Where should the external finish line of the maxilla be located?

Where should the external finish line of the maxilla be located?

• A. 2 mm palatal to the palatal surfaces of adjacent teeth
• B. On the incisal edge
• C. At the buccal mucogingival junction
• D. At the central palate

Answer: (A)

The location of the external finish line for the maxilla should be placed a small distance behind the palatal surfaces of the adjacent teeth, specifically about 2 mm palatal to those surfaces. This positioning places the border on the hard palate in a zone that is comfortable for the tissues, allows a good tissue seal, and keeps the border out of contact with the tooth surfaces so the denture base can seat and function without irritating the adjacent teeth. It also provides an appropriate area for border molding and helps prevent impingement on the gingival tissues. Placing the finish line on the incisal edge would intrude into the tooth and disrupt occlusion and stability. Locating it at the buccal mucogingival junction would place the border on the cheek side rather than the palate, compromising support and seal. Simply saying it is at the central palate is too vague and could place the border too far posteriorly or in an area that affects the vibrating line, increasing gag reflex and reducing retention.

The location of the external finish line for the maxilla should be placed a small distance behind the palatal surfaces of the adjacent teeth, specifically about 2 mm palatal to those surfaces. This positioning places the border on the hard palate in a zone that is comfortable for the tissues, allows a good tissue seal, and keeps the border out of contact with the tooth surfaces so the denture base can seat and function without irritating the adjacent teeth. It also provides an appropriate area for border molding and helps prevent impingement on the gingival tissues.

Placing the finish line on the incisal edge would intrude into the tooth and disrupt occlusion and stability. Locating it at the buccal mucogingival junction would place the border on the cheek side rather than the palate, compromising support and seal. Simply saying it is at the central palate is too vague and could place the border too far posteriorly or in an area that affects the vibrating line, increasing gag reflex and reducing retention.