BACKGROUND: The most commonly used nerve block procedure to anesthetize the mandibular arch is the classical inferior alveolar nerve block (IANB). In 1973, Gow-Gates developed a new procedure known as the Gow Gates nerve block, to achieve anesthesia in the same area with fewer complications. METHODOLOGY: The study comprised 80 patients who reported for the surgical removal of impacted third molar. The patients were randomly assigned into two groups- Group I received Gow-gates nerve block and Group II were administered classical IANB. Positive aspiration, meantime for the onset of anesthesia, mouth opening before and after each block and pain during the surgical procedure were compared. RESULTS: Group 1 yielded positive aspiration in 2.5% of the cases (one patient) and 15% had positive aspiration in Group 2 (six patient). The mean time taken for onset of anesthesia was 6.16 min in Group 1 as compared to 2.78 min in Group 2. While comparing the quality of anesthesia between the blocks, 87.5% of the patients in Group 1 and Group 2 had successful anesthesia equally i.e., 35 of the 40 patients fell into category 1 and 2 of the eight-point category rating scale in both the groups and the remaining five patients (12.5%) in both the groups had unsuccessful anesthesia. CONCLUSION: Both approaches offer quality anesthesia in the posterior mandibular area when meticulously followed. The percentage of unsuccessful anesthesia in the Gow-Gates group could be attributed to the inexperience of the operator. Postoperative comfort and patient satisfaction were greater in the other group. Copyright:
BACKGROUND: The most commonly used nerve block procedure to anesthetize the mandibular arch is the classical inferior alveolar nerve block (IANB). In 1973, Gow-Gates developed a new procedure known as the Gow Gates nerve block, to achieve anesthesia in the same area with fewer complications. METHODOLOGY: The study comprised 80 patients who reported for the surgical removal of impacted third molar. The patients were randomly assigned into two groups- Group I received Gow-gates nerve block and Group II were administered classical IANB. Positive aspiration, meantime for the onset of anesthesia, mouth opening before and after each block and pain during the surgical procedure were compared. RESULTS: Group 1 yielded positive aspiration in 2.5% of the cases (one patient) and 15% had positive aspiration in Group 2 (six patient). The mean time taken for onset of anesthesia was 6.16 min in Group 1 as compared to 2.78 min in Group 2. While comparing the quality of anesthesia between the blocks, 87.5% of the patients in Group 1 and Group 2 had successful anesthesia equally i.e., 35 of the 40 patients fell into category 1 and 2 of the eight-point category rating scale in both the groups and the remaining five patients (12.5%) in both the groups had unsuccessful anesthesia. CONCLUSION: Both approaches offer quality anesthesia in the posterior mandibular area when meticulously followed. The percentage of unsuccessful anesthesia in the Gow-Gates group could be attributed to the inexperience of the operator. Postoperative comfort and patient satisfaction were greater in the other group. Copyright:
Surgical removal of mandibular 3rd molar is one of the most commonly performed maxillofacial procedures. Dental treatment has been synonymous with pain since time immemorial, and this is the sole reason why patients are anxious in seeking it. Administration of local anesthesia is the major step before the commencement of this common maxillofacial procedure. Hence, efficient pain control is of utmost importance.There are various techniques to anesthetize the mandible by targeting the inferior alveolar nerve at different locations. Classical inferior alveolar nerve block (IANB) is the most commonly used technique to anesthetize the lower arch. However, the success rate of the IANB is in fact only modest and is associated with complications such as accidental intravascular injection and nerve injury.To increase the success rate of mandibular anesthesia and to reduce its complications, Gow-Gates in 1973 introduced a new technique for attaining anesthesia of the hemimandible. This new alternative approach relays on both intraoral and extraoral landmarks unlike the classical IANB which depends only on intraoral landmarks. Several studies have shown higher success rates with the Gow-Gates nerve block (92%–100%) than the conventional inferior alveolar nerve technique (65%–86%).[123]This present study done to evaluate the efficacy of mandibular anesthesia with a Classical IANB and Gow-Gates mandibular nerve block for the surgical removal of the mandibular third molar.
METHODOLOGY
The study was conducted in the Department of Oral and maxillofacial surgery at MES Dental College, Perinthalmanna, Kerala.A total of 80 patients were included in the study, forty of whom were administered Gow-Gates (Group I) and the other forty were given classical IANB (Group II) for the surgical removal of the mandibular third molar.
RESULTS
Data was compared using SPSS (IBM, Newyork, USA) software. The values were represented in Number (%) and mean ± standard deviation Onset of anesthesia and mouth opening was analyzed using “t-test.” Quality of anesthesia will be analyzed using “Mann–Whitney U test.The age of the patients ranged from 18 to 34 years where the mean age of patients in Group 1 was 25.1 ± 4 and in Group 2 was 25.3 ± 4.5. Statistically, the difference in mean age between two groups was not significant (P = 0.855) which indicated that the distribution of patients according to age in both the groups are homogenous.Out of the 40 patients in Group 1, 20 were male patients and 20 were female patients. Whereas in Group 2, 15 subjects were female and 25 were male. Chi-square test was done to assess the significance and was found to be statistically insignificant (P = 0.260) which also indicated that the gender distribution in both groups are homogeneous.When comparing the positive aspiration among both the groups, Group 1 yielded positive aspiration in 2.5% of the cases (one patient) and 15% had positive aspiration in Group 2 (six patient). This difference was statistically significant.The mean time taken for onset of anesthesia was 6.16 min in Group 1 as compared to 2.78 min in Group 2. Statistically, this difference was significant (P < 0.01).In Group 1, the mean mouth opening before the intervention was 45.3 mm and after the administration of gowgates technique it became 45.8 mm. This difference in mouth opening was statistically significant (P = 0.018).In Group 2, there was no change in the mean mouth opening (43.0 mm) before and after administration of IANB. When comparing the mean mouth opening between the groups, the result was statistically insignificant.While comparing the quality of anesthesia between the blocks, 87.5% of the patients in Group 1 and Group 2 had successful anesthesia equally i.e., 35 of the 40 patients fell into category 1 and 2 of the eight-point category rating scale in both the groups and the remaining five patients (12.5%) in both the groups had unsuccessful anesthesia-category 3 and 4 of the eight-point category rating scale. Statistically, this result was insignificant.
DISCUSSION
In order to anesthetize the mandibular teeth, there are different injection methods, the classical IANB being the most widely employed and probably the most effective injection technique in obtaining mandibular anesthesia. It can also be difficult to perform and even when correctly administered, has the greatest rate of clinical errors. This technique is often referred to as the Halsted technique, named after William Stewart Halsted, MD, who, in 1884, delivered the first recorded injection of a local anesthetic (epinephrine cocaine) for oral surgery in a patient.Gow-Gates first described a true mandibular nerve block in 1973 to overcome the disadvantages of the IANB. He claimed 98.4% Grade A anesthesia, including ipsilateral central incisor anesthesia; a 1.6 percent positive aspiration incidence; a relatively insignificant failure rate; and good acceptance by the patient. Its higher success rate, its lower incidence of positive aspiration, and the absence of problems with accessory sensory innervation to the mandibular teeth are significant advantages of the Gow-Gates technique over IANB. The only apparent disadvantage is a relatively minor one: While learning the Gow-Gates mandibular nerve block, an administrator experienced with the IANB may feel uncomfortable with the GowGates technique. Indeed, the incidence of unsuccessful GGMNB anesthesia may be as high as (if not higher than) that of IANB until clinical experience is gained by the administrator.In the present study, while comparing the number of positive aspiration between the blocks, one patient of the total 40 patients yielded positive aspiration while administering the GowGates block (2.5%) and in 6 patients IANB yielded positive aspiration (15%). Yang et al. 2013[4] found that no patients in the GowGates group and 5 in the IANB group had positive aspiration which was similar to the result of our present study. In another similar study done by Dubey et al. in 2017, positive aspiration was observed in 4 (8%) patients in the IANB group and none in the GowGates group. The reduction in the positive aspirations in the gowgates gates group is due to the fact that the site of needle placement is 1–2 mm anteriomedial to the condylar neck which is comparatively an avascular area.The numbness of the lower lip was taken taken as the onset of anesthesia in this study. Mean time taken for the onset of action in the gowgates group was 6.16 min and in the IANB group, it was 2.78 min which was comparable to the study done by Maqsood et al.[5] where in the mean onset of action in GowGates group was 3.29 ± 1.80 min and in the IANB group, it was 1.73 ± 0.91 min. In other studies which compared the onset of action of gowgates technique and IANB, Li in 2009[6] reported that 69 patients in the GowGow group felt no pain within 5 min of injection, whereas in the IANB group 118 patients felt no pain within the same duration (Each group had 210 patients). The data from these two aforementioned studies were pooled in and analyzed statistically by Yu et al. in 2017.[7] The results indicated that the conventional IANB technique has a statistically significant faster analgesic onset time than the GowGates method.Sequential appearance of anesthesia, in our study was found to be starting from the canine region-buccal aspect followed by the lingual and then the buccal aspect of the 1st molar which signifies that the IAN was the first nerve to be anesthetized followed by the lingual and then the long buccal nerve. This is likely due to the anatomical positioning of the fibers in the nerve trunk.An eight-point category rating scale was used to assess the quality of the anesthesia in our study. 87.5% of patients (35 patients) in both groups had a successful anesthesia-not requiring a second injection to complete the procedure. 12.5% did require a second injection to complete the procedure which was considered unsuccessful. This difference between the groups was not statically significant. Kohler et al.[8] demonstrated a higher success rate for extractions with the Gow-Gates technique when the volume was increased from 1.8 to 3.6 mL (18% vs. 82%). Both the techniques in the current study used a 1.8 mL volume to maximize the amount of anesthetic solution used. Todorovic et al.[9] found that the conventional IANB was better than the Gow-Gates technique while comparing between the blocks for extractions. Agren and Danielsson,[10] Montagnese et al.,[11] and Hung et al.[12] used the pulp tester to evaluate anesthesia and found no difference between the Gow-Gates and conventional IANBs. Therefore, for pulpal anesthesia, success should not be significantly different between the two techniques.On comparing the effect of mouth opening before and after the administration of the blocks, the GowGates group had a mean increase of 0.5 mm whereas the IANB group did not show any change in the mouth opening.
CONCLUSION
The percentage of successful anesthesia in both the groups was same which implies that both approaches offer quality anesthesia in the posterior mandibular area when meticulously followed. In contrast to the conventional technique, Gow-Gates technique demands greater skill. The percentage of unsuccessful anesthesia in Gow-Gates group in the present study could be attributed to the inexperience of the operator in administering the nerve block. The time required for anesthesia to commence in GowGates group was greater than that of the conventional group, so it is advisable that the operator should have an idea about the onset of action and not to repeat the block. In all cases, lingual, long buccal, and inferior alveolar branches were anesthetized using Gow-Gates technique and single branch failure was not observed, indicating that no additional block or infiltration is required once the block becomes successful. Compared to the inferior dental nerve block procedure, postoperative comfort and patient satisfaction were greater in the other group.The study also suggests that the technique of Gow-Gates is superior to IANB but requires skill and greater expertise that one gains with practice. The current analysis was carried out by a single operator and was unicentric. Further multicentric trials can then be carried out with a wider sample size for accurate clinical findings.