Anesthetic testing is most effective in localizing pain

Selective Anesthesia When  symptoms  are  not  localized  or  referred,  the  diagnosis may be challenging. Sometimes the patient may not even be able to specify whether the symptoms are emanating from the maxillary or mandibular arch. In these instances, when pulp testing is inconclusive, selective anesthesia may be helpful.If  the  patient  cannot  determine  which  arch  the  pain  is coming from, then the clinician should first selectively anesthetize  the  maxillary  arch.  This  should  be  accomplished  by using a periodontal ligament (intraligamentary) injection. The injection  is  administered  to  the  most  posterior  tooth  in  the quadrant  of  the  arch  that  may  be  suspected,  starting  from  the distal sulcus. The anesthesia is subsequently administered in an anterior direction, one tooth at a time, until the pain is eliminated. If the pain is not eliminated after an appropriate period of time, then the clinician should similarly repeat this technique on the mandibular teeth below. It should be under-stood that periodontal ligament injections may anesthetize an adjacent tooth and thus are more useful for identifying the arch rather than the specific tooth. Cohen's Pathway of the Pulp ed:11th Pg20