0000000000063945
AUTHOR
Gerhard Michael Doll
showing 8 related works from this author
Efficacy of protection by latex gloves during orthodontic therapy.
2000
The wearing of gloves during orthodontic or dental treatment is generally indicated for reasons of hygiene and protection against infection. This study was aimed at determining the extent and localization of perforations caused by the various orthodontic treatment techniques and interrupting the infection barrier. The impermeability was tested by means of a water retention test according to European standard EN 455, Part 1, performed on 1600 Centramed (Centramed, Koblenz), Tekmedic and SafeEx non-sterile disposable latex gloves (both by Safe Med, Switzerland) and Safe Gan latex gloves with an additional acrylate coating (also by Safe Med). The perforation rate in unused gloves was between 0…
Size discrepancy of apical bases and treatment success in angle Class III malocclusion.
2001
The aim of this retrospective clinical study was to measure the apical bases and determine their size relationship in Class III malocclusion cases before and after orthodontic treatment, in order to evaluate their significance for the treatment success. Maxillary and mandibular apical bases were measured on study models of 104 Class III cases treated by conventional orthodontics, using a specifically constructed conveyance apparatus, and related to each other as an index. Treatment success was quantitatively assessed as the percentage change of PAR scores obtained from the pretreatment and posttreatment study models. Statistically significant relationships were disclosed between the measure…
Vergleichende Untersuchung zur Genauigkeit der Lokalisierung kephalometrischer Referenzpunkte bei Anwendung digitaler und konventioneller Aufnahmetec…
1991
Ziel der vorliegenden Arbeit war die Darstellung moglicher Vorteile der digitalen Lumineszenzradiographie fur die Kephalometrie. Dazu wurden konventionell und digitalisiert gewonnene Fernrontgenseitenbilder vergleichend ausgewertet. Der subjektive Eindruck einer verbesserten simultanen Darstellung der knochernen Strukturen und des Weichteilprofils in digitalen Aufnahmen lies sich statistisch belegen. So fanden sich bezuglich der Identifikation einzelner Referenzpunkte nach Anwendung des F-Testes signifikante Unterschiede. Die Beurteilung der mit der digitalen Lumineszenzradiographie gewonnenen uberlegenen Ergebnisse erfolgt unter Einbeziehung der Xeroradiographie sowie Versuchen der nachtra…
Landmark identification on direct digital versus film-based cephalometric radiographs: A human skull study
2002
The purpose of this study was to investigate differences in landmark identification on vertically scanned, direct digital and conventional (18 x 24 cm) cephalometric radiographs. Eight observers, all orthodontists or postgraduate orthodontic students, recorded 6 landmarks twice on 3 digital and 3 conventional cephalograms obtained from 3 human skulls in a standardized fashion. Digital images were displayed on a 15.1-in TFT monitor in 3:1 mode (20 x 26 cm). Recordings were transferred into standardized coordinate systems and evaluated separately for each coordinate. After correcting for magnification, precision was assessed with Maloney-Rastogi tests, and intraobserver and interobserver repr…
Relationship between Patient Discomfort, Appliance Acceptance and Compliance in Orthodontic Therapy
2000
Orthodontic treatment is occasionally a discomfort to patients, due to pain or functional restrictions. In this context, several retrospectively planned studies were performed in the 1980s, but correlations between different aspects of patient discomfort were not investigated. The present study aimed at examining and structuring the psychogenic dimensions of patient discomfort. Furthermore, the impact of the patient's attitude on the intensity of discomfort was to be evaluated in addition to the influences of appliance therapy. The study was performed with 67 patients aged from 9 to 32 years. Prior to insertion of a new appliance, psychogenic scales reflecting their attitude towards orthodo…
Morphological parameters as predictors of successful correction of Class III malocclusion
2001
The aim of the study was to assess pre-treatment cephalometric parameters and measurements of the size of the apical bases as predictors of successful orthodontic correction of Class III malocclusions. Pre- and post-treatment lateral cephalograms and study models of 80 completed Class III subjects were examined to obtain 23 cephalometric parameters taken mainly from the analyses of McNamara and Schwarz, and to measure the size of the apical bases. Success of occlusal correction was evaluated as the percentage change of peer assessment rating score during treatment, which was used as the dependent variable in multivariate statistical analyses testing the predictive value of the parameters as…
Reliability and validity of the Digigraph 100 in orthodontic diagnosis.
2001
Cephalometric analyses of lateral cephalograms allow important statements to be made on diagnosis and treatment planning. Such radiographs should, however, be taken with a considerable reduction in radiation exposure. With the Digigraph 100 (Dolphin Imaging Systems Inc., USA) a cephalometric technique based on distance measurements of emitted sonic signals is now available. This study was aimed at determining the degree to which this procedure can cope with the requirements of reliability and validity in the field of orthodontics. For this purpose 50 volunteers were examined by conventional cephalometry with manual tracing of lateral cephalograms as well as by sonic cephalometry, with Jarab…
Statistical methods for the comparison of measurements derived from orthodontic imaging
2000
Biometric comparison procedures for dental imaging methods with continuous outcome were reviewed, mainly concentrating on assessment and comparison of accuracy and precision according to the study design. Univariate graphical and numerical representations of corresponding deviations were summarized to derive a 'check list' of minimum information necessary to compare the measurement methods. The methods reviewed in this investigation are illustrated by the comparison of conventional (radiographic) cephalometry versus assessment using the DigiGraph in 50 female children. A paired t-test and the corresponding confidence interval approach were used to assess deviations in location of two imagin…