Orthodontic Procedures & Appliances Flashcards

During orthodontic bracket bonding, what is the primary purpose of acid etching the enamel surface?

Answer: To create microporosities in enamel that allow the adhesive to mechanically interlock

Phosphoric acid etching dissolves enamel crystalline structure to create micro-tags and porosities; when adhesive flows into these spaces and sets, it forms a strong mechanical bond.

A fixed lingual retainer bonded to the inside surface of the anterior teeth is designed primarily to:

Answer: Permanently maintain anterior tooth positions and prevent relapse

Fixed lingual retainers provide passive, permanent retention of corrected anterior tooth positions, particularly in the mandibular anterior region where relapse tendency is highest.

Which instrument is specifically designed to place and tuck the ends of metal orthodontic ligature ties beneath the arch wire?

Answer: Ligature director

A ligature director (also called a ligature tucker) has a notched or hooked tip used to push the twisted ends of wire ligatures under the arch wire so they do not irritate soft tissue.

In orthodontic assessment, 'overjet' is defined as:

Answer: The horizontal distance between the lingual surface of the upper incisors and the facial surface of the lower incisors

Overjet measures the horizontal (sagittal) protrusion of the maxillary incisors beyond the mandibular incisors; normal overjet is approximately 2–3 mm.

What is the primary purpose of a space maintainer placed in a child's mouth after premature loss of a primary tooth?

Answer: To preserve the arch space so the permanent tooth can erupt into proper position

Without a space maintainer, adjacent teeth drift into the space left by a prematurely lost primary tooth, reducing arch length and blocking or impacting the permanent successor.

After cementation of a fixed space maintainer, what is the most critical verification step?

Answer: Verifying the appliance does not interfere with occlusion and that all cement margins are fully sealed

Occlusal interference can cause discomfort and supra-eruption, while unsealed cement margins allow oral fluids under the band, leading to secondary caries and appliance failure.

Which statement best describes the legal scope of an EFDA's role in orthodontic procedures?

Answer: EFDAs may place and remove orthodontic appliances and take impressions under the supervision of a licensed dentist

EFDAs are authorized to perform expanded clinical functions—such as placing separators, cementation of bands, bracket bonding, and taking impressions—but only under direct supervision; diagnosis and treatment planning remain the dentist's responsibility.