Face height measured between two arbitrary anatomical points when the teeth are in maximum intercuspation.

Vertical Dimension of Rest (VDR)

Face height measured between two arbitrary anatomical points when the mandible is in physiologic rest position.

Bennett Angle

Angle formed in the horizontal plane by the non-working condyle moving medially relative to a sagittal reference line.

Bennett Movement (Immediate Side Shift)

Bodily lateral translation of the working-side condyle during early lateral mandibular excursion.

Progressive Side Shift

Continuous medial translation of the non-working condyle that occurs proportionally as the mandible moves laterally.

Protrusive Occlusion

Occlusal contacts produced when the mandible moves forward from maximum intercuspation.

Anterior Guidance

Disocclusion of posterior teeth driven by lingual concavities of maxillary anterior teeth during protrusion and lateral excursion.

Occlusal Interference

Any premature occlusal contact that inhibits or deviates harmonious mandibular closure and excursive gliding movements.

Centric Interference

Premature contact causing mandibular deviation during closure from centric relation directly into maximum intercuspation.

Working Interference

Undesirable posterior contact on the working side that prevents smooth contact along the anterior guiding teeth.

Non-Working Interference

Contact on the balancing side that disrupts working-side guidance and generates destructive oblique shear forces.

Protrusive Interference

Premature posterior contact occurring during straight forward mandibular movement, preventing anterior guidance.

Frankfort Horizontal Plane

Cephalometric reference line connecting porion (upper margin of external auditory meatus) to orbitale (inferior border of orbit).

Camper's Line (Ala-Tragus Line)

Line from inferior border of ala of nose to superior border of tragus; approximates the orientation of the occlusal plane.

Terminal Hinge Axis

Transverse horizontal axis through both condyles about which pure rotational movement occurs during initial opening (up to ~20 mm).

Facebow

Caliper-like device used to record the spatial position of the maxillary arch relative to the TMJ hinge axis and cranial landmarks.

Semi-Adjustable Articulator

Instrument that reproduces condylar path inclinations and lateral shift using patient-specific interocclusal records.

Fremitus

Palpable or visible functional vibration of a tooth under occlusal loading during centric or excursive contacts.

Primary Occlusal Trauma

Tissue damage caused by excessive occlusal forces applied to a tooth with healthy, normal periodontium.

Secondary Occlusal Trauma

Tissue damage caused by normal or excessive occlusal forces acting on a tooth with compromised periodontal attachment.

Abfraction

Wedge-shaped cervical tooth loss hypothesized to result from biomechanical flexure forces during heavy eccentric occlusion.