Anatomic and Anaesthetic Considerations of Greater Palatine Nerve Block in Indian Population
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[Downloaded free from http://www.sjmms.net on Thursday, March 03, 2016, IP: 197.163.82.182] ORIGINAL ARTICLE Anatomic and Anaesthetic Considerations of Greater Palatine Nerve Block in Indian Population Nidhi Sharma, Rohit Varshney1, Sudhakar Ray Departments of Anatomy, 1Anaesthesia, Teerthankar Mahaveer Medical College, Moradabad, Uttar Pradesh, India Correspondence: Dr. Rohit Varshney, Assistant Professor, Department of Anaesthesia, Teerthankar Mahaveer Medical College, Delhi Road, Moradabad, Uttar Pradesh - 244 001, India. E-mail: [email protected] ABSTRACT Background: Greater palatine nerve block holds its importance for anaesthesia and analgesia in different maxillofacial surgical procedures. Accuracy in localization of greater palatine foramen is required for its successful implication in regional block, although racial variations exist in various population groups. Aims: To study the morphometry of greater palatine foramen and its location with nearby anatomical landmarks in Indian population. Material and Methods: A total of one hundred dry skulls (60 males and 40 females) were collected and observed for the study. Various parameters were noted from greater palatine foramen on both sides, together with its location with respect to maxillary molar tooth. Along with that the angle between midline maxillary suture and Incisive foramen- Greater palatine foramen is measured. Results: 198 sides were measured and the most common location of greater palatine foramen was found to be medial to third molar tooth (71.21%). The mean distance from greater palatine foramen to midline maxillary suture on right and left sides were 14.82 ± 1.34 mm and 14.79 ± 1.57 mm, statistically insignifi cant. The angle between midline maxillary suture and incisive foramen-greater palatine foramen was 20.81° ± 2.47°on right side and 20.58° ± 2.69°on left side.The direction of the opening of greater palatine canal onto the hard palate was observed to be antero-medial in 60.10% of cases. Conclusions: Our study reveals the importance of usage of various anatomical parameters for precise location of greater palatine foramen, establishment of specifi c measurements in each population group and thereby applying such measurements for successful greater palatine nerve block. Key words: Greater palatine foramen, greater palatine nerve block, morphometry ﻣﻠﺨﺺ ﺍﻟﺒﺤﺚ : ﺗﻬﺪﻑ ﻫﺬﻩ ﺍﻟﺪﺭﺍﺳﺔ ﻟﻘﻴﺎﺱ ﺃﺷﻜﺎﻝ ﺍﻟﺜﻘﺒﺔ ﺍﻟﺤﻨﻜﻴﺔ ﺍﻟﻜﺒﺮﻯ ﻭﻣﻮﻗﻌﻬﺎ ﺑﺎﻟﻨﺴﺒﺔ ﻟﻠﻤﻌﺎﻟﻢ ﺍﻟﺘﺸﺮﻳﺤﻴﺔ ﺍﻟﻘﺮﻳﺒﺔ ﻟﺪﻯ ﺍﻟﻬﻨﻮﺩ. ﻭﺗﻤﺖ ﺍﻟﺪﺭﺍﺳﺔ ﻋﻠﻰ ﻣﺎﺋﺔ ﺟﻤﺠﻤﺔ ﻟﺴﺘﻴﻦ ﺭﺟﻼ ﻭﺍﺭﺑﻌﻴﻦ ﺇﻣﺮﺃﺓ ﺑﻤﻌﺎﻳﻴﺮ ﻣﺨﺘﻠﻔﺔ ﻣﻦ ﺍﻟﺜﻘﺒﺔ ﺍﻟﺤﻨﻜﻴﺔ ﺍﻟﻜﺒﺮﻯ ﺑﻄﺮﻓﻲ ﺍﻟﺠﻤﺠﻤﺔ. ﻭﺿﺤﺖ ﺍﻟﺪﺭﺍﺳﺔ ﺃﻫﻤﻴﺔ ﺍﺳﺘﺨﺪﺍﻡ ﺍﻟﻤﻌﺎﻳﻴﺮ ﺍﻟﻤﺨﺘﻠﻔﺔ ﻟﺘﺤﺪﻳﺪ ﻣﻮﻗﻊ ﺍﻟﺜﻘﺒﺔ ﺍﻟﺤﻨﻜﻴﺔ ﺍﻟﻜﺒﺮﻯ ﺑﺼﻮﺭﺓ ﺩﻗﻴﻘﺔ ﻭﺗﺤﺪﻳﺪ ﻗﻴﺎﺳﺎﺕ ﻣﺤﺪﺩﺓ ﻟﻜﻞ ﻣﺠﻤﻮﻋﺔ ﺳﻜﺎﻧﻴﺔ ﻭﻣﻦ ﺛﻢ ﺍﺳﺘﺨﺪﺍﻡ ﻫﺬﻩ ﺍﻟﻘﻴﺎﺳﺎﺕ ﻟﺘﺨﺪﻳﺮ ﺍﻟﻌﺼﺐ ﺍﻟﺤﻨﻜﻲ ﺍﻷﻛﺒﺮ. Access this article online INTRODUCTION Quick Response Code: Website: The greater palatine nerve is a branch of maxillary nerve, www.sjmms.net emerging from greater palatine foramen (GPF) and supplying the mucous membrane of hard palate, postero- DOI: 10.4103/1658-631X.142548 inferior part of lateral wall of nose and medial wall of maxillary sinus. Saudi Journal of Medicine & Medical Sciences | Vol. 2 | Issue 3 | December 2014 | 197-201 197 [Downloaded free from http://www.sjmms.net on Thursday, March 03, 2016, IP: 197.163.82.182] Sharma, et al.: Morphometry of greater palatine nerve block The greater palatine nerve block is commonly used for local 4. Distance from the center of the GPF to the posterior anaesthesia in different maxillofacial and dental procedures.[1] border of the incisive foramen (IF); Two extensively used techniques for intraoral greater palatine 5. Direction of opening of the GPF into the oral cavity; nerve block had been described in literature (high tuberosity/ 6. Angle between the MMS and line joining the IF with greater palatine canal approach). Considering the prospects GPF. of safety and ease of applicability greater palatine approach is more commonly practiced.[2] The measurements related to GPF were taken with double tipped compass and then transferred to verniercalipers The greater palatine nerve block is commonly employed (least count 0.01 mm) to measure the distances. The for anaesthetising hard palatal tissue distal to the canines dimensions were taken three times by the same person and medial to midline. It is a more suitable technique and mean was taken, thus increasing the accuracy of for providing analgesia in patients undergoing palatal the data.The direction of the opening of GPF into the surgeries as compared to opioids which are associated oral cavity was determined with the help of 25 G spinal [3] with various side effects. However, diffi culty in exact needle. All measurements were done bilaterally and localization of GPF leads to inability in obtaining directly on the dry skulls. The angle between the MMS adequate anaesthesia and analgesia.[4] and the line from the IF and the GPF were measured and calculated on digital photographs using the Vista Metrix Extensive medline search revealed different landmarks for the specifi c location of GPF. Hamilton[5] described its software (Skill Crest, Version 1.38, 2012). location near the posterior border of hard palate medial to Statistical Analysis: Mean ± standard deviation [mean posterior alveolus, Ferreria[6] depicted its position in the ± SD], median and range were calculated. Student’s hard palate at the level of the dihedral angle (formed by t-test was used for paired and independent samples. the horizontal lamina of the palatine bone and the inner Data analysis was done by using Statistical Package for surface of the maxillary alveolar process) and Rizzolo and Madeira[7] advocated its presence at the posterolateral Social Sciences (SPSS) version 19 and P-value < 0.05 angle of the palatine bone, next to the last molar tooth. was considered statistically signifi cant. Moreover, the 2nd molar tooth is an unstable reference RESULTS point of GPF among different races and in conditions like periodontitis.[8-10] The total number skulls examined was: 100 [198 sides] Limited literature availability for localization of were males and 40 were females 60 appropriate position of GPF in Indian maxilla together The number of sides not examined due to destruction: with marked racial variation raises the idea behind the Right-0, Left-2 aim of our study to evaluate the location and direction So the total number of slides examined was 198. of the opening of GPF into the oral cavity in dry adult Indian skulls. MATERIALS AND METHODS A total of one hundred dry skulls (60 males and 40 females) collected from medical and dental colleges of Teerthanke Mahaveer University, India, were used for the study. We excluded all child skulls and the skulls with damaged hard palate/greater palatine canal. The following parameters were measured [Figure1]: 1. Location of the GPF in relation to maxillary molar tooth; 2. The center of the GPF to the midline maxillary suture (MMS); Figure 1: Hard palate. IF – Incisive foramen; GPF – Greater palatine foramen; MMS – Midline maxillary suture; PBHD – Posterior border of 3. The center of the GPF to the posterior border of hard palate; M2 – Maxillary second molar; M3 – Maxillary third molar; hard palate (PBHP); A – Angle between the MMS and the line from the IF and the GPF 198 Saudi Journal of Medicine & Medical Sciences | Vol. 2 | Issue 3 | December 2014 [Downloaded free from http://www.sjmms.net on Thursday, March 03, 2016, IP: 197.163.82.182] Sharma, et al.: Morphometry of greater palatine nerve block Greater palatine foramen was observed in all the studied DISCUSSION skulls. In our study, 95.96% of GPF were located medially and Most common location of GPF was found to be in line antero-medially to third maxillary molar tooth. Ajmani with third molar tooth with the incidence of 71.21% et al,[8] Saralaya and Nayak[10] and Sujatha et al.,[11] followed by the position between second and third molar observed the location of GPF in Indian skulls adjacent tooth in 49% of skulls. However the presence of GPF to third and second-third maxillary molar tooth in 97.14, behind the third molar tooth in 8% skulls was the rarest 98.80 and89.10% cases, respectively. Similar locations location. No foramen was found opposite to second of GPF were encountered in the skulls of most of the molar tooth [Table 1]. cases by different investigators among various ethnic groups (Nigerian, Brazilian, Chinese, Greek, Iraq and The dimensions of GPF and its linear relationship Kenyan).[8,9,12-15] In Brazilian skulls,[13] GPF was located with surrounding anatomical landmarks on skull distal to third molar in 38.94% cases while we observed were summarized in Table 2. The mean distance from it in only 4.04% of cases. Location of GPF at the lingual GPF to MMS was 14.82 ±1.34 mm on right side and side of second molar was not found in any of our case 14.79 ± 1.57 mm on left side. The minimum distance but Ajmani et al.,[8] observed the same in 17% of Nigerian from GPF to MMS recorded was 13.12 mm and skulls. The above data from different population groups maximum was 15.51 mm. The mean distances between reveal that wide variability was seen for accurate location GPF-IF on right and left sides (37.74 ± 2.39 and of GPF. The importance of accurate localization of GPF 37.89 ± 2.83) mm and GPF-PBHP on right and left not only curtails down the possibilities of failed nerve sides (4.39 ± 1.73 and 4.53 ± 1.23) mm. However, no blocks but also decreases the number of pricks which statistical signifi cance was observed among any of the adds up suffering to the patient. above mentioned dimensions [Table 2]. Chrcanovic et al.,[13] observed the distance between GPF- The angle between MMS and IF-GPF was statistically MMS as 14.68 ± 1.56 mm and 14.44 ± 1.43 mm on the insignifi cant between both sides (20.81° ± 2.47°on right right and left sides respectively.