Fifth Stage Orthodontics Study Models

Accurate plaster reproductions of teeth and surrounding soft tissues, used for diagnosing occlusion and dentition.

Accurate reproduction of teeth and surrounding tissues, symmetrical and pleasing, clear view of occlusion from below, consistent with design measurements, smooth, glossy, and marker-proof.

Using study models to plan a course of action for correcting dental issues.

Examining the way upper and lower teeth meet by looking at the models.

The positions of the upper and lower jaws in relation to each other.

Assessment of dental anatomy, intercuspation, arch form, curves of occlusion; evaluating occlusion with articulators; measuring treatment progress; detecting abnormalities; calculating space discrepancies.

Study models can help patients visualize and understand their dental treatment, thus improving their commitment.

Using study models to compare a patient's dental condition before, during, and after treatment.

Actual impression of the dental arch and surrounding soft tissues.

Stone base supporting the anatomic portion, shaped for aesthetic appeal.

Method to estimate arch width based on maxillary incisor measurements.

Greatest width of maxillary incisors, measured in millimeters.

Distance between upper first premolars.

Estimated premolar region width, using formula based on incisor measurement.

Method to analyzing dental models by comparing measured and calculated width in premolar and molar regions.

Preliminary actions to prepare study models for analysis, like removing excess material and nodules.

The sum of the mesiodistal width of all teeth from the first molar to the first molar, including the molars themselves, measured on dental casts.

The distance from a reference point on the midline of the upper or lower jaw to the distal surface of the first molar, measured along the occlusal plane.

The width of the dental arch measured at the top of the buccal cusp of the first premolar.

The width of the apical base of the jaw measured from the canine fossa on one side to the other, about 8mm below the interdental papilla.

(PMD x 100) / TTM

(PMBAW x 100) / TTM

(BAL x 100) / TTM

Bolton's analysis helps determine the disproportion between the size of the maxillary and mandibular teeth, to plan the best treatment for ideal interdigitation, overjet, overbite, and alignment of teeth.

A method to assess tooth size discrepancies between the upper and lower arches by comparing the sum of mesiodistal widths of maxillary and mandibular teeth.

The ratio of the sum of mesiodistal widths of 12 mandibular teeth to the sum of 12 maxillary teeth, ideally 91.3%.

The ratio of the sum of mesiodistal widths of 6 mandibular anterior teeth to the sum of 6 maxillary anterior teeth, ideally 77.2%.

When the overall ratio or anterior ratio exceeds the ideal percentage, indicating more tooth material in the lower arch.

A method to assess the discrepancy between arch length and tooth material, primarily in the lower arch.

The measured distance along the lower arch, from one first molar to the other, determined using a soft brass wire.

Similar to Carey's analysis, but applied to the upper arch, assessing the discrepancy between arch length and tooth material in the upper arch.

A misalignment or improper fit of the teeth, often due to a discrepancy between arch length and tooth material.

A formula used to estimate the width of maxillary and mandibular canines and premolars based on the width of the lower incisors.

A replica of a patient's teeth and surrounding structures made from trimmed study models, used for simulating tooth movements and treatment planning.

Aids in visualising tooth size discrepancies, determining extraction needs, simulating the effect of tooth movement, and motivating patients by showing them potential improvements.

The difference between the amount of space available in the dental arch and the total width of the teeth.

Encouraging patients to complete treatment by showing them the expected improvements and involving them in the planning process.

The wire is positioned along the mesial side of the lower first permanent molar, then follows the buccal cusps of premolars, incisal edges of anteriors, and finally continues along the mesial side of the first molar on the opposite side.

In Carey's analysis, the arch length is determined by placing a wire along the cingulum of proclined anterior teeth or the labial surface of retroclined anterior teeth.

Total tooth material is calculated by summing the mesiodistal widths of all teeth anterior to the first molars.

The difference between the measured arch length and the total tooth material.

A discrepancy of 0 to 2.5 mm suggests minimal tooth material excess, which can be addressed through proximal stripping.

A discrepancy between 2.5 and 5 mm indicates the need for extraction of the second premolar.

When the discrepancy exceeds 5 mm, extraction of the first premolar is typically required.

To assess the space available in the arch for the upcoming permanent teeth, helping with space management and necessary occlusal adjustments.