1. A method of providing a three-dimensional scan of a dental arch area, the arch area having two segments and a connecting area between the two segments, the method comprising: affixing a connecting-geometry tool with at least one definable feature relative to the dental arch area, the at least one definable feature overlaying at least part of the connecting area; scanning the arch area to produce a scanned dataset of the arch area; determining data relating to the definable feature of the connecting-geometry tool overlaying the connecting area based on the scanned dataset; and determining the dimensions of the connecting area based on the data relating to the definable feature.