Facial and glossal distribution of anaesthesia after inferior alveolar nerve block.

The aim of this study was to subjectively determine the distribution of anaesthesia by mapping areas of sensory loss following inferior alveolar nerve block. Fifty healthy dental students were the subjects of this study (men 32, women 18). They were asked to draw the anaesthetized area on a diagram of the face and tongue 20 min after inferior alveolar nerve block. They evaluated the degree of anaesthesia by touching their faces and moving their tongues. All of the 50 subjects reported anaesthesia in the facial area. Of these, 21 (42%) reported the cutaneous distribution of anaesthesia on mental nerve territory only. Seventeen subjects (34%) reported anaesthesia on mental and buccal nerve territory. Nine subjects (18%) reported anaesthesia on mental, buccal, and auriculotemporal nerve territory. Two subjects (4%) reported anaesthesia on mental and auriculotemporal nerve territory and one subject (2%) on mental, buccal and infra-orbital nerve territory. Forty-seven of the 50 subjects (94%) reported anaesthesia of the tongue with the various degree of anaesthesia according to the area. Of these, 17 subjects (34%) reported strong anaesthesia on the anterior area and weak anaesthesia on the middle part of the tongue. Nineteen subjects (38%) reported strong anaesthesia of the lateral area and weak anaesthesia on the medial area, and 11 subjects (22%) reported anaesthesia on only the lateral side of the tongue. Three subjects (6%) reported no anaesthesia of the tongue. The distribution of anaesthesia of the facial and glossal regions determined subjectively after inferior alveolar nerve block, varies significantly between individuals.