K. Schwenzer-Zimmerer

New aspects of breast volume measurement using 3-dimensional surface imaging.

Precise and objective calculation of breast volume is helpful to evaluate the aesthetic result of breast surgery, but traditional methods are unsatisfactory. Three-dimensional (3D) scanning of the body surface allows reproducible and objective assessment of the complex breast region but requires further investigation before clinical application. The main goal of this study was to investigate the precision and accuracy of breast volume measurement using 3D body scanning. Five independent observers standardized the 3D scanning method using 2 dummy models (n = 200) and examined its applicability with 6 test subjects and 10 clinical patients (n = 2220). Breast volume measurements obtained with the 3D-scanner technology were compared with reference measurements obtained from test subjects through nuclear magnetic resonance imaging. The mean deviation of the breast volume measurements of 1 test subject by all observers, expressed as percentage of volume, was 2.86 ± 0.98, significantly higher than the deviation for the dummy models, 1.65 ± 0.42 (P < 0.001). With respect to all clinical patients, the mean measurement precision obtained preoperatively was less precise than that obtained postoperatively (3.31 ± 1.02 versus 1.66 ± 0.49, respectively). Interobserver differences in measurement precision were not statistically significant. The mean breast volumes obtained by nuclear magnetic resonance imaging (441.42 ± 137.05 mL) and 3D scanning (452.51 ± 141.88 mL) significantly correlated (r = 0.995, P < 0.001). Breast volume measurement with 3D surface imaging represents a sufficiently precise and accurate method to guarantee objective and exact recording.

Optimization of 3-dimensional imaging of the breast region with 3-dimensional laser scanners

The anatomic conditions of the female breast require imaging the breast region 3-dimensionally in a normal standing position for quality assurance and for surgery planning or surgery simulation. The goal of this work was to optimize the imaging technology for the mammary region with a 3-dimensional (3D) laser scanner, to evaluate the precision and accuracy of the method, and to allow optimum data reproducibility. Avoiding the influence of biotic factors, such as mobility, we tested the most favorable imaging technology on dummy models for scanner-related factors such as the scanner position in comparison with the torso and the number of scanners and single shots. The influence of different factors of the breast region, such as different breast shapes or premarking of anatomic landmarks, was also first investigated on dummies. The findings from the dummy models were then compared with investigations on test persons, and the accuracy of measurements on the virtual models was compared with a coincidence analysis of the manually measured values. The best precision and accuracy of breast region measurements were achieved when landmarks were marked before taking the shots and when shots at 30 degrees left and 30 degrees right, relative to the sagittal line, were taken with 2 connected scanners mounted with a +10-degree upward angle. However, the precision of the measurements on test persons was significantly lower than those measured on dummies. Our findings show that the correct settings for 3D imaging of the breast region with a laser scanner can achieve an acceptable degree of accuracy and reproducibility.

Quantitative 3D soft tissue analysis of symmetry prior to and after unilateral cleft lip repair compared with non-cleft persons (performed in Cambodia)

OBJECT The aim of this study was to evaluate the clinical application of three-dimensional (3D) imaging and morphological analysis with subsequent individual therapy planning and postoperative 3D symmetry control in comparison with data from non-cleft persons. DESIGN This was a prospective study using a 3D surface-imaging and evaluation system in cleft patients and non-cleft persons. The pre- and postoperative 3D facial profiles were recorded from the patients using a 3D laser scanner. The preoperative 3D image was analyzed qualitatively and quantitatively for an individual therapy planning. On the basis of ratios and scores, based on empirical regions of interest, the technique of cleft repair was designed individually. The postoperative result was evaluated regarding symmetry. The surgically created soft tissue shift was defined quantitatively and visualized with vectors. The postoperative symmetry was compared with 3D data from a group of non-cleft persons of the same ethnical group. PATIENTS Eleven patients (mean age 13.8 years, median 13, minimum 2, maximum 41 years) with either a unilateral isolated cleft lip, a cleft lip and alveolus or a complete unilateral cleft lip, alveolus and palate and 25 non-cleft persons (8 children between 4 and 12 years, 17 adults (9 men, 8 women) between 18 and 50 years). All these persons investigated were Asians of Khmer origin. RESULTS The analysis permitted quantitative 3D evaluation. The 3D anthropometric data of the non-cleft Khmer persons were collected and named the gold standard of symmetry in this ethnical group. All postoperative 3D images reached symmetrical values within the range of the normal cohort. Soft tissue shifts from pre- to postoperative sites could be visualized. CONCLUSION A new method for registration was described enabling follow-up registration in patients when growing older. This 3D soft tissue analysis can be a useful tool in quantitative analysis and objective follow-up control in cleft patients. It offers deeper insight into the complex morphology to be treated and could contribute to individualisation of surgical procedures.

Accuracy and precision of the three-dimensional assessment of the facial surface using a 3-D laser scanner

Three-dimensional (3-D) recording of the surface of the human body or anatomical areas has gained importance in many medical specialties. Thus, it is important to determine scanner precision and accuracy in defined medical applications and to establish standards for the recording procedure. Here we evaluated the precision and accuracy of 3-D assessment of the facial area with the Minolta Vivid 910 3D Laser Scanner. We also investigated the influence of factors related to the recording procedure and the processing of scanner data on final results. These factors include lighting, alignment of scanner and object, the examiner, and the software used to convert measurements into virtual images. To assess scanner accuracy, we compared scanner data to those obtained by manual measurements on a dummy. Less than 7% of all results with the scanner method were outside a range of error of 2 mm when compared to corresponding reference measurements. Accuracy, thus, proved to be good enough to satisfy requirements for numerous clinical applications. Moreover, the experiments completed with the dummy yielded valuable information for optimizing recording parameters for best results. Thus, under defined conditions, precision and accuracy of surface models of the human face recorded with the Minolta Vivid 910 3D Scanner presumably can also be enhanced. Future studies will involve verification of our findings using test persons. The current findings indicate that the Minolta Vivid 910 3D Scanner might be used with benefit in medicine when recording the 3-D surface structures of the face

Psychosocial functioning and sleep patterns in children and adolescents with cleft lip and palate (CLP) compared with healthy controls

Objective: The aim of this study was twofold: to assess psychological functioning, interactional competencies, and sleep patterns in children and adolescents with cleft lip and palate (CLP), and to compare these results with those from age- and gender-matched controls. It was hypothesized that participants with CLP would exhibit greater difficulties in psychological functioning, more interactional difficulties, and poorer sleep patterns than those without CLP. Participants: Thirty-two children and adolescents with CLP and 34 controls were recruited. Ages ranged from 6 to 16 years. Main Outcome Measures: For psychosocial assessment, the Strength and Difficulties Questionnaire (SDQ) and a questionnaire on interactional competencies (PIELCQ) were completed; for sleep assessment, a sleep log was completed for seven consecutive nights. Results: Participants with and without CLP did not differ with respect to emotional problems, conduct problems, or hyperactivity. With respect to interactional competencies, participants with CLP were six times more likely to report difficulties. Unfavorable sleep patterns were associated with psychosocial strain but not with the presence of CLP. Conclusions: Results indicate that children and adolescents with CLP may report that they have sleep irregularities as often as those without CLP. In adolescence, the presence of CLP may be associated with increased difficulties. Consequently, skill training to improve context-related social competencies may be appropriate.

Odontogenic myxoma: Diagnostic and therapeutic challenges in paediatric and adult patients – A case series and review of the literature

INTRODUCTION Odontogenic myxomas are benign but locally invasive tumours originating from primordial mesenchymal tooth forming tissues which do not metastasise. We present a series of two paediatric and two adult cases and focus on differences in diagnostic and therapeutic approaches between children and adults based on our own experience and a critical review of the literature.

Systematic Contact-Free 3D Topometry of the Soft Tissue Profile in Cleft Lips

Objective: To evaluate the clinical application of three-dimensional (3D) imaging for the analysis of a broad variety of cleft lips and to conduct a systematic analysis. Design: This was a prospective study using a noncontact 3D laser scanner to acquire the preoperative 3D facial profiles. The data sets were analyzed qualitatively and quantitatively. The data were expressed by ratios and scores. Patients: Forty nonsedated patients (1 to 39 years, average age 2.7 years) with unilateral cleft lip, cleft lip and alveolus, or complete unilateral cleft in Cambodia. Results: The acquired 3D data sets (mean acquisition time: 2.5 seconds) from facial surfaces were of diagnostic quality in 27 of 40 patients (average age, 14.2 years). In these cases all anatomical structures could be mapped precisely by means of landmark positioning in the range of millimeters. A new method of systematic analysis could be elaborated, allowing for data set expression independent of size and growth factors. In children under age 3, the measuring procedure was of limited value because of motion artifacts and was successful in only 6% (1 of 15) of these patients. Conclusion: The system offers a solid and precise tool for 3D imaging of the complex cleft lip anatomy in compliant patients and is useful for preoperative cleft assessment and follow-up. However, the application is limited in moving infants or uncooperative adults because of scanning time and acquisition method. The development of motion tracking and faster devices could eliminate motion artifacts.

Oral bacterial cultures in nontraumatic brain abscesses: results of a first-line study.

OBJECTIVE Bacterial cultures from nontraumatic brain abscesses (BAs) frequently contain oral bacteria. We assessed bacterial cultures from BAs and oral infective sources for a bacterial match. STUDY DESIGN Bacterial samples from brain abscesses and oral abscesses, and at sites with probing depths >or=3.5 mm were taken from 11 nontraumatic BA patients and analyzed. RESULTS Brain abscess bacterial cultures were obtained in 9 of the 11 cases, which revealed 5 cases of Streptococcus milleri group bacteria and 4 cases of subgingival flora. The bacteriologic results were interpreted taking all medical and bacteriologic findings into account, which made an oral origin of the BAs most likely in 6 of the 11 cases: from an oral abscess and from the subgingival flora in 3 cases each. CONCLUSIONS Early collaboration between neurosurgeons, infectious disease specialists, and oral-maxillofacial surgeons will aid the identification and treatment of suspected oral sources of nontraumatic BAs.

Evaluation of Precision and Accuracy Assessment of Different 3-D Surface Imaging Systems for Biomedical Purposes

Three-dimensional (3-D) surface imaging has gained clinical acceptance, especially in the field of cranio-maxillo-facial and plastic, reconstructive, and aesthetic surgery. Six scanners based on different scanning principles (Minolta Vivid 910®, Polhemus FastSCAN™, GFM PRIMOS®, GFM TopoCAM®, Steinbichler Comet® Vario Zoom 250, 3dMD DSP 400®) were used to measure five sheep skulls of different sizes. In three areas with varying anatomical complexity (areas, 1 = high; 2 = moderate; 3 = low), 56 distances between 20 landmarks are defined on each skull. Manual measurement (MM), coordinate machine measurements (CMM) and computer tomography (CT) measurements were used to define a reference method for further precision and accuracy evaluation of different 3-D scanning systems. MM showed high correlation to CMM and CT measurements (both r = 0.987; p < 0.001) and served as the reference method. TopoCAM®, Comet® and Vivid 910® showed highest measurement precision over all areas of complexity; Vivid 910®, the Comet® and the DSP 400® demonstrated highest accuracy over all areas with Vivid 910® being most accurate in areas 1 and 3, and the DSP 400® most accurate in area 2. In accordance to the measured distance length, most 3-D devices present higher measurement precision and accuracy for large distances and lower degrees of precision and accuracy for short distances. In general, higher degrees of complexity are associated with lower 3-D assessment accuracy, suggesting that for optimal results, different types of scanners should be applied to specific clinical applications and medical problems according to their special construction designs and characteristics.

Facial acquisition by dynamic optical tracked laser imaging: a new approach

Three-dimensional capture of the surface of soft tissue is a desirable support for documentation and therapy planning in plastic and reconstructive surgery concerning the complex anatomy of the face, particularly cleft lip and palate (CLP). Different scanning systems are used for capturing facial surfaces. These systems are mostly based on a static linear measuring arrangement. Established systems work on the basis of coded white light or linear laser triangulation and digital stereophotogrammetric approaches. Shadowing effects occur with these devices. These effects may be avoided by a radical new approach first used in automotive industries that employs a mobile, flexible handheld laser scanner with simultaneous registration by optical tracking. The aim of this study was to assess the suitability of this scanner for surgical procedures on the human face in operating theatre. Five babies aged about 3 months with cleft deformities (one CLP, one bilateral CLP, three isolated cleft lips) were captured directly: twice preoperatively, twice postoperatively and twice after 7 days. An industrial standard specimen and two plaster cast masks of CLP babies were taken and subsequently measured to assess reliability and validity of the device. Masks were measured to reflect the complex surface of the cleft deformity. Data evaluation was done with respect to completeness of the data sets, as well as reliability and validity of the system. Missing data caused by shadowing could be avoided in all images. Even complex areas with undercuts could be reproduced completely and precisely with an accuracy in the sub-millimetre range.