the functional relationship of the maxillary and mandibular anterior teeth which control mandibular movement.
a mechanical device which represents the temporomandibular joints, the mandible and the maxillae to which diagnostic casts may be attached to simulate manidbular movements.
- the occlusion of the teeth when the jaws are closed together in the normal position. Synonyms for centric occlusion are (1) maximum intercuspation, (2) habitual centric, (3) acquired centric and (4) the intercuspal position. Centric occlusion is a "tooth to tooth" relationship and may easily be affected by dental treatment.
the most superior position of the condyles in the glenoid fossae with the discs in place. Centric relation is a mandible to cranium relationship, nQ1 a tooth to tooth relationship. Centric relation is reproducible and can be used as a starting point for many restorative procedures.
the functional relationship of the hard and soft tissues of the temporomandibular joints which control mandibular movement
(cuspid protected occlusion) cuspid on working side is the only tooth contacting in a working side movement. All other posterior teeth are not in occlusal contact.
the act or process of swallowing of food. During swallOWing in the adult, the mandible is stabilized by bringing the teeth into centric occlusion and the like are brought together in order to seal the oral cavity.
a positive likeness of a part or parts of the oral cavity for the purpose of study and treatment planning.
there is a movement and/or force involved when one chews, bites, holds object or clenches the teeth. This movement or application of force between the arches is dynamic occlusion. (see "Static Occlusion")
an instrument which records the relation of the maxillary dental arch to the cranium for transfer of the maxillary cast to the articulator.
the distance between the occluding surfaces of the maxillary and mandibular teeth when the mandible is in its physiologic rest position. The normal amount of freeway space is 2-4 millimeters.
Cuspid and posterior teeth on the working side contact evenly as a unit in working side movement.
In the initial phase of opening from centric relation, the condyles hinge or rotate around a fixed transverse axis. This phase of opening is called hinge opening and occurs for the first 20-25 millimeters of opening. (See "Translatory Opening.)
deals with the centric occlusion relationship of the multicusped posterior teeth. As these teeth occlude, some of the cusps contact the opposing tooth or teeth. Other cusps do not contact the opposing tooth or teeth; they overlap the buccal or lingual surfaces of the opposing teeth.
It is during the static phase of occlusion that tooth positions in the arch and their relations to opposing teeth are noted. In general each tooth occludes or functions with two opposing teeth. This relationship is known as interdigitation and the pattern is an established one.
Exceptions to Interdigitation
The two exceptions to the concept of interdigitation are the mandibular central incisors and the maxillary third molars. These teeth typically interdigitate with only one opposing tooth. A mandibular central incisor interdigitates with the opposingmaxillary central incisor. A maxillary third molar interdigitates with the opposing mandibular molar.
the condition which exists when opposing teeth do not occlude in accordance with an acceptable standard.
a reshaping of the teeth to result in a more physiologic relation of the teeth, their supporting structures, the muscles of mastication and/or the temporomandibular joints.
an occlusal contact which alters or restricts mandibular movement.
an occlusal contact where opposing teeth touch prior to the other teeth.
an artificial occlusal appliance used to modify the occlusion on a temporary or trial basis.
Physiologic Rest Position
the postural position of the mandible when the head is in an upright position and the associated muscles are in a state of minimal contraction. The physiologic rest position has also been referred to as the postural rest position and the clinical rest position.
when the teeth touch lightly together in centric occlusion with the jaws relaxed so that there is neither force nor movement.
the second phase of opening in which the condyles glide or translate down the articular eminences. This phase of opening is preceded by hinge opening.
crush food into the opposing fossae and/or between the marginal ridges (occlusal embrasures).
overlap and in some instances gUide the centric cusps into occlusion. The opposing inclined surfaces of the centric and non-centric cusps provide the shearing action for food comminution.
Maxillary Centric Cusps
all the lingual cusps of the maxillary premolars and molars. The lingual cusps of the maxillary premolars and the distolingual cusps of maxillary molars make contact on the distal marginal ridges of opposing mandibular teeth. The alternate centric stops for these cusps are the opposing mesial marginal ridges. The mesiolingual cusps of the maxillary molars contact the central fossae of the opposing mandibular molars.
Mandibular Centric Cusps
the buccal cusps of the mandibular premolars and molars. The buccal cusps of the mandibular premolars and the mesiobuccal cusps of the mandibular molars make contact on the mesial marginal ridges of opposing maxillary teeth.
Cusp-Marginal Ridge Occlusion
The alternate centric stops for these cusps are the opposing distal marginal ridges.
The distobuccal cusps of the mandibular molars contact the central fossae of the opposing maxillary molars.
Tooth providing the basis for morphological classification of occlusion
Mandibular First Molar
Class I Ideal Occlusion
When the mesiobuccal cusp of the maxillary first molar opposes the mesiobuccal developmental groove of the mandibular first molar
Requirements of Class I Ideal Occlusion
- 1. ideal interdigitation
- 2. ideal skeletal relationship
- 3. ideal overjet
- 4. ideal overbite
- 5. no impactions
- 6. no missing teeth
- 7. no supernumerary teeth
Class I Malocclusion
If one or more of the seven requirements of Class 1 Ideal Occlusion is not met and the MB cusp of the Max 1st opposes the MB Dev Groove
Class II Malocclusion
the mesiobuccal cusp of the maxillary first permanent • molar is anterior to the mesiobuccal developmental groove of the mandibular first there are division 1 and 2. Division 1 is if there is excessive overjet of anterior teeth. Division 2 if there is excessive lingual inclination of the maxillary central incisors and an excessive labial inclination of the maxillary lateral incisors
Class III Malocclusion
the mesiobuccal cusp of the maxillarv first permanent molar is posterior to the mesiobuccal developmental groove of the mandibular first permanent molar. The anterior teeth may or may not be in cross bite
Positions of Mandible To Consider in Restorations
Centric Occlusion and Protrustive Movement
Incisal Guide Table
is the mechanical equivalent on the articulator to the anterior guidance of the patient
3 uses of incisal guide table
- 1. it protects the anterior teeth on mounted stone models from wear during excursive movements
- 2. it may reproduce and maintain existing anterior guidance during the fabrication of anterior restorations
- 3. it may reproduce and maintain provisional anterior guidance during the fabrication of temporary crowns and final restorations
- represents border movements in the mid-sagittal plane
- they are:
- 1. maximum protrusion
- 2. incisal edge-to-edge position
- 3. centric occlusion
- 4. centric relation
- 5. masticatory cycle
- 6. hinge opening
- 7. normal opening
- 8. maximum opening
- • postural rest position