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.

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.

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.

[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.

[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.

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.

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.

[Melanotic neuroectodermal tumor of infancy]. / Der melanotische neuroektodermale Tumor des Säuglingsalters.

BACKGROUND: The melanotic neuroectodermal tumor of infancy is a rare and so far as being classified neoplasm with a high rate of recurrence for one year after diagnosis. Since Krompecher described 1918 the tumor at first, only about 200 cases are reported until today, mostly with manifestation in the maxillary region. CASE-REPORTS: The authors present two infants at the age of six and eight weeks with first clinical manifestation of the tumor in the maxillary region. Although there were no other common signs, the tumor destroyed wide areas of the mid-face. In spite of a treatment with radical surgery, recurrences occur rapidly in the first living year. CONCLUSIONS: Our clinical and histological findings show characteristics of local malignant growth. For these facts the radical resections of the primary tumor and its recurrences are individually the therapeutical consequences. A follow up of seven years of one infant shows a hypoplasm of the mid-face as a result of the inhibition of further growth by the loss of germs after maxillary hemisection.

[Frey syndrome]. / Frey-Syndrom.

AIMS: The incidence of Frey's syndrome after parotidectomy as cited in the literature varies distinctively. Strategies for successful treatment are also assessed differently. PATIENTS: Between 1980 and 1994 a total of 372 parotidectomies were performed in 364 patients at the Bochum University Hospital. RESULTS: After an average of 18 months following parotidectomy, 86 patients (23.5%) developed Frey's syndrome. Thirty-five patients were treated with scopolamine ointment. The symptoms improved in nine cases after an average of 25 months of therapy. Of the patients receiving no treatment (n = 20), seven improved after an average follow-up of 20 months. Therapy with scopolamine ointment did not elicit significantly better results compared to no treatment at all. CONCLUSION: Gustatory sweating after parotidectomy still has to be regarded as an unpleasant complication which is difficult to cure.

[Associated anomalies in lip-maxillopalatal clefts]. / Assoziierte Anomalien bei Lippen-Kiefer-Gaumen-Spalten.

BACKGROUND: Retrospective studies of cleft lip and palate patients suggest a multifactorial aetiology for this condition. Many patients exhibit multiple defects, often removed from the orofacial region. The frequency and location of such coexistent abnormalities vary between studies. PATIENTS: A retrospective case-note study of 1,737 individuals with orofacial cleft, treated between 1974 and 1998 at our centre, was undertaken to assess the frequency of associated malformations and syndromes. RESULTS: Associated malformations were found to be present in 33% of all cases investigated. In nearly one half of these individuals (48%), defects could be attributed to recognisable syndromes. Patients with isolated palatal clefts (45.6%) and those with bilateral clefts of the lip and palate (35.3%) were particularly well-represented. The following problems were observed relatively frequently: Cerebral anomalies (16%), facial anomalies (14%), heart malformations (15%), anomalies of the extremities (9%) and urogenital tract abnormalities (8%). In contrast, endocrine aberrations were identified sporadically (0.5%). A partial situs inversus was found only in one case. CONCLUSION: As clefts of the lip and palate are frequently associated with additional malformations, the importance of thorough interdisciplinary neonatal screening cannot be over emphasised.

[Methods of pain therapy in mouth, jaw and facial surgery]. / Methoden der Schmerztherapie in der Mund-, Kiefer- und Gesichtschirurgie.

Pain therapy in the oral and maxillofacial region is still a problem. Before starting therapy, the genesis of pain has to be carefully clarified. The article presents the most important syndromes, aspects concerning diagnosis and differential diagnosis as well as therapeutic schemata.

[Clinical manifestations of CHARGE association in the area of the mouth, jaw and face]. / Klinische Manifestationen der CHARGE-Assoziation im Mund-, Kiefer- und Gesichtsbereich.

Clinical experience of 11 patients with CHARGE association is reviewed. The study comprised six girls and five boys. All presented with congenital heart disease. Eight had bilateral choanal atresia. Coloboma affecting either one or both eyes was detected in nine children. Nine patients suffered abnormal pinnae or deafness. In addition to major abnormalities, further anomalies of the orofacial region and the upper airways occurred in all patients. All children exhibited velopharyngeal incoordination and swallowing problems often resulting in recurrent aspiration pneumonia. Three patients had cleft lip and palate. Both micrognathia and high-arched palate were present in two patients. Facial palsy was observed in six patients. Optimal management requires a multidisciplinary approach with active coordination and cooperation between the appropriate specialties. The anatomical repair of bilateral choanal atresia should be performed as early as possible. In our experience, the transpalatal approach is far more satisfactory than the transnasal. It gives the surgeon the opportunity of direct access and anatomical repair. After the child has grown stronger, a long-term management is desirable including developmental and feeding training.

[Complications following piercing in the oral and facial region]. / Komplikationen nach Piercing im Mund und im Gesicht.

The increasing distribution and social acceptance of body piercing induced us to investigate the nature and rate of complications brought about by this fashionable injury of the unscathed body. All dentists, maxillofacial surgeons and clinics within the region of the association of dentists of Bremen were asked to register all patients presenting between June and October 1998 in whom piercings of the head and neck area were visible. Response was good; 699 piercings in 273 persons were recorded and some exemplary photographs made. Some 47 persons showed local complications which ranged from keloid formation and temporary infections to cartilage necrosis and disturbances in sensibility. General diseases were described as well, mainly allergies and hepatitis. In accordance with the seriousness of the complication the medical treatment required varied. Nine persons had to be treated in hospital. In 14 cases patients suffered permanent damage. Piercings cause severe complications and considerable expense to the public health service.

[Follow-up studies of 3-dimensional osteoplastic reconstruction of the extremely atrophied maxilla combined with implants]. / Verlaufskontrollen der dreidimensionalen osteoplastischen Rekonstruktion des extrem atrophierten Oberkiefers in Kombination mit Implantaten.

In the severely resorbed maxilla, a 10-year success rate of only 49-74% of implants in combination with autogenous bone grafts has been reported. We developed a modified technique of antral inlay grafting and lateral and vertical onlay grafting of the severely resorbed maxilla for inserting implants to retain dentures. The clinical and radiologic results are presented. In 21 patients with severely resorbed edentulous maxillae, a total of 20 bilateral and one unilateral antral inlay graftings and lateral and vertical onlay graftings were performed after a prosthodontic setup. We opened the maxillary sinus by removing a bony window from the anterolateral wall and, after elevation of the sinus lining, grafted the sinus floor with corticocancellous iliac crest bone grafts. The maxilla was also augmented in the lateral and vertical direction. The bone grafts were fixed by osteosynthesis. After a median of 5 months, a total of 134 implants (Brånemark) were placed and later loaded by prosthodontic rehabilitation. Computed tomography (CT) scans were taken before the grafting procedure, immediately after grafting, after 4 months, and every year thereafter. A total of 94.8% of the implants were successful at the time of the abutment operation. After loading, two additional failures were seen in an average follow-up period of 2.5 years. Most patients were provided with implant-borne dentures. CT scans showed an average initial gain of vertical bone height of 3.7-17.7 mm. One year after grafting, a loss of 1.3 mm or 7% occurred. In the following 2 years, no major atrophy was observed. Statistical analysis showed no correlation between sex, bone height before augmentation, augmented bone height, and resorption of the grafted bone. We observed undisturbed healing and obtained large vertical bone heights, a high success rate, minimal resorption, and fully satisfactory prosthodontic rehabilitation; we can thus recommend our modified technique of reconstruction of the severely resorbed maxilla for routine use.

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.

[Mandibular fractures. An epidemiological study of a 10-year cohort]. / Unterkieferfrakturen. Eine epidemiologische Studie anhand eines 10-jährigen Kollektivs.

From 01-01-1981 to 12-31-1990 512 patients with isolated mandibular fractures, 161 patients with combined midfacial-/mandibular fractures and 15 patients with combined frontobasal-/midfacial-/mandibular fractures were treated. During that period the number of isolated mandibular fractures doubled, whereas the frequency of combined mandibular fractures was nearly constant. The male/female ratio was 3.1 to 1. The more severe the combined mandibular fractures had been, the less female patients were concerned. Most of the patients were between 16 and 30 years old followed by 31 to 45 year old patients. The main reason for isolated mandibular fractures had been assaults, followed by falls and road traffic accidents, whereas most of the combined mandibular fractures were caused by road traffic accidents. The numbers of single and double fractures of the mandible were nearly equal. Certain and uncertain signs of fractures are mostly unreliable, so that an X-ray is needed. A combined conservative and surgical treatment shows the best results and guarantees the reintegration of the patient in the every-day life as early as possible.

[Thermographic quantification of sensory and sympathetic nerve lesions in mandibular fractures--a prognostic criterium?]. / Thermografische Quantifizierung sensibler und sympathischer Nervläsionen bei Unterkieferfrakturen--ein Prognosekriterium?

As a rule, damage to segmental afferent nerves by trauma is accompanied with local impairment of sympathic functions. Standardized quantification of subjective items concerning the deficit of sensibility is quite problematical. Investigation by electrophysiological means yield not more than qualitative issues. In contrast, changes of sympathetic status and reaction of dependent dermatomas are quantitatively measurable by thermography. -26 patients with unilateral mandibular fractures complained of different posttraumatic or postoperative sensible impairment of the third branch of the trigeminal nerve. In the course of onto 3 years area and quality of the concerned neural defect were correlated to skin temperature that was measured by contact thermography and compared to the opposite reference region.- In all cases the early posttraumatic period showed a difference in temperature of the corresponding skin areas (delta T = 0.43 +/- 0.24 C). In 20 of 26 cases a relation between the changes of temperature concerning time and area and the sensible improvement could be seen. There was an individual time-lag between these developments. Side-comparing thermography was able to forecast improvement in 17 of 26 cases. Thus, the issued device provides statements about the amount and the course of posttraumatic loss of sensibility.