Quantitative Assessment of Point-of-Care 3D-Printed Patient-Specific Polyetheretherketone (PEEK) Cranial Implants.

Recent advancements in medical imaging, virtual surgical planning (VSP), and three-dimensional (3D) printing have potentially changed how today's craniomaxillofacial surgeons use patient information for customized treatments. Over the years, polyetheretherketone (PEEK) has emerged as the biomaterial of choice to reconstruct craniofacial defects. With advancements in additive manufacturing (AM) systems, prospects for the point-of-care (POC) 3D printing of PEEK patient-specific implants (PSIs) have emerged. Consequently, investigating the clinical reliability of POC-manufactured PEEK implants has become a necessary endeavor. Therefore, this paper aims to provide a quantitative assessment of POC-manufactured, 3D-printed PEEK PSIs for cranial reconstruction through characterization of the geometrical, morphological, and biomechanical aspects of the in-hospital 3D-printed PEEK cranial implants. The study results revealed that the printed customized cranial implants had high dimensional accuracy and repeatability, displaying clinically acceptable morphologic similarity concerning fit and contours continuity. From a biomechanical standpoint, it was noticed that the tested implants had variable peak load values with discrete fracture patterns and failed at a mean (SD) peak load of 798.38 ± 211.45 N. In conclusion, the results of this preclinical study are in line with cranial implant expectations; however, specific attributes have scope for further improvements.

Cold Ablation Robot-Guided Laser Osteotome (CARLO®): From Bench to Bedside.

BACKGROUND: In order to overcome the geometrical and physical limitations of conventional rotating and piezosurgery instruments used to perform bone osteotomies, as well as the difficulties in translating digital planning to the operating room, a stand-alone robot-guided laser system has been developed by Advanced Osteotomy Tools, a Swiss start-up company. We present our experiences of the first-in-man use of the Cold Ablation Robot-guided Laser Osteotome (CARLO®). METHODS: The CARLO® device employs a stand-alone 2.94-µm erbium-doped yttrium aluminum garnet (Er:YAG) laser mounted on a robotic arm. A 19-year-old patient provided informed consent to undergo bimaxillary orthognathic surgery. A linear Le Fort I midface osteotomy was digitally planned and transferred to the CARLO® device. The linear part of the Le Fort I osteotomy was performed autonomously by the CARLO® device under direct visual control. All pre-, intra-, and postoperative technical difficulties and safety issues were documented. Accuracy was analyzed by superimposing pre- and postoperative computed tomography images. RESULTS: The CARLO® device performed the linear osteotomy without any technical or safety issues. There was a maximum difference of 0.8 mm between the planned and performed osteotomies, with a root-mean-square error of 1.0 mm. The patient showed normal postoperative healing with no complications. CONCLUSION: The newly developed stand-alone CARLO® device could be a useful alternative to conventional burs, drills, and piezosurgery instruments for performing osteotomies. However, the technical workflow concerning the positioning and fixation of the target marker and the implementation of active depth control still need to be improved. Further research to assess safety and accuracy is also necessary, especially at osteotomy sites where direct visual control is not possible. Finally, cost-effectiveness analysis comparing the use of the CARLO® device with gold-standard surgery protocols will help to define the role of the CARLO® device in the surgical landscape.

Comparing the Bone Healing After Cold Ablation Robot-Guided Er:YAG Laser Osteotomy and Piezoelectric Osteotomy-A Pilot Study in a Minipig Mandible.

BACKGROUND AND OBJECTIVE: To take major advantage of erbium-doped yttrium aluminium garnet (Er:YAG) lasers in osteotomy-like freedom of cutting geometries and high accuracy-the integration and miniaturization of the robot, laser, and navigation technology was tried and applied to minipigs. The investigators hypothesized laser osteotomy would render acceptable bone healing based on the intraoperative findings and postoperative cut surface analysis. STUDY DESIGN/MATERIALS AND METHODS: We designed and implemented a comparative bone-cutting surgery in the minipig mandible with a cold ablation robot-guided Er:YAG laser osteotome (CARLO) and a piezoelectric (PZE) osteotome. The sample was composed of different patterns of defects in the mandibles of six grown-up female Goettingen minipigs. The predictor variable was Er:YAG osteotomy and PZE osteotomy. The outcome variable was the cut surface characteristics and bone healing at 4 and 8 weeks postoperatively. Descriptive and qualitative comparison was executed. RESULTS: The sample was composed of four kinds of bone defects on both sides of the mandibles of six minipigs. We observed more bleeding during the operation, open-cut surfaces, and a faster healing pattern with the laser osteotomy. There was a possible association between the intraoperative findings, postoperative cut surface analysis, and the bone healing pattern. CONCLUSIONS: The results of this study suggest that characteristic open-cut surfaces could explain favorable bone healing after laser osteotomy. Future studies will focus on the quantification of the early healing characteristics after laser osteotomy, its diverse application, and the safety feature. Lasers Surg. Med. © 2020 Wiley Periodicals LLC.

A simple, effective, universal, and reusable osteotomy tool for jaw reconstructions with microvascular fibula transplants.

BACKGROUND: Precise, expensive individual saw guides are used with increasing frequency for the reconstruction of mandibular defects with fibular grafts. In this report, an alternative is presented - the Multiuse Cutting Jig (MUC-Jig, proprietary development). It is reusable, suitable for all patients, requires simple planning based on conventional CT imaging, and is more economical. METHODS: To investigate its precision, we conducted a nonblinded experimental study, with ten participating craniomaxillofacial surgeons. Osteotomies of four different fibula segments were carried out at the same angulation, with groups defined according to the proximal and distal fixed angulation: 45°, 30°, 15°, or 0°. The sagittal cut was performed proximally, with the coronal cut performed distally. The resulting 40 segments (n = 40) were analyzed with their Tx length (primary endpoint) and osteotomy angles, and compared to the original planning. RESULTS: The mean (SD) relative deviation of all grafts from the original planning was -0.08 mm (1.12) in length and -0.71° (3.15) for the angle. Only 45° (-2.04 ±â€¯3.71°) and 30° (-1.07 ±â€¯2.52°) cuts differed significantly (p < 0.05) from smaller angle grafts. The mean (SD) absolute deviation was 0.81 mm (0.27) in length and 2.13° (0.93) in graft angles. For individual transplants, 45° cuts (1.28 ±â€¯1.03 mm) differed significantly (p < 0.005) from others. We observed no differences in relative length or absolute angle deviation. CONCLUSIONS: The MUC-Jig is precise and cost-effective for osteotomies with medium angles and smooth reconstructions of template-guided procedures.

Oct4 and Hnf4α-induced hepatic stem cells ameliorate chronic liver injury in liver fibrosis model.

Direct conversion from fibroblasts to generate hepatocyte like-cells (iHeps) bypassing the pluripotent state has been described in previous reports as an attractive method acquiring hepatocytes for cell-based therapy. The limited proliferation of iHeps, however, has hampered it uses in cell-based therapy. Since hepatic stem cells (HepSCs) possess self-renewal and bipotency with the capacity to differentiate into both hepatocytes and cholangiocytes, they have therapeutic potential for treating liver disease. Here, we investigated the therapeutic effects of induced HepSCs (iHepSCs) on a carbon tetrachloride (CCl4)-induced liver fibrosis model. We demonstrate that Oct4 and Hnf4a are sufficient to convert fibroblasts into expandable iHepSCs. Hepatocyte-like cells derived from iHepSCs (iHepSC-HEPs) exhibit the typical morphology of hepatocytes and hepatic functions, including glycogen storage, low-density lipoprotein (LDL) uptake, Indocyanine green (ICG) detoxification, drug metabolism, urea production, and albumin secretion. iHepSCs-derived cholangiocyte-like cells (iHepSC-CLCs) expressed cholangiocyte-specific markers and formed cysts and tubule-like structures with apical-basal polarity and secretory function in three-dimensional culture condition. Furthermore, iHepSCs showed anti-inflammatory and anti-fibrotic effects in CCl4-induced liver fibrosis. This study demonstrates that Oct4 and Hnf4α-induced HepSCs show typical hepatic and biliary functionality in vitro. It also presents the therapeutic effect of iHepSCs in liver fibrosis. Therefore, directly converting iHepSCs from somatic cells may facilitate the development of patient-specific cell-based therapy for chronic liver damage.

The Use of Finite Element Method Analysis for Modeling Different Osteotomy Patterns and Biomechanical Analysis of Craniosynostosis Correction.

PURPOSE: Several post-processing algorithms for 3D visualization of the skull in craniosynostosis with their specific advantages and disadvantages have been already described. The Finite Element Method (FEM) described herein can also be used to evaluate the efficacy of the cutting patterns with respect to an increase in the projected surface area under assumed uniform loading of the manipulated and cut bone segments. METHODS: The FEM analysis was performed. Starting with the classic cranial osteotomies for bifrontal craniotomy and orbital bandeau a virtually mirroring of the unaffected triangular shaped frontal bone was performed to achieve a cup-shaped sphere of constant thickness of 2.5 mm with a radius of 65 mm. Mechanical properties required for the analysis were Young's modulus of 340 MPa and Poisson's ratio of 0.22. Four different cutting patterns from straight to curved geometries have been projected onto the inner surface of the sphere with a cutting depth set to 2/3rds of the shell thickness. The necessary force for the deformation, the resulting tensions and the volume loss due to the osteotomy pattern were measured. RESULTS: Better outcomes were realized with pattern D. The necessary force was 73.6% smaller than the control group with 66N. Best stress distribution was achieved. Curved cutting patterns led to the highest peak of stress and thus to a higher risk of fracture. Straight bone cuts parallel to the corners or to the thighs of the sphere provided a better distribution of stresses with a small area with high stress. Additionally, also with pattern D a surface increase of 20.7% higher than reference was registered. CONCLUSION: As a proof of concept for different cutting geometries for skull molding in the correction of craniosynostosis, this computational model shows that depending of the cutting pattern different biomechanical behavior is achieved.

Accuracy of soft tissue prediction in surgery-first treatment concept in orthognathic surgery: A prospective study.

PURPOSE: The purpose of this study was to provide a quantitative accuracy assessment of soft tissue predictions generated by a computer-aided maxillofacial planning system in patients undergoing orthognathic surgery following the "surgery-first" treatment. MATERIALS AND METHODS: For this study, we looked at 16 patients with open bite dentofacial-dysmorphosis who underwent orthognathic surgery. Surgeries were planned using conventional sketches and the newly developed computer-assisted SOTIRIOS planning software (developed by the authors). Validation procedures were performed in the following steps: (1) Standardized registration of the pre- and postoperative CT volumes; (2) Automated adjustment of the bone-related preoperative planning to the actual postoperative bony displacement; (3) Simulation of soft tissue changes according to the definitive bony movements; and (4) Calculation of soft tissue differences between the predicted and the actual 6-month postoperative results by distance mapping. RESULTS: The program produced a clinically satisfactory 3D soft tissue prediction, with a mean error of 1.46 mm ± 1.53 mm. The program was suitable for use in virtual surgical planning without technical assistance. CONCLUSION: This study shows that the program is quite accurate, enabling the surgeon to predict the outcome of the soft tissue. This has the potential to promote the routine application of the surgery-first approach in patients suffering from open bite.

Performing partial mandibular resection, fibula free flap reconstruction and midfacial osteotomies with a cold ablation and robot-guided Er:YAG laser osteotome (CARLO®) - A study on applicability and effectiveness in human cadavers.

OBJECTIVE: Aim of the study was to prove the safety, accuracy characteristics of contact-free laser osteotomy executed with the cold ablation and robot-guided Er:YAG laser osteotome in a human cadaver test. MATERIAL AND METHODS: On six human cadavers mandible resections with a swallowtail like pattern were performed with the laser system on each side. The defects were reconstructed with a fibula graft of identical design and enlarged by 0.2 units. Mandibles and fibulas width as well surgery times were recorded. Additionally a Le Fort I and median mandible split were done. Macroscopically, the bone margins were examined for necrosis. RESULTS: Laser osteotomies of the mandible up to a depth of 23 mm were possible without any thermal damage. Repeatability and precision of the system could be easily assessed. With the navigation system precise control of localization was achievable. Mean surgery time for the mandible resection was 13.32 min and for the fibula osteotomy 12.38 min. CONCLUSION: The simply transmission of a cold ablation and robot-guided laser osteotome in an operation room identical environment for surgical interventions could be demonstrated. Precise osteotomy patterns with freedom in the design and carbonisation-free cut surfaces have been shown.

A worldwide comparison of the management of surgical treatment of advanced oral cancer.

INTRODUCTION: Microvascular surgery following tumor resection has become an important field of oral and maxillofacial surgery (OMFS). Following the results from management of T1/T2 floor-of-mouth and tongue squamous cell carcinoma (SCC) in German-speaking countries, Europe, and worldwide, this paper presents specific concepts for the management of resection and reconstruction of T3/T4 SCC of the maxillary and mandibular alveolar process and tongue. METHODS: The DÖSAK questionnaire was distributed in three different phases to a growing number of maxillofacial units worldwide. Within this survey, clinical patient settings were presented to participants and center-specific treatment strategies were evaluated. RESULTS: A total of 188 OMFS units from 36 different countries documented their treatment strategies for T3/T4 maxillary and mandibular alveolar process and tongue SCC. The extent of surgical resections and subsequent reconstructions is more consistent than with T1/T2 tumors, although the controversy surrounding continuity resections and mandible-sparing procedures remains. For continuity resection of the mandible the fibula free flap is the most frequently used bone replacement, whereas maxilla reconstruction concepts are less consistent, ranging from locoregional coverage concepts and different microvascular reconstruction options to treatment via obturator prosthesis. CONCLUSION: Results from treatment strategies for T3/T4 tumors underline the limited evidence for the appropriate amount of resection and subsequent reconstruction process, especially in cases involving the mandible. Prospective randomized trials will be necessary in the long term to establish valid treatment guidelines.

Facial asymmetry correction with moulded helmet therapy in infants with deformational skull base plagiocephaly.

PURPOSE: The recommendation issued by the American Academy of Pediatrics in the early 1990s to position infants on their back during sleep to prevent sudden infant death syndrome (SIDS) has dramatically reduced the number of deaths due to SIDS but has also markedly increased the prevalence of positional skull deformation in infants. Deformation of the base of the skull occurs predominantly in very severe deformational plagiocephaly and is accompanied by facial asymmetry, as well as an altered ear position, called ear shift. Moulded helmet therapy has become an accepted treatment strategy for infants with deformational plagiocephaly. The aim of this study was to determine whether facial asymmetry could be corrected by moulded helmet therapy. MATERIALS AND METHODS: In this retrospective, single-centre study, we analysed facial asymmetry of 71 infants with severe deformational plagiocephaly with or without deformational brachycephaly who were undergoing moulded helmet therapy between 2009 and 2013. Computer-assisted, three-dimensional, soft-tissue photographic scanning was used to record the head shape before and after moulded helmet therapy. The distance between two landmarks in the midline of the face (i.e., root of the nose and nasal septum) and the right and left tragus were measured on computer-generated indirect and objective 3D photogrammetry images. A quotient was calculated between the two right- and left-sided distances to the midline. Quotients were compared before and after moulded helmet therapy. Infants without any therapy served as a control group. RESULTS: The median age of the infants before onset of moulded helmet therapy was 5 months (range 3-16 months). The median duration of moulded helmet therapy was 5 months (range 1-16 months). Comparison of the pre- and post-treatment quotients of the left vs. right distances measured between the tragus and root of the nose (n = 71) and nasal septum (n = 71) revealed a significant reduction of the asymmetry (Tragus-Nasion-Line Quotient: 0.045-0.022; p < 0.0001; Tragus-Subnasale-Line Quotient: 0.045-0.021; p < 0.0001). The control group without treatment showed no significant change in the quotient (Tragus-Nasion-Line Quotient no helmet: 0.049-0.055/Tragus-Subnasale-Line Quotient no helmet: 0.039-0.055). CONCLUSION: Moulded helmet therapy can correct facial symmetry in infants with deformational plagiocephaly and associated facial and basal skull asymmetry.

A worldwide comparison of the management of T1 and T2 anterior floor of the mouth and tongue squamous cell carcinoma - Extent of surgical resection and reconstructive measures.

INTRODUCTION: Microvascular surgery following tumor resection has become an important field of oral maxillofacial surgery (OMFS). Following the results on general aspects of current reconstructive practice in German-speaking countries, Europe and worldwide, this paper presents specific concepts for the management of resection and reconstruction of T1/T2 squamous cell carcinoma (SCC) of the anterior floor of the mouth and tongue. METHODS: The DOESAK questionnaire was distributed in three different phases to a growing number of maxillofacial units worldwide. Within this survey, clinical patient settings were presented to participants and center-specific treatment strategies were evaluated. RESULTS: A total of 188 OMFS units from 36 different countries documented their treatment strategies for T1/T2 anterior floor of the mouth squamous cell carcinoma and tongue carcinoma. For floor of mouth carcinoma close to the mandible, a wide variety of concepts are presented: subperiosteal removal of the tumor versus continuity resection of the mandible and reconstruction ranging from locoregional closure to microvascular bony reconstruction. For T2 tongue carcinoma, concepts are more uniform. CONCLUSION: These results demonstrate the lack of evidence and the controversy of different guidelines for the extent of safety margins and underline the crucial need of global prospective randomized trials on this topic to finally obtain evidence for a common guideline based on a strong community of OMFS units.

Microsurgical reconstruction of the head and neck region: Current concepts of maxillofacial surgery units worldwide.

INTRODUCTION: Microvascular surgery following tumor resection has become an important field of oral maxillofacial surgery (OMFS). Following the surveys on current reconstructive practice in German-speaking countries and Europe, this paper presents the third phase of the project when the survey was conducted globally. METHODS: The DOESAK questionnaire has been developed via a multicenter approach with maxillofacial surgeons from 19 different hospitals in Germany, Austria and Switzerland. It was distributed in three different phases to a growing number of maxillofacial units in German-speaking clinics, over Europe and then worldwide. RESULTS: Thirty-eight units from Germany, Austria and Switzerland, 65 remaining European OMFS-departments and 226 units worldwide responded to the survey. There is wide agreement on the most commonly used flaps, intraoperative rapid sections and a trend towards primary bony reconstruction. No uniform concepts can be identified concerning osteosynthesis of bone transplants, microsurgical techniques, administration of supportive medication and postoperative monitoring protocols. Microsurgical reconstruction is the gold standard for the majority of oncologic cases in Europe, but worldwide, only every second unit has access to this technique. CONCLUSION: The DOESAK questionnaire has proven to be a valid and well accepted tool for gathering information about current practice in reconstructive OMFS surgery. The questionnaire has been able to demonstrate similarities, differences and global inequalities.

How much dentists are ethically concerned about overtreatment; a vignette-based survey in Switzerland.

BACKGROUND: Overtreatment (or unnecessary treatment) is when medical or dental services are provided with a higher volume or cost than is appropriate. This study aimed to investigate how a group of dentists in Switzerland, a wealthy country known to have high standards of healthcare including dentistry, evaluated the meaning of unnecessary treatments from an ethical perspective and, assessed the expected frequency of different possible behaviors among their peers. METHODS: A vignette describing a situation that is susceptible for overtreatment of a patient was presented to a group of dentists. The vignette was followed by five options. A questionnaire including the vignette was posted to 2482 dentists in the German-speaking areas of Switzerland. The respondents were asked to rate each option according to their estimation about its prevalence and their judgment about the degree to which the behavior is ethically sound. RESULTS: 732 completed questionnaires were returned. According to the responses, the most ethical and the most unethical options are considered to be the most and the least prevalent behaviors among dentists practicing in Switzerland, respectively. CONCLUSIONS: Suggesting unnecessary treatments to patients seems to be an ethically unacceptable conduct in the eyes of a sample of dentists in Switzerland. Although the respondents believed their colleagues were very likely to behave in an ethical way in response to a situation that is susceptible to overtreatment, they still seemed to be concerned about the prevalence of unethical behaviors in this regard.

A comparative investigation of bone surface after cutting with mechanical tools and Er:YAG laser.

BACKGROUND AND OBJECTIVES: Despite of the long history of medical application, laser ablation of bone tissue became successful only recently. Laser bone cutting is proven to have higher accuracy and to increase bone healing compared to conventional mechanical bone cutting. But the reason of subsequent better healing is not biologically explained yet. In this study we present our experience with an integrated miniaturized laser system mounted on a surgical lightweight robotic arm. STUDY DESIGN/MATERIALS AND METHODS: An Erbium-doped Yttrium Aluminium Garnet (Er:YAG) laser and a piezoelectric (PZE) osteotome were used for comparison. In six grown up female Göttingen minipigs, comparative surgical interventions were done on the edentulous mandibular ridge. Our laser system was used to create different shapes of bone defects on the left side of the mandible. On the contralateral side, similar bone defects were created by PZE osteotome. Small bone samples were harvested to compare the immediate post-operative cut surface. RESULTS: The analysis of the cut surface of the laser osteotomy and conventional mechanical osteotomy revealed an essential difference. The scanning electron microscopy (SEM) analysis showed biologically open cut surfaces from the laser osteotomy. The samples from PZE osteotomy showed a flattened tissue structure over the cut surface, resembling the "smear layer" from tooth preparation. CONCLUSIONS: We concluded that our new finding with the mechanical osteotomy suggests a biological explanation to the expected difference in subsequent bone healing. Our hypothesis is that the difference of surface characteristic yields to different bleeding pattern and subsequently results in different bone healing. The analyses of bone healing will support our hypothesis.

A computer-based comparative quantitative analysis of surgical outcome of mandibular reconstructions with free fibula microvascular flaps.

The free fibula osteoseptocutaneous flap is the standard for reconstruction of extensive mandibular defects. The procedure must be precise to achieve the required functional and aesthetic results. The aim of the present study was to calculate retrospectively the exact differences in surgical outcome based on preoperative and postoperative Computed Tomography data sets. Ten patients with unilateral reconstructions of the mandible with a fibula based on conventional planning were analyzed quantitatively, applying mirroring techniques with direct comparison of the theoretically optimum with the actual reconstruction. The results showed that there is a significant discrepancy between what is actually achieved and the theoretical optimum. The result of the present retrospective analysis shows that there is room for further improvement of the outcome in complex mandible reconstruction cases.

Microsurgical reconstruction of the head and neck--current concepts of maxillofacial surgery in Europe.

INTRODUCTION: Microvascular surgery following tumour resection has become an important field of oral maxillofacial surgery (OMFS). This paper aims to evaluate current microsurgical practice in Europe. METHODS: The questionnaire of the DOESAK collaborative group for Microsurgical Reconstruction was translated into English, transformed into an online based survey and distributed to 200 OMFS units with the aid of the European Association for Cranio-Maxillo-Facial Surgery (EACMFS). RESULTS: 65 complete and 72 incomplete questionnaires were returned. Hospitals from the United Kingdom, France, Italy, the Netherlands, Spain, Belgium, Greece, Slovenia and Lithuania participated. 71% of contributing centres were university hospitals, 87% out of these perform microvascular tumour surgery at least on a two-weekly base. Overall complication rate was at around five percent. Most frequently used transplants were the radial forearm flap and the fibular flap. The perioperative management varied widely. Success factors for flap survival, however, were uniformly rated, with the surgical skill being the most important factor, followed by the quality of postoperative management. Medication seems to play a less important role. CONCLUSION: Within Europe microvascular surgery is a common and safe procedure for maxillofacial reconstructive surgery in the field of OMFS. While there is a major accordance for the surgical procedure itself and the most frequently used flaps, perioperative management shows a wide variety of protocols with low presumed impact on surgical outcome.

[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.

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.

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.

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.