A coronectomy is a term applied to the removal of only the crown of a tooth. This is reserved for teeth that are impacted with pathology (disease) on the surface and healthy roots. Frequently, a retained, impacted tooth (usually a wisdom tooth) will be exposed with infection around the crown.
The roots of long-standing impacted teeth are often tightly adhered or even fused to the bone. It is very traumatic to try and remove them. This is particularly important if they are near vital structures, the nerve in the lower and the sinus in the upper jaw. If the roots are not infected, they can be left behind. If the roots are infected, they are usually looser in the bone and can be easily removed.
Long-term studies have been done that show this to be a less traumatic technique that solves the problem. If one has multiple long-standing impacted wisdom teeth, they don’t all have to be removed. At some point in life, they should be treated as individual teeth. Observation of impacted teeth is perfectly appropriate if there is no pathology.
A panoramic radiograph and perhaps 3 dimensional CT scan of the jaws would be necessary. At the consultation appointment (link), we would discuss the advantages and disadvantages of the technique.