Maxillary Nerve Variations and Its Clinical Significance
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Sai Pavithra .R et al /J. Pharm. Sci. & Res. Vol. 6(4), 2014, 203-205 Maxillary Nerve Variations and Its Clinical Significance Sai Pavithra .R,Thenmozhi M.S Department of Anatomy, Saveetha Dental College Tamil nadu. Abstract: The aim of this review is to collect data from the literature and gives a detailed description of the innervation of the maxilla. We carried out a search of studies published in PubMed up to 2011, including clinical and anatomical studies .several articles has has been published regarding the anatomical variations of the maxillary nerve supplies. The purpose of this paper is to demonstrate the variation in the paths and communications of the maxillary nerve which should be considered by the clinicians as nerve supply,assumed prime importance to oral surgeons to understand better and to avoid complications associated with anaesthesia and surgical procedures. Key words: maxillary nerve, clinical variations THE MAXILLARY NERVE: foramen is usually a single foramen but several studies 1. Anatomical variations of the maxillary nerve supply. have proven to have two or three foramen[2-8]. A low 2. Anatomical variations of the infraorbital nerve. percentage (4.7%) was observed during a study on 3. Anatomical variations of the superior alveolar nerve 1064 skulls, with a higher frequency on the left side, 4.Anatomical variations of the greaterpalatine nerve. both in male and in female skulls[9]. The distance from 5. Anatomical variations of the nasopalatine nerve. the infraorbital foramen to the inferior border of the [10-13] orbital rim is from 4.6 to 10.4 mm . AXILLARY NERVE: Since the infraorbital nerve block is often used to The maxillary nerve is a sensory nerve. After its origin achieve regional anaesthesia of the face, the study of from the trigeminal ganglion,the maxillary nerve passes frequency and position of accessory infraorbital through the cavernous sinus below the ophthalmic foramen are useful to reduce anaesthetic and surgical nerve exits through the foramen rotundum and enters complications, especially in trunk block of the into the pterygopalatine Fossa. In the fossa, several infraorbital nerve. sensory branches are given off the meningeal branches, the superior alveolar nerves, the zygomatic and ANATOMICAL VARIATIONS OF THE SUPERIOR infraorbital nerves. The other nerve originate from the ALVEOLAR NERVE: Pterygopalatine ganglion and nasopalatine nerve. The superior alveolar nerve is given off from the maxillary nerve in the pterygopalatine fossa, runs in ANATOMICAL VARIATION OF MAXILLARY NERVE the infraorbital canal and divides into branches, which SUPPLY: supply the maxillary teeth .The contribution of the Knowledge of the anatomical variations of the three alveolar nerves to the maxillary teeth maxillary nerve is necessary for a surgeon while innervations has been reported being different. The performing maxillofacial surgery and regional block superior molar teeth are normally innervated from the anaesthesia. In the literature, there is little data posterior superior alveolar nerve and occasionally from concerning the maxillary nerve component. Previous the middle superior alveolar nerve, whereas there is no observation had no significant variations relating to the innervation to the first molar from the anterior superior ophthalmic and maxillary nerves. On the contrary, alveolar nerve[14,15]. In superior premolar teeth, it is anatomical variations were found in 20% of cases in interesting to observe that some patients have only two relation with the mandibular nerve and its branches[1]. maxillary alveolar nerves and that the middle superior alveolar nerve, the innervation ascribes to the premolar ANATOMICAL VARIATION OF INFRA ORBITAL NERVE: teeth was often missing and was provided by the The infraorbital nerve is a direct extension of the posterior superior alveolar nerve. [15,16]. The innervation maxillary division of the trigeminal nerve . It courses of the canine and incisor teeth is normally due to anteriorly through a canal within the bone of the orbital anterior superior alveolar nerve; Robinson and floor and provides superior alveolar nerves for the Wormald showed that there was a wide variation to the sensory innervations of the maxillary teeth. The branching pattern of the anterior superior alveolar infraorbital nerve then emerges from the infraorbital nerve and the middle superior alveolar nerve within the foramen and gives 4 branches, the inferior palpebral, anterior surface of the maxilla[17]. the external nasal, the internal nasal and the superior There are no anatomical predictors of the innervation labial branches for the sensory innervation to the skin pattern. Therefore, clinicians may have to modify their of the eyelid, nose, cheek and upper lip. Infraorbital approach to avoid anaesthetic procedure failure. 203 Sai Pavithra .R et al /J. Pharm. Sci. & Res. Vol. 6(4), 2014, 203-205 ANATOMICAL VARIATIONS OF POSTERIOR SUPERIOR ALVEOLAR NERVE : The posterior superior alveolar nerve originates from the maxillary nerve just before it enters infra orbital groove(fig1).Then it gives several branches to gingival and mucosa of teeth. Then it enters the posterior alveolar canal on the infra temporal surface of maxilla and gives off branches to the mucuous membrane of maxillary sinus and upper molar teeth. Several variations in the branching patterns of this nerves has been recorded has single or multiple nerve root . [24] Mc Daniel found that posterior superior alveolar THE ANTERIOR SUPERIOR ALVEOLAR NERVE: nerve had one branch in 21% two branch in 30% and The anterior superior alveolar nerve comes from the three branches in 25% of specimens. Branching pattern infraorbital nerve at variable distances from the of this nerve should be considered during anaesthetic infraorbital foramen. The nerve arises from the middle procedure in this nerve, the different origins of the and anterior thirds of the infraorbital posterior superior alveolar nerve compared to the nerve and courses in the infraorbital canal. After middle and the anterior branches offers the possibility entering the anterior surface of the maxilla, it courses to anesthetise only the posterior branch. Indeed, the across the maxilla towards the canine fossa before posterior superior alveolar nerve is approached near the branching and forming the superior dental plexus maxillary tuberosity, whereas the anterior superior located in the maxillary alveolar process. alveolar nerve in the region of infraorbital foramen. The anterior superior alveolar nerve was present as a The posterior superior alveolar nerve block may not single trunk in 75%, of cases as reported by cause complete maxillary molar anaesthesia due to the McDanil[24]; in 35% there was a diffuse fine plexus of presence of branches from the palatine nerve that could the anterior superior alveolar nerve branches overlying innervate the molar and premolar teeth[25] the canine fossa. The presence of a superior dental plexus appears to be favoured by multiple posterior branches and by the presence of a middle branch or an anterior branch with multiple main branches. ANATOMICAL VARIATIONS OF THE PALATINE NERVE: The greater palatine nerve is the anterior branch of the palatine nerve it runs in the inferior area of the hard palate and innervates the palatal gingiva and the hard palate. The palatine nerve is distributed to the roof of the mouth, soft palate, tonsil, and lining membrane of the nasal cavity. Most of its fibres derive from the sphenopalatine branch of the maxillary nerve. In older textbooks, it is usually categorized as anterior, middle, and posterior palatine nerve. More recent textbooks fig:1 simplify the distribution into the greater palatine nerve and the lesser palatine nerve Variations of the location of greater palatine foramen have been reported[18,19]. The first description of the location of the greater THE MIDDLE SUPERIOR ALVEOLAR NERVE: palatine foramen was reported by Matsuda[20]. In Middle superior alveolar nerve arises from infra orbital [24] particular, it was opposite the maxillary second or third neve when it is the infraorbital canal.McDaniel molar[21] anywhere between the maxillary second and reported that the middle superior alveolar nerve third molar [22]. 5 A recent study[19] confirmed the followed the classical description in only 30% of presence of the foramen opposite the maxillary third examined cases whilst the majority of middle branch molar (54.87%) distal to the maxillary third molar entered the formation of a nerve plexus that supplied (38.94%) and between the maxillary second and third the teeth. When the middle branch was absent, the molar (6.19%). The greater palatine nerve can innervation of the premolar teeth may be provided by sometimes gives additional branches for the molar and secondary branches of the anterior superior alveolar premolar maxillary teeth. Variation has to be nerve, by the posterior superior alveolar nerve or by a considered for a complete and adequate superior nervous plexus between these two nerves. Even if this alveolar nerve block. situation is not easily detectable, this variation should be considered during anaesthetic procedures. 204 Sai Pavithra .R et al /J. Pharm. Sci. & Res. Vol. 6(4), 2014, 203-205 ANATOMICAL VARIATIONS OF THE NASOPALATINE 5. Rath EM. Surgical treatment of maxillary nerve injuries, The infraorbital nerve. Atlas Oral Maxillofac Surg Clin North Am NERVE: 2001;9(2):31–41. The nasopalatine nerve is a branch of the 6. Bressan C, Geuna S, Malerba G, Giacobini G, Giordano M, sphenopalatine nerve. The nasopalatine nerve is a Robecchi MG, Vercellino V. Descriptive and topographic branch of the maxillary division of the trigeminal anatomy of the accessory infraorbital foramen. Clinical nerve. It passes through the pterygopalatine ganglion, implications in maxillary surgery. Minerva Stomatol 2004;53(9):495–505. enters the sphenopalatine foramen and passes medially 7. Gupta T. Localization of important facial foramina across the roof of the nose to the upper part of the encountered in maxillo-facial surgery. Clin Anat posterior border of the nasal septum. It then passes 2008;21(7):633–40. forward in the mucous membrane of the nasal septum, 8.