Follow-Up to the Parathesia Case

I had the parasthesia patient in for a check up yesterday. The parasthesia or rather dysesthesia involves the teeth from 44 to 46. The implant was placed in the 47 region.The teeth feel "dead" to use the patient's own words. All else is fine. There is no problem with the lips, tongue or gingiva. The wound is healing well. The postop OPG shows the implant well clear of the nerve. I am puzzled. What could it be?Here are some options

• A twist drill that damaged the nerve while preparing the osteotomy- This is most likely. Although I was as careful as could be (of course!). Hopefully given that all other sensations are normal ,sensation should return sooner or later. Once more the need for careful measurement, preop OPG's and CT Scans and the use of stops. Even better would be the use of a surgical guide with depth control.
• Pressure on the nerve as a result of bleeding ,edema etc in the osteotomy. This too should resolve. Is it worth backing out the implant? Not in the case of a tapered implant such as this. Turning it back even a turn will more often than not result in a loss of stability.
• An accessory canal. Not unknown but the CT Scan of the patient does not seem to show any accessory canals.
• The loss of sensation is easier for the patient to get used to than altered sensation or pain .