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.

Near-real time oculodynamic MRI: a feasibility study for evaluation of diplopia in comparison with clinical testing.

OBJECTIVE: To demonstrate feasibility of near-real-time oculodynamic magnetic resonance imaging (od-MRI) in depicting extraocular muscles and correlate quantitatively the motion degree in comparison with clinical testing in patients with diplopia. METHODS: In 30 od-MRIs eye movements were tracked in the horizontal and sagittal plane using a a TrueFISP sequence with high temporal resolution. Three physicians graded the visibility of extraocular muscles by a qualitative scale. In 12 cases, the maximal monocular excursions in the horizontal and vertical direction of both eyes were measured in od-MRIs and a clinical test and correlated by the Pearson test. RESULTS: The medial and lateral rectus muscles were visible in the axial plane in 93% of the cases. The oblique, superior and inferior rectus muscles were overall only in 14% visible. Horizontal (p = 0,015) and vertical (p = 0,029) movements of the right eye and vertical movement of the left eye (p = 0,026) measured by od-MRI correlated positively to the clinical measurements. CONCLUSIONS: Od-MRI is a feasible technique. Visualization of the horizontal/vertical rectus muscles is better than for the superior/inferior oblique muscle. Od-MRI correlates well with clinical testing and may reproduce the extent of eye bulb motility and extraocular muscle structural or functional deteriorations. Key Points • Oculodynamic MRI technique helps clinicians to assess eye bulb motility disorders • MRI evaluation of eye movement provides functional information in cases of diplopia • Oculodynamic MRI reproduces excursion of extraocular muscles with good correlation with clinical testing • Dynamic MRI sequence supplements static orbital protocol for evaluation of motility disorders.

Spinal epidural abscess: aetiology, predisponent factors and clinical outcomes in a 4-year prospective study.

Spinal epidural abscess (SEA) is a rare, but serious, condition with multiple causes. We prospectively studied the aetiology, predisposing factors, and clinical outcomes of SEA in all patients with SEA treated in our hospital's neurosurgical service from 2004 to 2008. For each patient, we recorded the medical history, comorbidities, focus of infection, pathogen(s), and outcome. The 36 patients (19 women and 17 men) ranged in age from 34 to 80 years old (mean 57; median 56). The SEA was primary (i.e., due to haematogenous spread) in 16 patients (44%); it was secondary to elective spinal procedures, either injections or surgery, in 20 patients (56%). The duration of follow-up was 12-60 months (mean 36; median 37.5). The most common pathogen, Staphylococcus aureus, was found in 18 patients (50%). Patients with primary SEA had different underlying diseases and a wider range of pathogens than those with secondary SEA. Only five patients (14%) had no major comorbidity; 16 of the 20 patients with secondary SEA (44% of the overall group) had undergone spinal surgery before developing the SEA; the treatment of the SEA involved multiple surgical operations in all 16 of these patients, and spinal instrumentation in 5 (14%); 22 patients (61% of the overall group) recovered fully.

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.

Does abdominoplasty with liposuction of the love handles yield a shorter scar? An analysis with abdominal 3D laser scanning.

The aim of this study was to evaluate the combination of abdominoplasty with liposuction of both flanks with regards to length of scar, complications, and patient's satisfaction. A retrospective analysis of 35 patients who underwent esthetic abdominoplasty at our institution between 2002 and 2004 was performed. Thirteen patients underwent abdominoplasty with liposuction of both flanks, 22 patients underwent conventional abdominoplasty. Liposuction of the flanks did not increase the rate of complications of the abdominoplasty procedures. We found a tendency toward shorter scars in patients who underwent abdominoplasty combined with liposuction of the flanks. Implementation of 3-dimensional laser surface scanning to objectify the postoperative outcomes, documented a comparable degree of flatness of the achieved body contouring in both procedures. 3-dimensional laser surface scanning can be a valuable tool to objectify assessment of postoperative results.

Clinical evaluation of semi-automatic open-source algorithmic software segmentation of the mandibular bone: Practical feasibility and assessment of a new course of action.

INTRODUCTION: Computer assisted technologies based on algorithmic software segmentation are an increasing topic of interest in complex surgical cases. However-due to functional instability, time consuming software processes, personnel resources or licensed-based financial costs many segmentation processes are often outsourced from clinical centers to third parties and the industry. Therefore, the aim of this trial was to assess the practical feasibility of an easy available, functional stable and licensed-free segmentation approach to be used in the clinical practice. MATERIAL AND METHODS: In this retrospective, randomized, controlled trail the accuracy and accordance of the open-source based segmentation algorithm GrowCut was assessed through the comparison to the manually generated ground truth of the same anatomy using 10 CT lower jaw data-sets from the clinical routine. Assessment parameters were the segmentation time, the volume, the voxel number, the Dice Score and the Hausdorff distance. RESULTS: Overall semi-automatic GrowCut segmentation times were about one minute. Mean Dice Score values of over 85% and Hausdorff Distances below 33.5 voxel could be achieved between the algorithmic GrowCut-based segmentations and the manual generated ground truth schemes. Statistical differences between the assessment parameters were not significant (p<0.05) and correlation coefficients were close to the value one (r > 0.94) for any of the comparison made between the two groups. DISCUSSION: Complete functional stable and time saving segmentations with high accuracy and high positive correlation could be performed by the presented interactive open-source based approach. In the cranio-maxillofacial complex the used method could represent an algorithmic alternative for image-based segmentation in the clinical practice for e.g. surgical treatment planning or visualization of postoperative results and offers several advantages. Due to an open-source basis the used method could be further developed by other groups or specialists. Systematic comparisons to other segmentation approaches or with a greater data amount are areas of future works.

Assessment of tumor margins in head and neck cancer using a 3D-navigation system based on PET/CT image-fusion - A pilot study.

OBJECTIVES: Determination of tumor margins in patients with squamous cell carcinoma of the head and neck (SCCHN) is mostly based on preoperative magnetic resonance imaging (MRI) or computed tomography scans (CT). Local recurrence of disease is often correlated with the presence of positive resection margins after surgical treatment. Positron emission tomography/computed tomography (PET/CT) imaging plays a crucial role in the assessment of patients with SCCHN. The purpose of this study was to determine whether PET/CT could predict tumor extension. METHODS: In 12 patients who underwent surgical treatment of primary SCCHN (Stage III-IV) F18-FDG PET/CT image-fusion was performed on a 3D navigation-system based workstation. Image-guided needle biopsies were obtained from four different, color-coded metabolic areas within the tumor. The histopathological findings were correlated with findings on corresponding PET/CT scans. RESULTS: 81.3% of biopsies from the central area were positive. Specimens taken from the outer metabolic zone were positive in 66.7% of the patients. The highest incidence of positive biopsies was found in the zone adjacent to the outermost area. There was a statistically significant difference in positive tumor histopathology when comparing the various metabolic zones (p = 0.03). CONCLUSION: Exact determination of tumor is an important research topic, although results remain controversial. The results of this study suggest that in some cases PET scans may overestimate tumor extension.

Comparison between breast volume measurement using 3D surface imaging and classical techniques.

Quantification of the complex breast region can be helpful in breast surgery, which is shaped by subjective influences. However, there is no generally recognized method for breast volume calculation. Three-dimensional (3D) body surface imaging represents a new alternative for breast volume computation. The aim of this work was to compare breast volume calculation with 3D scanning and three classic methods, focusing on relative advantages, disadvantages, and reproducibility. Repeated breast volume calculations of both breasts in six patients (n=12) were performed using a 3D laser scanner, nuclear magnetic resonance imaging (MRI), thermoplastic castings, and anthropomorphic measurements. Mean volumes (cc) and mean measurement deviations were calculated, and regression analyses were performed. MRI showed the highest measurement precision, with a mean deviation (expressed as a percentage of mean breast volume) of 1.56+/-0.52% compared with 2.27+/-0.99% for the 3D scanner, 7.97+/-3.53% for thermoplastic castings, and 6.26+/-1.56% for the anthropomorphic measurements. Breast volume calculations using MRI showed the best agreement with 3D scanning measurement (r=0.990), followed by anthropomorphic measurement (r=0.947), and thermoplastic castings (r=0.727). Compared with three classical methods of breast volume calculation, 3D scanning provides acceptable accuracy for breast volume measurements, better spatial interpretation of the anatomical area to be operated on (due to lack of chest deformation), non-invasiveness, and good patient tolerance. After this preliminary study and further development, we believe that 3D body surface scanning could provide better preoperative planning and postoperative control in everyday clinical practice.

A new system for computer-aided preoperative planning and intraoperative navigation during corrective jaw surgery.

A new system for computer-aided corrective surgery of the jaws has been developed and introduced clinically. It combines three-dimensional (3-D) surgical planning with conventional dental occlusion planning. The developed software allows simulating the surgical correction on virtual 3-D models of the facial skeleton generated from computed tomography (CT) scans. Surgery planning and simulation include dynamic cephalometry, semi-automatic mirroring, interactive cutting of bone and segment repositioning. By coupling the software with a tracking system and with the help of a special registration procedure, we are able to acquire dental occlusion plans from plaster model mounts. Upon completion of the surgical plan, the setup is used to manufacture positioning splints for intraoperative guidance. The system provides further intraoperative assistance with the help of a display showing jaw positions and 3-D positioning guides updated in real time during the surgical procedure. The proposed approach offers the advantages of 3-D visualization and tracking technology without sacrificing long-proven cast-based techniques for dental occlusion evaluation. The system has been applied on one patient. Throughout this procedure, we have experienced improved assessment of pathology, increased precision, and augmented control.

Computer-aided position planning of miniplates to treat facial bone defects.

In this contribution, a software system for computer-aided position planning of miniplates to treat facial bone defects is proposed. The intra-operatively used bone plates have to be passively adapted on the underlying bone contours for adequate bone fragment stabilization. However, this procedure can lead to frequent intra-operatively performed material readjustments especially in complex surgical cases. Our approach is able to fit a selection of common implant models on the surgeon's desired position in a 3D computer model. This happens with respect to the surrounding anatomical structures, always including the possibility of adjusting both the direction and the position of the used osteosynthesis material. By using the proposed software, surgeons are able to pre-plan the out coming implant in its form and morphology with the aid of a computer-visualized model within a few minutes. Further, the resulting model can be stored in STL file format, the commonly used format for 3D printing. Using this technology, surgeons are able to print the virtual generated implant, or create an individually designed bending tool. This method leads to adapted osteosynthesis materials according to the surrounding anatomy and requires further a minimum amount of money and time.

Osteosynthesis using cannulated headless Herbert screws in mandibular angle fracture treatment: A new approach?

INTRODUCTION: Fractures of the mandibular angle are a common type of facial skull fracture. Although operative treatment includes a wide range of fixation techniques, a definite gold standard method has yet to be established. Headless, cannulated Herbert screws, often used in many forms of minimally invasive trauma surgery, provide functional and stable fracture fixation. MATERIALS AND METHODS: In a prospective, double-randomised, controlled, parallel-group - designed, in vitro trial, the biomechanical behaviour of the Herbert bone screw system was compared to that of a conventional locking plate system in 40 mandibular angle fractures of human mandible cadaver phantoms. RESULTS: The mean stress values were 250 (±68.0) N in the plate subgroup and 200 (±61.0) N in the screw subgroup. The respective mean strain values were 7.90 (±2.7) mm and 6.90 (±2.2) mm, and the respective mean stiffness were values 1.10 (±0.61) N/m and 0.78 (±0.40) N/m. The differences in the results obtained using the two treatments were not significant (p = 0.55). CONCLUSIONS: The biomechanical behaviour of the two fixation systems within the tested loads did not significantly differ with respect to postoperative parameters clinically relevant in osteosynthesis. Both systems met the mandibular angle assessment criterion, which is considered to be sufficient for clinical use. The results indicate the potential clinical utility of these two systems, and recommend further testing.

Complications in tissue expansion: A logistic regression analysis for risk factors.

BACKGROUND: Tissue expansion is frequently used in reconstructive surgery. Although the surgical procedure is typically considered simple, reported complication rates of tissue expansions exceed 40%. There is little evidence concerning risk factors for complications in tissue expansion in body regions other than breast. The aim was to determine risk factors for complications in non-breast tissue expansion. METHODS: 34 patients treated with subcutaneous tissue expanders between 2005 and 2014 were analyzed. Demographic data, body-mass index (BMI), mean arterial blood pressure (MAP), treatment indications, expansion site, previous expansion therapies in the same body region, smoking history, as well as expander characteristics (shape, volume, and filling mechanism) were ascertained. Complications were assessed and ranked according to severity based on the Clavien-Dindo classification. Binary logistic regression analysis adjusted for clinical characteristics was used. A p<0.05 was considered as statistically significant. RESULTS: Complications were observed in 26 out of 71 expanders analyzed (36.6%), of whom 10 led to therapy failure. Expanders used in the limbs, female gender, and high expander volume turned out as significant risk factors. Patients with both a high MAP and low BMI developed tissue necrosis significantly more often (p=0.002). The use of tissue expansion after a burn was not associated with an increased risk for complications. CONCLUSIONS: This is the first study revealing female gender and low BMI as risk factors in tissue expander surgery. Thus, careful patient selection is mandatory to avoid complications in tissue expansion. Burn patients do not develop complications more often.

Use of a modified high submandibular approach to treat condylar base fractures: Experience with 44 consecutive cases treated in a single institution.

PURPOSE: The aim of this article is to present our experience treating fractures of the condylar base with a modification of the high submandibular approach (HSA). MATERIALS AND METHODS: Between June 2012 and April 2015, 44 fractures of the condylar base were treated in the Department of Oral and Maxillofacial Surgery of the Medical Hospital of Graz using the modified HSA. RESULTS: We did not observe any damage (even transient) to the facial nerve or any complication related to violation of the parotid capsule (such as a salivary fistula, Frey syndrome, or a sialocele). CONCLUSIONS: This approach provides good access to the condylar base, ensuring easier internal fixation, excellent protection of the facial nerve and parotid gland, and good cosmetic results.

Two case reports with literature review of the EEC syndrome: Clinical presentation and management.

We report on siblings who suffer from EEC syndrome and show our experiences of the "Basel concept" of cleft lip/palate repair based on the early, one-stage closure of all components. It is performed in the age of 3-4 months to provide early normal conditions for anatomy and muscle function.

Compared to controls, patients with ruptured aneurysm and surgical intervention show increase in symptoms of depression and lower cognitive performance, but their objective sleep is not affected.

OBJECTIVES: Patients with aneurysmal subarachnoid haemorrhage (aSAH) have impaired sleep and cognitive performance together with more difficulties in social and everyday life. Hypocortisolism has also been reported. However, a study assessing all dimensions between aSAH severity, objective and subjective sleep, cortisol secretion, cognitive performance and social and everyday life has not so far been performed. The aim of the present study was therefore two-fold: (1) to assess, in a sample of patients with aSAH, objective and subjective sleep, cognitive functioning, social skills and cortisol secretion concurrently, and (2) to compare patients on these variables with a control group. METHODS: Twenty-one patients (17 females; mean age: 58.80 years) with ruptured aneurysm and surgical intervention and 21 (14 females; mean age: 58.90 years) age- and gender-matched controls took part in the study. Assessments covered objective sleep-EGG recordings, subjective sleep, salivary cortisol analysis, and psychological functioning including memory performance, mood, and emotion recognition. RESULTS: Compared to healthy controls, patients had lower scores for verbal memory performance and emotion recognition; they also reported more marked depressive symptoms and complained of poor sleep. However, no differences were found for objective sleep or cortisol secretion. Subjective and objective sleep, cortisol secretion and psychological functioning were unrelated. CONCLUSIONS: Findings indicate that patients with aSAH face psychological rather than physiological issues.

Cortisol levels and sleep patterns in infants with orofacial clefts undergoing surgery.

BACKGROUND: Traumatic events during early infancy might damage infants' psychobiological functioning, such as sleep and cortisol secretion. Infants born with orofacial clefts (OFCs) undergo functional, anatomical, and aesthetic surgery. The aim of the present study was to determine whether infants with OFC and undergoing OFC surgery show deteriorated sleep and cortisol secretion compared with healthy controls and with their presurgery status. METHODS: A total of 27 infants with OFC (mean age: 22 weeks) and 30 healthy controls (mean age: 23 weeks) took part in the study. For infants with OFC, sleep actigraphy was performed and saliva cortisol was analyzed 5 days before, during, and 5 days after surgery. For controls, sleep and saliva cortisol were assessed similarly, except for the period taken up with surgery. RESULTS: Compared with healthy controls, infants with OFC undergoing OFC surgery did not differ in sleep and cortisol secretion. Their sleep and cortisol secretion did deteriorate during the perisurgical period but recovered 5 days postsurgery. CONCLUSION: In infants with OFC undergoing corrective surgery, the pattern of results for sleep and cortisol suggests that OFC surgery does not seem to constitute a traumatic event with long-term consequences.

[Cone beam computed tomography and radiation dosage: application frequency and knowledge of dentists in Switzerland]. / Digitale Volumentomographie und Strahlenbelastung: Kenntnisstand, Anwendungsfrequenz und Indikationsspektrum bei Schweizer Zahnärzten.

The use of cone beam computed tomography (CBCT) among Swiss dentists increases from year to year. The aim of this study was to investigate the application frequency and the knowledge about CBCT and radiation dosage in a representative Swiss dentist sample. A standardized questionnaire about knowledge on CBCT was personally handed out or sent by post to 1,000 dentists in Switzerland (return postage was free of charge). 278 dentists returned the questionnaire. Descriptive statistics, correlation analysis of general variables and written answers of the questionnaires were evaluated. Most dentists were aware of radiation dosage and potential use of the CBCT and are interested in continuing education on CBCT.

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.

One-stage cleft repair outcome at age 6- to 18-years -- a comparison to the Eurocleft study data.

The optimisation of the relation between quality of outcome and burden of care is difficult in the treatment of cleft lip and palate. We analysed long-term outcome after one-stage repair of clefts to assess the benefits and limitations of this form of treatment. Thirty-three patients aged 6-18 years who had had lip repair, two-flap palatoplasty, and corticocancellous alveolar bone grafts at 6 months of age were divided into three age groups (6-11, 12-14, and 15-18 years) and compared with mean outcome data from the Eurocleft centres and with cephalometric standards of healthy people. Fifteen of the 33 patients were assessed for nasalance. Maxillary protrusion (SNA) and intermaxillary relation (ANB) in the one-stage groups differed significantly from those of healthy people, but not from corresponding means in the Eurocleft study. In 61% the Bergland score for alveolar ossification was grade I or II, and in 15% it was grade III; 24% had secondary alveolar bone grafting. No palatal fistulas occurred and nasalance did not differ significantly from that of healthy controls. As each patient generally had a primary operation and one secondary procedure, they benefited from half the number of surgical steps of multistage procedures. However, one-stage procedures led to significant disturbance in growth, but the degree of this was similar to mean values of multistage procedures in the Eurocleft study. Primary alveolar bone grafting led to inconsistent alveolar ossification and was suspected to interfere with anterior maxillary growth so it has been abandoned.

Intraoperative vascular anatomy, arterial blood flow velocity, and microcirculation in unilateral and bilateral cleft lip repair.

BACKGROUND: Cleft lip repair aims to normalize the disturbed anatomy and function. The authors determined whether normalization of blood circulation is achieved. METHODS: The authors measured the microcirculatory flow, oxygen saturation, and hemoglobin level in the lip and nose of controls (n = 22) and in patients with unilateral and bilateral cleft lip-cleft palate. The authors measured these parameters before lip repair (n = 29 and n = 11, respectively), at the end of lip repair (n = 27 and 10, respectively), and in the late postoperative period (n = 33 and n = 20, respectively). The arterial flow velocity was measured in unilateral groups at the same time points (n = 13, n = 11, and n = 12, respectively). Statistical differences were determined using analysis of variance. RESULTS: Before surgery, the arterial flow velocities and microcirculation values were similar on each side of the face and between groups. The microcirculatory flow was significantly higher in the prolabium of bilateral patients than in the philtrum of controls. All circulation values in unilateral and bilateral patients in the late postoperative period were within the range of controls and of those before surgery. Intraoperatively, the authors consistently found a perforating artery on the superficial side of the transverse nasalis muscle. CONCLUSIONS: There appears to be no intrinsic circulatory deficit in unilateral and bilateral cleft lip-cleft palate patients. The increased flow in the prolabium indicates a strong hemodynamic need in this territory, compelling its vascular preservation. Whether surgical preservation of the nasalis perforator artery is of long-term benefit should be addressed in future studies. CLINICAL QUESTION/LEVEL OF EVIDENCE: Therapeutic, V.