Title : Influence of growth on failure of inferior alveolar nerve block
Abstract:
In children, repeated injection of the local anaesthetic solution due to failure of IANB can be a tedious task as it may result in a negative behaviour of the child and there exists the risk of administering the solution above the recommended safe dose. This is due to varied positions of mandibular canal that carry inferior alveolar nerve. The internal surface of the ramus is punctured by the mandibular foramen, situated halfway between the anterior and posterior borders of the ramus at the level of the occlusal surfaces of the lower teeth, and through which the inferior alveolar nerve and vessels enter the mandibular canal, ultimately terminating at the mental foramen. The mandibular canal is present as a single conduit in most individuals and is classified into three types according to Carter and Keen, 1971. Type I: inferior alveolar nerve is a single large structure lying in a bony canal; Type II: the nerve is situated substantially lower down the mandible; and Type III: the inferior alveolar nerve separates posteriorly into two large branches, corresponding to bifid mandibular canal. Such anatomical variations, along with operator technique, are a cause of failed inferior alveolar nerve block (IANB) anaesthesia. By following the landmarks, the anaesthetic solution is delivered as close as possible to the mandibular foramen. Literature lacks the data about varying position of mandibular foramen from childhood till adolescence. Thus keeping this in mind, this review was conducted to assess the changing positions of mandibular foramen in relation to child’s growth and development from childhood to adolescence using radiographical techniques.