Use of computer technology for image-assisted risk assessment/evaluation of proposed dental treatments is described, in particular a method and apparatus for determining the impact of a proposed dental modification on the temporomandibular joint(s), e.g. to obtain information relating to that impact. Use of a virtual articulator is described to determine the impact of a proposed dental modification on the temporomandibular joint(s). This dental modification includes, but is not limited to, the replacement of one or more teeth by artificial teeth, the replacement of one or more parts of a tooth by a prosthetic reconstruction such as a dental crown or veneer, the rearrangement of one or more existing teeth (orthodontic treatment), the distraction of one or both jaws in order to reposition the teeth (orthognatic treatment) and/or modifications of the occlusal surfaces of the teeth.