Maxillary Plates Research Articles

Dutrapona, a new genus and three new species of Gyponini (Insecta: Hemiptera: Cicadellidae) from Central and South America

A new leafhopper genus of the tribe Gyponini, Dutrapona gen. nov., is proposed and described based on males of three newly described species from Central and South America: Dutrapona tenuis sp. nov. (type species) from Alajuela, Costa Rica, Dutrapona reticulata sp. nov. from Napo, Ecuador, and Dutrapona zahniseri sp. nov. from Coclé, Panama. The new genus resembles genera of the Hecalapona complex in sharing characteristics such as: body yellow without maculae and dorsoventrally flattened, crown moderately produced with anterior margin rounded and projected over anterior margins of eye, crown-face transition distinct and thin, maxillary plates narrow and not extending to clypeus apex and forewing with narrow appendix. However, Dutrapona gen. nov. can be distinguished from other Gyponini genera by the combination of the following of characteristics: ocelli positioned closer to midline and posterior margin of the crown, crown-face transition spatulate with two well defined carinae, male sternite VIII longer than wide, male pygofer with a pair of small caudal denticulated processes, subgenital plates short, and aedeagus with a pair of basilateral elongate processes.

Ceciamaralia, a new genus of Dorvilleidae (Annelida) from deep waters of the Southwest Atlantic Ocean and an insight into its relationship within the family.

Dorvilleidae Chamberlin, 1919 is a family of Annelida containing some of the smallest 'polychaetes' species, being poorly studied worldwide, and with little knowledge regarding its diversity and occurrence. Samples obtained in oceanographic campaigns performed in the Southwest Atlantic Ocean (Brazilian coast) revealed a high number of specimens of dorvilleids, adding to our knowledge of the family's biodiversity. A detailed morphological analysis of these organisms has revealed a new genus, Ceciamaralia gen. nov., with two new species. The new genus differs from other Dorvilleidae genera in (i) the robust and enlarged pharynx which are frequently everted, (ii) unique composition of maxillae, with an elongated pair of serrated basal plates and one pair of anterior free maxillary plates with a long and thin anterior spine and (iii) ventral cirri present only in few first chaetigers. Ceciamaralia lanai gen. et sp. nov. is characterized by the presence of a broad and large dorsal cirrus on a few anterior parapodia and by furcate chaeta in supra-acicular fascicles. While Ceciamaralia nonatoi gen. et sp. nov. presents one geniculate chaeta instead of one furcate, the absence of dorsal cirri and, in some specimens, the absence of palps. A cladistic analysis supported the monophyly of Ceciamaralia gen. nov. by four synapomorphies related to the unique morphology of its maxillae, pharynx and appendages. This study is part of several recent taxonomic studies aiming to elucidate and increase the knowledge of Dorvilleidae, since it is part of a Ph.D project focused on the family.

Bone-Anchored Maxillary Protraction for Adolescents with Cleft Palate and Class III Malocclusion: A Case Series

To describe the long-term treatment course of bone-anchored maxillary protraction (BAMP) and evaluate orthognathic surgical indications after BAMP Retrospective case series Craniofacial/Cleft Palate Program at the Orthopaedic Institute for Children in Los Angeles, CA Twelve male patients with cleft palate (CP), unilateral cleft lip and palate (UCLP), or bilateral cleft lip and palate (BCLP) and Class III malocclusion treated with BAMP (mean age: 11.4 ± 2.6 years) were included. BAMP treatment was performed by placement of bone-anchored maxillary and mandibular plates connected with intraoral Class III dental elastics or maxillary plates connected to a facemask. We retrospectively assessed BAMP treatment variables, including age at surgery, revision surgeries, and treatment duration. The primary goal was correction to class I occlusion. Twelve patients underwent BAMP treatment for an average of 4.4 ± 2.4 years. Two patients were corrected to class I occlusion at the time of this report. Le Fort I advancement was no longer required in two patients (16.7%), it was required for nine patients (75.0%) and was completed for one patient following BAMP treatment (8.3%). This preliminary report demonstrated that BAMP treatment may be associated with a minimal reduction in the requirement for Le Fort I advancement at skeletal maturity. Future studies with larger sample sizes are necessary to confirm this association.

Anti-microbial efficiency of gaseous ozone's combined use with fluoride and chlorhexidine on time-related oral biofilm: an in situ study on pediatric patients.

Oral biofilm formation is the main reason for both caries progression and soft tissue diseases. Preventing the formation and promotion of biofilm has been known as the first attempt to prevent the development of caries and soft tissue problems in the oral cavity. The present study aimed to assess the effect of ozone and its combined use with chlorhexidine (CHX) and fluoride on the complex biofilm formation of pediatric patients under in situ conditions. Extracted bovine teeth were sterilized and cut into 2 × 3 mm2 sections. The samples were placed in removable maxillary plates and 10 healthy individuals (6 boys, 4 girls; aged 7-14 years) were asked to wear these plates for 6, 24 and 48 hours. Afterwards, the tooth samples were removed, and anti-plaque agents were applied to the time-related plaque formation. Plaque thickness and viable bacterial percentages were detected by confocal laser scanning microscopy. All materials used in the study decreased the plaque formation and the percentage of viable microorganisms compared with the control group (physiological saline). In 6- and 24-hour biofilm evaluations, ozone-CHX was the most effective group in decreasing the plaque thickness (P > 0.05). Ozone-CHX and Ozone-Fluoride groups were found to be better in 48-hour biofilm assessments in caries-free group (P > 0.05). Ozone-CHX group showed a better inhibitory effect on the viability of microorganisms in 6-, 24- and 48-hour biofilm formations (P < 0.05). Although CHX has been known as the gold standard for inhibiting the oral biofilm formation, according to the results of the study, gaseous ozone and its combined use with CHX have shown better results in reducing the biofilm thickness and viable bacterial percentages of in situ formed time-related biofilm formation in pediatric patients. The use of gaseous ozone can be preferred in clinical conditions in pediatric patients instead of the CHX agents.

Description of three new species of Hyalella Smith, 1874 (Crustacea: Amphipoda) from Southeast Mexico.

Lacandona tropical rainforest is an area with an important hydrological and biological role in Mexico, nevertheless there are few studies about freshwater macrofauna. In this study, we described three new species collected in three different water bodies in the Lacandona tropical rainforest: H. parva from lake Nahá with a minute body size without mucronations on pleonites 1-2, H. montebellensis from lake La Esmeralda with two dorsoposterior carinae on pleonites 1 and 2 (mucronations) and one seta almost at mid-ventral margin of gnathopod 1, and H. lacandonis from lake Península with minute dorsal mucronations on pleonites 1-2 and 2-3 setae on the hind margin of basis of gnathopod 1. Hyalella montebellensis n. sp. and H. lacandonis n. sp. have almost the same number of articles in flagellum of antennae 1-2, both species present four pappose setae on the inner plate of maxilla 1 and telson subquadrate, longer than wide.

Jaw morphology and function in Drilonereis cf. filum (Oenonidae, Annelida).

Representatives of the extant family Oenonidae (Annelida, Eunicida) have a prionognath jaw apparatus, with maxillae having forceps-like elements, a number of asymmetrical dentate plates and long slender carriers, which is characteristic of some fossil forms known from the Paleozoic epoch. Therefore, data on the fine structure and functional morphology of Oenonidae jaws are helpful for the interpretation of fossil materials. The fine structure of the jaw apparatus and the ventral pharyngeal organ is studied in one species of the Oenonidae (Annelida)-Drilonereis cf. filum. The material was collected in the soft bottom of Marseille Bay (Mediterranean) and examined with the help of TEM and histological techniques. A three-dimensional (3D) reconstruction was made from a complete series of semithin sections. The entire jaw apparatus is about 500 µm in length; it includes ventral mandibles and four pairs of maxillae, connected with long paired dorsal carriers and an unpaired ventral carrier. While retracted, it reaches the VIII-XI chaetigers. The most solid part of the maxillary apparatus, that is, maxillae I and II, are 2.5-5 µm thick. The plate consists of a monolithic array of merged scleroprotein granules in which perforations, that is, spaces remaining from microvilli, are visible; the basal part of the maxillary plate is a layer of loosely arranged collagen fibers penetrated with microvilli and has no signs of sclerotization. A study of the jaws of Drilonereis cf. filum showed the presence of common jaw patterns in Eunicida order. Like the jaws of Dorvilleidae, Eunicidae, Onuphidae, and Lumbrineridae, the jaws of Drilonereis are formed at the basis of a typical annelid cuticle's transformation with epi- and basicuticular layers, and its impregnation by merging scleroprotein granules. Through the nature of sclerotization, the jaws of D. cf. filum are similar to those of Dorvilleidae, Histriobdellidae, and the juvenile jaws of Mooreonuphis stigmatis (Onuphidae). Analysis of the 3D-reconstructions of the D. cf. filum jaw apparatus shows that the MxI of this species, and probably of other Oenonidae with dorsal and ventral carriers, can make grasping motions by fixing the joint of the right and left MxI in the two-door hinge type. In general, the overall structure of the jaw apparatus of D. cf. filum and the mechanics of its work shows greater similarity with that of Dorvilleidae than with the jaw apparatus of extant Labidognatha and Simmetrognatha (Onuphidae, Eunicidae, Lumbrineridae). The need for compactization of the jaw apparatus when moving in dense sediment or in the burrows is probably one of the factors determining its structure.

New genus and species of the family Aeduellidae (Actinopterygii) from the Lower Goldlauter Formation (Asselian, Lower Permian) of the Thuringian

A new aeduellid actinopterygian Amelangia ornata gen. et sp. nov. is described from the Lower Goldlauter Formation of the Thuringian Forest (Lower Permian, Germany). Distinguishing characters of the newly described taxon are a large dermosphenotic, an unusually large number of suborbital bones, a maxilla with a low maxillary plate, a distinct sculpture consisting of tubercles on the operculum and suboperculum, the presence of a single branchiostegal ray, and a pectoral fin with a scaly basal lobe. The preserved characters place the new genus close to the genera Aeduella and Bourbonnella. The newly described genus and species is similar to an isolated operculum and suboperculum recovered from the Lower Permian of the Krkonoše Piedmont Basin in the Bohemian Massif.

First record of the genus Eliberidens (Annelida: Dorvilleidae) from the Southwestern Atlantic Ocean and cladistic analysis of the genus

Knowledge on the family Dorvilleidae Chamberlin, 1919 is still limited, mainly due to the scarcity of studies and the rarity of many genera and species in samples collected from shallow waters to great depths. This work presents a two folds aim: i) report the first record of Eliberidens from the Southwestern Atlantic Ocean, with Eliberidens forceps Wolf, 1986 and Eliberidens hartmannschroederaeHilbig, 1995; ii) providing a morphological cladistic analysis to test the monophyly of Eliberidens and its relationship with related genera. These new records increase the taxonomic knowledge and distribution of dorvilleids in the Southern Hemisphere through a detailed description of Eliberidens species. The cladistic analysis supports the monophyly of the taxon Eliberidens by two synapomorphies: presence of geniculate chaeta with short distal end in the first parapodia and the absence of maxillary plates of superior row. The genus is a sister group of the clade formed by all dorvilleids included in the present analysis, excluding Gymnodorvillea.

Custom Plates in Orthognathic Surgery: A Single Surgeon's Experience and Learning Curve.

Virtual surgical planning (VSP) now allows for the fabrication of custom plates in orthognathic surgery. The senior author was an early adopter, using VSP and stereolithographic splints for over a decade, before transitioning to custom plates in 2019. The authors present our experience and learning curve with this new technology and compare results to a prior cohort of orthognathic patients. A retrospective chart review identified patients undergoing orthognathic surgery with the senior author between 2016 and 2021. All underwent VSP and stereolithographic splint formation, and then either traditional or custom-plate fixation. Demographics, perioperative variables, and postoperative outcomes were analyzed. Traditional fixation consisted of craniomaxillofacial plates, bent intraoperatively by the surgeon to adapt to the facial skeleton. Custom plates were prefabricated and prebent to fit drill holes outlined by customized cutting guides. Forty-three patients underwent surgery in the study period, 25 (58.1%) with traditional fixation hardware and 18 (41.9%) with custom plates. The surgical technique evolved throughout the custom-plate cohort, with the most recent technique involving custom maxillary plate fixation and traditional mandibular plate fixation. When comparing this group of patients to the prior cohort of traditional fixation patients, operative time significantly decreased (mean 233 minutes versus 283 minutes, P = 0.044), without significant difference in complications. Patient-specific cutting guides and custom plates allow for precise spatial positioning of the osteotomized jaw in the orthognathic surgery. Unsurprisingly, obstacles must be overcome in adopting this new technology; here, we outline our experience and technical modifications that have resulted in increased surgical efficiency with comparable outcomes.

Effect of miniscrew insertion angle in the maxillary buccal plate on its clinical survival: a randomized clinical trial

IntroductionThis study sought to assess the effect of miniscrew insertion angle (vertical and oblique) on its clinical survival under shearing forces in orthodontic patients undergoing canine retraction.Materials and methodsIn this split-mouth randomized controlled clinical trial, 50 miniscrews were placed bilaterally in 25 patients with 45° and 90° insertion angles relative to a line perpendicular to the occlusal plane distal to the maxillary first premolar extraction site. Allocation of insertion angles to the right/left side was random using the Random Allocation Software. The patients, clinician, and statistician were blinded to the allocation of miniscrews to the side of jaw. The patients were followed-up monthly for 6 months. The primary outcome was the clinical survival of miniscrews, which was evaluated at each follow-up session. The secondary outcomes were the miniscrew stability based on the Periotest value (PTV) and the level of pain experienced by patients at 1, 12, and 24 h, and 7 days after miniscrew placement using a visual analog scale (VAS). Data were analyzed using paired t-test, repeated measures ANOVA, and McNemar’s test.ResultsThe clinical survival rate of miniscrews placed at 90° and 45° angles was 76% and 88%, respectively. This difference was not statistically significant (P = 0.375). No significant difference was noted between the two groups regarding the PTV or the pain score either (P > 0.05).ConclusionClinically, the insertion angle of miniscrews (90° versus 45° relative to a line perpendicular to the occlusal plane) has no significant effect on the miniscrew survival rate or stability during orthodontic treatment.Trial registrationThis trial was registered at www.irct.ir (IRCT20190901044659N1).ProtocolThe protocol was published after trial commencement.

Morphological and molecular analysis of Willowsia nigromaculata (Collembola, Entomobryidae, Entomobryinae) reveals a new cryptic species from the United States

Commonly reported as a household pest throughout the northern hemisphere, Willowsia nigromaculata (Lubbock) is among the most abundant and widely distributed springtails. However, taxonomic uncertainty due to incomplete morphological descriptions based on specimens from different continents may lead to incorrect identifications and/or prevent the recognition of distinct lineages within this morphospecies. Here, we perform the first comprehensive morphological and genetic comparison between W. nigromaculata specimens collected from North America and Europe. Morphological and genetic evidence reveals that populations in the United States and France represent two distinct nigromaculata-like species, but a phylogenetic analysis indicates both species may also be present in Canada. Based on these results, we redescribe W. nigromaculata from France, provide a description for Willowsia neonigromaculata sp. nov. from the United States, and propose new diagnostic characters for their separation, including the number of inner appendages on the maxillary sublobal plate. We also highlight the need for morphological and molecular investigations of additional populations to better understand the diversity and distribution of W. nigromaculata and related species.

The rhynchosaur record, including a new stenaulorhynchine taxon, from the Chañares Formation (upper Ladinian–?lowermost Carnian levels) of La Rioja Province, north-western Argentina

Rhynchosaurs were quadrupedal, bulky herbivorous archosauromorph diapsids with a highly specialized dental apparatus. This group is restricted to the Triassic Period and became extremely abundant worldwide during the late Carnian, numerically dominating some of the first dinosaur-bearing assemblages. Despite their high abundance in upper Carnian beds of South America, rhynchosaurs are restricted to a handful of specimens in the latest Ladinian–early Carnian tetrapod assemblages of this continent. Here, we improve the record of one of the oldest rhynchosaur assemblages of South America with the detailed description of all the rhynchosaur specimens currently known from the Tarjadia Assemblage Zone (AZ) (late Ladinian–?earliest Carnian) of the Chañares Formation (Ischigualasto-Villa Unión Basin, La Rioja Province). Most of these specimens were only preliminarily reported before, and as part of this revision we name the new taxon Elorhynchus carrolli gen. et sp. nov. based on one of these specimens, which represents the first new taxon for the Chañares Formation in 22 years. Elorhynchus carrolli and three more rhynchosaur specimens from the Chañares Formation are identified as stenaulorhynchine rhynchosaurs based on the presence of a crowded field of numerous lingual teeth in the dentary and the presence of small occlusal teeth in the maxillary tooth plate. Although their morphology is congruent, we did not refer the other stenaulorhynchine specimens to Elorhynchus carrolli because they lack diagnostic overlapping character states between them. Nevertheless, there is no current evidence for the presence of more than one rhynchosaur species in the Chañares Formation. The description of Elorhynchus carrolli and the other stenaulorhynchines from the Chañares Formation reinforces biostratigraphical links with the Dinodontosaurus AZ (Santa Maria Supersequence) of southern Brazil and the Lifua Member of the Manda Beds of Tanzania. http://zoobank.org/urn:lsid:zoobank.org:pub:E2662419-8AD5-4C1E-9900-BD1380BE65A4

Inclined bite plane: indications and application

Background: The prevalence of malocclusion in Indonesia is about 80% of the population and is a fairly common dental and oral health problem so that treatment of malocclusion from an early age is very important and needed. One of malocclusion treatment for preventing malocclusion is the use of removable orthodontic devices in the form of inclined bite plane. Con-clusion: Inclined bite plane can be made on the orthodontic plate of maxilla and mandible. In the maxilla inclined bite plane can function as a functional appliance in treatment of Class II malocclusion division 1, as a retention device after treatment using twin blocks and in the mandible serves to correct anterior crossbite.

Revision of the genus Platygerris White, 1883 (Hemiptera: Heteroptera: Gerridae), with descriptions of two new species from Colombia

Platygerris White comprises true bugs that inhabit the surface of water in moderate to fast-flowing freshwater habitats. This genus differs from Cylindrostethus Mayr and Potamobates Champion (Gerridae: Cylindrostethinae) by having a short and flattened body; the mandibular and maxillary plates fused; and the omphalium, lateral groove, and lateral evaporatorium of the scent apparatus inconspicuous. In this paper, we redescribe Platygerris, describe two new species from Colombia, and redescribe P. asymmetricus Hungerford, P. caeruleus Champion and P. depressus White. In addition, we present an updated identification key to the species of the genus. For the first time, the cuticular structure is described for the genus based on electron microscopy.

A new species of the genus Hyalella (Crustacea, Amphipoda) from northern Mexico.

A new species, Hyalella tepehuanasp. nov., is described from Durango state, Mexico, a region where studies on Hyalella have been few. This species differs from most species of the North and South American genus Hyalella in the number of setae on the inner plate of maxilla 1 and maxilla 2, characters it shares with Hyalella faxoni Stebbing, 1903. Nevertheless, H. faxoni, from the Volcan Barva in Costa Rica, lacks a dorsal process on pereionites 1 and 2. Also, this new species differs from other described Hyalella species in Mexico by the shape of the palp on maxilla 1, the number of setae on the uropods, and the shape of the telson.

Residual setup error in the canine intracranial region after megavoltage, kilovoltage, or cone-beam computed tomographic image guidance for radiation therapy.

Sources of residual setup error after image guidance include image localization accuracy, errors associated with image registration, and inability of some treatment couches to correct submillimeter translational errors and/or pitch and roll errors. The purpose of this experimental study was to measure setup error after image-guided correction of the canine intracranial region, using a four degrees-of-freedom couch capable of 1 mm translational moves. Six cadaver dogs were positioned 45 times as for clinical treatment using a vacuum deformable body cushion, a customizable head cushion, a thermoplastic mask and an indexed maxillary plate with a dental mould. The location of five fiducial markers in the skull bones was compared between the reference position and after megavoltage (MV), kilovoltage (kV) and cone-beam computed tomography (CBCT)-guided correction using orthogonal kV images. The mean three-dimensional distance vectors (3DDV) after MV, kV and CBCT-guided correction were 1.7, 1.5 and 2.2 mm, respectively. All values were significantly different (P < .01). The 95th percentiles of the 3DDV after online MV, kV and CBCT-guided correction were 2.8, 2.6 and 3.6 mm, respectively. Residual setup error in the clinical scenario examined was on the order of millimetres and should be considered when choosing PTV margins for image-guided radiation therapy of the canine intracranial region.

S4B-25 SESSION 4B: ORTHOGNATHIC / TREACHER-COLLINS MINIMAL DISRUPTION DISTRACTION IN SEVERE MANDIBULOFACIAL DYSOSTOSIS

Introduction: Severe Nager and Treacher Collins (TCS) patients frequently fail conventional distraction techniques. Degloving for osteotomy access and hardware retrieval delays bony healing and affects relapse. Further, high distraction forces in mandible-borne distractors may result in hardware failure, TMJ injury, or poor patient tolerance. To counter this, we designed a minimal access approach with transconjunctival high LeFort through reconstructed orbital floors combined with minimal dissection BSSO. Custom, non-buried anchorage devices permit aggressive, halo-borne counterclockwise traction. This approach has optimized airway outcomes and dramatically improved stable correction in our cohort. Methods: A total of 21 severe TCS or Nager patients underwent Lefort III/BSSO distraction osteogenesis were examined. 13 had prior MDO operation and 9 had a tracheostomy. Prior to Lefort III, malar and periorbital augmentation were performed using BMP2-soaked particulate allograft bone. This was performed serially (mean 2.7). Minimal dissection transconjunctival Lefort III and BSSO were then performed. Custom non-buried locking plates are designed to permit fixation between tooth roots. The maxillary plate is 1 piece to stabilize the hemimaxillas. The mandible plate is passed through a transmental tunnel to provide joystick-control of the distraction fragment. These are asymmetrically distracted from a RED device, the maxilla is consolidated once adequate counterclockwise advancement is achieved. The mandible is overdistracted to permit airway clearance and a consolidation period and/or intermaxillary fixation following distraction. Results: The number of distraction correlated with severity of midfacial deformity. In contrast, degree of micrognathia in infants and young children was not correlated with need for repeat distraction. Early mandibular distraction avoided secondary maxillary changes and was also associated with minimal loss of mandibular correction. Significant midface soft tissue advancement often required subsequent canthoplasty (14), midface bony contouring (10) or nasal dorsum augmentation with rib graft (4). 5 patients required a later bimaxillary advancement. Of the patients with tracheostomy 3/5 are decannulated and another two are eligible but prefer to finish ear reconstruction prior to decannulation. Conclusion: By combining minimal access techniques and custom hardware, we avoid soft tissue degloving and achieve enhanced outcomes in severe Treacher Collins and Nager syndrome. This regimen permits aggressive counterclockwise movement, more completely correcting both upper airway obstruction and facial aesthetics in patients with severe mandibulofacial dysostosis.

A new species of Hyalella (Crustacea, Amphipoda, Hyalellidae) from the Puna biogeographic province in Argentina.

A new species of freshwater amphipod belonging to genus Hyalella is described from a peatbog at high altitudes (3,650 to 4,400 m above sea level) in the Puna region (Salta province, northwestern Argentina). The new species can be distinguished from other hyalellid species by the following combination of characters: dorso-posterior flanges on pleonites I–III; palp on maxilla 1 reaching almost half of distance between base of palp and base of setae on outer plate, and two papposerrate setae on the inner margin of inner plate of maxilla 2; propodus of gnathopod 1 hammer-shaped, inner face with seven serrate setae; propodus of gnathopod 2 ovate; male uropod 1 without curved seta on inner side of inner ramus; ramus of uropod 3 shorter than peduncle; six pair of sternal gills on pereionites II–VII.A detailed morphological description and illustrations of the new species are provided. In Argentina, the new species represents the third record for the genus at altitudes greater than 2,000 m a.s.l., after H.kochi and H.fossamancinii (Dos Santos et al. 2008, González 2003), and the first record above 4,000 m a.s.l. Some comments about distributional and ecological aspects of the new species are included. With this new species, the number of Hyalella species known from Argentina and Falkland Islands (Islas Malvinas) rises to 12.

Removal of a maxillary tumor with simultaneous placement of intraosseous zygomatic implants

The study objective is to report a case of successful placement of intraosseous zygomatic implants for functional and aesthetic rehabilitation of a patient with a maxillary defect resulted from maxillary resection for right-sided stage IIB maxillary sarcoma (сT2N0M0, G3). Materials and methods . A 34-year-old male patient visited a doctor in P.A. Herzen Moscow Oncology Research Institute with complaints of maxillary tumor. During the examination of the oral cavity, we found a dense endophytic tumor in the area of two missing teeth (17 and 18) involving the alveolar process and palatine process of the maxilla. Computed tomography revealed destruction of the alveolar process, lateral, medial, and posterior walls of the maxillary sinus on the right, and tumor invasion into the right iliac fossa, pterygopalatine fossa, and right maxillary sinus. We also observed tumor destruction of the right palatine process of the maxilla. The patient was diagnosed with osteogenic sarcoma. Results. The patient received 4 courses of polychemotherapy with cisplatin and doxorubicin, which resulted in disease stabilization. Then the patient underwent en-block resection of the fragment of the right maxilla with alveolar and palatine processes, fragments of the zygomatic bone, wings of the sphenoid bone on the right side, and adjacent soft tissues. Simultaneously, we placed two zygomatic implants to provide supportfor the maxillary plate denture. To create an additional supporting point, we extracted tooth 11 and installed an implant with external hexagonal connection. Later, we produced and installed a specially designed palatal obturator. Conclusion. Installation of removable dentures supported by implants ensures complete and rapid rehabilitation, allowing a patient to chew, swallow, and speak normally. A palatal obturator on implants supports the soft tissues of the medial face, thus ensuring complete aesthetic rehabilitation.

Cognateosymtes serraticoxae, new genus, new species, a pleustid amphipod from the Sea of Japan (Crustacea: Amphipoda: Gammaridea: Pleustidae: Eosymtinae).

The new genus Cognateosymtes gen. nov. and new species C. serraticoxae sp. nov. are described from the shelf of western Sakhalin Island. The new genus has a set of features specific to the subfamily Eosymtinae: strongly ridged molar grinding surface of mandible and presence of a medial seta; inner plate of maxilla 1 with 2 strong apical plumose setae; inner plate of maxilla 2 with 2 strong submarginal setae, positioned subapically; pereopods 1 and 2 (gnathopods), propodal palmar margins lacking submedial tooth. Cognateosymtes differs from Eosymtes by the combination of character states: antenna 1, peduncular segment 1 with strong anterodistal processes; outer and inner plates of maxilla 2 with numerous apical setae; maxilliped, palp segment 2 linear, inner margin densely setose; coxae 1-3, posterodistal cusps multiple; dactylus of pereopods 3-7 the short. The key to the amphipod genera of the subfamily Eosymtinae Bousfield Hendrycks, 1994 is given.