[Impacted third molar root abnormality with mandibular canal close position as a presupposing factor to inferior alveolar nerve trauma]. / Anomalii stroeniya kornei tret'ikh molyarov, tesno prilegayushchikh k nizhnechelyustnomu kanalu, kak predraspolagayushchii faktor travmy nizhnego al'veolyarnogo nerva.

OBJECTIVE: The aim of the study is reducing the risks of surgical injury to the inferior alveolar nerve, by taking into account individual topographic and anatomical features, improving diagnostic methods, and techniques for removing retinated teeth with a close fit to the mandibular canal. MATERIAL AND METHODS: An examination was conducted in the Department of Surgical Dentistry (CBCT/OPG) and surgical treatment of 223 patients, with a close fit of the roots of the retinated lower third molar to the mandibular canal. Microslips of teeth with roots intact during removal (n=96) of the main group and the control group (n=52) were prepared with a Micromet Remet manual petrographic machine. The sections were carried out along the longitudinal axis of the tooth with the capture of the area of close fitting of the nerve, the teeth from the control group were sawed longitudinally along the axis of the root. The measurement of the macroanatomic features of the roots was carried out with a micrometer (MCC-MP-100 0.001 electronic «CHEESE¼, manufactured in the Russian Federation), measurements of the thickness of dentine and cement tissues on macroglyphs were carried out using a microscope calibration ruler with an accuracy of 0.01 mm. RESULTS: In the main group, three types of attachment of the mandibular canal to the root of the third molars were distinguished: 20 (96) cases of inter-root attachment of the mandibular canal, 42 (96) apical, 34 (96) lateral (buccal and lingual). A number of anomalies in the structure of the roots of the third molars have been revealed, which are a factor in injury to the neurovascular bundle of the mandibular canal during tooth extraction. The surface of the roots, as well as the microscopes of the tooth sections adjacent to the mandibular canal, were studied under a microscope. CONCLUSION: A number of specific anomalies of the roots of retinated third molars formed by root dilaceration, thinning of cement tissues, hypercementosis, which are formed at the site of the mandibular canal.In the presence of a deep indentation on the root of the tooth, as well as in the presence of areas of apical hypercementosis in the form of a «spike¼, the probability of nerve injury during tooth extraction increases many times, which must be taken into account when removing retinated third molars.

[Microanatomy features in third molars roots adjacent to mandibular canal]. / Osobennosti anatomii kornei tret'ikh molyarov i nizhnechelyustnogo kanala pri ikh tesnom prileganii.

THE PURPOSE: Of the study is to reduce the risk of postoperative neuropathy of the inferior alveolar nerve by improving diagnostic methods, assessment of individual topographic and anatomical features and extraction technique of impacted teeth adjacent to the mandibular canal. MATERIALS AND METHODS: According to the CBCT examination, orthopantomography and macroscopic examination of removed third molars roots (n=140) the relative position of the mandibular canal and the roots of the third molars were studied. RESULTS: Three variants of close mandibular canal and third molars position have been identified. In the lateral and apical nerve position, the root surface depressions were detected. With inter-radicular position fit, the mandibular canal and the nerve bundle form a «bed¼ in between impacted tooth roots. CONCLUSION: The injury of neurovascular bundle prognosis during extraction with an interadicular mandibular position depends on roots anatomy and their convergence degree. If the interradicular distance is less than the diameter of the mandibular canal, nerve injury during tooth extraction is inevitable, in such cases coronectomy is indicated.

[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.

[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.

[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.

[Dental care for patients at risk of adverse reaction to local anesthetics]. / Stomatologicheskaia pomoshch' patsientam s riskom razvitiia pobochnykh reaktsii na mestnye anestetiki.

The study comprised 53 patients with side effect history to local anesthetics. The reasons for the occurrence of adverse reactions to local anesthetics was analyzed, and the frequency of their occurrence in dental practice was studied. It was found that in most patients (85%) with 'allergic reactions' to local anesthetics the diagnosis was unreasonable and incompetent. In most cases psychosomatic reactions were mistaken for an immediate allergic reaction. The prevalence of adverse reactions to local anesthetics was 1 case per 448 injections (1:448), true allergic reactions was documented in 0.1% cases.