. Concept of pain. Reaction of the body to pain, postoperation injury. Local anesthetics.Anatomy of jaw area. Definition of pain. One of the most successful definitions of pain is Academician Anokhin, who described the pain as «a kind of mental condition, defined set of physiological processes in the nerv system, which caused a devastating powerful or irritation». Pain - a phenomenon that affects different aspects of human activity and society in general. It is a symptom of many acute and chronic human diseases, and creates a number of health problems, social and economic. It’s very hard find someone who at least once fill a pain in life. And their own experience and the experience of many generations of living things makes us avoid the pain and deal with them. Accordingly the problem of pain is devoted to a large number of scientific studies, conflicting theories and hypotheses. In dental pain identifies two factors physiological and psychological pain. Pain is a physiological reaction to a number of stages: contact of receptors, the reaction of the central brain structures and Afferent mechanisms of pain as a complex vegetative and motor reactions, which affect all the vital and support functions of the body. In this kind of classification we have some specific. Because which is that the basis of psychological factors of pain is psychogenic chemical reaction. Pain is produced by evolutionary process that occurs when action on the body injured factors or by inhibition of nerve system . Pain is negative biological necessity, as its formation is always associated with a change of fundamental homeostatic constants. The most significant of these is the integrity of the containment body (skin, mucous membranes, peritoneum, etc..) And the oxygen level of tissue. In response to damage in the body activated reparative processes and is mobilizing function of organs and systems that support oxygen of tissues. On the other hand, the damage leads to activation of neuroendocrine structures that provide an integrativecontrolling activity of the CNS. According to some authors, there are three types of (physical) physiological pain, depending on their causes: - Pain caused by external influences. while maintaining the integrity of peripheral organs and functions of the central mechanisms that modulate pain. Localization : skin, mucous membrane. - Pain associated with internal pathological processes. In the case of such skin pain usually does not participate, except for direct or indirect damage pain kept gear that modulate pain and holding on Afferent fibers; - Pain that came as a result of damage to the nervous system and its apparatus Afferent (neuralgia, phantom pain) Psychogenic pain reason mainly psychological or emotional factors (emotional condition of the individual, the surrounding situation) and is a phenomenon, formed integrated anatomical, physiological, psychological components, each with its own structure. The mechanism of formation and transmission of pain impulse. Reception, transmission and analysis nonitseptyvnoyi information, as well as a pain sensation provided by the central and peripheral neural entities and consist of the following processes: transduction, transmission, modulation and perception (rice). Transduction is the process of perception, and transformation nonitseptyvnoyi information encoded receptor apparatus of the nervous system. Specific pain receptors (notsitseptory) nerve endings, characterized by high touch threshold. Especially rich in their skin, cornea, mucous membrane, peritoneum, ham. blood vessel walls. By nature, the specific pain receptors are hemotseptyvete They activate under the influence of chemical agents that are generated during tissue damage. Today, we know three types of this substances. 1. Fabric (serotonin, histamine, acetylcholine, prostaglandins leykotriyeny, K + ions and H +). 2. Plasma (kallidyn, bradykinin). 3. Neurogenic (substance P). Fabric pain mediators directly activate the terminal branching bezmiyelinovyh fibers in the skin, muscle and visceral nerve ending. Prostaglandins themselves do not cause pain, but enhanced the effect nonitseptyvnoyi influence. Plasma alloheny causes pain both directly and by increasing vascular insight that leads to tissue edema. Substance P released from nerve endings acting on receptors that are localized at the membrane, and depolyaryzuyuchy it help generate momentum nonitseptyvnoho flow. Transmission nonitseptyvnoyi lies in transmitting information across the nerve guide and integrative centers (CNS) Fibers involved in transmitting pain impulses are divided into: 1) thick mielinovi A-β fibers that conduct impulses from mechanic receptor a speed of 30-70 m / s; 2) miyelynovi A fiber-fiber transmitting pulses of pain and temperature sensitivity of the speed of 12-30 m / s; 3) somatic and bezmiyelinovi posthahnlionarni C-fibers, which conduct impulses at a speed of 0.25 - 1 m / sec. Depending on the activation of a certain diameter fibers distinguish different types of pain. Modulation is process of information transfer in neural system. Following way: horn of the spinal cord to the reticular formation of the brain . It ends with ways nerve branch systems. A contact reticular formation of the hypothalamus, basal nuclei and limbic brain neuroendocrine and implemented motivational-emotive component of pain sensation .Pertseptshion formation takes place in the brain. (first and second somatic sensitivity zone, stress reaction) In accordance with the above drugs for pain relief can be divided into the following groups: 1. Drugs that affect the transduction : Anesthesia in surgical dentistry. Historically, visiting the dentist was associated with unavoidable pain and fear of their occurrence. This pattern manifests itself today, despite a long history of anesthesia and modern features of its implementation, because anesthesia when their conduct is one of the most pressing problems of dentistry, and especially in surgery. Anesthesia - a loss of pain sensitivity, which is achieved by a complex of activities aimed at the temporary exclusion of the central or peripheral nervous system. Depending on this are divided into general anesthesia (anesthesia) and local. Anesthesia in surgical dentistry. Despite significant progress general anesthesia and application of new narcotic drugs should be noted that the main method of anesthesia in dental practice are still local anesthesia. It is very popular and widely are using under a hospital and clinics. Knowledge of topographic features anatomy of upper and lower jaws, and innervations blooding and anesthesia techniques allow possibility achieve full anesthesia required areas of tissues. Local anesthesia has several advantages: it does not require a expensive equipment, ease of implementation, minimal toxicity. After surgery under local anesthesia patient does not require special medical supervision and may be dismissed to home .Na date knowledge of the principles of local anesthesia, its types and methods of conducting is absolutely necessary for the dentist of any account, especially for the dentist-surgeon. Anatomical considerations: Trigeminal nerve: Sensory divisions: ○ Ophthalmic division V1 ○ Maxillary division V2 ○ Mandibular division V3 Motor division: ○ Masticatory- masseter, temporalis, medial and lateral ○ ○ ○ ○ pterygoids Mylohyoid Anterior belly of the digastric Tensor tympani Tensor veli palatini Maxillary Division (V2): Exits the cranium via foramen rotundum of the greater wing of the sphenoid Travels at the superior most aspect of the pterygopalatine fossa just posterior to the maxilla Branches divided by location: Inter-cranial Pterygopalatine Infraorbital Facial Maxillary Division (V2): Branches: Within the cranium- middle meningeal nerve providing sensory innervation to the dura mater Within the pterygopalatine fossa○ Zygomatic nerve ○ Pterygopalatine nerves ○ Posterior superior alveolar nerve Maxillary Division (V2): Within the pterygopalatine fossa Zygomatic nerve: ○ Zygomaticofacial nerve- skin to cheek prominence ○ Zygomaticotemporal nerve- skin to lateral forehead Pterygopalatine nerves: ○ Serves as communication for the pterygopalatine ganglion and the maxillary nerve ○ Carries postganglionic secretomotor fibers through the zygomatic branch to the lacrimal gland Maxillary Division (V2): Within the pterygopalatine fossa Pterygopalatine nerves: ○ Orbital branches- supplies periosteum of the orbits ○ Nasal branches- supplies mucous membranes of superior and middle conchae, lining of posterior ethmoid sinuses, and posterior nasal septum. Nasopalatine nerve- travels across the roof of nasal cavity giving branches off to the anterior nasal septum and floor of nose. Enters incisive foramen and provides palatal gingival innervation to the premaxilla Maxillary Division (V2): Within the pterygopalatine fossa Pterygopalatine nerves: ○ Palatine branches- greater (anterior) and lesser (middle or posterior) palatine nerves Greater palatine: travels through the pterygopalatine canal and enters the palate via the greater palatine foramen. Innervates palatal tissue from premolars to soft palate. Lies 1cm medial from 2nd molar region Lesser palatine: emerges from lesser palatine foramen and innervates the mucous membranes of the soft palate and parts of the tonsillar region Maxillary Division (V2): Within the pterygopalatine fossa Pterygopalatine nerves: ○ Pharyngeal branch- exits the pterygopalatine ganglion and travels through the pharyngeal canal. Innervates mucosa of the portions of the nasal pharynx ○ Posterior superior alveolar nerve (PSA): branches from V2 prior to entrance into infraorbital groove. Innervates posterior maxillary alveolus, periodontal ligament, buccal gingiva, and pulpal tissue (only for 1st, 2nd, and 3rd molars) Maxillary Division (V2): Infraorbital canal branches: Middle superior alveolar (MSA): ○ Provides innervation to the maxillary alveolus, buccal gingiva, periodontal ligament, and pulpal tissue for the premolars only Anterior superior alveolar (ASA): ○ Provides innervation to the maxillary alveolus, buccal gingiva, periodontal ligament, and pulpal tissue for the canines, lateral and central incisors ○ Branches 6-8mm posterior to the infraorbital nerve exit from infraorbital foramen Maxillary Division (V2): Facial branches: Emerges from the infraorbital foramen Branches consist of: ○ Inferior palpebral- lower eyelid ○ External nasal- lateral skin of nose ○ Superior labial branch- upper lip skin and mucosa Mandibular division (V3): Largest branch of the trigeminal nerve Composed of sensory and motor roots Sensory root: Originates at inferior border of trigeminal ganglion Motor root: Arises in motor cells located in the pons and medulla Lies medial to the sensory root Mandibular division (V3): Branches: The sensory and motor roots emerge from the foramen ovale of the greater wing of the sphenoid Initially merge outside of the skull and divide about 2-3mm inferiorly Branches: ○ Branches of the undivided nerve ○ Branches of the anterior division ○ Branches of the posterior division Mandibular division (V3): Branches of the undivided nerve: Nervus spinosus- innervates mastoids and dura Medial pterygoid- innervates medial pterygoid muscle ○ Branches into Tensor veli palatini Tensor tympani Mandibular division (V3): Branches of the anterior division: Buccal nerve (long buccal and buccinator): ○ Travels anteriorly and lateral to the lateral pterygoid muscle ○ Gives branches to the deep temporal (temporalis muscle), masseter, and lateral pterygoid muscle Mandibular division (V3): Branches of the anterior division: Buccal nerve (long buccal and buccinator): ○ Continues to travel in antero-lateral direction ○ At level of the mandibular 3rd molar, branches exit through the buccinator and provide innervation to the skin of the cheek ○ Branches also stay within the retromandibular triangle providing sensory innervation to the buccal gingiva of the mandibular molars and buccal vestibule Mandibular division (V3): Branches of the posterior division: Travels inferior and medial to the lateral pterygoid ○ Divisions: Auriculotemporal Lingual Inferior alveolar Mandibular division (V3): Branches of the posterior division: Auriculotemporal: all sensory ○ Transverses the upper part of the parotid gland and posterior portion of the zygomatic arch ○ Branches: Communicates with facial nerve to provide sensory innervation to the skin over areas of the zygomatic, buccal, and mandibular Communicates with the otic ganglion for sensory, secretory, and vasomotor fibers to the parotid Mandibular division (V3): Branches of the posterior division: Auriculotemporal: all sensory ○ Branches: Anterior auricular- skin over helix and tragus External auditory meatus- skin over meatus and tympanic membrane Articular- posterior TMJ Superficial temporal- skin over temporal region Mandibular division (V3): Branches of the posterior division: Lingual: ○ Lies between ramus and medial pterygoid within the pterygomandibular raphe ○ Lies inferior and medial to the mandibular 3rd molar alveolus ○ Provides sensation to anterior 2/3rds of tongue, lingual gingiva, floor of mouth mucosa, and gustation (chorda tympani) Mandibular division (V3): Branches of the posterior division: Inferior alveolar: ○ Travels medial to the lateral pterygoid and lateroposterior to the lingual nerve ○ Enters mandible at the lingula ○ Accompanied by the inferior alveolar artery and vein (artery anterior to nerve) ○ Travels within the inferior alveolar canal until the mental foramen ○ Mylohyoid nerve- motor branch prior to entry into lingula Mandibular division (V3): Branches of the posterior division: Inferior alveolar: ○ Provides innervation to the mandibular alveolus, buccal gingiva from premolar teeth anteriorly, and the pulpal tissue of all mandibular teeth on side blocked ○ Terminal branches Incisive nerve- remains within inferior alveolar canal from mental foramen to midline Mental nerve- exits mental foramen and divides into 3 branches to innervate the skin of the chin, lower lip and labial mucosa Local anesthetic instruments: Anesthetic carpules Syringe Needle Mouth props Retractors Local anesthetic instruments: Carpules: 1.7 or 1.8cc Pre-made in blister packs or canisters Contains preservatives for epinephrine and local anesthetics Local anesthetic instruments: Syringe Aspirating type Non-aspirating type Local anesthetic instruments: Needle: Multiple gauges used ○ 25g ○ 27g *used at UTMB ○ 30g Length: ○ Short- 26mm ○ Long- 36mm *used at UTMB Monobeveled Local anesthetic instruments: Topical anesthetic: Used prior to local anesthetic injection to decrease discomfort in non-sedated patients Generally benzocaine (20%) Local anesthetic instruments: Maxillary anesthesia: 3 major types of injections can be performed in the maxilla for pain control Local infiltration Field block Nerve block Maxillary anesthesia: Infiltration: Able to be performed in the maxilla due to the thin cortical nature of the bone Involves injecting to tissue immediately around surgical site ○ Supraperiosteal injections ○ Intraseptal injections ○ Periodontal ligament injections Maxillary anesthesia: Field blocks: Local anesthetic deposited near a larger terminal branch of a nerve ○ Periapical injections- Maxillary anesthesia: Nerve blocks: Local anesthetic deposited near main nerve trunk and is usually distant from operative site ○ Posterior superior alveolar -Infraorbital ○ Middle superior alveolar ○ Anterior superior alveolar -Greater palatine -Nasopalatine Maxillary anesthesia: Posterior superior alveolar nerve block: Used to anesthetize the pulpal tissue, corresponding alveolar bone, and buccal gingival tissue to the maxillary 1st, 2nd, and 3rd molars. Maxillary anesthesia: Posterior superior alveolar nerve block: Technique ○ Area of insertion- height of mucobuccal fold between 1st and 2nd molar ○ Angle at 45° superiorly and medially ○ No resistance should be felt (if bony contact angle is to medial, reposition laterally) ○ Insert about 15-20mm ○ Aspirate then inject if negative Maxillary anesthesia: Middle superior alveolar nerve block: Used to anesthetize the maxillary premolars, corresponding alveolus, and buccal gingival tissue Present in about 28% of the population Used if the infraorbital block fails to anesthetize premolars Maxillary anesthesia: Middle superior alveolar nerve block: Technique: ○ Area of insertion is height of mucobuccal fold in area of 1st/2nd premolars ○ Insert around 10-15mm ○ Inject around 0.9-1.2cc Maxillary anesthesia: Anterior superior alveolar nerve block: Used to anesthetize the maxillary canine, lateral incisor, central incisor, alveolus, and buccal gingiva Maxillary anesthesia: Anterior superior alveolar nerve block: Technique: ○ Area of insertion is height of mucobuccal fold in area of lateral incisor and canine ○ Insert around 10-15mm ○ Inject around 0.9-1.2cc Maxillary anesthesia: Infraorbital nerve block: Used to anesthetize the maxillary 1st and 2nd premolars, canine, lateral incisor, central incisor, corresponding alveolar bone, and buccal gingiva Combines MSA and ASA blocks Will also cause anesthesia to the lower eyelid, lateral aspect of nasal skin tissue, and skin of infraorbital region Maxillary anesthesia: Infraorbital nerve block: Technique: ○ Palpate infraorbital foramen extra-orally and place thumb or index finger on region ○ Retract the upper lip and buccal mucosa ○ Area of insertion is the mucobuccal fold of the 1st premolar/canine area ○ Contact bone in infraorbital region ○ Inject 0.9-1.2cc of local anesthetic Maxillary anesthesia: Greater palatine nerve block: Can be used to anesthetize the palatal soft tissue of the teeth posterior to the maxillary canine and corresponding alveolus/hard palate Maxillary anesthesia: Greater palatine nerve block: Technique: ○ Area of insertion is ~1cm medial from 1st/2nd maxillary molar on the hard palate ○ Palpate with needle to find greater palatine foramen ○ Depth is usually less than 10mm ○ Utilize pressure with elevator/mirror handle to desensitize region at time of injection ○ Inject 0.3-0.5cc of local anesthetic Maxillary anesthesia: Nasopalatine nerve block: Can be used to anesthetize the soft and hard tissue of the maxillary anterior palate from canine to canine Maxillary anesthesia: Nasopalatine nerve block: Technique: ○ Area of insertion is incisive papilla into incisive foramen ○ Depth of penetration is less than 10mm ○ Inject 0.3-0.5cc of local anesthetic ○ Can use pressure over area at time of injection to decrease pain Maxillary anesthesia: Maxillary nerve block (V2 block): Can be used to anesthetize maxillary teeth, alveolus, hard and soft tissue on the palate, gingiva, and skin of the lower eyelid, lateral aspect of nose, cheek, and upper lip skin and mucosa on side blocked Maxillary anesthesia: Maxillary nerve block (V2 block): Two techniques exist for blockade of V2 ○ High tuberosity approach ○ Greater palatine canal approach Maxillary anesthesia: Maxillary nerve block (V2 block): High tuberosity approach technique: ○ Area of injection is height of mucobuccal fold of maxillary 2nd molar ○ Advance at 45° superior and medial same as in the PSA block ○ Insert needle ~30mm ○ Inject ~1.8cc of local anesthetic Maxillary anesthesia: Maxillary nerve block (V2 block): Greater palatine canal technique: ○ Area of insertion is greater palatine canal ○ Target area is the maxillary nerve in the pterygopalatine fossa ○ Perform a greater palatine block and wait 3-5 mins ○ Then insert needle in previous area and walk into greater palatine foramen ○ Insert to depth of ~30mm ○ Inject 1.8cc of local anesthetic Mandibular anesthesia: Infiltration techniques do not work in the adult mandible due to the dense cortical bone Nerve blocks are utilized to anesthetize the inferior alveolar, lingual, and buccal nerves Provides anesthesia to the pulpal, alveolar, lingual and buccal gingival tissue, and skin of lower lip and medial aspect of chin on side injected Mandibular anesthesia: Inferior alveolar nerve block (IAN): Technique involves blocking the inferior alveolar nerve prior to entry into the mandibular lingula on the medial aspect of the mandibular ramus Multiple techniques can be used for the IAN nerve block ○ IAN ○ Akinosi ○ Gow-Gates Mandibular anesthesia: Inferior alveolar nerve block (IAN): Technique: ○ Area of insertion is the mucous membrane on the medial border of the mandibular ramus at the intersection of a horizontal line (height of injection) and vertical line (anteroposterior plane) ○ Height of injection- 6-10 mm above the occlusal table of the mandibular teeth ○ Anteroposterior plane- just lateral to the pterygomandibular raphe Mandibular anesthesia: Mandibular anesthesia: Mandibular anesthesia: Mandibular anesthesia: Inferior alveolar nerve block (IAN): Mouth must be open for this technique, best to utilize mouth prop Depth of injection: 25mm Approach area of injection from contralateral premolar region Use the non-dominant hand to retract the buccal soft tissue (thumb in coronoid notch of mandible; index finger on posterior border of extraoral mandible) Mandibular anesthesia: Inferior alveolar nerve block (IAN): Inject ~0.5-1.0cc of local anesthetic Continue to inject ~0.5cc on removal from injection site to anesthetize the lingual branch Inject remaining anesthetic into coronoid notch region of the mandible in the mucous membrane distal and buccal to most distal molar to perform a long buccal nerve block Mandibular anesthesia: Akinosi closed-mouth mandibular block: Useful technique for infected patients with trismus, fractured mandibles, mentally handicapped individuals, children Provides same areas of anesthesia as the IAN nerve block Mandibular anesthesia: Akinosi closed-mouth mandibular block: Area of insertion: soft tissue overlying the medial border of the mandibular ramus directly adjacent to maxillary tuberosity Inject to depth of 25mm Inject ~1.0-1.5cc of local anesthetic as in the IAN Inject remaining anesthetic in area of long buccal nerve Mandibular anesthesia: Mental nerve block: Mental and incisive nerves are the terminal branches for the inferior alveolar nerve Provides sensory input for the lower lip skin, mucous membrane, pulpal/alveolar tissue for the premolars, canine, and incisors on side blocked Mandibular anesthesia: Mental nerve block: Technique: ○ Area of injection mucobuccal fold at or anterior to the mental foramen. This lies between the mandibular premolars ○ Depth of injection ~5-6mm ○ Inject 0.5-1.0cc of local anesthesia ○ Message local anesthesia into tissue to manipulate into mental foramen to anesthetize the incisive branch Local anesthetics: Types: Esters- plasma pseudocholinesterase Amides- liver enzymes Duration of action: Short Medium Long Local anesthetics: Agent: Lidocaine with epi (1 or 2%) Lidocaine without epi Mepivacaine without epi (3%) Bupivacaine with epi (0.5%) Articaine with epi (4.0%) Dose: 7mg/kg Onset/Duration: Fast/medium 4.5mg/kg Fast/short 5.5mg/kg Fast/short 1.3mg/kg Long/long 7mg/kg Fast/medium *ADULT DOSES IN PATIENTS WITHOUT CARDIAC HISTORY Local anesthetics: Dosing considerations: Patient with cardiac history: ○ Should limit dose of epinephrine to 0.04mg ○ Most local anesthesia uses 1:100,000 epinephrine concentration (0.01mg/ml) Pediatric dosing: ○ Clark’s rule: Maximum dose=(weight child in lbs/150) X max adult dose (mg) ○ Simple method= 1.8cc of 2% lidocaine/20lbs Local anesthesia complications: Needle breakage Pain on injection Burning on injection Persistent anesthesia/parathesia Trismus Hematoma Infection Local anesthesia complications: Edema Tissue sloughing Facial nerve paralysis Post-anesthetic intraoral lesion Herpes simplex Recurrent aphthous stomatitis Local anesthesia complications: Toxicity Clinical manifestations ○ Fear/anxiety ○ Restlessness ○ Throbbing headaches ○ Tremors ○ Weakness ○ Dizziness ○ Pallor ○ Respiratory difficulty/palpitations ○ Tachycardia (PVCs, V-tach, V-fib) Local anesthesia complications: Allergic reaction: More common with ester based local anesthetics Most allergies are to preservatives in premade local anesthetic carpules ○ Methylparaben ○ Sodium bisulfite ○ metabisulfite