[Classification of lower impacted third molars position and their interrelationship with mandibular canal]. / Klassifikatsii vidov retentsii nizhnikh tret'ikh molyarov i ikh anatomicheskogo vzaimoraspolozheniya s nizhnechelyustnym kanalom.

Classification of lower Impacted third molars position and their interrelationship with mandibular canal have a great scientific, theoretical and practical importance. An attempt to systematize and classify all anatomical impacted third molars position has been made by many authors. Based on our scientific literature search, we found: 8 impacted third molars classifications, 7 third molars and mandibular canal interposition classifications, as well as 5 classifications of mandibular canal anatomical branching variants. Most classifications are proposed by the author to predict third molar eruption perspective, determine level of operation complexity and prevent mandibular canal damage. New clinical classification development of impacted third molars interrelationship with mandibular canal, which combined the radiological PR, CBCT criteria, neurovascular bundle trauma prognosis, and operative technic choice can be actual.

[Stafne defect as a rare anomaly of the lower jaw growth]. / Defekt Stafne ­ redkaya anomaliya razvitiya nizhnei chelyusti.

Defects in mandible growth are of undoubted interest for practical healthcare. During the diagnosis, for a more accurate diagnosis and differential diagnosis, it is necessary to understand the criteria for the norm and pathology of diseases of the jaw bones. Often in the body of the mandible at the level of the lower molars, slightly below the maxillofacial line, defects are detected in the form of a depression of the cortical layer towards the unchanged buccal cortical plate. These defects, being the clinical norm, need to be differentiated with many tumor diseases of the maxillofacial region. The literature sources indicate that the cause of these defects is the pressure of the capsule of the submandibular salivary gland in the area of the fossa on the lower jaw. Modern additional diagnostic methods, for example, CBCT and MRI, make it possible to identify a Stafne defect.

[Aspiration test as dental anesthesia safety criterion]. / Aspiratsionnyi test kak kriterii bezopasnosti obezbolivaniya v stomatologii.

Intravascular anesthetic injection can lead to acute toxic reaction even the minimal dose of the drug was administered. The aspiration test is a generally accepted standard for local anesthesia in medicine, specially designed to reduce the risk of emergency conditions. Medical instruments should be adapted for aspiration test, the local anesthetic carpule should have a retention notch, and the dental syringe plunger need to have retention elements. The aspiration test protocol may vary. For legal protection of the doctor the aspiration test result should be described in the patient's medical record.

[Surgical treatment tactics in patients with third molars located close to mandibular canal]. / Taktika lecheniya patsientov pri udalenii tret'ikh molyarov nizhnei chelyusti, prilezhashchikh k nizhnechelyustnomu kanalu.

The tight fit of the roots of the third molars to the mandibular canal is the main predisposing factor of injury to the inferior alveolar nerve during tooth extraction surgery. Surgical treatment of 92 patients diagnosed with pericoronitis, retention of the third molar of the mandible, close fit of the roots of the third molar to the mandibular canal was performed. Four types of close fit of the roots of the third molars to the mandibular canal were revealed, according to CBCT, OPTG and clinical data. Most cases of paresthesia after the removal of the third molars are associated with an anatomical variation in the structure of the mandibular canal, in which the canal walls are partially formed by the cement of the tooth root. Two variants of postoperative management of the surgical wound are proposed, when an open section of the neurovascular bundle is detected at the bottom of the hole.

[Bisphosphonate-related osteonecrosis of the jaws]. / Bisfosfonatnye osteonekrozy chelyustei.

The number of patients with metabolic osteopathies and oncological diseases occurring with the formation of bone metastases is constantly growing and requires special attention not only of oncologists, but also maxillofacial surgeons, dental surgeons and periodontists, due to severe complications from the oral cavity, against the background of antiresorptive therapy with bisphosphonates. These drugs are associated with the development of necrotic processes of the jaw bones and surrounding tissues. It is worth noting the fact that the development of complications after taking these drugs leads to a significant increase in the suffering of patients. The importance of an integrated approach to the treatment and prevention of such complications is extremely important, as it reduces the risk of possible complications and improves the quality of life of this group of patients.

[Root dislocation into the mouth floor as a complication of lower impacted third molar extraction]. / Khirurgicheskaya taktika pri dislokatsii kornya v myagkie tkani dna polosti rta v khode udaleniya nizhnego retinirovannogo tret'ego molyara.

Root dislocation into soft tissues during lower jaw third molar extraction belongs to clinically rare complications. The thickness of the cortical plate on the third molar lingual side does not exceed 1.5 mm. Working with an elevator, or headpiece, it is possible to push the roots into the adjacent soft tissue. It is not possible to remove displaced tooth fragment through the socket, it requires additional surgical access from the lingual side. The authors described three clinical cases of root dislocation during third molar removing. Successful surgical treatment was done.

[Lower teeth anesthesia in patients with limited mouth opening]. / Obezbolivanie nizhnikh zubov u patsientov s ogranicheniem otkryvaniya rta.

Limited mouth opening is a common pathology in dental practice. Dental treatment of these group patients is hindered by low access to oral cavity, which complicates operative, prosthetic and surgical interventions. Local anesthesia is also difficult due to changes in anatomical landmarks, changes in bone structures and soft tissues ratio. M.M. Weisbrem and Gow-Gates technique in case with limited mouth opening 1-2 cm is ineffective. Mandibular convention block is more universal, as it is oriented to bone structures without binding to soft tissues. Variation of local anesthesia techniques at a various mouth opening degrees are offered.

[Prevention of lingual nerve damage by removing stones from submandibular salivary gland duct]. / Profilaktika povrezhdenii yazychnogo nerva pri udalenii konkrementov iz protoka podnizhnechelyustnoi slyunnoi zhelezy.

The aim of the study was to elaborate lingual nerve sparing procedure of submandibular gland duct stones extraction. The study involved 43 patients with syalolithiasis treated in Oral Surgery Unit of Central Research Institute of Dentistry and Maxillofacial Surgery in 2013-2015. It was shown that to prevent lingual nerve and artery injury submandibular salivary gland duct should be dissected to the level of obstruction thus allowing adequate visualization of anatomical correlations especially when removing stones from the distal part of the duct.

[Topographic features of lingual nerve and its relationship with other anatomical structures in maxillolingual groove].

By surgical interventions in maxillolingual groove area one should consider anatomical variations and topography of vessels, glands ducts and lingual nerve to prevent their injury. At the Department of Operative Surgery and Topographic Anatomy of the First Moscow State Medical University named after I.M. Sechenov we carried out anatomical study on cadavers (men and women, n=30).The study revealed topographical features of the lingual nerve and its relationship to other anatomical structures in the maxillolingual groove. It was found out that at the level of the second molar (96%) lingual nerve "crosses" duct of submandibular salivary gland, at the level of the third molar lingual nerve is located under the duct and lateral to it, closer to the inner surface of the body of the mandible. At the level of the first molar lingual nerve is located above and medial to Wharton duct and passes along sublingual-lingual muscles (m.hyoglossus).

[Anatomical rationale for lingual nerve injury prevention during mandibular block].

The topographic and anatomical study of lingual nerve structural features was done. It was revealed that during mandibular anesthesia possible lingual nerve injury can occur if puncture needle is lower than 1 cm. of molars occlusal surface level. The position of the lingual nerve varies withmandible movements. At the maximum open mouth lingual nerve is not mobile and is pressed against the inner surface of the mandibular ramus by the medial pterygoid muscle and the temporal muscle tendon. When closing the mouth to 1.25±0.2 cmfrom the physiological maximum, lingual nerve is displaced posteriorly from the internal oblique line of the mandible and gets mobile. On the basis of topographic and anatomic features of the lingual nervestructure the authors recommend the re-do of inferior alveolar nerve block, a semi-closed mouth position or the use the "high block techniques" (Torus anesthesia, Gow-Gates, Vazirani-Akinozi).