Podcast
Questions and Answers
What does Wilson’s curve describe?
What does Wilson’s curve describe?
What is described by the curve of occlusion?
What is described by the curve of occlusion?
Which curve ensures balanced occlusion in complete dentures?
Which curve ensures balanced occlusion in complete dentures?
What is distinctive about Monson’s curve?
What is distinctive about Monson’s curve?
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The curve of Spee is primarily observed from which point?
The curve of Spee is primarily observed from which point?
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The term 'glabella' refers to which anatomical location?
The term 'glabella' refers to which anatomical location?
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Which curve of occlusion is also known as the anti-Monson?
Which curve of occlusion is also known as the anti-Monson?
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What does normal occlusion primarily refer to?
What does normal occlusion primarily refer to?
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How many occlusal contacts are typically found in normal occlusion?
How many occlusal contacts are typically found in normal occlusion?
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What is meant by the term 'arch length discrepancy'?
What is meant by the term 'arch length discrepancy'?
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Which of the following describes the stability of occlusion vertically?
Which of the following describes the stability of occlusion vertically?
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What is classified as Class II in arch size?
What is classified as Class II in arch size?
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Which teeth are positioned more buccally in the dental arch?
Which teeth are positioned more buccally in the dental arch?
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What is the neutral zone in dentistry?
What is the neutral zone in dentistry?
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What happens to occlusal stability after tooth extraction?
What happens to occlusal stability after tooth extraction?
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Which of the following teeth generally have only one antagonist?
Which of the following teeth generally have only one antagonist?
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What is true about the vertical overlap (overbite) in centric occlusion?
What is true about the vertical overlap (overbite) in centric occlusion?
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Which cusps are categorized as the supporting cusps in the occlusion principles?
Which cusps are categorized as the supporting cusps in the occlusion principles?
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What describes the primary function of closure stoppers during mandibular closure?
What describes the primary function of closure stoppers during mandibular closure?
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In the context of occlusal contacts, which statement is correct regarding A, B, and C contacts?
In the context of occlusal contacts, which statement is correct regarding A, B, and C contacts?
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Which description correctly identifies non-centric cusps in occlusion?
Which description correctly identifies non-centric cusps in occlusion?
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Which principle best describes the concept of cusp-fossa occlusion patterns in centric occlusion?
Which principle best describes the concept of cusp-fossa occlusion patterns in centric occlusion?
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What is the primary feature of cusp-marginal ridge occlusion?
What is the primary feature of cusp-marginal ridge occlusion?
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In cusp-fossa occlusion, what arrangement is described?
In cusp-fossa occlusion, what arrangement is described?
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What is a critical benefit of using cusp-fossa occlusion?
What is a critical benefit of using cusp-fossa occlusion?
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During centric occlusion, what should occur between the Equalizers and Stoppers?
During centric occlusion, what should occur between the Equalizers and Stoppers?
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What type of occlusion is characterized by a tripod contact?
What type of occlusion is characterized by a tripod contact?
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Which cusp of the maxillary first molar fits into the central fossa of the lower first molar?
Which cusp of the maxillary first molar fits into the central fossa of the lower first molar?
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Which of the following describes tooth-to-two-teeth occlusion?
Which of the following describes tooth-to-two-teeth occlusion?
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What forces are improved by cusp-fossa occlusion during mastication?
What forces are improved by cusp-fossa occlusion during mastication?
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In centric occlusion, which teeth typically have only one antagonist?
In centric occlusion, which teeth typically have only one antagonist?
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Horizontal overlap (overjet) occurs when the incisal ridges of which teeth extend labially or buccally to those of the opposing arch?
Horizontal overlap (overjet) occurs when the incisal ridges of which teeth extend labially or buccally to those of the opposing arch?
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What are the supporting cusps also known as in the context of centric occlusion?
What are the supporting cusps also known as in the context of centric occlusion?
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Which statement best describes the role of closure stoppers during mandibular closure?
Which statement best describes the role of closure stoppers during mandibular closure?
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What is the relationship between the buccal cusps of the posterior teeth termed?
What is the relationship between the buccal cusps of the posterior teeth termed?
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Which occlusal relationship is essential for maintaining occlusal stability according to the contacts defined?
Which occlusal relationship is essential for maintaining occlusal stability according to the contacts defined?
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Which of the following describes the characteristics of guiding cusps?
Which of the following describes the characteristics of guiding cusps?
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What type of occlusion involves the interaction between the mesial inclines of the lower teeth and the distal inclines of the upper teeth?
What type of occlusion involves the interaction between the mesial inclines of the lower teeth and the distal inclines of the upper teeth?
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What type of occlusion involves the interdigitation of the cusps and fossae of one tooth with those of only one opposing tooth?
What type of occlusion involves the interdigitation of the cusps and fossae of one tooth with those of only one opposing tooth?
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Which structure best describes the contact mechanism in cusp-marginal ridge occlusion?
Which structure best describes the contact mechanism in cusp-marginal ridge occlusion?
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Which cusp of the maxillary first molar fits into the central fossa of the lower first molar during occlusion?
Which cusp of the maxillary first molar fits into the central fossa of the lower first molar during occlusion?
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What is the primary mechanical advantage provided by tripod contacts in cusp-fossa occlusion?
What is the primary mechanical advantage provided by tripod contacts in cusp-fossa occlusion?
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What is a notable feature of the cusp-fossa occlusion pattern found in only 5% of natural teeth?
What is a notable feature of the cusp-fossa occlusion pattern found in only 5% of natural teeth?
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Which of the following is NOT an advantage of using cusp-fossa occlusion?
Which of the following is NOT an advantage of using cusp-fossa occlusion?
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Which cusp of the mandibular first molar fits into the mesial fossa of the maxillary first molar?
Which cusp of the mandibular first molar fits into the mesial fossa of the maxillary first molar?
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Study Notes
Introduction and Definitions
- Occlusion describes the static relationship of the maxillary and mandibular teeth when occluding.
- Normal occlusion commonly exists in the absence of disease.
- Normal occlusion presents with 138 occlusal contacts between 32 teeth.
- Dental arch form refers to the geometric shape of the dental arch viewed horizontally.
Normal Arch Size
- The maxillary arch tends to be larger than the mandibular arch resulting in maxillary teeth "overhanging" mandibular teeth.
Arch Length Discrepancy
- Abnormal relationships between the size of the mandible and/or maxilla and their component teeth are viewed in the occlusal plane.
- A class II discrepancy refers to a small mandible.
- A class III discrepancy refers to a large mandible.
Teeth Position In Dental Arch
- Certain teeth, due to their size, are positioned lingually or labially to the ideal curve.
- The labial surface of maxillary lateral incisors is more lingually placed.
- The buccal surface of cuspids are more buccally placed.
- The buccal surface of maxillary first molars are positioned buccally.
Stability of the Occlusion Vertically
- The maintenance of tooth position vertically depends on occlusal and eruptive forces.
- Balanced forces will keep the occlusion stable.
- Tooth extraction disrupts occlusion due to reduced occlusal force and tooth shifting.
Stability of the Occlusion Horizontally
- Lip and cheek pressure from the outside and tongue pressure from the inside maintain the teeth horizontally.
- The neutral zone is the potential space where the forces between lips/cheeks and tongue are equal.
Curvatures of the Dental Arches
- The curve of occlusion is the average curve of the incisal and occlusal surfaces of the anterior and posterior teeth.
Curve of Spee
- The cusps and incisal ridges display a curved alignment in a point opposite the first molars.
Monson’s Curve
- Each cusp and incisal edge touches or conforms to a segment of a spherical surface with an 8-inch diameter.
Curve of Wilson
- The cusp tips in both sides of molars in a frontal section form a mediolateral curve.
Curve of Pleasure (Anti-Monson)
- A helicoid curve of occlusion that when viewed frontally forms a convex curve, except for the last molars which reverse the pattern.
Compensating Curve
- The curvature of the occlusal plane of complete dentures, created to permit balanced occlusion.
Cusp-Marginal Ridge Occlusion
- This type of occlusion occurs when a cusp fits into a fossa and another cusp of the same tooth fits into the embrasure area of two opposing teeth.
- This pattern is present in 95% of natural teeth.
- The mesio-palatal cusp of the maxillary first molar fits into the central fossa of the lower first molar.
- The disto-palatal cusp of the maxillary first molar fits into the distal marginal ridge of the lower first molar and the mesial marginal ridge of the second molar.
- The mesio-buccal cusp of the mandibular first molar fits into the distal marginal ridge of the second premolar and the mesial marginal ridge of the maxillary first molar.
- The disto-buccal cusp of the mandibular first molar fits into the maxillary central fossa.
Cusp-Fossa Occlusion
- This type of occlusion occurs when most or all of the cusps fit into fossae.
- The cusps and fossae of one tooth interdigitate with the cusps and fossae of only one opposing tooth.
- This pattern is present in 5% of natural teeth.
- The cusp ridges make a tripod of contact with the fossa, leaving the cusp apex out of occlusion.
- The mesio-palatal cusp of the maxillary first molar fits into the central fossa of the lower first molar.
- The disto-palatal cusp of the maxillary first molar fits into the distal fossa of the lower first molar.
- The mesio-buccal cusp of the mandibular first molar fits into the mesial fossa of the maxillary first molar.
- The disto-buccal cusp of the mandibular first molar fits into the maxillary central fossa.
Advantages of Cusp-Fossa Occlusion
- Prevents food impaction.
- Centric relation closure forces are nearer the long axes of the tooth.
- Improves stability.
- Used when the mesiodistal relationship of opposing teeth favors it.
- Used in full mouth/full arch reconstruction.
Centric Holding Cusps & Centric Stops
- The supporting cusps (PU-BL) are the lingual cusps of the maxillary posterior teeth and the buccal cusps of the posterior mandibular teeth.
- Centric stops are areas of contact that a supporting cusp makes with opposing teeth.
Non-Centric (Guiding or Shear) Cusps
- Guiding cusps (BU-LL) are sharper and more outward placed than the supporting cusps and provide horizontal and vertical overlap over them.
A, B, and C Contacts
- Contact between the buccal cusps of the posterior teeth is an A contact.
- The common contact between the stamp cusps is a B contact.
- Contact between the lingual cusps of the posterior teeth is a C contact.
- The B contacts in centric occlusion must be obtained and maintained for occlusal stability.
Closure Stoppers and Equalizers
- The closure of the mandible occurs in a curved upward path.
- Upon closure, mesial inclines of lower teeth contact distal inclines of uppers. These contacts are called Closure Stoppers (ML-DU).
- The distal inclines of the lowers contact the mesial inclines of the uppers. These contacts are called Equalizers (MU-DL).
- Both Closure Stoppers and Equalizers should occur in centric occlusion.
- The supporting cusps (PU-BL) act as Closure Stoppers and Equalizers during mandibular closure.
- PU-BL means palatal upper, buccal lower.
- ML-DU means mesial lower, distal upper.
- MU-DL means mesial upper, distal lower.
Functional Form of the Teeth
- C; cusp
- CR; cusp ridge
- MR; marginal ridge
- TR; triangular ridge
- CF; central fossa
- MRF; marginal ridge fissure
Facial and Lingual Relations of Each Tooth to its Antagonist
- In centric occlusion, each tooth on one arch occludes with two teeth on the opposing arch except for:
- Mandibular central incisors
- Maxillary third molars (occludes with one tooth)
Horizontal Overlap (Overjet)
- The incisal ridges or buccal cusp ridges of maxillary teeth extend labially or buccally to the incisal ridges or buccal cusp ridges of the mandibular teeth in centric occlusion.
Vertical Overlap (Overbite)
- The incisal ridges of the maxillary anterior teeth extend below the incisal ridges of the mandibular anterior teeth in centric occlusion.
Centric Holding Cusps (Supporting or Stamp) Cusps & Centric Stops
- Lingual cusps of maxillary posterior teeth and buccal cusps of mandibular posterior teeth are supporting cusps.
- Centric stops are areas of contact made by supporting cusps with opposing teeth.
Non-Centric (Guiding or Shear) Cusps
- Guiding cusps (BU-LL) (Mandibular lingual & maxillary buccal) are sharper and more outward placed than supporting cusps.
- They provide horizontal and vertical overlap over supporting cusps.
Centric Holding Cusps in Posterior Cross Bite Relationship
- In this relationship, supporting cusps on the crossbite side would need to be flattened or re-contoured.
A, B and C Contacts
- A contact: Contact between the buccal cusps of posterior teeth
- B contact: Common contact between stamp cusps
- C contact: Contact between lingual cusps of posterior teeth
- B contacts in centric occlusion must be obtained and maintained for occlusal stability.
Closure Stoppers & Equalizers
- Closure of the mandible occurs in a curved upward path.
- Closure Stoppers (ML-DU): Mesial inclines of lower teeth contact distal inclines of upper teeth.
- Equalizers (MU-DL): Distal inclines of lower teeth contact mesial inclines of upper teeth.
- Simultaneous contacts of stoppers and equalizers should occur in centric occlusion.
Cusp – Marginal Ridge Occlusion
- One stamp cusp fits in a fossa and the other stamp cusp of the same tooth fits into the embrasure area of two opposing teeth (“tooth-to-two-teeth” occlusion or a “cusp-embrasure” occlusal pattern).
- Present in 95% of natural teeth.
- Plunger cusp effect
Cusp-Fosse Occlusion
- Most or all stamp cusps fit into fossae.
- Cusps and fossae of one tooth interdigitate with cusps and fossae of one opposing tooth (“tooth-to-one-tooth” occlusion)
- Present in 5% of natural teeth.
- Tripod Contact in Cusp Fosse Occlusion: Cusp ridges make a tripod of contact with the fossa, leaving the cusp apex out of occlusion. This provides escapement spaces, necessary for efficient mastication.
Advantages of Cusp Fosse Occlusion
- Prevents food impaction
- Centric relation closure forces are closer to the long axes of the tooth
- Improves stability
- Used when:
- Mesiodistal relationship of opposing teeth favors it
- Full mouth/full arch reconstruction
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Description
Test your knowledge on dental occlusion, arch size, and the classifications of dental discrepancies. This quiz covers definitions, normal occlusion, and the positioning of teeth in the dental arch. Ideal for dental students and professionals looking to review essential concepts.