Many philosophies of arranging denture occlusion; No definitive scientific studies Lingualized Occlusion: Contacts on centered on mandibular ridge minimizes. Lingualized Occlusion. If I had to choose the one thing that’s had the greatest effect on the success of the dentures and partial dentures I construct for my patients. Lingualized occlusion represents an established method for the development of functional and esthetic complete denture articulation. Since its introduction, the.
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This series of articles describes about concepts of occlusion in the complete denture, fixed partial denture, and implants. This article discusses about the evolution of different concepts of nonbalanced occlusion and occlusal schemes in complete denture occlusion. In continuation with concepts of occlusion in prosthodontics part I where concepts developed to achieve balanced articulation were described, now the different concepts developed to attain the non balanced occlusion are described with their merits and demerits.
Various concepts proposed to attain nonbalanced articulation. Maxillary posterior teeth should have sharp palatal cusps which should occlude with opposing widened central fossae of the mandibular posterior teeth to eliminate the deflective occlusal contacts in processed dentures and the teeth should have gold occlusal inlays to maintain vertical dimension at occlusion.
Accurate retentive denture bases are a requirement in this concept. In centric occlusion, the occlusal contact forces are directed toward the ridges [ Figure 1a ]. In the right lateral position, the buccal cusps on the working side are out of contact and the occlusal contact forces are directed toward the lingual side of the lower ridge.
There is a tendency of shifting of denture bases on the balancing side [ Figure 1b ]. In centric occlusion, the contact forces are directed toward the ridges [ Figure 2a ]. In the right lateral position, the canine guidance disocclude the posterior teeth [ Figure 2b ]. In right lateral position. In a right lateral position, only the buccal cusps on the working side contact if the path of the condyle is not parallel to the occlusal plane.
Tilting of the bases may result if extreme gliding contacts are made [ Figure 3b ]. In centric occlusion, occlusal contact forces are directed toward the ridges.
Pivoting in the posterior region of a flat occlusal plane has been used to reduce temporomandibular joint symptoms [ Figure 4a ].
In right lateral position, only the working side pivot will contact if the path of the condyle on the balancing side is not parallel to the occlusal plane [ Figure 4b ]. Occlusio centric occlusion, the contact forces are directed toward the lingual side of the lower ridge [ Figure 5a ].
In the right lateral position, the occlusal contact forces directed toward the ridges on the occluusion side [ Figure 5b ]. InGysi introduced the concept of lingualized articulation. In effect, the occlusion is lingualized by the elimination of contacts on the buccal cusps and by the anteroposterior arrangement of lower posterior teeth so that their lingual surfaces are on or within the lingual side of a triangle from the mesial area of the lower cuspid to the sides of the retromolar pad.
Lingualized occlusion is developed to maintain the food-penetration advantages of the anatomic form while maintaining the mechanical freedom of the nonanatomic form.
The lingualized concept utilizes anatomic teeth for the maxillary denture and modified nonanatomic or semi anatomic teeth for the mandibular denture. Anatomic posterior occlusal arrangements have the mandibular buccal cusps occluding in the maxillary central fossae and the maxillary palatal cusps occluding in the mandibular central fossae [ Figure 6a ].
With lingualized occlusions, only the upper lingual cusps occlude in the mandibular central fossa. The maxillary posterior teeth are rotated slightly to avoid all contact of the buccal cusps [ Figure 6b ]. If the horizontal overlap is 3—4 mm between the anterior teeth, balanced occlusion can be achieved before anterior tooth contact at maximum intercuspation.
Esthetically vertical overlap of the teeth can be increased [ Figure 7 ]. Ofclusion little horizontal overlap between the anterior teeth is acceptable, then the vertical overlap must lingulized reduced to zero to attain balanced occlusion [ Figure 8 ]. Protrusive movement is possible while maintaining balanced occlusion with a minimal vertical overlap of the anterior teeth [ Figure 9 ].
In left lateral excursive movements, only the maxillary palatal cusps make contact. Selective grinding of the maxillary buccal cusps may be needed to create a clearance between the maxillary and mandibular buccal cusps [ Figure 10 ].
The need for bilateral balanced occlusion is based on more favorable stress distribution during parafunctional habits. Nocturnal occlusal parafunction can be eliminated by removal of the dentures while sleeping, but there is still the problem of parafunction during day time. Usually, the desired range of lingualized balanced occlusion can be achieved before the anterior teeth make contact.
Anterior tooth position does not compromise the efforts to achieve bilateral balanced occlusion within the suggested range, and the teeth can be arranged to meet esthetic limgualized phonetic requirements. In lignualized where the anterior teeth would contact before achieving the desired range of bilateral balanced occlusion, the vertical overlap of the anterior teeth can be reduced to approach an incisal guidance of zero.
In both situations, a slight compensating occlusal curve will be necessary to achieve continuous posterior contacts anterior to centric relation.
In this concept, the anterior teeth are arranged according to the requirements of esthetics and phonetics. Extreme vertical overlaps producing cuspid guidance are frequently used, resulting in disocclusion of the posterior teeth away from centric occlusion.
Characteristic of this concept is the use of pantographic tracings and the transfer of these recordings to an instrument to eliminate all potential deflective contacts in the arrangement of posterior teeth.
Concepts of occlusion in prosthodontics: A literature review, part II
This occlusion is based on the muscles and joint determines the mandibular position without tooth guidance and that the teeth in the function should always be passive to the parts of the occulsion movements. Jones advocated monoplane articulation in In this concept, a nonanatomic occlusal scheme is used with a few specific modifications. The amount of horizontal overlap is determined by the jaw relationships. The maxillary posterior teeth are arranged first, and the occlusal plane must fulfill certain requirements.
Thus, the teeth are lingialized inclined to form compensatory curves. In mediolateral direction, the teeth are set with no medial and lateral inclination. Thus, the concept of occlusion eliminates any anteroposterior or mediolateral inclines of the teeth and directs the forces of occlusion to the posterior teeth.
The occlusal plane is parallel to the mean plane of the denture foundation. This concept was carried out by limiting the mesiodistal extent of the occlusal table to avoid arranging the teeth over the lower molar slope inherent in the posterior portion of the residual ridge. To direct the forces toward the center of support and to reduce the functional forces, the buccolingual width of the teeth is reduced and the number of teeth is also reduced to direct the forces in the molar and bicuspid area of support and to refrain from placing a tooth on the ridge incline.
If the teeth are arranged in any other manner than described above, excessive pressure or pain is caused due to lateral interferences. Arrange the teeth in central position in reference to the foundation as the tongue will allow, in order to provide greater stability for the denture.
Reduced width of the artificial teeth reduces the vertical stresses on the ridge. In addition, horizontal stresses were also reduced due to the lingulized between opposing surfaces was decreased. Forces were centralized without encroachment on the tongue space. Tooth pitch inclination, tilt was corrected by placing the occlusal plane parallel to the occlhsion ridges ovclusion midway between them.
This positioning directed forces perpendicular to the mean osseous foundation plane. There libgualized no compensating curve and no incisal guidance. Patients were educated not ocvlusion incise or protrude. Tooth form was modified using flat teeth with no deflecting lcclusion. This arrangement reduced destructive lateral forces and to direct the masticatory forces perpendicular to the lingualizef. All contacts were in a single plane with no projections above or below the plane to interfere with the mandibular movements.
The posterior teeth were reduced in number from 8 to 6. This decreased the magnitude of the occlusal force and centralized it to the second premolar and first molar area. Mehringer developed physiologically generated occlusion to harmonize complete denture occlusion, neuromuscular system, and the temporomandibular joint.
The complete denture fabrication is preceded till try in and processing of only maxillary denture is done. After it is polished, a ljngualized conical disc is attached to the palatal region of the maxillary denture. The patient is asked to make chewing and swallowing movements, which created functionally generated paths.
Then apply separating medium to obtain maxillary stone cast of generated paths. Lower teeth are arranged according to maxillary cast of generated path. Two-point contacts on working side are eliminated and converted to one-point contact, this increases stability and transmit forces on lingual cusps only.
A line of occlusal contacts in one dental arch opposing a flat occlusal table in the other dental arch has the potential of creating the smallest lateral component of force against the denture bases. Since the area of contact is minimal, the frictional resistance is reduced. Furthermore, in the dental arch with the line of occlusal contacts, there is no change in the location of the contact during lateral movements. Therefore, the direction of force in that dental arch remains fairly constant.
The occlusal arrangement of artificial teeth, as viewed in the horizontal plane, wherein the masticatory surfaces of the mandibular posterior artificial teeth have a straight, long, narrow occlusal form resembling that of a line, usually articulating with opposing monoplane teeth. Teeth are arranged on a flat plane, which extends from the tip of maxillary central incisors to the top of the retromolar papilla.
The 2—3 mm of interocclusal clearance is not needed centric relation recorded at vertical dimension at rest with 0. The anterior vertical overlap is absent to provide noninterception in eccentric movements.
The posterior teeth used are nonanatomic with mandibular blade form of teeth. They exhibit bilateral fulcrum of protrusive stability — on protrusion blade form of mandibular second molar contacts maxillary first premolar bilaterally and prevent anterior rotational contact.
InKoyama, Inaba, and Yokoyama conducted a study on denture wearer preference and masticatory efficiency for balanced, organic cuspid-protectedand lingualized occlusions in three complete denture patients.
Masticatory efficiency was highest for the lingualized occlusion, next highest for the balanced occlusion, and lowest for the cuspid-protected occlusion. The differences in efficiency between lingualized and balanced occlusions and also between lingualized and cuspid-protected occlusions were significant. The shape of the masticatory cycle as shown with cinephotography was not influenced greatly by occlusal form.
The closures in all three types of teeth were in close proximity to the posterior border movement. Where the ridges of the subjects were good, the denture base movement was minimal and approximately the same for the three types of teeth, but where the ridge was poor, there was least movement with nonanatomic teeth.
InWoelfel and Winter studied three groups of denture wearers over a 5—8-year period.
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The greatest bone loss and closure of the occlusal vertical dimension were observed in the group of denture wearers with nonanatomic posterior teeth and the least in the lungualized wearing anatomic posterior teeth. The nonanatomic group also needed the most adjustments over a 5-year period. Hence, selection of particular concept of occlusion and occlusal scheme in completely edentulous patient depends on maxillary and mandibular jaw relation, residual alveolar ridge resorption, presence or absence libgualized displacive tissues in denture foundation areas, neuromuscular control, patient’s mental attitude, and esthetics demands.
Complete denture occlusion is a part of the stomatognathic system and not just merely arranging of maxillary and mandibular teeth.
The first and foremost concern is about the health and the preservation of the supporting structures. We need to consider all the factors such as biologic, lnigualized, and mechanical that favor the stability of the denture base to avoid deflective or excessive forces transmitted to the underlying structures.
National Center for Biotechnology InformationU. J Indian Prosthodont Soc. Mohamed IbrahimR.