In 1973, Gow-Gates decided to share the technique for inferior alveolar nerve anaesthesia which he had been using with complete satisfaction for thirty years. The eponym refers to the dentist George A.E. Gow-Gates who actually reported a 99% success rate. Though not on a level with the results reported by its creator, several clinicians welcomed the new idea: with failure rates of around 20%, in fact, the standard method of inferior alveolar nerve anaesthesia may well represent one of the most frustrating clinical phases, both for professionals and for patients.
It must be stressed that the Gow-Gates technique is not really an alternative to the usual method. It actually involves blocking the mandibular nerve, i.e., it affects the entire third branch of the fifth pair of cranial nerves and, obviously, all of its lower branches: in addition to the inferior alveolar nerve, the lingual, mylohyoid, mental, incisor, auriculotemporal and vestibular nerves.
Once applied effectively, therefore, nothing additional will be necessary for any intervention on the mandibular arch. As regards the indications for use, there are no real differences between the Gow-Gates technique and the alveolar nerve block. The same is true for the contraindications: the most significant concerns those patients who have difficulty in opening the mouth. On the other hand, some authors report problems as regards the operator who, if very familiar with the traditional technique, may have difficulty learning the new one.
Performance of the Gow-Gates technique to anaesthetise the inferior alveolar nerve
If one advantage is a higher success rate, a further advantage is the percentage of positive aspirations, equal to about 2%, and therefore much lower than the 10–15% of the conventional technique.
In operational terms, Malamed recommends using a long 25 G needle. The patient, supine with neck hyperextended (possibly semi-supine), is encouraged to open the mouth as wide as possible.
There are both extraoral and intraoral landmarks. On one side, the lower border of the tragus (triangular notch) and the angle of the mouth; on the other side, the mesiobuccal cusp of the upper second molar indicates the height at which the needle is inserted. The point of penetration is the mucosa of the mesial aspect of the mandibular ramus, distal to the same upper second molar. Positionally, this is near the neck of the condyle, just below the insertion of the external pterygoid muscle. The technique involves insertion to a depth of approximately 25 mm, until contact is made with the bone: after having retracted the needle by 1–2 mm, the aspiration test is carried out. If negative, the anaesthetic solution is slowly injected.