Oral Ana lec Midterm quiz #1

compensating curves

are the anteroposterior (sagittal) and mediolateral (frontal) curves in the occlusal surfaces of teeth that achieve balanced occlusion. These curves compensate for the space created during mandibular movements (protrusion and lateral movements) by ensuring simultaneous and balanced tooth contact

curve of wilson

the mediolateral (side-to-side) curvature of the posterior teeth in the dental arch, defined by an imaginary line drawn through the buccal and lingual (or palatal) cusp tips. It is concave in the mandibular arch and convex in the maxillary arch. This curve allows for balanced occlusion by ensuring that the lingual cusps of the mandibular molars are lower than their buccal counterparts, preventing occlusal interferences during jaw movement

curve of spee

the anatomical, anterior-posterior (front-to-back) curvature of the mandibular occlusal plane, extending from the tip of the lower canine to the last molar. This naturally occurring curve is viewed from the side (sagittal plane) and is essential in orthodontics for diagnosing malocclusion and planning treatment

curve of monson

a theory proposing an ideal occlusion where all the buccal (cheek-side) cusps and incisal (cutting) edges of the teeth touch or conform to the surface of an imaginary sphere, typically described as being 8 inches (or 20.3 cm) in diameter, with the sphere's center located at the glabella (the bony prominence between the eyebrows). Proposed by American dentist G. S. Monson in 1920, it represents a three-dimensional spherical occlusal plane

Bonwill triangle

is a triangle formed by the contact point of the mandibular central incisors and the right and left mandibular condyles.

4in/10.16cm

this is the measurement of the sides of the Bonwill equilateral triangle

spherical theory of occlusion

proposed that the lower teeth move over the surface of upper teeth as over a surface of a sphere with a diameter of 8 inches, the center of the sphere is located in the region of glabella

bunodont

describes molar teeth that have low, rounded, or conical cusps; This type of dentition is common in omnivorous mammals, such as humans, because it is adapted for a mixed diet by pounding and grinding food rather than shearing it.

lophodont

having transverse ridges on the grinding surfaces, characteristic of some ungulates; having teeth with transverse ridges on the grinding surfaces.

isognathous

a biological term describing a condition where the upper and lower jaws have similar width or are of equal jaw width, allowing the molar teeth to align with each other. This differs from anisognathous animals, which have unequal jaw widths, a trait common in most domestic animals

pig

example of isognathous animal; has equal jaw

selenodont molars

They are a type of cheek tooth found in ruminant herbivores, characterized by crescent-shaped cusps that form ridges on their grinding surfaces; This specific molar structure, with its exposed layers of enamel and dentine forming ridges, is highly effective for the grinding motion used to break down tough plant matter in their diet

anisognathous

is a term, primarily used in zoology and dentistry, that describes a condition where the upper and lower dental arches (jaws) are of unequal width, with the upper jaw typically being wider than the lower jaw. This anatomical difference in jaw width is opposed to isognathous, which refers to jaws of equal width

Haplodont/Triconodont/Tritubercular molar/Quadritubercular molar

The Four phylogenetic classes of tooth forms:

Haplodont

describes molar teeth that have simple, conical crowns lacking any ridges, cusps, or tubercles, representing the most basic form of a tooth. This type of dentition is characterized by its straightforward, single-cone structure and is typically found in animals like the northern fur seal, where the teeth are primarily used for gripping and combat rather than complex chewing

triconodont

having or being teeth with three simple cones; compare trituberculy.

Tritubercular molar

is a type of mammalian molar tooth characterized by having three prominent cusps (tubercles) arranged in a triangular shape, forming the basic, ancestral pattern for much of mammalian tooth evolution. This primitive triangular form, known as the trigon, is considered the foundational stage from which more complex molar teeth, such as the quadritubercular molars, developed

Quadritubercular molar

molars have a hypocone, an additional fourth cusp on the lingual (tongue) side of the upper molar, located posterior to the protocone

reptilian stage

also known as haplodont; represented by the simplest form of tooth, the single cone; Usually includes many teeth in both jaws that limit movement; there is no occlusion of the teeth in this class, and teeth are used mainly for 1) prehension or combat and 2) procurement of food

early mammalian stage

also known as triconodont; this exhibits 3 cups in the development of posterior teeth; The largest or anthropologically the original cusp is centered with a smaller cusp located anteriorly and another posteriorly; example dog

triangular stage

also known as tritubercular molar; exhibits teeth of three-cornered shape (triangle), with the teeth bypassing each other more or less when the jaw opened or closed; this stage created projections that are triangular in form that occlude with an antagonist in the opposing jaw

quadritubercular stage

also known as the lower molars, exhibits teeth of four projections to establish occlusion with tritubercular molars; 4 cusps in a quadrangle and there is now occlusion; example primates and humans

triangle/trapeziod/rhomboid

these are the geometries of crown outlines

geometric fiugres

all aspects of each tooth crown except the incisal or occlusal aspects may be outlined schematically within three of these,

trapezoid

Facial and lingual aspects of all teeth may be represented with this shape of various dimensions shortest of the uneven sides toward the tooth cervix. The length of the uneven sides is toward the occlusal or incisal aspect

triangle

proximal crown outline of anterior teeth; the schematic outline of the crown from the proximal aspect can be triangular in form. The base of this is toward the cervix, while the apex is toward the incisal ridge; a wide base of the crown for strength, tapered outlines (labially and lingually) to a thin ridge to facilitate the penetration of food

trapezoid

proximal outline of maxillary posterior teeth including the premolars; they are this shape in outline, and the largest of the uneven sides is toward the tooth cervix, and the shortest of the uneven sides is towards the occlusal surface

rhomboid

proximal crown outline of the mandibular posterior teeth, it is this shape