Möglichkeiten zur objektiven Beurteilung von Narben

Aim of the study

Cosmetic outcome of surgical treatment in the facial region is influenced by the appearance of the scar. The purpose of this investigation was to evaluate the objectivity and validity of various methods for the assessment of scars.

Material and methods

45 patients undergoing facial surgery were examined three months after surgery. Three maxillofacial surgeons evaluated the wounds in a blinded manner using a visual analog scale (VAS). The patients also used the VAS for evaluation of their own scar. The surface of the scars was also measured by optical profilometry. Finally, the colour of the scars was analysed using both the RGB colour model and the HSV colour model.

Results

Interestingly, there was no significant correlation between the values of R (red) as assessed by the three surgeons. However, there was a very strong correlation between the values of H (hue) as assessed by the three raters. The appearance of the surface was more important in the patients’ evaluation than in the raters’ assessment.

Conclusion

The hue of a scar as measured in terms of the H value in the HSV colour model is an objective and reliable measure for assessing the cosmetic outcome of facial surgery.     

Three-dimensional quantification of color-marked occlusal paths on anatomically oriented casts

STATEMENT OF PROBLEM: The analysis of occlusal contacts on mounted diagnostic casts is an important task in prosthetic diagnostics. However, it is still restricted mainly to qualitative aspects because existing measuring techniques fail to provide 3-dimensional data for more than a few single points in acceptable time. PURPOSE: The aim of this study was to develop a method for quantifying occlusal contacts and paths by using anatomically oriented diagnostic casts and to design the method to allow fast acquisition of digital 3-dimensional coordinates. MATERIAL AND METHODS: Plaster casts with color-marked contacts were digitized optically with a profilometric system based on the fringe projection technique. Digital camera images taken simultaneously were used to define the contact areas by marking them either manually or automatically with the help of image-processing routines. Three-dimensional coordinates were determined by finding the corresponding points within the profilometric data set. RESULTS: Color-marked contact areas on diagnostic casts were successfully digitized with a computer-controlled, automatic setup in approximately 30 seconds. The accuracy of the acquired 3-dimensional data was estimated to be better than 60 microm in lateral and 30 microm in height resolution. The data set was visualized and evaluated in a skull related coordinate system. SUMMARY: This study verified the use of a new tool to quantify color-marked occlusal contacts on diagnostic casts in terms of spatial coordinates. The resulting digital data may be stored easily and analyzed numerically as well as visualized 3-dimensionally with computer graphic equipment. Because the anatomic orientation of the casts is maintained throughout the measurement process, it is possible to compare the data with electronically registered condyle paths and therefore to investigate, for example, their relation to the corresponding guidance paths of the frontal teeth and the canines in dynamic occlusion.     

Respiratory protection during high-fidelity simulated resuscitation of casualties contaminated with chemical warfare agents

Emergency room personnel are threatened by secondary poisoning when treating victims affected by chemical warfare agents. Therefore, resuscitation skills practised with respiratory protection equipment in place require evaluation. We investigated the influence of wearing air-purifying respirators on the simulated resuscitation of chemical warfare agent casualties. We studied 22 anaesthetic trainees in a simulated resuscitation scenario requiring five set tasks, either unprotected, wearing a binocular visor respirator or a panoramic visor respirator in a randomised, crossover study. Treatment times did not differ between the three groups, with mean (SD) times to complete the tasks being 122 (8) s without a mask, 126 (7) s when wearing the panoramic visor mask and 129 (8) s when wearing the binocular respirator mask. All anaesthetists preferred the panoramic visor in terms of visual orientation but 88% of them rated the binocular mask as being more comfortable. Modern respirators have a negligible effect on simulated resuscitation scenarios for victims affected by chemical warfare agents. Panoramic visor respirators allow better visual orientation for anaesthetists during simulated resuscitation.     

Three-dimensional acquisition and visualization of dental arch features from optically digitized models

A method for the acquisition and evaluation of 3D coordinates from anatomically oriented plaster casts is presented, which is based on optical phase shifting profilometry (a fringe projection technique). With the computer-controlled setup, measurements from different views can be combined to obtain a complete three dimensional reconstruction of the model surface. To allow faster evaluation, the result is converted into a range image. From this digital data set the characteristic features like cusp tips can be identified and located semi-automatically. Based on these marks, quantitative values for differences between situation models like local displacements, e.g. during orthodontic treatment, can be determined. The results are visualized as interactively controllable 3D computer graphics, which helps to make spatial relations clearer.     

Der Einfluß der Zahnprothese auf die Stimme

It is well known that alterations to the oral cavity caused by dental prostheses may affect speech articulation, although influences on the voice are not assumed. In addition to the vocal fundamental frequency, vibrations of the vocal chords generate overtones. Through the shape of the larynx and the upper airway, resonances and antiresonances are formed, and in this way overtones are amplified to a variable extent. Nozzle changes caused by a dental prosthesis in the oral cavity may possibly influence overtones but influences on the vocal fundamental frequency seem unlikely. The influence of dental prostheses on the voice is demonstrated in a patient who owned two different dental prostheses. The fundamental frequency rose by up to five semitones during speech and his vocal range increased by up to four semitones when a thin denture was used instead of a normal denture. When the position of the mandible was checked by intraoral needle point placement, a more rostral position of the mandible was recorded with the thin denture than with the normal denture. Sagittal magnetic resonance tomography imaging also showed that the larynx was in a more cranial position. This change was presumed to be due to an upward movement of the larynx induced by the tongue, which itself was found to be in a more cranial position with the thin denture. In this situation, increased tension of the laryngeal muscles were believed to induce a rise in fundamental frequency, shifting the voice range toward higher frequencies. These findings show that dental prostheses can cause vocal changes in individual cases. The etiology of this occurrence is still not clear. Its consequences, however, should be known to the dentist, ENT surgeon and phoniatrist if patients notice changes in their voice after having altered or replaced their dentures.     

Der Einflu? der Zahnprothese auf die Stimme

Bekannterma?en k?nnen sich durch Zahnprothesen bedingte Ver?nderungen der Mundh?hle auf die Aussprache auswirken. Einflüsse auf die Stimme sind aber zun?chst nicht anzunehmen. Neben der Erzeugung der Grundfrequenz werden von den Stimmlippenschwingungen auch Obert?ne erzeugt. Durch die Form des Ansatzrohres werden Resonanzen und Antiresonanzen gebildet und so die Obert?ne in unterschiedlichem Ausma? verst?rkt. Ver?ndert die Zahnprothese das Ansatzrohr, k?nnen m?glicherweise die Obert?ne beeinflu?t werden, doch scheinen Ver?nderungen der Stimmgrundfrequenz eher unwahrscheinlich. In dieser Kasuistik wird gezeigt, da? bei einem Probanden, der im Besitz zweier unterschiedlicher Zahnprothesen ist, die Sprechstimmfrequenz beim Lesen eines Textes mit der dünneren und leichteren Zahnprothese (Prothese 1) um bis zu 5 Halbt?ne ansteigt. Im Singstimmfeld ist der Singstimmumfang im Hochtonbereich um bis zu 4 Halbt?ne erweitert. Wird die Unterkieferposition mit dem intraoralen Stützstiftregistrat überprüft, so ist der Unterkiefer mit der Prothese 1 gegenüber der Prothese 2 geringfügig nach vorn verschoben. Im sagittalen Magnetresonanztomogramm imponiert der Larynx weiter kranial. M?glicherweise wird der Kehlkopf durch die bei der dünneren Prothese h?her stehende Zunge nach kranial bewegt. Eine h?here Spannung der Larynxmuskulatur k?nnte zu einem Anstieg der Grundfrequenz und zu einer Erweiterung des Singstimmumfangs im Hochtonbereich führen. Die Versorgung mit einer Zahnprothese kann sich also im Einzelfall auf die Stimme auswirken. Wenn auch die Ursache dieser Beobachtung zum jetzigen Zeitpunkt noch nicht zu kl?ren ist, sollte das Ph?nomen dem behandelnden Zahnarzt, aber auch dem HNO-Arzt und dem Phoniater bekannt sein, wenn Patienten nach der Neu- oder Umversorgung mit einer Zahnprothese eine Ver?nderung der Stimme bemerken.     

Sleep-disordered breathing and effects of non-invasive ventilation on objective sleep and nocturnal respiration in patients with myotonic dystrophy type I

Patients with myotonic dystrophy type I (DM1) may develop nocturnal hypoventilation, requiring non-invasive ventilation. Data on long-term adherence to non-invasive ventilation, or sleep and ventilation outcomes are scarce. We retrospectively collected baseline polysomnography and capnometry results from 36 adult patients with sleep-related symptoms (42.9?±?12.5 years, 20 female), plus follow-up sleep study records from those treated with non-invasive ventilation. Sleep-disordered breathing was found in 33 patients (91.7%) including 8 (22.2%) with daytime hypercapnia. Twenty-six patients (72.2%) showed nocturnal hypoventilation on transcutaneous capnometry. The sensitivity of oximetry to detect nocturnal hypoventilation was only 0.38. Twenty-eight patients (77.8%) showed sleep apnea, which was predominantly obstructive (n?=?8), central (n?=?9), or “mixed” (n?=?11). Thirty-two patients were initiated on non-invasive ventilation which significantly improved ventilation and oxygenation in the first night of treatment. Follow-up revealed stable normoxia and normocapnia without deterioration of sleep outcomes for up to 52 months. Adherence to treatment was low to moderate, with substantial inter-individual variability.Sleep disordered breathing is highly prevalent in adult DM1 patients complaining of daytime sleepiness, and non-invasive ventilation significantly, rapidly and persistently improves nocturnal gas exchange. Capnometry is superior to oximetry for detection of nocturnal hypoventilation. Adherence to non-invasive ventilation remains a major issue in DM1, and long-term treatment benefits should be individually assessed.     

Spectrum of neuropsychiatric features associated with velocardiofacial syndrome (Deletion 22q11.2)

Microdeletion 22q11.2 (22q11DS) is the most frequent chromosomal deletion known in man. Velocardiofacial syndrome is one of numerous clinical syndromes that can be attributed to this micro deletion. There is an increasing recognition of associations with neuropsychiatric disorders. Particularly, schizophrenic psychosis, attention-deficit/hyperactivity disorder (ADHD), intellectual impairment and learning disabilities, seizures and motoric abnormalities have been identified in patients with 22q11DS. Recent studies supported the association of schizophrenia and 22q11DS, but the pathogenetic implications for idiopathic schizophrenia are still controversial. We report on two clinical cases in which psychotic symptoms led to the molecularcytogenetic diagnosis of microdeletion 22q11.2. Additionally, this article gives a systematic review of literature regarding psychiatric disorders, neurologic symptoms and partly corresponding morphological brain abnormalities in 22q11 deletion syndromes.