The blocks of the face remained the poor relations of the peripheral locoregional anaesthesia. Except some pilot centers, the disaffection of these blocks is due to a group of factors: knowledge necessary of the complexes anatomy of facial innervation, the technicality of realisation, the frequency of bilateral blocks, the fear of incidents on a very vascularised zone like the face. However with the evolution these last years of the locoregional anaesthesia, the creation of practice formative centers, these blocks start to diffuse itself. The contribution of new molecules of anaesthetic less toxic buildings, the neurostimulation which found its place, even on the level of the face, made grow the benefice risks ratio. The rise of the ambulatory practices, to which the blocks of face are adapted perfectly, gave an impulse to these practices, in spite of very interesting at fragile or old patients and in urgency. Finally a good collaboration with the surgical operator will allow a better precision in the indication of these blocks thus reducing the risks of incidents. |
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| Mandibular nerve block | |
The material for performing this block is standard neurostimulation needle, with court bevel of 50 mm (24G) connected to a syringe luer lock; a nervestimulator with motor stimulation, the duration of stimulation starting from 0,1 milliseconds (ms). A cutaneous pen marker. Two approach for the mandibular block, traditional procedure and neurostimulation procedure. |
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| Traditional procedure | |
The point of puncture is done in a semi-circumferential zone with upper limit by the zygomatic arch and between coronoid apophysis and condyl process. The needle is directed perpendicular to the skin and will butt against the pterygoid apophysis (7, 21) towards 20 to 30 mm of deep; then this one will again be directed in top and to come behind under the oval foramen around 30-40 mm of deep where the injection will be performed. This block is relatively easy, but there is a notable rate of failure (7); thus in a series of 49 blocks, one notes 4 failures (21). In addition the presence of the maxillary artery and the penetration with the blind technique expose to the risk of vascular complications (7, 21). |
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Procedure with motor neurostimulation The point of puncture is the same, the similar procedure for the first sequence. A neurostimulator is necessary; with the duration of stimulation are 0.1 milliseconds. Information will have been made during the anaesthesia consultation. The technique is simplified, indeed:
For a complete mandibular block it is the best technique, with an easier nervous location, and can be surest, although currently there are not series published. In our experiment (publication in progress) on 100 blocks performed with stimulation, we practically noted not safe failure, 5 complements on the mental nerve; no serious complication except two diffusions with the facial nerve spontaneously resolutive. The injection will be very slow with 0,10 to 0,15 ml.Kg-1 on average, of anaesthetic solution. The mandibular territory supplies, when performed complete block;
The rate of success remains for the accustomed centers, higher than 80% for a complete block and a traditional technique: in the series referred to above one notes 91% of success [21]. The stimulation technique allows a higher success rate (> 95%) and simplifies the approach. Nevertheless a defect in a territory can be corrected by troncular distal block on the branches of the mandibular nerve (auriculotemporal, mental, alveolar inferior). Many indications for the mandibular block in surgery. Alls acts on the lower lip, the mandibular skin zone and temporal skin zone, the chin; mandibular bone surgery. And inferior dental surgery. In emergency, fracture of the mandible, wound of the tongue, superficial wounds in a mandibular territory. The other indications are analgesia:
A perineural mandibular catheter, according to the same procedure of installation, can be used with discontinuous injections of ropivacaïne 0,2% (see further). This block is not very painful: sedation can be necessary however. Except the failure few complications are published [7]: thus in a series one notes, of the difficulties of opening of mouth, the regressive facial paralysis, of nauseas, a cephalgias, a haematoma, representing nevertheless 9 complications out of 49 blocks [21]. The neurostimulation seems to reduce the risk of potential complications. |
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| Auriculotemporal nerve block | |
The material for performing this block is an intradermal needle (26 G 5/8, 16 mm) connected to a syringe luer lock by an extension cable; or a needle with court bevel of 25 mm (24 G), standard neurostimulation needle. A cutaneous pen marker. |
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The point of puncture is done in front of the tragus to 15 mm, the needle penetrates to 10 mm in medial of this point, in moves towards the tragus, the injection is made right in front of this one. The injection must be very slow by means of 1 to 2 ml of anaesthetic solution, with a lateral direction. After the shrinking of the needle a discrete massage supports the diffusion of the product. The territory supplies by the auriculotemporal block is, the auricle of ear, anterior zone, the external auditory canal and the temporal skin zone on the top of the ear lobe [6]. This block is very easy, with a big success, simple, without major risk. The indications of the auriculotemporal block are in surgery: acts on the auricle of the ear, in association with the great auricular nerve (see further); tegumental surgery of the temporal zone. In emergency: all multiple wounds of the scalp, in the temporal zone. Finally in complement of a mandibular block which would not be complete on the temporal territory: indeed after a mandibular block, the auriculotemporal nerve is blocked only in 22% of the cases [26] and can be easily blocked by local way. The vascular puncture of the superficial temporal vessels is possible; they are however deeper than the nerve and the use of needle with bevel short tiny room the risk of vascular penetration with the proviso of progressing slowly. |
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| Mental nerve block | |
The mental nerve leaves by the mental foramen near the labial commeasure and the first premolar [7]; its artery accompanies it. It takes an upper and medial direction for supply the chin, the lower lip, gencive, the teeth (incisors and the canine). |
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The material for performing this block is an intradermal needle (26 G 5/8, 16 mm) connected to a syringe luer lock by an extension cable; or a needle with court bevel of 25 mm (24 G), standard neurostimulation needle. A cutaneous pen marker. The point of puncture is done at the edge lateral to 10 mm of the mental foramen [27], located with the finger and marked with the pen. |
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The needle will seek the bone contact, with a medial direction, towards the foramen [19]; then one will inject. To reject an injection in the mental foramen. The injection is very slow with 2 to 3 ml of anaesthetic solution, and a medial direction. After the shrinking of the needle a discrete massage supports the diffusion of the product. The territory supplies by the mental nerve is, inferior lip, chin, gencivies, teeth (incisors and canine). The mental block is a very easy block, with very good success. The indications of the mental block are in surgery all acts on the lower lip, the teeth, gencivies, and the chin [18]. In emergency: facial wounds in labial zone, medial mandibular zone and mental zone: a bilateral block is then necessary. In odontology: acts on the incisors and the canine. The cutaneous puncture and the bone contact are sensitive: sedation can be necessary. The puncture in the mental foramen risk involving nervous lesions with paraesthesias [7]; a risk of haematoma is related to an uninsured technique [6]. Inferior alveolar nerve block Although this nerve is not "facial", it can be useful in the event of incomplete mandibular block or of alternative to the mental block [26]. The inferior alveolar nerve is a terminal branch of the mandibular nerve, it progresses in a bone mandibular tunnel all the length of the horizontal branch, to finish with the mental foramen where it gives the mental nerve. The material for performing this block is an intradermal needle (26 G 5/8, 16 mm) connected to a syringe luer lock by an extension cable; or a needle with court bevel of 25 mm (24 G), standard neurostimulation needle. A cutaneous pen marker. Only one puncture procedure will be retained, that endo-oral, will be said to the Spix spine [7]. The needle is directed towards the medial face the vertical mandibular branch, in contact with the Spix spine, before the canal bone penetration of the nerve; The injection is very slow with 2 to 3 ml of anaesthetic solution. The territory of inferior alveolar nerve is an inferior tooth; sometimes the lingual nerve is reached [26]. The indications for the inferior alveolar block are a dental surgery or also for rescue a defective mandibular block. This block is very easy and frequently performed by odontologists. A possible lesion of the lingual nerve with dysesthesias of the lingual edge and loss of the taste [7, 26] are noted; a lesion of the facial nerve (resolutive paralysis) is also noted. More rarely [7]: a superior laryngeal block, vascular lesion, an injection will intra muscular (pterygoid) involving a blocking temporomandibular articulation. |
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Indications With surgery type Tegumental surgery The explosion of the indications of the surgery of facial surface made strongly develop the requests for facial blocks. Practically all the teguments are accessible to these techniques. The carcinologic surgery of face (basocellular tumour and spinocellular tumour) with or without local scrap of rebuilding is integrated perfectly in this diagram [7, 18, 19], the more so as it is often practised at subjects at the risks (old patient, or at the patient risk) and more and more, into ambulatory surgery. Plastic surgery and cosmetic like face lipostructure, localised repair of scars, face lifting and especially, upper and lower blepharoplasty, surgery of the lips, the chin, and the "separated" ears. In emergency the wounds of the face also profit from these techniques [7]: indeed the interest of small volume of local anaesthetic, not deforming the banks of the wound, will facilitate repair [7]. The anaesthesia for the scalp is included in the same category that it is in emergency, or to ensure a good postoperative analgesia in neurosurgery. Thus the face and the upper eyelids will be accessible with supraorbital block and supratrochlear block; the cheek and the lips with an infraorbital block or maxillary block; for the nose one will need bilateral infraorbital and nasal blocks; finally for the chin and the inferior lips a mental block is enough. However for broad acts covering several territories it is to better extend nervous blocking; thus for a lipostructure of the face interesting the maxillary territory and the mandibular territory in their totality. It is advised to make maxillary and mandibular blocks at their origin, if one chooses a regional anaesthesia. Maxillofacial surgery In this indication the alone regional anaesthesia is exceptionally used [7]. Nevertheless simple gestures as the mandibular osteotomy can be carried out under blocks [21]. Generally these techniques accompany a traditional general anaesthesia to carry out an operational analgesia and especially great quality postoperative analgesia. Practically all the facial bone surgery can be performed with complementary block of the trigeminal branches; it is then preferable to perform these blocks at a waked up patient, especially if one chooses a neurostimulation. Nasal surgery The rhinoplasty, associating blocks of face and general anaesthesia optimizes comfort, and the hemodynamics effects and gets a great quality postoperative analgesia. With the operational circumstances and patient It is an indication of choice at the subjects at the risks:
Interesting indication also in emergency, at the patient not with jeun, with an often surface surgery. Within the framework of ambulatory surgery the these blocks have a dominating place, allowing, acts in full safety with a remarkable residual analgesia facilitating the return with the social life in the day surgery. Contraindications The general counter-indications are those of any
regional anaesthesia, in particular [27]: The counter-indications due to the patient are especially:
The reserves due to the operator must be taken into account. The variable level of difficulty of these blocks is solved only by one anatomical knowledge and a hands-on training preliminary [7, 27]. A few blocks are of easy and durable acquisition: supraorbital, infraorbital, mental, nasal, ear block, very safe from serious complications. On the other hand the blocks carried out in the "plexus" beginning, like the maxillary nerve and the mandibular nerve, are more delicate, with a rate of less raised success, even for accustomed, and with risks of complications raised in the literature. Only the neurostimulation although not evaluated, seems in this case to facilitate the access to these blocks. Blocks for analgesia Postoperative analgesia The tegumental surgery can be controlled in postoperative analgesia plan by prolonged facial blocks. A local anaesthetic of long duration, with an additive drug, allows a very good quality of postoperative analgesia (EVA < III), during at least ten hours. In certain cases, a postoperative analgesic block could be performed after the end of surgery. Catheters Some rare indications of prolonged analgesia by perineural catheter are described [28, 29, 30]; primarily within the framework of a major carcinologic surgery (postoperative analgesia) or of a complementary treatment to an algic pathology rebel with the traditional treatments, like an in eradicable orofacial cancer [28]. They will get a good quality and stable analgesia. The sites of realisation are the nerves located in a fossa: maxillary nerve in rotundum foramen (suprazygomatic way) or by infrazygomatic way [30]; mandibular nerve near the oval foramen. The technique of realisation of these catheters is same with that of the simple block except that the perform is optimized by the use of motor stimulation for the mandibular nerve. The catheters will be introduced only one centimetre beyond the nozzle and will be fixed with a wire (the head being very mobile). Currently the choice rather goes worms of the discontinuous injections with a local anaesthetic to low concentration (ropivacaine 0,2%). On a short series as a double blind study (8 patients) a team showed that the postoperative analgesics consumption over 4 postoperative days was very low in the catheter group, and very significant compared to the group without regional anaesthesia [30]. Medical indication For a long time the nerves of the face and especially the trigeminal nerve, were targeted for the treatment of the pains on the level of the face [1, 31]. Some indications with diagnostic and therapeutic aiming exist on the level of the face. All the neuralgias of the maxillary nerve (superior alveolar nerve), and the mandibular nerve (inferior alveolar nerve), can be relieved by blocks. Nervous alcoholisations can use the same procedures as those, which are employed for the anaesthetic blocks. Rare but effective indications exist like the treatment with mandibular block, of a trismus associated a hypoxic encephalopathy [32]. COMPLICATIONS Vascular complication The facial vascular richness is the essential cause of the major risk, which is the vascular breach [7, 18, 21] with on the pharmacological plan an intense and fast resorption of the anaesthetic solution and the possibility of an intravascular injection. All the nerves are accompanied by an artery (supra and infraorbital) or close to a significant arterial axis (mandibular nerve and maxillary artery); only the maxillary nerve with the foramen rotundum is above the vessels. In order to have a time of rise of the plasmatic concentrations in the local anaesthetic, longest possible it is necessary: to inject most slowly possible, to use small volumes and to associate an additive drug, standard clonidine. Neurological complication The only notorious accidents are the extension of the anaesthesia to the motor nerves: facial paralysis, ptose of superior eyelid; all these incidents are regressive spontaneously. The specific accident is the risk of paraesthesias due to the wound of one nerve at the exit of its foramen with oedema and suffering: the injection in the foramen is to be rejected formally. Articular complication A characteristic: the intramuscular injection in the pterygoid muscles can involve a blocking of the temporomandibular articulation with limited oral opening and trismus [33]. Toxic complication They are due either to the vascular passage, or with a fast resorption of the anaesthetic solution. They do not present characteristics and are superposable with those of the other peripheral blocks (arm or leg). CONCLUSION The regional anaesthesia of the face is accessible by two types of blocks; deep blocks supplies a large territory, specialised perform and not easy realisation; and the superficial blocks of very easy access and simple to realise, but with more reduced territories where they could be associated. |
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Movie of mental nerve block 
