Gibberellin-regulated proteins: Emergent allergens

About 10 years ago, a protein family was shown for the first time to contain allergenic members, gibberellin-regulated protein (GRP). The first reported member was from peach, Pru p 7. One can hypothesize that it was not detected before because its physicochemical characteristics overlap with those of lipid transfer protein (LTP), a well-known allergen, or because the exposure to GRP increased due to an increase in the gibberellin phythormone level in plant food, either exogenous or endogenous. Like LTPs, GRPs are small cationic proteins with disulfide bridges, are resistant to heat and proteolytic cleavage, and are involved in the defense of the plant. Besides peach, GRP allergens have been described in Japanese apricot (Pru m 7), sweet cherry (Pru av 7), orange (Cit s 7), pomegranate (Pun g 7), bell pepper (Cap a 7), strawberry (Fra a GRP), and also in pollen with a restriction to Cupressaceae tree family (Cup s 7, Cry j 7, and Jun a 7). IgE cross-reactivities were described between GRPs, and the reported peach/cypress and citrus/cypress syndromes may therefore be explained because of these GRP cross-reactivities. GRPs are clinically relevant, and severe adverse reactions may sometimes occur in association with cofactors. More than 60% and up to 95% sequence identities are calculated between various allergenic GRPs, and three-dimensional models show a cleft in the molecule and predict at least three epitopic regions. The structure of the protein and its properties and the matrix effect in the original allergenic source should be unraveled to understand why, despite the ubiquity of the protein family in plants, only a few members are able to sensitize patients.

A rare low-grade myofibroblastic sarcoma in lower jaw with the resemblance to benign lesions

Background

Low-grade myofibroblastic sarcoma (LGMS) is a rare solid infiltrative soft tissue tumor with a predilection for the head and neck region.

Case presentation

We report the diagnostic steps of a fast-growing lesion of the lower left jaw in a 45-year-old otherwise healthy woman. A first biopsy and subsequent histopathological examination showed potential differentials of a benign myofibroma, benign nodular fasciitis or an LGMS. This diagnostic overlap was a challenge for the decision of the further treatment approach. The treatment consisted of a segmental en bloc resection of the mandible including the second premolar, first and second molar. Histopathological examination of the resected tumor confirmed an LGMS.

Conclusion

The histopathologic resemblance of LGMS to a range of benign and reactive tumors may lead to misdiagnosis and mistreatment. The rarity of LGMS explains the lack of established treatment protocols. This case shows the importance of adequate clinical decisions, expertise in the histopathology of rare tumors and interdisciplinary exchange to achieve state-of-the-art patient management.

No apparent association between dental implants and mandibular fractures resulting from external forces

OBJECTIVES

Dental implants are cylindrical metallic screws inserted into the jawbone to replace missing teeth. Their location may affect the pattern of fractures that occur as a result of the traumatic forces to the mandible. The aim of this study was to investigate possible influences of dental implants on the patterns of mandibular fractures triggered by external forces.

MATERIAL AND METHODS

In this observational cross-sectional study, a total of 390 patients with mandibular fractures diagnosed between February 2016 and December 2020 were examined and the presence or absence of dental implants in the fracture gap was noted. Clinical and radiological data were analyzed in relation to the fracture line, the dental status, and the location of any implants.

RESULTS

A total of 16 patients (4.1%) had previously placed dental implants in the mandible. Various fracture patterns were observed. Some yielded typical fracture lines located in the anatomically weak areas along the roots of the incisors, the mental foramina, and long-rooted molars. Occasionally, fracture lines were detected in combination with condylar fractures. Dental implants were not directly involved in any fracture line, except one. In that case, the fracture line extended from the alveolar process straight along the implant body, mimicking initial disintegration of the implant, with erosion of the surrounding bone.

CONCLUSIONS

Once dental implants have osseointegrated, mandibular fractures are rarely projected along the implant surface.

CLINICAL RELEVANCE

This observational retrospective cross-sectional study failed to associate mandibular fracture lines with the presence of dental implants.

What Are Possible Contributors to Associated Dental Injury in Mandibular Fractures?

PURPOSE

Among previous reports on dental injuries associated with mandibular fractures, there are few investigating the conditions under which dental injuries commonly occur. The aim of this study was to determine specific characteristics of mandibular fractures accompanied by dental injuries.

METHODS

This retrospective cohort study included dentate patients with mandibular fractures treated at a tertiary trauma center between 2011 and 2019. The data were analyzed according to 2 outcome variables: patients with additional dental injuries and patients without. The predictor variables were patient age, sex, accident mechanism, number and location of mandibular fractures, and presence of submental lacerations. Odds ratios for the risk factors for dental injury were calculated in conjunction with descriptive statistics. Binary logistic regression analysis was also performed to identify the factors associated with dental injuries as dependent variables.

RESULTS

Of 252 patients who had only mandibular fractures, 95 (37.7%) had associated dental injuries. In the group with dental injuries, 55.8% of mandibular fractures were caused by a fall (P = .003). Condyle fractures (77.9%) with dislocation (67.6%) and bilateral involvement (41.9%) were more common than in the group without dental injuries (P < .001). In patients with dental injuries, the incidence of 3 or more fractures (29.5%) was significantly higher than in the group without dental injuries. Dental injuries were more likely to occur in patients with concomitant submental lacerations (confidence interval (CI) 1.135-4.983, P = .02), and the risk of dental injury was significantly lower in the presence of angle fractures (CI 0.113-0.999, P = .045).

CONCLUSIONS

A frontal impact involving the anterior part of the mandible is often associated with condyle and multiple mandibular fractures. This seems to be the typical mechanism for concomitant dental injuries. Submental laceration can be considered a prime sign of associated dental injuries.

The impact of the size of bone substitute granules on macrophage and osteoblast behaviors in vitro

Objective

Bone substitute (BS) size might influence the clinical outcomes of guided bone regeneration (GBR) procedures. The aim of the present study was to investigate the influence of BS size on macrophage (Mφ) and osteoblast behaviors in vitro.

Materials and methods

Two different granule sizes (S and M/L) were assessed for four different commercial BSs: deproteinized bovine bone mineral (DBBM), biphasic calcium phosphate type 1 (BCP1), BCP type 2 (BCP2), and carbonate apatite (CO₃Ap). The BSs were compared for their impacts on the cell viability and differentiation potential of THP-1-derived Mφs and human osteoblast-like Saos-2 cells.

Results

The smaller granules showed higher material volumes and surface areas than the larger granules. Significantly higher viability of Mφs and Saos-2 cells was observed with the DBBM_L-size granules than with the DBBM_S-size granules. Gene expression experiments in Mφs revealed few differences between the two sizes of each BS, although higher CD206 mRNA levels were observed in the BCP1_L group and the CO₃Ap_M group than in the respective S-size groups on day 1. Only DBBM showed significantly higher mRNA levels of osteogenic markers, including Runx2 and osteocalcin, in Saos-2 cells in the S-size group than in the L-size group.

Conclusions

The S-size and L-size DBBM granules exhibited clear differences in cell outcomes: cells cultured on the S-size granules exhibited lower cell viability, higher osteopromotive ability, and no noticeable Mφ polarization changes.

Clinical relevance

A smaller granule size might be advantageous due to greater bone regeneration potential in the use of DBBM granules to treat defects.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00784-021-03804-z.

Investigating the effect of antiseptic solution on the release of interleukin-6 and transforming growth factor beta 1 from human gingival fibroblasts using wound healing assays

This in vitro study evaluated the effect of different antiseptics and different concentrations thereof in a model of wound healing using human gingival fibroblasts. The fibroblasts were rinsed with four different antiseptic solutions: sodium hypochlorite (HYP), hydrogen peroxide (H₂O₂), chlorhexidine digluconate (CHX), and benzalkonium chloride (BC). The effect on the release of interleukin-6 (IL-6) and transforming growth factor beta 1 (TGF-β1) was investigated using enzyme-linked immunosorbent assays (ELISAs). In addition, the effects of the antiseptics on wound healing at 1, 12, 24, and 48 h were assessed through a wound healing assay. The viability of the fibroblasts rinsed with antiseptics was investigated with respect to the concentrations inhibiting cell growth by 50% (IC₅₀), 25% (IC₂₅), and ≤2% (IC₂). A statistically significant increased release of IL-6 was obtained with BC IC₂₅ and IC₂ after 12, 24, and 48 h (P < 0.01). For TGF-β1, no significant release was found for CHX IC₂ after 24 and 48 h or for IC₅₀ and IC₂₅ after 12 h. There was no significant effect on wound healing capacity for CHX or for BC IC₂₅ and IC₂. This study demonstrated that antiseptic rinses of human gingival fibroblasts alter the release of IL-6 and TGF-β1 and impact wound healing capacity, with both BC and CHX conferring neutral effects.

Motion-Induced Transition of Positronium through a Static Periodic Magnetic Field in the Sub-THz Region

Atoms moving in a static periodic field experience a time-dependent oscillating field in their own rest frame. By tuning the frequency, an atomic transition can be induced. So far, this type of transition has been demonstrated in the EUV region or at higher frequencies by crystalline fields and in the microwave region by artificial fields. Here, we present the observation of the transition of positronium (Ps) in the sub-THz region by using an energy-tunable Ps beam with a multilayered magnetic grating. This grating produces a microsized periodic field, whose amplitude corresponds to a huge energy flux of ∼100  MW cm^{-2}, resulting in the efficient magnetic dipole transition.

Changing trends in epidemiology and management of facial trauma in a Swiss geriatric population

OBJECTIVE

To assess the prevalence and surgical treatment of facial fractures in a Swiss population aged 65 and over.

BACKGROUND

The knowledge of the characteristics of geriatric trauma may help to prevent injuries and better allocate clinical resources for the management of multimorbid patients.

MATERIAL AND METHODS

This study retrospectively evaluated a cohort of 181 patients who presented at the Bern University Hospital in Switzerland from May 2012 to September 2016. Data on age, gender, aetiology and type of trauma, treatment and complications, co-morbidities and associated injuries were obtained.

RESULTS

Women were most frequently affected (55.2%). Mean age was 80 years. Zygomatic complex fractures were the most frequent type of fractures (37%), followed by isolated orbital fractures (27.6%). Falls were the most common cause of trauma (76.1%). Thirty-five per cent of all patients were taking anticoagulation or platelet aggregation medication. Hospitalisation was required in 88.4%, whereby 92.3% of the patients underwent surgical treatment. Surgery had to be performed immediately in three cases to treat compression of the optic nerve. Median hospital length of stay was 4 days, with 68% of patients returning to a domestic environment and 32% being transferred to another institution for further treatment.

CONCLUSION

The most common cause of facial injuries is a fall while standing in a domestic environment. Midface fractures were the most common type of fractures.

Randomized controlled trial on efficacy of oligomeric formula (HINE E-GEL®) versus polymeric formula (MEIN®) enteral nutrition after esophagectomy for esophageal cancer with gastric tube reconstruction

The efficacy of early enteral nutrition after esophageal cancer surgery has been reported. However, the choice of formula and management of diarrhea are important to achieve the goal of enhanced recovery after surgery. The aim of this study is to assess the frequency of diarrhea/completion rate of enteral nutrition regimen as primary endpoints and the postoperative nutritional status/body composition analysis/operative morbidity as secondary endpoints was compared between the two nutrition groups. Among the 122 patients who underwent esophagectomy for esophageal cancer between December 2015 and September 2017, 67 patients who met the eligibility criteria were randomly assigned to receive enteral nutrition with either HINE E-GEL® (HINE group; n = 33) or MEIN® (MEIN group; n = 34). The incidence of diarrhea was significantly lower in the HINE group (18.2 % vs. 64.7 %, P < 0.001). The score of Bristol scale of POD 6/7 was significantly lower in the HINE group (P = 0.019/P = 0.006, respectively). The completion rate of enteral nutrition regimen was significantly higher in the HINE group (97.4 % vs. 86.6 %, P = 0.002). The Controlling Nutritional Status scores and total protein levels at 6 months after surgery were significantly better in the HINE group (P = 0.030 and P = 0.023, respectively), indicating improved tendency in nutritional status in the HINE group. However, there were no significant differences in Prognostic Nutritional Index values, blood test results, rapid turnover proteins, body mass index, or body composition between the two groups. HINE E-GEL compared with MEIN may reduce the frequency of diarrhea, enabling patients to adhere to the scheduled enteral nutrition plan. Also, maintenance of nutritional status with HINE E-GEL was comparable or potentially better in some nutrition components to that with MEIN, indicating that HINE E-GEL can be an option for enteral nutrition following esophageal surgery to achieve the goal of successful completion of scheduled enteral nutrition and smooth transition to the normal diet.

[Borreliosis-associated orofacial pain: A case report]

Lyme borreliosis is a prevalent disease with a wide variety of clinical manifestations. However, only a few pertinent references are found in the dental literature. Considering the diversity of differential diagnoses, borreliosis-associated orofacial pain may be a challenge for treatment providers and patients alike. The aim of this case report is to emphasize the importance of a sound, structured medical history and assessment to identify severe cases early and to start interdisciplinary therapy if indicated.

Effectiveness of modified oral steroid administration for preventing esophageal stricture after entire circumferential endoscopic submucosal dissection

Esophageal stricture occurs at a high rate after endoscopic submucosal dissection, especially after entire circumferential dissection, leading to poor quality of life. This retrospective cohort study evaluated the stricture rate in circumferential mucosal defect cases following modified steroid administration. We enrolled 22 consecutive patients who underwent entire circumferential endoscopic submucosal dissection for superficial esophageal cancer between April 2010 and April 2015 at our hospital. Until January 2013, a systemic steroid-prednisolone-was administered at 30 mg/day and tapered over 8 weeks in the original method group (original group). From February 2013, 30 mg of prednisolone was administered orally for 3 weeks and then the dose was reduced in 5 mg decrements every 3 weeks. This group was classified as the modified method group (modified group). We retrospectively compared the stricture rates between the two groups. The postoperative stricture rate was significantly lower in the modified group (36.4%; 4/11 patients) than in the original group (82%; 9/11 patients; P = 0.04). The mean number of endoscopic balloon dilatation procedures was significantly lower in the modified group (6.2 ± 11.3) than in the original group (19.4 ± 15.3; P = 0.023). Pneumonia and oral herpes infection, which are adverse events potentially associated with steroid administration, were observed in the original group. Candida esophagitis, arthritis, and steroid-related myopathy were observed in the modified group. This modified systemic steroid administration was effective for patients with entire circumferential mucosal defect. The safety of this method was also demonstrated.

Regeneration of the Junctional Epithelium and Connective Tissue after Transplantation of Detergent-Processed Allo-Teeth

The authors have developed a new artificial dental implant and evaluated it in a dog model in terms of its potential to produce: I) regeneration of junctional epithelium; II) regeneration and attachment of connective tissue. The implants were constructed from allo-teeth. We removed the cell components from the periodontal ligaments of these teeth with a detergent (1% TritonX-100); the remaining acellular periodontal ligament acted as an extracellular matrix upon which regeneration and attachment could proceed. We placed 10 of these implants in the just-extracted sites of three beagle dogs. We observed regeneration of both junctional epithelium and connective tissue at all implant sites after 3 months. The connective tissue was attached in all cases. Use of the acellular periodontal ligament as an extracellular matrix may facilitate regeneration of host periodontal ligament tissue, thus contributing to recovery of host immunological defense and long-term oral function.

Development of a System for Measurement and Analysis of Tremor Using a Three-axis Accelerometer

Objectives: The aim of the study was to develop a low-cost and compact system for analysis of tremor using a three-axis accelerometer (the Wii Remote (Nintendo)). To analyze tremor, we hypothesized that the influence of gravitational acceleration should be separated from that of movement. This hypothesis was tested experimentally and we also attempted to record and analyze tremor using our system in a clinical ward.

Methods: A system for tremor measurement and analysis was developed using the three-axis accelerometer built into the Wii Remote. The frequency and amplitude of mechanical oscillation were calculated using methods for frequency analysis of the axis of largest variance and an estimation of tremor amplitude.

Results: The system consists of a program for measurement and analysis of Wii Remote acceleration (Tremor Analyzer), a Wii Remote, a Bluetooth USB adapter and a Web camera. The Tremor Analyzer has a GUI (graphical user interface) that is divided into five segments. The sampling period of the analyzer is 30 msec. To confirm the hypothesis, mechanical oscillations were fed to the Wii Remote. The peak frequency of the power spectrum and the frequency of the oscillation generator were in good agreement, except at 1 Hz (0.01 G) and 2 Hz (0.02 G). With a change in the sum of squares of the three axes from 1.0 to 1.8 (G), the estimated and generated amplitude (0.3 cm) were in close agreement.

Conclusions: This system using a Wii Remote is capable of analyzing frequency and estimated amplitude of tremor between 3 Hz and 15 Hz.

Polyglycolic acid sheet and fibrin glue for preventing esophageal stricture after endoscopic submucosal dissection: a historical control study

There have been several reports that steroid administration is effective at preventing strictures after endoscopic submucosal dissection (ESD). However, adverse events after steroid use are of great concern. We have reported that shielding with a polyglycolic acid (PGA) sheet and fibrin glue can be useful for prevention of stricture after ESD. We conducted a retrospective analysis of efficiency of shielding with a PGA sheet and fibrin glue for prevention of esophageal stricture compared with intralesional steroid injection. ESD was performed on a total of 489 lesions in 400 patients for superficial esophageal cancer from January 2012 to July 2016. Of these, 39 lesions were enrolled in the study group (PGA sheet and fibrin glue) and 31 lesions were enrolled in the control group. The incidence of postoperative stricture at 6 weeks and the number of sessions of endoscopic balloon dilatation (EBD) required to resolve any strictures were evaluated. The post-ESD stricture rate was 9.1% in the study group (3/33 patients), which was not significantly lower than the stricture rate of 10.3% in the historical control group (3/29 patients; p = 1.00). The mean number of EBD was 0.057 ± 0.24 in the study group and 1.9 ± 5.1 in the control group, which was not significant (P = 0.95). PGA sheet and fibrin glue appear to be a promising option for the prevention of esophageal stricture similar to the effect of intralesional steroid injection.

Vascular density of superficial esophageal squamous cell carcinoma determined by direct observation of resected specimen using narrow band imaging with magnifying endoscopy

Observation of the microvasculature using narrow band imaging (NBI) with magnifying endoscopy is useful for diagnosing superficial squamous cell carcinoma. Increased vascular density is indicative of cancer, but not many studies have reported differences between cancerous and noncancerous areas based on an objective comparison. We observed specimens of endoscopic submucosal dissection (ESD) using NBI magnification, and determined the vascular density of cancerous and noncancerous areas. A total of 25 lesions of esophageal squamous cell carcinoma that were dissected en bloc by ESD between July 2013 and December 2013 were subjected to NBI magnification. We constructed a device that holds an endoscope and precisely controls the movement along the vertical axis in order to observe submerged specimens by NBI magnification. NBI image files of both cancerous (pathologically determined invasion depth, m1/2) and surrounding noncancerous areas were created and subjected to vascular density assessment by two endoscopists who were blinded to clinical information. The invasion depth was m1/2 in 20, m3/sm1 in four and sm2 in one esophageal cancer lesion. Mean vascular density was significantly increased in cancerous areas (37.6 ± 16.3 vessels/mm2) compared with noncancerous areas (17.6 ± 10.0 vessels/mm2) (P < 0.05). The correlation coefficients between vascular density determined by two endoscopists were 0.86 and 0.81 in cancerous and noncancerous areas, respectively. Receiver operating curve (ROC) analysis revealed that the area under the curve (AUC) of vascular density was 0.895 (95% CI, 0.804-0.986). For this ROC curve, sensitivity was 78.3% and specificity was 87.0% when the cutoff value of vascular density was 26 vessels/mm2. NBI magnification confirmed significant increases in vascular density in cancerous areas compared with noncancerous areas in esophageal squamous cell carcinoma. The rates of agreement between vascular density values determined by two independent operators were high.

Periosteum-Induced Bone Formation by Distraction Osteogenesis: Histologic and Microcomputed Tomography Analysis

PURPOSE

Strains tending to pull the periosteum away from the bone are typically osteogenic. The aim of this study was to assess the influence of periosteum on de novo bone formation in a rat calvaria model of distraction osteogenesis.

MATERIALS AND METHODS

A total of 28 rats were randomized in four experimental groups considering two treatment modalities. Periosteum was either left intact or completely excised. In half of the animals, the distraction plate was covered with a collagen membrane. All animals were subjected to a 7-day latency period and a 10-day distraction period. The samples were harvested after a 2-week consolidation period and analyzed histologically and by means of microcomputed tomography (micro-CT).

RESULTS

New bone in all animals originated from the original bone surface. Two groups of animals with periosteum, with membrane (24.56 ± 5.26) and without membrane (21.83 ± 14.04), showed significantly more bone volume compared with groups without periosteum, with membrane (2.72 ± 1.08, P = .003) and without membrane (4.25 ± 2.33, P = .014). There were no significant differences between the four groups in bone mineral density. Groups pooled together for the presence of periosteum demonstrated significantly more bone volume (P < .001) and bone mineral density (P = .028) than groups without periosteum. No differences were found for groups pooled for the barrier membrane application.

CONCLUSION

The periosteum plays an indispensable, but indirect role in the osteogenic process during periosteal distraction osteogenesis.

Propofol-fentanyl interaction in Beagles - Apnea, response to mechanical ventilation, endotracheal tube, and tetanic stimulation

The objective of this study was to characterize the propofol-fentanyl interaction in Beagles for four pharmacodynamic endpoints: apnea, response to mechanical ventilation, endotracheal tube, and tetanic stimulation. After anesthesia was induced with varying combinations of propofol and fentanyl, the pharmacodynamic endpoints were assessed in intubated dogs (n=6) using the cross-over design. Effective concentrations of propofol plasma concentration (Cp) and fentanyl Cp were assessed using additive, reduced Greco, Minto, and hierarchical interaction models. The interaction was best described as synergistic by the hierarchical model. A 1ng/mL fentanyl Cp reduced the effective propofol Cp to half or less of that without fentanyl for all endpoints. An additional increment of fentanyl Cp to 5ng/mL or higher hardly reduced effective propofol Cp for all endpoints except response to tetanic stimulation. Additionally, the effective propofol Cp in 50% dogs for response to tetanic stimulation (15% increase of heart rate) was lower than that for the other endpoints at fentanyl Cp >7ng/mL. Peripheral oxygen saturation decreased below 90% after extubation in five treatments in which fentanyl Cps were ≥5ng/mL. Propofol and fentanyl interacted synergistically. To avoid patient-ventilator dyssynchrony and hypoxemia after extubation, fentanyl Cp at 1-5ng/mL may be appropriate in intubated dogs. When a dog responds to mechanical ventilation or endotracheal tube at a high fentanyl Cp >5ng/mL under propofol anesthesia even if the dog tolerate to tetanic stimulation, it may be necessary to increase propofol Cp to eliminate the responses because an additional fentanyl may be little impact.

Polymorphisms in PTCH1 Affect the Risk of Ameloblastoma

Ameloblastoma is the most common odontogenic tumor, but the genetic nature of the changes in the tumor cells has been unclear. Mutations of CTNNB1 or PTCH1 are observed in many human tumors. Both CTNNB1 and PTCH1 are important in tooth development and are expressed in ameloblastoma. The aim of this study was to investigate whether genetic alterations of CTNNB1 and PTCH1 are present in ameloblastoma. We investigated 14 cases of ameloblastoma. The polymorphisms found in the ameloblastoma patients were further examined in a subsequent case-control study. We found a CTNNB1 mutation in one case of plexiform-type ameloblastoma. CGG triplet repeat-number polymorphism (CGG7/CGG8) in the 5′-untranslated region of PTCH1 was observed. The proportion of CGG8 alleles was significantly higher in the ameloblastoma group. The results of this study indicate a possible relationship between the CGG8 allele in PTCH1 and the risk for ameloblastoma.

Moving the mandible in orthognathic surgery - A multicenter analysis

Orthognathic surgery has always been a classical focus of maxillofacial surgery. Since more than 100 years, various surgical techniques for mandibular repositioning have been developed and clinically tested. Since the establishment of plate and screw osteosynthesis, orthognathic surgery became more stable and safe. Nowadays, different surgical methods for mobilising the mandible are existing. This international multicenter analysis (n = 51 hospitals) is providing first evidence based data for the current use of different surgical methods. The dominating techniques were Obwegeser/dal Pont (61%) followed by Hunsuck/Epker (37%) and Perthes/Schlössmann (29%). The main osteosynthesis materials were plates (82%), bicortical screws (23.5%), or a combination of both (5.9%). 47% of all centers reported to use several surgical methods at the same time, depending on the anatomical problem and the surgeon's preference. This shows that different surgical methods seem to work as comparable, safe, and reliable procedures in everydays clinical practise. On this basis, further prospective studies could evaluate possible advantages for our patients.

Electromyogram biofeedback training for daytime clenching and its effect on sleep bruxism

Bruxism contributes to the development of temporomandibular disorders as well as causes dental problems. Although it is an important issue in clinical dentistry, no treatment approaches have been proven effective. This study aimed to use electromyogram (EMG) biofeedback (BF) training to improve awake bruxism (AB) and examine its effect on sleep bruxism (SB). Twelve male participants (mean age, 26·8 ± 2·5 years) with subjective symptoms of AB or a diagnosis of SB were randomly divided into BF (n = 7) and control (CO, n = 5) groups to undergo 5-h daytime and night-time EMG measurements for three consecutive weeks. EMG electrodes were placed over the temporalis muscle on the habitual masticatory side. Those in the BF group underwent BF training to remind them of the occurrence of undesirable clenching activity when excessive EMG activity of certain burst duration was generated in week 2. Then, EMGs were recorded at week 3 as the post-BF test. Those in the CO group underwent EMG measurement without any EMG BF training throughout the study period. Although the number of tonic EMG events did not show statistically significant differences among weeks 1-3 in the CO group, events in weeks 2 and 3 decreased significantly compared with those in week 1, both daytime and night-time, in the BF group (P < 0·05, Scheffé's test). This study results suggest that EMG BF to improve AB tonic EMG events can also provide an effective approach to regulate SB tonic EMG events.

The role of postoperative prophylactic antibiotics in the treatment of facial fractures: a randomized, double-blind, placebo-controlled pilot clinical study. Part 2: Mandibular fractures in 59 patients

The aim of this study was to evaluate the difference between a 5-day and a 1-day postoperative course of antibiotic on the incidence of infection after mandibular fractures involving the alveolus. Sixty-two patients with fractures of the mandible involving the dentoalveolar region were randomly assigned to 2 groups, both of which were given amoxicillin/clavulanic acid 1.2 g intravenously every 8 h from admission until 24 h postoperatively. The 5-day group were then given amoxicillin/clavulanic acid 625 mg orally every 8 h for another 4 days. The 1-day group was given an oral placebo at the same intervals. Follow-up appointments were 1, 2, 4, 6, 12 weeks and 6 months postoperatively. Development of an infection was the primary end point. Fifty-nine of the 62 patients completed this study. Six of the 30 patients in the 5-day group (20%) and 6 out of the 29 in the 1-day group (21%) developed local wound infections. Three of the 6 in the 1-day group developed purulent discharge and swelling. One patient in the 5-day group developed a rash on the trunk. There were no significant differences in the incidence of infection or side effects between the groups. In fractures of the mandible involving the alveolus, a 1-day postoperative course of antibiotic is as effective in preventing infective complications as a 5-day regimen.

Severe destruction of the temporomandibular joint with complete resorption of the condyle associated with synovitis, acne, pustulosis, hyperostosis, and osteitis syndrome

The synovitis, acne, pustulosis, hyperostosis, and osteitis (SAPHO) syndrome consists of a combination of inflammatory bone disorders and dermatologic pathology. Bone lesions as a form of diffuse sclerosing osteomyelitis in the mandible occur in the posterior body and ramus. Bone lesions rarely spread to the temporomandibular joint (TMJ) where ankylosis may result. Herein we present an unusual case of SAPHO syndrome with TMJ involvement in which severe destruction of the TMJ occurred. We observed an extension of the invasive soft tissue lesion into the infratemporal fossa from the TMJ with complete resorption of the condyle. In contrast to other previously reported cases, in our case the condyle was strongly suspected as the primary site of the bone lesion with subsequent extension to the ramus and infratemporal fossa. The destructive nature and related symptoms resembled a malignant tumor.

Far-infrared optical conductivity of CeCu2Si2

We investigated the optical reflectivity of the heavy-fermion metal CeCu(2)Si(2) in the energy range 3 meV-30 eV for temperatures between 4 and 300 K. The results for the charge dynamics indicate a behavior that is expected for the formation of a coherent heavy quasiparticle state: upon cooling the spectra of the optical conductivity indicate a narrowing of the coherent response. Below temperatures of 30 K a considerable suppression of conductivity evolves below a peak structure at 13 meV. We assign this gap-like feature to strong electron correlations due to the 4f-conduction electron hybridization.

Optical study of archetypical valence-fluctuating Eu systems

We have investigated the optical conductivity of the prominent valence-fluctuating compounds EuIr(2)Si(2) and EuNi(2)P(2) in the infrared energy range to get new insights into the electronic properties of valence-fluctuating systems. For both compounds, we observe upon cooling the formation of a renormalized Drude response, a partial suppression of the optical conductivity below 100 meV, and the appearance of a midinfrared peak at 0.15 eV for EuIr(2)Si(2) and 0.13 eV for EuNi(2)P(2). Most remarkably, our results show a strong similarity with the optical spectra reported for many Ce- or Yb-based heavy-fermion metals and intermediate valence systems, although the phase diagrams and the temperature dependence of the valence differ strongly between Eu systems and Ce- or Yb-based systems. This suggests that the hybridization between 4f and conduction electrons, which is responsible for the properties of Ce and Yb systems, plays an important role in valence-fluctuating Eu systems.

Alveolar bone grafting in association with polyostotic fibrous dysplasia and bisphosphonate-induced abnormal bone turnover in a bilateral cleft lip and palate patient: a case report

A case is presented of extensive alveolar bone grafting in a patient with bilateral cleft lip and palate and polyostotic fibrous dysplasia. The patient previously underwent bisphosphonate therapy. Because of an abnormal and often decreased bone turnover caused by the fibrous dysplasia and the bisphosphonate therapy, bone grafting in such a patient poses several potential difficulties. In addition, the histomorphometric analysis of the bone grafts showed markedly decreased bone turnover. However, alveolar bone grafting using the iliac crest was performed successfully. Sufficient occlusion was achieved by postoperative low-loading orthodontic treatment.

Neurolytic effects of ampicillin on the rat infraorbital nerve

PURPOSE

The aim of this study was to investigate the histomorphological changes of the infraorbital nerve of rats treated with ampicillin.

MATERIALS AND METHODS

The infraorbital nerve was approached through the infraorbital foramen, and 0.01 ml of ampicillin dissolved in distilled water was injected taking care not to damage the nerve. Saline solution was used in control animals. Nerves were dissected and after routine histology processing analysed by light microscopy.

RESULTS

Cross-section of the nerve treated with ampicillin showed damaged axons with disintegration of heavily myelinated fibres, while thinly myelinated fibres remain unaffected. In the saline group, no damage was observed. The signs of regeneration of the damaged infraorbital nerves were detected on the fourth post-operative week.

CONCLUSION

Ampicillin can cause peripheral nerve damage when injected perineurally.

Relative contributions of osteogenic tissues to new bone formation in periosteal distraction osteogenesis: histological and histomorphometrical evaluation in a rat calvaria

BACKGROUND

The relative contributions of different, potential factors to new bone formation in periosteal distraction osteogenesis are unknown.

PURPOSE

The aim of the present study was to assess the influence of original bone and periosteum on bone formation during periosteal distraction osteogenesis in a rat calvarial model by means of histology and histomorphometry.

METHODS

A total of 48 rats were used for the experiment. The contribution of the periosteum was assessed by either intact or incised periosteum or an occlusive versus a perforated distraction plate. The cortical bone was either left intact or perforated. Animals were divided in eight experimental groups considering the three possible treatment modalities. All animals were subjected to a 7-day latency period, a 10-day distraction period and a 7-day consolidation period. The newly formed bone was analyzed histologically and histomorphometrically.

RESULTS

New, mainly woven bone was found in all groups. Differences in the maximum height of new bone were observed and depended on location. Under the distraction plate, statistically significant differences in maximum bone height were found between the group with perforations in both cortical bone and distraction plate and the group without such perforations.

CONCLUSIONS

If the marrow cavities were not opened, the contribution to new bone formation was dominant from the periosteum. If the bone perforations opened the marrow cavities, a significant contribution to new bone formation originated from the native bone.