Transition from fractal-dendritic to compact islands for the 2D-ferroelectric SnSe on graphene/Ir(111).

Epitaxial growth is a versatile method to prepare two-dimensional van der Waals ferroelectrics like group IV monochalcogenides which have potential for novel electronic devices and sensors. We systematically study SnSe monolayer islands grown by molecular beam epitaxy, especially the effect of annealing temperature on shape and morphology of the edges. Characterization of the samples by scanning tunneling microscopy reveals that the shape of the islands changes from fractal-dendritic after deposition at room temperature to a compact rhombic shape through annealing, but ripening processes are absent up to the desorption temperature. A two-step growth process leads to large, epitaxially aligned rhombic islands bounded by well-defined110-edges (armchair-like), which we claim to be the equilibrium shape of the stoichiometric SnSe monolayer islands. The relaxation of the energetically favorable edges is detected in atomically resolved STM images. The experimental findings are supported by the results of our first-principles calculations, which provide insights into the energetics of the edges, their reconstructions, and yields the equilibrium shapes of the islands which are in good agreement with the experiment.

SF-assemblin, the structural protein of the 2-nm filaments from striated microtubule associated fibers of algal flagellar roots, forms a segmented coiled coil.

The microtubule associated system I fibers of the basal apparatus of the flagellate green alga Spermatozopsis similis are noncontractile and display a 28-nm periodicity. Paracrystals with similar periodicities are formed in vitro by SF-assemblin, which is the major protein component of system I fibers. We have determined the amino acid sequence of SF-assemblin and show that it contains two structural domains. The NH2-terminal 31 residues form a nonhelical domain rich in proline. The rod domain of 253 residues is alpha-helical and seems to form a segmented coiled coil with a 29-residue repeat pattern based on four heptads followed by a skip residue. The distinct cluster of acidic residues at the COOH-terminal end of the motifs (periodicity about 4 nm) may be related to tubulin binding of SF-assemblin and/or its self assembly. A similar structure has been predicted from cDNA cloning of beta-giardin, a protein of the complex microtubular apparatus of the sucking disc in the protozoan flagellate Giardia lamblia. Although the rod domains of SF-assemblin and beta-giardin share only 20% sequence identity, they have exactly the same length and display 42% sequence similarity. These results predict that system I fibers and related microtubule associated structures arise from molecules able to form a special segmented coiled coil which can pack into 2-nm filaments. Such molecules seem subject to a strong evolutionary drift in sequence but not in sequence principles and length. This conservation of molecular architecture may have important implications for microtubule binding.

Snoring in cleft patients with velopharyngoplasty.

Some patients with cleft lip/palate or isolated cleft palate seem to develop snoring as one possible symptom of an obstructive sleep apnoea syndrome after velopharyngoplasty (VPP). The aim of this paper was to determine whether there was a difference in the posterior airway space (PAS) between patients with a VPP who snored and those who did not. Four standard parameters were measured in lateral cephalograms of 20 patients with cleft lip/palate and isolated cleft palate, without diagnosis of further syndromes (e.g. Pierre Robin sequence), having undergone VPP, to examine the dimensions of the PAS. Data were set in correlation to the symptom of snoring, and compared with those of 40 patients without cleft undergoing orthodontic treatment and with 20 patients with cleft lip/palate or isolated cleft palate but not VPP. Metric parameters were significantly different after VPP in patients with clefting and snoring compared to the group of cleft patients without snoring. All patients with clefts exhibited at least in one dimension a constriction when compared to patients without clefting. In conclusion, cleft lip/palate and isolated cleft palate patients tend to have constrictions of the PAS. VPP may induce snoring and further narrowing. Recall and analysis for obstructive sleep apnoea syndrome should be mandatory.

Patients' knowledge and expectations regarding dental implants: assessment by questionnaire.

Today, modern implant dentistry appeals to a wide population, but the decision for and the success of implants depend on the knowledge and expectations of patients. The aim of this study was, with the help of a questionnaire, to evaluate the level of patient knowledge before a professional consultation was performed, and hence to be better prepared in the interests of patient awareness. Fifty-eight percent of 315 patients questioned thought that implants require the same care as natural teeth, 61% expected an additional payment of 2000 Euro or less, 80% held the function of an implant-supported overdenture as very important and 54% attached great importance to the aesthetics. The expectations that patients have for an implant-supported set are high in contrast to their willingness to make additional payments. There are still misconceptions regarding costs, and these must be resolved individually in practice.

Outcomes after surgical treatment of facial skin basal cell carcinomas.

BACKGROUND: Missing recurrences and the aesthetic outcomes after reconstructions of the face are preoccupations in the surgical treatment of basal cell carcinomas. Hence, the different reconstructive techniques in particular and the rate of recurrence are evaluated in this study. PATIENTS: 205 patients receiving resections of basal cell carcinomas and facial skin reconstructions were included and data were analyzed. RESULTS: The rate of recurrence was 7.3% after follow-up at an average of 2.5 years (0.5-5 years). Local flaps, full-thickness skin grafts and skin extension closures were carried out most often; indications for split-thickness skin grafts were rare. Sensitivity disturbances occurred in only 3.6% of skin extension closures and in 11.7% of local flaps, but in 22.7% of full-thickness skin grafts and in 38.7% of split-thickness skin grafts. The aesthetic outcomes were evaluated through clinical inspection and by using patients' scale. They were classified as "unobtrusive" and "excellent or good" in 88.4% of local flaps and in 92.6% of skin extension closures, but in only 66.4% of full-thickness skin grafts and in 54% of split-thickness skin grafts. CONCLUSION: Local flaps and skin extension closures provide better aesthetic and neurological outcomes after facial skin reconstructions. However, skin grafts are alternative procedures for critical indications of local flaps.

Transcutaneous electric nerve stimulation (TENS) in the therapy of chronic facial pain. Preliminary report.

Chronic facial pain remains a therapeutic problem. We report on 29 patients (37 nerves involved), who were treated with transcutaneous electric nerve stimulation (TENS). Pain reduction was achieved in 27 patients (93%) while in 5 patients it was possible to stop the treatment because they were constantly free from pain. Two patients did not respond to TENS therapy. It was possible to reduce or discontinue the use of analgesics in 79% of the cases. There were no severe side effects. Therefore, TENS should be seen as a simple, safe and effective method of treatment for many forms of chronic facial pain, as opposed to other invasive surgical procedures.

The innervation of the trapezius muscle in connection with radical neck-dissection. An anatomical study.

The accessory nerve, the cervical plexus, the sternocleidomastoid and trapezius muscles and neighbouring structures were examined in 47 corpses. Considerable inter- as well as intra-individual differences could be found both in the course and shape of the accessory nerve and in the participation of the cervical plexus in the innervation of the trapezius muscle. The great variation in the manifestation of the shoulder-arm-syndrome in patients after radical neck-dissection can thus be explained. Finally a new method of restoring the innervation of the trapezius muscle is proposed.

Reasons for patients' discontent and litigation.

INTRODUCTION: Discontent and litigation among patients is a problem which increasingly preoccupies the medical profession. AIM: We aim to analyse the origin of discontent and litigation and to help avoiding these claims. MATERIAL: One hundred and seventy-eight medical expert opinions were evaluated, all made following examination of the complainant. METHODS: Depending on the results of the clinical examination and the study of the files it was determined whether there was either a case of malpractice or insufficient informed consent, or no fault at all in a legal sense. In addition the patient and the surgeon were questioned as to their point of view regarding the procedure and their communication and relationship before and after treatment. RESULTS: Frequent complaints were pain (either during treatment or afterwards), major swelling or bleeding, disturbances of trigeminal or facial nerve function, poor scar formation, loss of teeth or fixtures, faulty occlusion and discrepancies between the expected and the actual result of treatment. In 26 cases actual faults made during medical treatment were discovered. In 49 further cases, poor explanation of the proposed procedure was the reason for complaint. In the majority of remaining cases, neither faulty treatment nor insufficient information given to the patient lead to the complaint but the patient's expectations were unrealistically high. CONCLUSION: A considerable proportion of lawsuits originate from misunderstandings, and not treatment errors: The surgeons often concentrate on the legal requirements of informed consent and neglect to explain the practical consequences of the operation; the patients in turn tend not to ask about possible complications.

Influence of fetal brain grafts on axotomized retinal ganglion cells.

The neurotrophic activity of fetal brain grafts next to the proximal stump of the transected optic nerve of adult rats was investigated. Axotomy (n = 25) reduced the original retinal ganglion cell population by 90% and the mean neuron size by one-third within 30 days. No increase in number or size of the surviving neurons could be found in any group receiving an embryonic brain graft (E16; spinal cord: n = 16, cerebral cortex: n = 16, tectum: n = 15, thalamus: n = 17) at the site of optic nerve transection, despite good survival of transplants. Although no positive effect on axotomized retinal ganglion cells could be found after transplantation of embryonic central nervous system structures, the same experimental model of the optic nerve seems to be valuable for further investigations of degeneration of traumatized retinal ganglion cells.

Stability of bone grafting and placement of implants in the severely atrophic maxilla.

A severely atrophic maxilla can be restored by bone grafts to allow the insertion of implants. We present 30 consecutive patients treated with autogenous inlay and onlay bone grafts from the iliac crest to the floor of the maxillary sinus and the alveolar crest. A total of 200 implants were inserted 4-6 months after bone grafting. A mean vertical increase in bone thickness of 14mm was achieved. After a mean bone loss of 1.3mm during the first year after bone grafting only minimal resorption was observed during the second and third year. Seven implants failed to integrate and a further four implants were lost during follow-up.

[Primary malignant melanoma of the oral cavity: a case report and review]. / Primär malignes Melanom der Mundhöhle: Kasuistiken und Ubersicht.

The oral cavity is a rare location for the development of primary malignant melanoma. Two cases of malignant melanoma of the superior alveolar process are described. The necessity of an early recognition and of clarification concerning the differential diagnosis of oral pigmentation as well as the treatment are discussed, together with a review of the literature.

Analysis of patients with a cleft of the soft palate with special consideration to the problem of velopharyngeal insufficiency.

The evaluation of therapy concepts for children suffering from cleft palate is an enormous challenge in modern oral and maxillofacial surgery and related disciplines. In the present retrospective survey 1300 patients having clefts, including the soft palate, were studied with special regard to speech improvement operations. Nine hundred fifty four patients had a cleft lip, alveolus and palate and 346 patients only isolated cleft palate. In 25.6% of the patients it was necessary to perform a secondary velopharyngoplasty for speech improvement after soft palate closure. Age of the subjects at the time of operation, primary or secondary soft palate closure, and the type of clefting were not significant factors for performing subsequent velopharyngoplasty. However, significant differences with respect to the need for a secondary velopharyngoplasty after soft palate closure were found when comparing the surgical experience of the surgeons.

Demographical and clinical aspects of sports-related maxillofacial and skull base fractures in hospitalized patients.

As many as 30% of all maxillofacial fractures (MFFs) and skull base fractures (SBFs) are reported to be sports-related. Participation in sporting activities has grown worldwide and the number of cases of sports-related injuries has also increased. The aim of this study was to evaluate the data of 3596 patients hospitalized by MFF or SBF over a 6-year period; 147 (4%) of these cases were sports-related (mean age 29.7±12.8 years). The highest incidence was found in patients aged 20-29 years (35%), and the fractures resulted mostly from ball sports (74%), especially soccer (59%) and handball (8%). The injuries involved different areas, with a significant prevalence of the midface complex (67%) compared with the mandible region (29%) and the skull base (4%). The commonest diagnoses associated with MFF and SBF were brain concussion (19%), laceration of the skin and soft tissue (16%), and dental injury (8%). Surgery was required for 88% of midface fractures. In cases of mandible fractures 52% were supplied with osteosynthesis. This study identified the significant number of severe sports-related injuries that occur each year, suggesting that changes of rules and safety standards are needed for the prevention of such injuries.

[Experiences with surgical management of facial basal cell carcinoma and procedures for plastic reconstruction]. / Erfahrungen in der chirurgischen Versorgung von Gesichtshautbasaliomen und plastischen Rekonstruktionsverfahren.

BACKGROUND: No recurrences and optimal aesthetic outcomes after R0 resection and plastic reconstruction of the face are the goals in the surgical treatment of basal cell carcinoma. The aim of this study was to evaluate recurrence rates and to evaluate different reconstructive techniques. PATIENTS AND METHODS: This study included 205 follow-up patients undergoing R0 resection of primary basal cell carcinoma and facial skin reconstruction between 1998 and 2002; data were analyzed retrospectively. RESULTS: The most frequent locations of basal cell carcinoma were the nasal (40.5%) and orbital (22.9%) regions. The rate of recurrence after 2.5 years (6 months-5 years) was 7.3%. Local flaps, full-thickness skin grafts, and sliding flaps were usually performed; indications for split-thickness skin grafts were rare. Disturbances of sensation were found in only 3.6% of the sliding flaps and in 11.7% of the local flaps, but 22.7% in full-thickness and 38.7% in split-thickness skin grafts. The aesthetic outcome, evaluated by clinical inspection and a patient satisfaction score, was classified as "unobtrusive" and "good or excellent" for 88.4% of local flaps, 92.6% of sliding flaps, but only for 66.4% of full-thickness and 54% of split-thickness skin grafts. CONCLUSION: Local flaps and sliding flaps result in better aesthetic and neurological outcomes after reconstruction of facial skin regions. Skin grafts have their indications as an alternative procedure in cases of critical indications for flaps.

[Pierre Robin sequence: postoperative complications following cleft palate surgery. A retrospective study covering 25 years]. / Pierre-Robin-Sequenz -- postoperative Komplikationen nach Gaumenspaltverschluss. Eine retrospektive Studie über 25 Jahre.

BACKGROUND: In a 25-year retrospective review of 1976-2000, the postoperative course after cleft palate surgery and pharyngeal flap surgery in 87 children with Pierre Robin sequence was studied. PATIENTS AND METHODS: The study comprised 114 interventions with 87 primary palatoplasties; 17 patients required palatal fistulae repair and 10 children were treated with secondary pharyngoplasty procedures. All children were divided into three postnatal risk groups according to the severity of their symptoms at birth and in the course of the early months of life. RESULTS: A direct correlation was seen between the incidence of early postnatal difficulties and the postoperative obstructive complications after cleft palate surgery and pharyngeal flap surgery. Thus, children experiencing obstructive problems at birth (high postnatal risk group) displayed more severe complications at the time after cleft palate repair. In children undergoing pharyngeal flap surgery not only early postoperative obstruction but also late obstructive sleep apnea can occur.

[Combination therapy of transcutaneous electric nerve stimulation and iontophoresis with benzydamine and diclofenac]. / Kombinationstherapie von Transkutaner Elektrischer Nerven-Stimulation und Iontophorese mit Benzydamin und Diclofenac.

Combined Therapy of Transcutaneous Electrical Nerve Stimulation and Iontophoresis with Benzydamine and Diclofenac. The combination of transcutaneous electrical nerve stimulation (TENS) and the iontophoresis of benzydamine and diclofenac in a counter-current field is a new method in the treatment of chronical pain of the head and neck region. Prior to a clinical study this method was tested in a preliminary examination in 15 healthy volunteers. Clinical and physical data were investigated from which a theoretical maximum value of the quantity of iontophorised non-steroidal antiphlogistics (NSAI) could be calculated. The actual achievable absorption is discussed. Based on these data it is concluded that a good effective tissue concentration of benzydamine and diclofenac can be achieved with iontophoresis by means of TENS.

[The treatment of neuralgiform facial pains with the combined therapy of transcutaneous electric nerve stimulation (TENS) and the iontophoresis of nonsteroidal antiphlogistics]. / Die Behandlung neuralgiformer Gesichtsschmerzen mit der Kombinationstherapie von transcutaner elektrischer Nervenstimulation (TENS) und Iontophorese nichtsteroidaler Antiphlogistika.

In a prospective study, 46 patients suffering from facial pain were treated by transcutaneous electrical nerve stimulation (TENS). In case of insufficient pain relief the combined use of TENS and iontophoresis of non-steroidal antiphlogistics was employed. Benzydamine was applied to the anode and diclofenac to the cathode instead of the contact gel, reducing average pain intensity to a marked 18%, compared to 81% to 63% by TENS only. Furthermore, the consumption of analgetics declined considerably with combined therapy. Severe side effects could not be registered. Therefore, this new combined therapy must be considered to be an alternative treatment before using systemic medication.

[Perineural application of glycerol and phenol-glycerol. Histomorphologic-morphometric study]. / Die perineurale Leitungsblockade mit Glycerin und Phenol-Glycerin. Eine histomorphologisch-morphometrische Studie.

In a long-term study the effect of glycerol and phenol-glycerol on rats mandibular nerve was analysed. The substances were applicated perineurally. Nerves treated with glycerol did not show any severe pathological changes. Only the number of desintegrations of myelin seemed to be more pronounced. This, however, was a transitary effect. On the contrary, nerves treated with phenol-glycerol showed the familiar picture of degeneration and regeneration. According to our results it can be stated that the perineural application of glycerol has no toxic and destructive effect on the nerve. Therefore, the perineural glycerol blocking will not cause severe side-effects and the method can be recommended in the therapy of chronic facial pain.

Facial trauma in children and adolescents.

Most studies on facial trauma in the pediatric age group focus on special subgroups. This investigation encompasses all traumatic facial injuries, minor and major, of children and adolescents. Epidemiological data of the type and pattern of injury of trauma patients less than 19 years of age, treated during a 3-year-period in a large metropolitan trauma centre were reevaluated. Of the 1385 patients, 68% had soft tissue injuries, 24% had dental trauma, and 8% fractures of facial bones. More than 90% suffered from minimal or minor trauma. The leading cause of injury was a fall, predominantly at the toddler stage. In adolescents an adult mechanism of trauma prevailed: over 60% of injuries were sequelae of an assault or altercation. The male sex predominated through all age groups and for all types of injuries. The bulk of soft tissue injuries are located within a small falling zone, extending from the nose to the mental area. There was a rising incidence of fractures of facial bones towards older age groups, mandibular fractures being the most common. Condylar fractures, with their potential impact on further growth of the mandible, are seen frequently in children and adolescents, making up 80% of the fractures of the lower jaw.