The authors describe a intraoral approach with Botox (R) onabotulinum toxin type A to treat trigeminal neuralgia of the maxillary branch applied on deep belly of the temporalis muscle. Six patients six with trigeminal neuralgia at maxillary branch without another reason to sutler this disease were treated by one application of Botox (R) onabotulinum toxin type A at deep belly of the temporalis muscle, in all of cases VAS was the element to measure the pain. These six patients reduce their clinical complaints of their painful condition and functional resolution at six months after the injection. Intraoral application of Botox (R) onabotulinum toxin type A to treat trigeminal neuralgia of the maxillary branch applied on deep belly of the temporal muscle is a good method to treat this clinical condition especially when: 1) all the different causes of trigeminal neuralgia of maxillary branch have been discarded; 2) there exists a relationship between deep belly of the temporalis muscle and maxillary nerve.