Edge Of Mandible Research Articles

A new fossil species of the extant genus Vicelva from mid-Cretaceous Kachin amber (Coleoptera: Staphylinidae).

A new species of the extant staphylinid genus Vicelva Moore & Legner, V. rasilis sp. nov., is reported from mid-Cretaceous Kachin amber of northern Myanmar. Vicelva rasilis is distinguishable from extant members of Vicelva by the smoother dorsal surface of head, pronotum and elytra, less prominent median projection of clypeus, unnotched mesal edge of mandibles, semiglabrous antennomere 6, and longer tarsomere 1. The pollen-containing coprolite attached to the beetle and the crystals within the beetle body provide valuable information about the biology and taphonomy of the fossil.

A Comprehensive Ultrasound Evaluation Approach of Lower Facial Structure Before Masseter Muscle Botulinum Toxin Injection.

Masseter reduction by botulinum neurotoxin A (BoNT-A) injection is a popular procedure in East Asia. Inappropriate injection can result in various complications. The aim of this study was to develop an approach for comprehensively evaluating the lower facial structure based on the shape of the mandible angle, the thickness of the masseter, and the thickness of subcutaneous fat. Clinical profiles and standard ultrasound images were collected from patients seeking masseter BoNT-A injections. Lower facial structures were evaluated based on 3 aspects: mandible, masseter, and subcutaneous fat and skin. The mandibular angle was classified as extroverted, straight, or introverted. The starting point of the middle part of the masseter was recorded. The thickness of the deep inferior tendon, the superficial and deep belly of the superficial part of the masseter, and their contractility were measured. Overall thickness and the thickness of subcutaneous fat and skin were also measured. Eighty-four masseters from 42 patients were included. Straight mandibular angles were the most common type of angle (48.81%), followed by introverted (26.19%) and extroverted angles (25.00%). The middle part of the masseter starts from 2.33 [0.36] cm (mean [standard deviation]) above the mandible edge, which is above the usual injection points. The superficial belly was thicker than the deep belly in both static and clenching states (P = .048, P = .001) and had greater contractility. The average overall thickness was 1.87 [0.29] cm. Comprehensive evaluation of the lower facial contour and structure based on ultrasound examination could be a reliable and replicable assessment approach.

Augmented reality for oral and maxillofacial surgery: The feasibility of a marker-free registration method.

Recognition of markers in the augmented reality system can reduce the additional cost of a guide plate required for the removal of benign tumours in oral and maxillofacial surgery, but the use of markers often has complex problems. In order to avoid the complex problem of using markers, an augmented reality system based on a marker-free registration method was proposed to track the contour of the mandible edge. Use the computer to perform preoperative planning on the jaw model, select and mark the path of maxillofacial lesion resection. This method has an error of the surface matching was mm, and an error of the surgical resection was mm. We demonstrate that the system can accurately enhance the display of the surgical path and provide guidance for the tradition of maxillofacial surgery.

Mandible bone density in adolescents with cerebral palsy using antiepileptic drugs

Objective: The aim of this study was to assess the bone density of the mandible in adolescents with cerebral palsy(CP) treated with antiepileptic drugs using one beam computed tomography (CBCT). Methods: The study wascarried out with 18 adolescents aged 12–18 years, undergoing routine dental treatment at the dental clinic ofAPCD-São Caetano do Sul. CBCT scans were of divided into two groups: G1 adolescents with CP using antiepilepticdrugs and G2 normoactive adolescents. A single dentomaxillofacial radiologist assessed and evaluated the imagesusing Dental Slice software and Image J. Fisher’s exact tests as well as paired and unpaired Student’s t-testswere performed. Results: Groups differed significantly with regard in the values of density (p < 0.001), withG1 presenting lower values compare to G2. G1 showed significantly lower density means on the right side, leftside, and right/left sides of the mandible edge than G2 (p < 0.001). Conclusion: CP patients using antiepilepticdrugs show evidence of bone mineral density loss of the mandible. KEYWORDSAntiepileptic drugs; Bone mineral density; Cone beam computed tomography; Mandibular indices; Osteoporosis.

Evaluation of mental foramen – A CBCT assessment

The knowledge on the anatomic characteristics and variations of Mental Foramen is very important in surgical procedures involving that area. The mental nerve may be injured during local anesthesia, endodontic treatment and other oral surgical procedures. Aim of the study: The study performed aimed at assessing position of the MF relative to the apices of the teeth and MF to lingual cortex and to the base of the mandible. Materials and Methods: The study was conducted using Care stream 9100 select CBCT machine on 50 patients. Measurements were made from the edges of the mental foramen to the lingual cortex, and to the base of the mandible. The inferential statistics were performed using “independent t-test” and the p-value (< 0.05) is calculated using the same. The statistics were performed using SPSS 20software. Results: In terms of the location of mental foramen, it is most commonly found in the line of long axis of 2nd premolar. In case of measurements of mental foramen from the lingual cortex and lower body of mandible. The lingual edge of MF to lingual cortex was located, on average of 3.3mm in males and 3.8mm in females and the lower edge of the MF was located, 8.4 mm (males) & 7.1 mm (females) above the lower edge of mandible. Conclusion: The location of the mental foramen greatly influences the surgical planning .Hence there is need and importance of studies involving the anatomical characteristics of the mental foramen, which permit procedures to the performed more safely on the mandible.

Measurement of Mandibular Condylar Height Based on Magnetic Resonance Imaging

The aim of this study was to find out the most appropriate method of measuring condylar height on temporomandibular joint (TMJ) magnetic resonance imaging (MRI). Traditional three-circle method, modified three-circle method and ramal plane (RP) method were used by 2 separate observers for the measurement of condylar height and long axis of condyle on TMJ MRI. Pearson correlation coefficient (PCCs), intra-class correlation coefficient (ICC), paired t test and Bland-Altman analysis were applied for the comparison of CH and long axis of condyle between 2 observers. Thirty-two patients' images were finally included in our study. Comparing the 3 methods, it was revealed that the RP method has the highest consistency among the observers, followed by the modified three-circle method, and the traditional three-circle method has the worst consistency. The RP method is preferred for measuring the condylar height on MRI. If mandible edge cannot be observed on MRI, the modified three-circle method is recommended.

Automatic Segmentation of Lower Jaw and Mandibular Bone in Digital Dental Panoramic Radiographs

Objectives: Panoramic x-ray is a medical imaging technique used in dentistry. This paper aims to present fully automatic segmentation algorithm to extract lower jaw and mandible from panoramic x-ray. Methods/Analysis: Panoramic x-rays provide features of various diseases like advanced periodontal diseases, cysts, tumors, impacted teeth, fractures in lower or upper jaw, etc. Image processing techniques are applied on these images to detect diseases automatically. Segmentation is an inevitable step in automation to extract disease features. Majority existing literature use semi-automatic method for segmentation of panoramic x-ray. The algorithm proposed in this paper is fully automatic method of segmentation. Findings: Panoramic x-rays give entire view of mouth and facilitate assessment of hard tissue structures of the facial area rather than assessment of dental carries. Segmentation of panoramic x-rays is an inevitable step in automating diagnosis of oral disorders like, tumor, cysts, fracture, etc. In this paper, an algorithm is developed for automatic segmentation of lower jaw and then mandibular bone in dental digital panoramic x-ray. Dental digital panoramic x-ray is a good quality image which does not require noise removal. The segmentation algorithm uses novel strips method where input image is subdivided in number of strips. These strips are further processed to separate lower jaw and mandible from input image. The algorithm is fully automatic and does not involve human intervention at any level. Paper presents analysis of number of strips as 3, 5, 7 and 9. The algorithm presented in this paper gives 93% success for segmentation of lower jaw and 90% success in segmentation of mandible structure when strip count is 5. Applications/Improvement: Strip method focuses ROI and ignores components like teeth, spinal cord shadow, etc. Central strip is useful to segment lower jaw whereas side strips are useful to detect mandible edge points.

Treatment of osteonecrosis of the jaw (ONJ) by medical ozone gas insufflation. A case report.

Osteonecrosis of the jaw (ONJ) is an adverse event reported in patients receiving cancer treatment, especially bisphosphonates and denosumab. A patient with multiple myeloma who underwent up to 22 intravenous zoledronic acid infusions without previous dental examination developed a devastating ONJ lesion in the right horizontal mandibular ramus. He was treated with local ozone gas applications every third day by means of a special bell to avoid O(3) diffusion. Azithromycin 500 mg/day was administered for 10 days prior to the O(3) applications. O(3) therapy resulted in sequestration of the necrotic bone after a median of 15 applications, following which surgery was necessary to remove it. Interestingly, removal was possible without the resection of the healthy mandible edge because of the presence of the bone sequestrum. Medical O(3) gas administration was effective and safe in a patient treated with bisphosphonates who developed a >2.5 cm ONJ lesion. Future research is needed to demonstrate the efficacy and tolerability of such treatment in a larger number of patients.

Mouthpart morphology and wild diet of zoeae of the ghost shrimp, Nihonotrypaea harmandi (Decapoda: Axiidea: Callianassidae)

To infer diet and feeding mode of zoea of Nihonotrypaea harmandi (Bouvier, 1901), fine functional morphology of the mouthparts and composition of undigested remnants of ingested prey organisms contained in the gut were investigated. A mesh-like structure was observed for the coxal and basal endites of the maxilla, which would be suitable for filter feeding. The mandible edge is equipped with many fine processes and resembles the mandible edge of herbivorous copepod. Abrasion of the incisor processes, which must be caused by frequent mastication of planktonic diatoms, was recognized within a molting interval. Furthermore, diatom frustules and their crushed fragments were frequently observed in the gut contents. These observations indicate that zoea of N. harmandi may regularly feed on phytoplankton, especially diatoms.

An Approach for Efficient Detection of Cephalometric Landmarks

In this paper, a method is developed for the automated identification of cephalometric landmarks in orthodontics. The process of soft tissue edge detection is divided into two steps: detecting the sub-images that contained the required landmarks using combination of the Histograms of Oriented Gradients (HOG) descriptor with the Support Vector Machine (SVM), then utilizing Thresholding and Mathematical Morphological (TMM) algorithm to trace soft tissue profile. In addition, the mandible's edge is detected by the Active contours without edges (Chan-Vese method). Finally, the landmarks of soft tissue profile and the mandible's edge are pinned based on analyzing the contour plot of these lines. The simulation results have high accuracy.

Insufficient irrigation induces peri‐implant bone resorption: an in vivo histologic analysis in sheep

To measure in vivo impact of dense bone overheating on implant osseointegration and peri-implant bone resorption comparing different bur irrigation methods vs. no irrigation. Twenty TI-bone implants were inserted in the inferior edge of mandibles of sheep. Different cooling procedures were used in each group: no irrigation (group A), only internal bur irrigation (group B), both internal and external irrigation (group C), and external irrigation (group D). The histomorphometric parameters calculated for each implant were as follows: %cortical bone-implant contact (%CBIC) and %cortical bone volume (%CBV). Friedman's test was applied to test the statistical differences. In group A, we found a huge resorption of cortical bone with %CBIC and %CBV values extremely low. Groups B and C showed mean %CBIC and %BV values higher than other groups The mean %CBV value was significantly different when comparing group B and group C vs. group A (P < 0.05). Significant differences in %CBIC were found also between group C and group A (P < 0.05). Thermal injury, due to insufficient irrigation, of hard bone caused massive resorption of the cortical bone and implant failure. Drilling procedures on hard bone need an adequate cooling supply because the bone matrix overheating may induce complete resorption of dense bone around implants. Internal-external irrigation and only internal irrigation showed to be more efficient than other types of cooling methods in preventing bone resorption around implants.

Efficacy and tolerability of medical ozone gas insufflations in patients with osteonecrosis of the jaw treated with bisphosphonates—Preliminary data: Medical ozone gas insufflation in treating ONJ lesions

Osteonecrosis of the Jaw (ONJ) is an adverse event reported especially in patients receiving cancer treatments regimen, bisphosphonates (BPs), and denosumab. We performed an open-label, prospective study in patients treated with zoledronic acid who developed ONJ lesions >2.5cm, and had no benefit after the treatment with the standard therapy, to evaluate the efficacy and tolerability of medical ozone (O3) treatment delivered as gas insufflations on each ONJ lesions.Twenty-four patients (mean age 62.5, range 41–80; 12 female) with bone metastases due to breast (11), prostate (4)and lung (4)cancers, myeloma (2), or osteoporosis (3), previously treated with zoledronic acid and not underwent dental preventive measures and with ONJ lesions >2.5cm, were observed and treated with topical O3 gas insufflation every third day for a minimum of 10 for each pathological area or till necrotic bone sequestrum or surgery. We used a special insufflation bell-shaped device adjusted to the specific characteristics of the patient, capable of eliminating any residue of O3 diffusion by degrading it and releasing O2 into the air. Azithromicin 500mg/day was administered for 10 days in all patients before the first three gas insufflation although they had previously received various cycles of antibiotics. Ten patients required more than 10 O3 gas insufflations due to multiple lesions and/or purulent sovrainfections; one patient received two further O3 insufflations while waiting the day of surgery. Six of 24 patients interrupted the O3 gas therapy for oncological disease progression (five patients) and for fear of an experimental therapy (one patient). Six patients had the sequestrum and complete or partial (one patient) spontaneous expulsion of the necrotic bone followed by oral mucosa re-epithelization after a range of 4–27 of O3 gas insufflations. No patient reported adverse events. In 12 patients with the largest and deeper ONJ lesions, O3 gas therapy produced the sequestrum of the necrotic bone after 10 to 38 insufflations; surgery was necessary to remove it (11 patients). Of interest, removal was possible without the resection of healthy mandible edge because of the presence of bone sequestrum.All together the response rate was 75.0% (95% CI, 53.3–90.2%) in ITT analysis and 100% (95% CI, 81.5–100%) in the PP analysis.In all patients treated with O3 gas ± surgery, no ONJ relapse appeared (follow-up mean 18 months, range 1–3 years). Medical O3 gas insufflations is an effective and safe treatment for patients treated with BPs who developed ONJ lesions >2.5cm.Short abstract: ONJ is an adverse event reported in patients receiving cancer treatments regimen, bisphosphonates and denosumab. We performed an open-label, prospective study in 24 patients with solid tumours, myeloma or osteoporosis due to hormonal therapy, treated with zoledronic acid without previuos preventive dental screening, who developed ONJ lesions >2.5cm, and had no benefit after standard therapy, to evaluate the efficacy and tolerability of medical ozone (O3) treatment delivered as gas insufflations on each ONJ lesions.The patients were treated with O3 every third day for a minimum of 10 for each pathological area or till necrotic bone sequestrum or surgery. Eleven patients required more than ten O3 gas insufflations. Six of 24 patients interrupted the therapy for oncological disease progression. Six patients had the sequestrum and complete or partial (one patient) spontaneous expulsion of the necrotic bone followed by oral mucosa re-epithelization after a range of 4 to 27 of O3 gas insufflations. No patient reported adverse events. In 12 patients with the largest and deeper ONJ lesions, O3 gas therapy produced the sequestrum of the necrotic bone after 10 to 38 insufflations; surgery was necessary to remove it (11 patients). Of interest, removal was possible without the resection of healthy mandible edge because of the presence of bone sequestrum.All together the response rate was 75.0% (95% CI, 53.3–90.2%) in ITT analysis and 100% (95% CI, 81.5–100%) in the PP analysis.In all patients treated with O3 gas ± surgery, no ONJ relapse appeared (follow-up mean 18 months, range 1–3 years).

Treatment of Osteonecrosis of the Jaw (ONJ) by Medical Ozone Gas Insufflation. A Case Report

Osteonecrosis of the jaw (ONJ) is an adverse event reported in patients receiving cancer treatment, especially bisphosphonates and denosumab. A patient with multiple myeloma who underwent up to 22 intravenous zoledronic acid infusions without previous dental examination developed a devastating ONJ lesion in the right horizontal mandibular ramus. He was treated with local ozone gas applications every third day by means of a special bell to avoid O3 diffusion. Azithromycin 500 mg/day was administered for 10 days prior to the O3 applications. O3 therapy resulted in sequestration of the necrotic bone after a median of 15 applications, following which surgery was necessary to remove it. Interestingly, removal was possible without the resection of the healthy mandible edge because of the presence of the bone sequestrum. Medical O3 gas administration was effective and safe in a patient treated with bisphosphonates who developed a &gt;2.5 cm ONJ lesion. Future research is needed to demonstrate the efficacy and tolerability of such treatment in a larger number of patients.

The long-awaited first instar larva of Paussus favieri (Coleoptera: Carabidae: Paussini)

Paussus favieri Fairmaire is one of only two species of the myrmecophilous carabid tribe Paussini known from Europe. Larvae are known from only 10 of the 580 paussine species. As in many beetles with considerably modified later instar larvae, the first instars represent a valuable source of informative characters for taxonomy and phylogenetic analyses (primary chaetotaxy, egg-bursters, etc.). Therefore, the discovery of the first instar larva of P. favieri is particularly important, as it represents only the second species for which this larval stage is known. In this paper we describe the behavior and morphology of the larval first instar of P. favieri (subtribe Paussina of Paussini) and compare it with that of Arthropterus sp. (subtribe Cerapterina), which is the only other 1st instar described in the Paussini. Most surprisingly, we found that the 1st instar of P. favieri lacks a prostheca, which was previously thought to be a synapomorphy of Paussina + Platyrhopalina. Rather, P. favieri has a unique mandibular structure that seems to be functionally analogous to the protheca. It is a long, broadly lanceolate, distinctly flattened structure apparently homologous to the medial mandibular seta (MN2*), which arises from an area behind the cutting edge of mandible. We predict that the function of the protheca and this similar structure in P. favieri are involved in a specialized feeding strategy that may include soliciting trophallaxis from their host ants. We also report some observations of the first instar hatching from the egg, feeding on liquid and a behaviour we interpret as a "calling behavior," all of which were videotaped and posted on the Tree of Life Web Project.

Unique zinc mass in mandibles separates drywood termites from other groups of termites

Previously, the presence of metals in arthropod mandibles has been linked with harder cuticle, and in termites, a 20% increase in hardness has been found for mandibles containing major quantities of zinc. The current study utilises electron microscopy and energy-dispersive X-ray microanalysis to assess incidence and abundance of metals in all extant subfamilies of the Isoptera. The basal clades contain no zinc and little to no manganese in the cutting edge of the mandible cuticle, suggesting that these states are ancestral for termites. However, experimentation with mandibles in vitro indicates the presence of some elements of the cuticular biochemistry necessary to enable uptake of zinc. The Termopsidae, Serritermitidae, Rhinotermitidae and Termitidae all contain minor quantities of manganese, while trace to minor quantities of zinc occur in all except the Serritermitidae. In contrast, all Kalotermitidae or drywood termites contain major levels of zinc in the mandible edge. Diet and life type are explored as links to metal profiles across the termites. The presence of harder mandibles in the drywood termites may be related to lack of access to free water with which to moisten wood. Scratch tests were applied to a set of mandibles. The coefficient of friction for Cryptotermes primus (Kalotermitidae) mandibles, when compared with species from other subfamilies, indicates that zinc-containing mandibles are likely to be more scratch resistant.

A new species of endemic frog belonging to genus Nannophrys Günther, 1869 (Anura: Dicroglossinae) from Sri Lanka

The paper describes a new frog of the genus Nannophrys from Sri Lanka. The new species is distinguished from all other Nannophrys species by the following combination of morphological characters; distal subarticular tubercle and penultimate subarticular tubercles of 4th toe are well separated (vs. these two tubercles close in all other species of the genus). Supernumerary tubercle absent or smaller than penultimate subarticular tubercle on 4th toe. A hard sharp narrow symphysial knob and close pair of sharp apophyses on anterior edge of mandible and symphysial knob lower than two apophyses (vs. all other species with a blunt wider symphysial knob and wider pair of apophyes on anterior edge of mandible, and symphysial knob of same height or higher than two apophyses. Palmar tubercles comparatively smaller, inner palmar tubercle separated from outer palmar tubercle (vs. other relatives possess palmar tubercles comparatively large, inner palmar tubercle connected with outer palmar tubercle). Ecological and distributional notes for the new species are given.

Repair of mandible defect with tissue engineering bone in rabbits

The aim of the present study was to investigate the effect of tissue engineering bone composed of bone marrow-derived osteoblasts and demineralized bone in repairing mandible defect. Bone marrow-derived osteoblasts of 20 rabbits were cultured and seeded into scaffold of allogeneic demineralized bone to construct tissue engineering bone graft in vitro, which was used to repair the 10 x 5-mm bone defect made in the same rabbit mandible edge. Implant of demineralized bone alone was as the control. Rabbits were killed according to the schedule: five after 2 weeks, five after 4 weeks, five after 8 weeks, five after 12 weeks, and the implants were harvested for gross, radiographic, and histological observation. New bone formation at the margin region of defect and osteogenesis at the centre were observed in the implant of tissue engineering bone, and the bone formation pattern included osteogenesis, osteoconduction, and osteoinduction. In the implant of demineralized bone alone, the major bone formation pattern was 'creeping substitute'. The tissue engineering bone graft constructed by autogenous bone marrow-derived osteoblasts and allogeneic demineralized bone was better than demineralized bone alone in bone formation capability, which might be an ideal graft for bone defect repair.

Comparative morphology of the feeding appendages of four mesozooplankton species in the Sundays River estuary

The morphology of feeding appendages of the coexisting estuarine copepods, Pseudodiaptomus hessei and Acartia longipatetla, and mysids, Rhopalophthalmus terranatalis and Mesopodopsis wooldridgei. were examined and compared as an aid in elucidating dietary differences. The robust mandibles of P. hessei copepodids compared to the more pointed and slender teeth with no molar region, of A. longipatella suggest that the latter species relies on more fragile food particles. Mandible edge indices indicate, however, omnivorous feeding by both species. No clear dietary differences could be deduced from the dimensions of the second maxillae of these copepods. Mandible edge indices calculated for the mysid species suggest a more herbivorous feeding mode in M. wooldridgei and a more carnivorous one in R. terranatalis, supporting previous studies on their diets. No interspecific differences between the mysid size classes were evident from edge indices. Significant increments in setae and setule lengths and spacing with increasing mysid size class were evident, reflecting differences in food particle sizes utilized. The morphological differences in the feeding apparatus could reflect differences in the diets between species and indicate differences in food particle sizes utilized by the various developmental stages within species. These differences in diet should reduce inter- and intraspecific competition.