Distinguish Class II elastics from Class III elastics and typical attachments.

Distinguish Class II elastics from Class III elastics and typical attachments.

• A. Class II elastics connect upper posterior teeth to lower anterior teeth to correct Class II.
• B. Class II elastics connect upper posterior teeth to lower posterior teeth.
• C. Class III elastics connect upper posterior teeth to lower anterior teeth.
• D. Class II elastics connect upper posterior teeth to lower anterior teeth to correct Class II; Class III elastics connect upper posterior teeth to lower posterior teeth or vice versa to correct Class III; attachments include elastic hooks or buttons.

Answer: (D)

Elastics are used to create interarch forces that modify the bite by tying teeth in opposite arches. For Class II correction, elastics run from upper posterior teeth to lower anterior teeth, pulling the upper back and/or guiding the lower teeth forward to reduce the Class II relationship. For Class III correction, elastics are placed between the arches in the opposite sense, typically connecting teeth in the lower arch to teeth in the upper arch in a way that encourages forward movement of the maxilla or backward movement of the mandible. The hardware used to anchor these elastics is straightforward—elastic hooks on brackets or buttons cemented to teeth provide the attachment points. This combination—orientation of the elastic path for each class and the common attachment methods—is why the described option is the best match.

Elastics are used to create interarch forces that modify the bite by tying teeth in opposite arches. For Class II correction, elastics run from upper posterior teeth to lower anterior teeth, pulling the upper back and/or guiding the lower teeth forward to reduce the Class II relationship. For Class III correction, elastics are placed between the arches in the opposite sense, typically connecting teeth in the lower arch to teeth in the upper arch in a way that encourages forward movement of the maxilla or backward movement of the mandible. The hardware used to anchor these elastics is straightforward—elastic hooks on brackets or buttons cemented to teeth provide the attachment points. This combination—orientation of the elastic path for each class and the common attachment methods—is why the described option is the best match.