COA Radiography & Diagnostic Imaging Flashcards

What is the primary diagnostic purpose of dental study models (plaster casts) in orthodontic records?

Answer: To evaluate occlusion, arch form, crowding, and tooth size relationships in three dimensions

Study models provide three-dimensional reproductions of the dentition that allow detailed analysis of occlusion, arch form, spacing, and crowding.

Which cephalometric measurement is primarily used to assess the vertical (hyperdivergent or hypodivergent) facial growth pattern?

Answer: Frankfort-mandibular plane angle (FMA)

The Frankfort-mandibular plane angle (FMA) measures the angle between the Frankfort horizontal and the mandibular plane, indicating vertical facial growth tendency.

What does a Bolton analysis evaluate in orthodontic diagnosis?

Answer: Tooth size discrepancy between maxillary and mandibular teeth

Bolton analysis compares the sum of mesiodistal widths of upper and lower teeth to identify tooth size discrepancies that could compromise final occlusion.

What patient head position is required for a standardized lateral cephalometric radiograph?

Answer: Upright with teeth in centric occlusion and Frankfort plane horizontal

A standardized cephalometric requires the patient upright, in centric occlusion, with the Frankfort plane parallel to the floor to ensure reproducibility.

What is the primary purpose of intraoral photographs in orthodontic records?

Answer: To visually document occlusion, alignment, and treatment progress

Intraoral photographs provide a visual baseline and ongoing documentation of tooth alignment, bracket placement, gingival health, and occlusal changes during treatment.

Which radiograph is best suited for detecting interproximal caries in posterior teeth by showing contact areas between adjacent teeth?

Answer: Bitewing radiograph

Bitewing radiographs capture the crowns of both upper and lower posterior teeth in one image, making interproximal caries and crest bone levels clearly visible.