A novel method for skin marking in radiotherapy: first clinical use of temporary organic tattoo seal.

An oil-based pen is widely used as a skin marker for identification of the isocenter and computed tomography (CT)-coordinate origin during radiotherapy. However, use of this pen has some disadvantages, including color loss and color migration. To address these problems, we have developed use of a temporary fashion tattoo (Inkbox) for skin marking. The utility and feasibility of Inkbox as an alternative to an oil-based pen were evaluated in this study. The study included patients from two centers who required skin marking for radiotherapy performed between December 2020 and March 2021. Skin markings were made with an oil-based pen or with Inkbox. The durability was recorded during daily irradiation. Skin markings with Inkbox were made in 32 patients. The total number of skin markings was 94: 64 with Inkbox and 30 with an oil-based pen. A questionnaire survey to evaluate each method was conducted among patients after radiotherapy. The median durations of marking were 16 and 4 days with Inkbox and an oil-based pen, respectively (p-value < 0.001). The survey showed that Inkbox had less impact on the daily lives of patients, including reduced color migration to clothes and less concern about disappearance of the marking. There were no adverse cutaneous side effects with Inkbox. The duration of marking with Inkbox is about 16 days, with little impact on daily life. These findings suggest that Inkbox is a potentially useful method of skin marking in radiotherapy.

Methyl-beta cyclodextrin and creatine work synergistically under hypoxic conditions to improve the fertilization ability of boar ejaculated sperm.

Although successful fertilization is completed by only 150 sperm in the pig oviduct, more than 50,000 sperms are required to achieve a fertilization rate of more than 70% by pig in vitro fertilization (IVF). In this study, to improve the efficiency of pig IVF, the effects of hypoxic conditions and treatment with creatine and methyl-beta cyclodextrin (MßCD) on the glycolytic pathway were investigated. Under low O2 conditions, zig-zag motility was strongly induced within 30 min; however, the induction disappeared at 60 min. Although caffeine suppressed zig-zag motility under low O2 conditions, creatine induced and sustained zig-zag motility until 120 min. Additionally, pretreatment with MßCD for 15 min greatly enhanced zig-zag motility via ATP production in sperm incubated with creatine under low O2 conditions. Sperm pretreated with MßCD were used for IVF in medium containing creatine under low O2 conditions. A fertilization rate of approximately 70% was achieved with only 1.0 x 104 sperms/mL, and there were few polyspermic embryos. Therefore, our novel method was beneficial for efficient production of pig embryos in vitro. Moreover, the zig-zag motility may be a novel movement which boar capacitated sperm exhibit in the culture medium.

Itaconate regulates the glycolysis/pentose phosphate pathway transition to maintain boar sperm linear motility by regulating redox homeostasis.

Mammalian cells improve redox homeostasis under reactive oxygen species (ROS) stress conditions via the enhancement of the pentose phosphate pathway (PPP). However, it is not clear how the cell reprograms glucose metabolism from glycolysis to the PPP. Hence, in the present study, we used boar sperm as a model to elucidate the mechanism by which the glycolysis/PPP transition occurs under ROS stress. The boar sperm treated with moderate glucose levels for 3 h exhibited increased sperm linear motility patterns, ATP levels and GSH/GSSG ratios and decreased ROS levels compared to the boar sperm treated without glucose. In addition, the hexokinase activity, glucose-6-phosphate dehydrogenase (G6PD) activity, NADPH level, NADPH/NADP+ ratio and mitochondrial activity were higher in the sperm treated with moderate glucose than in those not treated with glucose. Interestingly, the enzyme activity of fructose-1,6-bisphosphate aldolase (ALDOA) was not significantly changed during the incubation. The sperm linear motility patterns were decreased by treatment with the G6PD inhibitor 6-aminonicotinamide. Moreover, moderate glucose treatment significantly increased the itaconate levels in sperm. Both endogenous and exogenous itaconate increased the total itaconate modifications and the itaconate-modified ALDOA levels in sperm, suggesting that under moderate-glucose conditions, glycolysis in the sperm was suppressed by an increase in the itaconate levels. Furthermore, the addition of itaconate improved the sperm linear motility patterns by suppressing glycolysis and enhancing oxidative phosphorylation (OXPHOS). Therefore, the itaconate generated from OXPHOS regulates the glycolysis/PPP transition to maintain redox homeostasis. In sperm, this itaconate-dependent mechanism plays an important role in maintaining their high linear motility.

Gene Expression and Protein Synthesis in Mitochondria Enhance the Duration of High-Speed Linear Motility in Boar Sperm.

Sperm motility patterns are continuously changed after ejaculation to fertilization in the female tract. Hyperactivated motility is induced with high glucose medium in vitro or the oviduct fluids in vivo, whereas sperm maintain linear motility in the seminal plasma or the uterine fluids containing low glucose. Therefore, it is estimated that sperm motility patterns are dependent on the energy sources, and the mitochondrial oxidative phosphorylation is activated to produce ATP in low glucose condition. To elucidate these hypotheses, boar sperm was incubated in different energy conditions with the transcription and translation inhibitors in vitro. Sperm motility parameters, mitochondrial activity, ATP level, gene expression and protein synthesis were analyzed. Sperm progressive motility and straight-line velocity were significantly increased with decreasing glucose level in the incubation medium. Moreover, the mitochondrial protein turnover meaning transcription and translation from mitochondrial genome in sperm is activated during incubation. Incubation of sperm with mitochondrial translation inhibitor (D-chloramphenicol) suppressed mitochondrial protein synthesis, mitochondrial activity and ATP level in sperm and consequently reduced the linear motility speed, but not the motility. Thus, it is revealed that the mitochondrial central dogma is active in sperm, and the high-speed linear motility is induced in low glucose condition via activating the mitochondrial activity for ATP generation.

Creatine enhances the duration of sperm capacitation: a novel factor for improving in vitro fertilization with small numbers of sperm.

STUDY QUESTION: Why are many sperm required for successful fertilization of oocytes in vitro, even though fertilization occurs in vivo when only a few sperm reach the oocyte? SUMMARY ANSWER: Creatine produced in the ovary promotes efficient fertilization in vivo; however, in vitro, creatine is not contained in the in vitro fertilization (IVF) medium. WHAT IS KNOWN ALREADY: The IVF medium enables capacitation of sperm. However, the IVF medium does not fully mimic the in vivo environment during fertilization. Consequently, fertilization in vitro is more inefficient than in the oviduct. STUDY DESIGN, SIZE, DURATION: Follicular and oviductal fluids were collected and then analyzed for creatine and glucose levels. To determine the physiological functions of creatine, the creatine antagonist 3-guanidinopropionic acid (GPA) was injected into hormonally primed mice. Using conventional IVF protocols, sperm were pre-incubated in IVF medium with creatine and then co-cultured with 10 ovulated cumulus-oocyte complexes (1-1000 per oocyte) in 50 µl medium droplets. PARTICIPANTS/MATERIALS, SETTING, METHODS: Glucose and creatine levels were measured using commercial enzymatic assay kits. The effect of creatine in vivo was assessed by mating experiments using mice treated with or without GPA just before ovulation. To assess the functions of sperm incubated in IVF medium containing creatine, we analyzed (1) the motility of sperm using computer-assisted sperm assay, (2) the capacitation level of sperm by western blot analyses, and (3) the condition of sperm acrosomes by peanut agglutinin lectin-FITC staining. MAIN RESULTS AND THE ROLE OF CHANCE: Oviductal creatine levels were significantly increased following ovulation. Injecting mice with GPA just before ovulation significantly reduced the number of fertilized oocytes. The addition of creatine to IVF medium enhanced sperm capacitation by increasing ATP levels. Successful fertilization was achieved with as few as five sperm/oocyte in the creatine group, and the number of fertilized oocytes was significantly higher than in the control without creatine (P < 0.01). LIMITATIONS, REASONS FOR CAUTION: In the present study, a pharmacological approach, creatine antagonist (GPA) treatment, but not a knockout mouse model, was used to understand the role of creatine in vivo. The role of creatine in fertilization processes can only be shown in a mouse model. WIDER IMPLICATIONS OF THE FINDINGS: A modified IVF technique using creatine-containing medium was developed and shown to markedly improve fertilization with small numbers of sperm. This approach has the potential to be highly beneficial for human assisted reproductive technologies, especially for patients with a limited number of good quality sperm. STUDY FUNDING/COMPETING INTEREST(S): This work was supported in part by JSPS KAKENHI Grant numbers JP24688028, JP16H05017 (to M.S.), and JP15J05331 (to T.U.), the Japan Agency for Medical Research and Development (AMED) (16gk0110015h0001 to M.S.), and National Institutes of Health (NIH-HD-076980 to J.S.R). The authors have nothing to disclose.

Cynomolgus monkey model of interleukin-31-induced scratching depicts blockade of human interleukin-31 receptor A by a humanized monoclonal antibody.

Scratching is an important factor exacerbating skin lesions through the so-called itch-scratch cycle in atopic dermatitis (AD). In mice, interleukin (IL)-31 and its receptor IL-31 receptor A (IL-31RA) are known to play a critical role in pruritus and the pathogenesis of AD; however, study of their precise roles in primates is hindered by the low sequence homologies between primates and mice and the lack of direct evidence of itch sensation by IL-31 in primates. We showed that administration of cynomolgus IL-31 induces transient scratching behaviour in cynomolgus monkeys and by that were able to establish a monkey model of scratching. We then showed that a single subcutaneous injection of 1 mg/kg nemolizumab, a humanized anti-human IL-31RA monoclonal antibody that also neutralizes cynomolgus IL-31 signalling and shows a good pharmacokinetic profile in cynomolgus monkeys, suppressed the IL-31-induced scratching for about 2 months. These results suggest that the IL-31 axis and IL-31RA axis play as critical a role in the induction of scratching in primates as in mice and that the blockade of IL-31 signalling by an anti-human IL-31RA antibody is a promising therapeutic approach for treatment of AD. Nemolizumab is currently under investigation in clinical trials.

The thermosensitive TRPV3 channel contributes to rapid wound healing in oral epithelia.

The oral cavity provides an entrance to the alimentary tract to serve as a protective barrier against harmful environmental stimuli. The oral mucosa is susceptible to injury because of its location; nonetheless, it has faster wound healing than the skin and less scar formation. However, the molecular pathways regulating this wound healing are unclear. Here, we show that transient receptor potential vanilloid 3 (TRPV3), a thermosensitive Ca(2+)-permeable channel, is more highly expressed in murine oral epithelia than in the skin by quantitative RT-PCR. We found that temperatures above 33°C activated TRPV3 and promoted oral epithelial cell proliferation. The proliferation rate in the oral epithelia of TRPV3 knockout (TRPV3KO) mice was less than that of wild-type (WT) mice. We investigated the contribution of TRPV3 to wound healing using a molar tooth extraction model and found that oral wound closure was delayed in TRPV3KO mice compared with that in WT mice. TRPV3 mRNA was up-regulated in wounded tissues, suggesting that TRPV3 may contribute to oral wound repair. We identified TRPV3 as an essential receptor in heat-induced oral epithelia proliferation and wound healing. Our findings suggest that TRPV3 activation could be a potential therapeutic target for wound healing in skin and oral mucosa.

[A case of appearance of a prominent rash in response to alternate-day S-1 administration as adjuvant chemotherapy for lower gingival cancer].

We report the development of a prominent rash in response to alternate-day S-1 administration in a patient with oral cancer. The patient was a 75-year-old woman with left-side lower gingival cancer(T4N1M0). After chemoradiotherapy, the patient underwent radical surgery. She was treated with oral S-1, administered on alternate days at a dosage of 80mg/day (orally, twice per day), as postoperative adjuvant chemotherapy. Edematous erythema, accompanied by strong itching and paraesthesia, appeared focally on the face and the limbs 1 month after beginning S-1 treatment. Since the rash was determined to be drug-induced, S-1 administration was stopped, and steroid, antihistamine, and topical steroid treatment was initiated. The symptoms gradually improved, and the rash disappeared without recurrence approximately 1 month later. Although alternate-day administration is considered to be a safe and effective method to administer S-1 oral therapy, it should be noted that cutaneous symptoms might appear after a fixed dosage is exceeded.

Generational differences in tooth size in the Japanese population: analysis of cohorts with a generation gap of four to five decades.

PURPOSE: Since early modern times, tooth size has reportedly been increasing in each successive generation. A detailed analysis of these trends can provide meaningful information for elucidating the origin of various problems caused by larger teeth, such as an abnormal dentition and occlusion. By using data from most recent generations, this study aimed to clarify the time course of changes in tooth size in the Japanese. MATERIALS AND METHODS: The dentitions of two Japanese cohorts comprising young individuals born in the 1980s and the 1990s were compared with those of another cohort of Japanese individuals born in the 1940s, approximately half a century earlier. The mesiodistal diameter of the tooth crowns was measured on plaster models and subjected to statistical analyses. RESULTS: A mean difference test revealed that each recent generation showed positive generational differences in the size of more than 50% of the tooth types. In addition, a deviation graph analysis indicated that the degree of change in tooth size varied with the tooth type or sampling site. Principal component analysis clearly showed an increase in tooth size on an individual basis in the more recent generations. CONCLUSIONS: This study revealed positive generational differences in tooth size in the Japanese population. The results may aid in understanding the development of abnormal dentitions and occlusion in recent Japanese populations.

Case of pediatric acute promyelocytic leukemia presenting as extramedullary tumor of the mandible.

BACKGROUND: Acute promyelocytic leukemia (APL) is a malignant subtype of acute myeloid leukemia caused by the PML-retinoic acid receptor (RAR)α fusion gene. APL may be discovered in adulthood and diagnosed after spontaneous gingival bleeding or difficulty in hemostasis after oral surgery such as tooth extraction. However, APL is extremely rare in children. METHODS AND RESULTS: A 1-year-old boy presented with a mass on the mentum of the mandible. The marked periosteal reaction was seen on CT and MRI, leading to strong suspicion of a malignant bone-derived tumor such as a sarcoma. Chromosome banding by fluorescence in situ hybridization (FISH) showed PML-RARα, confirming the diagnosis of APL. Treatment with tretinoin was immediately initiated. No signs of recurrence have been noted 1 year after treatment. CONCLUSIONS: We report herein a rare case involving an infant with APL who presented with an extramedullary tumor of the mandible, whom we treated with good results.

A bispecific antibody to factors IXa and X restores factor VIII hemostatic activity in a hemophilia A model.

Hemophilia A is a bleeding disorder resulting from coagulation factor VIII (FVIII) deficiency. Exogenously provided FVIII effectively reduces bleeding complications in patients with severe hemophilia A. In approximately 30% of such patients, however, the 'foreignness' of the FVIII molecule causes them to develop inhibitory antibodies against FVIII (inhibitors), precluding FVIII treatment in this set of patients. Moreover, the poor pharmacokinetics of FVIII, attributed to low subcutaneous bioavailability and a short half-life of 0.5 d, necessitates frequent intravenous injections. To overcome these drawbacks, we generated a humanized bispecific antibody to factor IXa (FIXa) and factor X (FX), termed hBS23, that places these two factors into spatially appropriate positions and mimics the cofactor function of FVIII. hBS23 exerted coagulation activity in FVIII-deficient plasma, even in the presence of inhibitors, and showed in vivo hemostatic activity in a nonhuman primate model of acquired hemophilia A. Notably, hBS23 had high subcutaneous bioavailability and a 2-week half-life and would not be expected to elicit the development of FVIII-specific inhibitory antibodies, as its molecular structure, and hence antigenicity, differs from that of FVIII. A long-acting, subcutaneously injectable agent that is unaffected by the presence of inhibitors could markedly reduce the burden of care for the treatment of hemophilia A.

Comprehensive Analysis of Bacterial Flora in Postoperative Maxillary Cyst Fluid by 16S rRNA Gene and Culture Methods.

Intracystic fluid was aseptically collected from 11 patients with postoperative maxillary cyst (POMC), and DNA was extracted from the POMC fluid. Bacterial species were identified by sequencing after cloning of approximately 580 bp of the 16S rRNA gene. Identification of pathogenic bacteria was also performed by culture methods. The phylogenetic identity was determined by sequencing 517-596 bp in each of the 1139 16S rRNA gene clones. A total of 1114 clones were classified while the remaining 25 clones were unclassified. A total of 103 bacterial species belonging to 42 genera were identified in POMC fluid samples by 16S rRNA gene analysis. Species of Prevotella (91%), Neisseria (73%), Fusobacterium (73%), Porphyromonas (73%), and Propionibacterium (73%) were found to be highly prevalent in all patients. Streptococcus mitis (64%), Fusobacterium nucleatum (55%), Propionibacterium acnes (55%), Staphylococcus capitis (55%), and Streptococcus salivarius (55%) were detected in more than 6 of the 11 patients. The results obtained by the culture method were different from those obtained by 16S rRNA gene analysis, but both approaches may be necessary for the identification of pathogens, especially of bacteria that are difficult to detect by culture methods, and the development of rational treatments for patients with POMC.

Nonmetric cranial variation of Jomon Japan: Implications for the evolution of eastern Asian diversity.

OBJECTIVES: The purpose of this study is to investigate the origin and expansion of the Jomon population, the Neolithic inhabitants of the Japanese archipelago, and peopling East/Northeast Asian region through a global comparison between the prehistoric samples from around the world. METHODS: R-matrix approach was applied to 20 nonmetric cranial traits for assessing the population structure and history of the Jomon. Pattern of ancient group relationships on a global scale was presented using network splitstree applied to distance matrix transformed from the R-matrix. RESULTS: The phenotypic variation is largest in Hokkaido region, followed by the regions of eastern Japan. The Chugoku region, the southwestern part of Japan, shows larger variance than eastern Japan. Global analyses including samples from Northeast Asia, Southeast Asia, Australia, West Asia, Europe, and North Africa dating roughly to the same chronological periods as those of the Jomon groups, indicate northern affinities of the Jomon and the distinction between Southeast and Northeast Asian series. CONCLUSION: The Jomon ancestors of the northern part of Japan might have expanded southward to Honshu Island with a series of bottlenecks. A possible gene flow from outside source or heterogeneous origin of western Jomon group was, at the same time, suggested. The network relationships of the Jomon with Northeast Asians and, to a lesser extent, with Southeast Asians based on the splitstree analysis may allow us to suppose that the Jomon may be one of the key populations for the studies of the evolution of eastern Asian diversity.

Excitation of rat spinal ventral horn neurons by purinergic P2X and P2Y receptor activation.

ATPgammaS, a nonhydrolyzable ATP analog, was found to dose-dependently generate an inward current at a holding potential of -70 mV (EC(50)=43 microM) in lamina IX neurons of rat spinal cord slices using the whole-cell patch-clamp technique. This inward current had an extrapolated reversal potential of -9 mV and was resistant to the Na(+)-channel blocker tetrodotoxin, glutamate-receptor antagonists or nominally Ca(2+)-free medium. ATP gamma S also increased the frequency and amplitude of glutamatergic spontaneous excitatory postsynaptic current (sEPSC); this action was dose-dependent and sensitive to tetrodotoxin. Unlike ATP gamma S, the P2X-receptor agonist, BzATP or alpha,beta-methylene ATP, did not change holding currents, but the current response produced by ATP gamma S disappeared in the presence of the P2-receptor antagonist PPADS. The sEPSC frequency and amplitude increase was observed with alpha,beta-methylene ATP, but not with the P2Y-receptor agonist, 2-methylthio ADP, UTP or UDP. The current response by ATP gamma S was suppressed by the addition of GDP beta S into the patch-pipette solution. As for ATP gamma S, 2-methylthio ADP produced an inward current, while UTP and UDP had no effect on holding currents. The P2Y(1)-receptor antagonist MRS2179 inhibited the ATP gamma S-induced inward current, but did not affect the sEPSC frequency and amplitude increase produced by ATP gamma S. These data indicate that extracellular ATP increases the excitability of lamina IX neurons by membrane depolarization (probably through non-selective cation-channel activation) and spontaneous excitatory transmission enhancement, which may be mediated by P2Y(1) and P2X receptors, respectively. This finding supports the idea that purinergic receptor antagonists provide a therapy for spinal cord injury.

Development of a novel PCR method to comprehensively analyze salivary bacterial flora and its application to patients with odontogenic infections.

OBJECTIVE: The objective of this study was to develop a novel polymerase chain reaction (PCR) method to comprehensively analyze salivary bacterial flora. STUDY DESIGN: The bacterial flora in the saliva of 10 healthy persons and 11 patients with odontogenic infections were examined using a DNA extraction method with a high level of cell destruction efficiency and a novel universal primer set to amplify approximately 580 bp of the 16S rDNA sequence. RESULTS: Streptococcus (54.5%), Neisseria (14.7%), Actinomyces (8.4%), Gemella (4.1%), Granulicatella (3.8%), and Prevotella (1.4%) were dominant in a total of 1655 clones examined from the saliva of the healthy subjects. The dominant genera differed among the patients with odontogenic infections (a total of 823 clones) and were entirely different from those of the healthy subjects. CONCLUSION: This novel comprehensive salivary bacterial flora analysis method may be a useful supportive method to identify causative agents of odontogenic infections.

Moraxella catarrhalis bacteraemia associated with prosthetic vascular graft infection.

Moraxella catarrhalis, formerly called Branhamella catarrhalis, 'Neisseria catarrhalis' or 'Micrococcus catarrhalis', is a Gram-negative, aerobic diplococcus frequently found as a colonizer of the upper respiratory tract. Over the last 20-30 years, this bacterium has emerged as a genuine pathogen, and is now considered an important cause of otitis media in children and an aetiological agent in pneumonia in adults with chronic obstructive pulmonary disease. However, bacteraemia due to M. catarrhalis has rarely been reported. Presented here is a case of M. catarrhalis bacteraemia associated with prosthetic vascular graft infection along with a review of the relevant literature.

TRPV2 expression in rat oral mucosa.

The oral mucosa is a highly specialised, stratified epithelium that confers protection from infection and physical, chemical and thermal stimuli. The non-keratinised junctional epithelium surrounds each tooth like a collar and is easily attacked by foreign substances from the oral sulcus. We found that TRPV2, a temperature-gated channel, is highly expressed in junctional epithelial cells, but not in oral sulcular epithelial cells or oral epithelial cells. Dual or triple immunolabelling with immunocompetent cell markers also revealed TRPV2 expression in Langerhans cells and in dendritic cells and macrophages. Electron microscopy disclosed TRPV2 immunoreactivity in the unmyelinated and thinly myelinated axons within the connective tissue underlying the epithelium. TRPV2 labelling was also observed in venule endothelial cells. The electron-dense immunoreaction in junctional epithelial cells, macrophages and neural axons occurred on the plasma membrane, on invaginations of the plasma membrane and in vesicular structures. Because TRPV2 has been shown to respond to temperature, hypotonicity and mechanical stimuli, gingival cells expressing TRPV2 may act as sensor cells, detecting changes in the physical and chemical environment, and may play a role in subsequent defence mechanisms.

[Two cases of recurrent oral cancer responding to radiochemotherapy with selective intra-arterial infusion of nedaplatin].

Nedaplatin, a cisplatin derivative, has been reported to be an effective anti-tumor agent for head and neck cancer. We experienced two patients with advanced recurrent oral cancers who received combination therapy of intra-arterial nedaplatin infusion and radiation therapy, and tumoricidal effects were obtained in these cases. At the end of 3 courses, a partial response(PR)was obtained with regression of the tumor in the first case, and FDGPET showed a complete regression of recurrent tumor for a complete response(CR)in another case. This combination therapy is quite safe and effective for the treatment of advanced oral cancers.

Measurement of anterior loop length for the mandibular canal and diameter of the mandibular incisive canal to avoid nerve damage when installing endosseous implants in the interforaminal region: a second attempt introducing cone beam computed tomography.

PURPOSE: To measure and compare the anterior loop length (ALL) for the mandibular canal and the mandibular incisive canal diameter (ICD) at its origin in cadavers using anatomy and cone beam computed tomography (CBCT) to safely install endosseous implants in the most distal area of the interforaminal region. MATERIALS AND METHODS: The ALL and ICD were measured using CBCT in 4 cadavers, and using anatomy in 71 cadavers. RESULTS: The ranges and mean +/- SD for the anatomic measurements were: ALL, 0.0 to 9.0 mm and 1.9 +/- 1.7 mm; ICD, 1.0 to 6.6 mm and 2.8 +/- 1.0 mm. The average discrepancies between CBCT and anatomic measurements were 0.06 mm or less for both the ALL and the ICD, which were less than the resolution of CBCT. CONCLUSIONS: Because large variations in measurements were observed, both for ALL and ICD, no fixed distance mesially from the mental foramen should be considered safe. The ALL and the ICD can be estimated from the CBCT measurement. The preoperative CBCT measurement yields important information for each case.

Oral rehabilitation using pre-shaped Epitec fixation systems after extensive maxillary tumor surgery.

Reconstruction of maxillary defects represents a major challenge for reconstructive surgeons. The authors describe two cases of malignant tumor on the maxilla that were successfully repaired using the immediate installation of prostheses supported with an Epitec-system during maxilla reconstruction. The Epitec-plates provided a strong retention source for the maxillodental prosthesis. To reduce the operation time and improve conformity to the remaining bone shape, a craniofacial skull model was fabricated using stereo-lithographic techniques. After trimming the model to simulate segmental resection, Epitec-plates were shaped to match the defect. A united Epitec-plate was fixed to the remaining bone immediately and easily after tumor resection. An immediate maxillary prosthesis was placed and was functional at the end of surgery. The Epitec-system provides effective materials for immediate prosthesis of extensive maxillary defects.