Reconstruction of an Extensive Midfacial Defect Using Additive Manufacturing Techniques.

Malignant peripheral nerve sheath tumors are extremely rare tumors arising in peripheral nerves. Only 17 cases involving the trigeminal nerve have ever been reported. These tumors have a very poor prognosis and very high rates of recurrence and metastases. Their recommended treatment involves complete tumor resection followed by radiation. This can be problematic in the head and neck region. We present a clinical case involving a 33-year-old female patient presenting with a slow-growing, exophytic mass of the anterior maxilla. Incisional biopsy and subsequent histological examination revealed a diagnosis of a malignant peripheral nerve sheath tumor. Surgical resection involved a complete maxillectomy, rhinectomy, and resection of the upper lip and aspects of the left and right cheeks. Reconstruction of the subsequent defect incorporated the placement of four zygomatic oncology implants to aid in retention of a facial prosthesis. These implants, however, were subsequently lost; and an anatomical model of the hard tissues was manufactured via 3D printing. This model was used to design and manufacture a titanium frame (customized implant) for the patient. The frame was then fixated and secured intraoperatively with 21 cortical screws. A maxillary denture and silicone facial prosthesis were also made to fit onto this frame. This is the first known case where additive manufacturing, via the use of rapid prototyping and 3D printing, was employed to manufacture a facial prosthesis.

Airway and feeding problems in infants with Fairbairn-Robin triad deformities.

BACKGROUND: The majority of patients with Pierre Robin sequence in the subdivision Fairbairn- Robin triad (FRT), are born with glossoptosis, retro-/micrognathia and cleft or agenesis of the palate leading to feeding difficulties and airway obstruction. There is limited literature on these problems, and on methods used to address them. OBJECTIVES: Community nurses in the Facial Cleft Deformity Clinic evaluate associated airway obstruction and feeding problems and devise nursing interactions to address these. This retrospective study examined the incidence of airway and feeding difficulties in the neonatal, pre-surgical period, as well as the surgical and nutritional management of these infants. METHOD: Retrospective records of 215 infants with FRT were examined and data on incidence, airway and feeding difficulties and surgical and nutritional management was collected. Descriptive statistics, including average and percentage values, were compiled. RESULTS: The incidence of FRT amongst the cleft palate patients was 6.0%, with 37.7% of these having feeding difficulties. However, surgical interventions such as glossopexy (5.6%), distraction osteogenesis (0.9%) and tracheotomy (2.3%) for airway management were seldom required. Most of the infants who had upper airway obstruction and feeding problems were handled by means of suction and drinking plates, along with additional specific feeding aids. This reduced airway obstruction in 70.6%, and feeding problems in 62.4% of these infants. CONCLUSION: Based on this study's finding the introduction of the suction and drinking plate and the use of specific types of feeding devices and surgical management can improve growth and development in infants with FRT.

Influence of rhBMP-2 on bone formation and osseointegration in different implant systems after sinus-floor elevation. An in vivo study on sheep.

BACKGROUND: Several studies have reported certain bone morphogenic proteins (BMPs) to have positive effects on bone generation. Although some investigators have studied the effects of human recombinant BMP (rhBMP-2) in sinus augmentation in sheep, none of these studies looked at the placement of implants at the time of sinus augmentation. Furthermore, no literature could be found to report on the impact that different implant systems, as well as the positioning of the implants had on bone formation if rhBMP-2 was utilized in sinus-lift procedures. PURPOSE: The aim of this study was to compare sinus augmentation with rhBMP-2 on a poly-d, l-lactic-co-glycolic acid gelatine (PLPG) sponge with sinus augmentation with autologous pelvic cancellous bone in the maxillary sinus during the placement of different dental implants. MATERIALS AND METHODS: Nine adult female sheep were submitted to bilateral sinus-floor elevation. In one side (test group) the sinus lift was performed with rhBMP-2 on a PLPG-sponge, while the contralateral side served as the control by using cancellous bone from the iliac crest. Three different implants (Bränemark(®), 3i(®) and Straumann(®)) were inserted either simultaneously with the sinus augmentation or as a two staged procedure 6 weeks later. The animals were sacrificed at 6 and 12 weeks for histological and histomorphometrical evaluations during which bone-to-implant contact (BIC) and bone density (BD) were evaluated. RESULTS: BD and BIC were significantly higher at 12 weeks in the test group if the implants were placed at the time of the sinus lift (p<0.05). No difference was observed between the different implant systems or positions. CONCLUSIONS: The use of rhBMP-2 with PLPG-sponge increased BIC as well as BD in the augmented sinuses if compared to autologous bone. Different implant systems and positions of the implants had no effect on BIC or BD.

Clinical aspects of a 2.0-mm locking plate system for mandibular fracture surgery.

PURPOSE: The use of a 2.0-mm locking plate system was evaluated in mandibular surgery. PATIENTS AND METHODS: 53 patients (42 male, 11 female) with a total of 56 mandibular fractures were treated with a 2.0-mm mini-locking-plate system and retrospectively examined. Gender, age, cause of fracture, surgical access, classification of fractures, osteosynthesis, postsurgical findings and complications were evaluated. RESULTS: Assault in male patients (mean age 31) was the most common aetiological factor. Fractures in women (mean age 43 years) mostly occurred due to falls. Mandibular angle fractures were the most common and this anatomical site also presented the highest complication rate. Only 6% of patients had minor occlusal disturbance postoperatively, and minor complications (infections and dehiscence) occurred in 14% of patients in this study. Major complications only occurred in one patient included in the study (1.9%). Risk factors for the development of complications in this series were a history of alcohol or tobacco use, mandibular angle fractures, associated facial fractures, presurgical occlusal disturbance and concomitant dental infections. Surgical access to the fracture and the interval from injury to surgery was not associated with the development of complications. CONCLUSIONS: The use of a 2.0-mm locking plate system with its advantages of improved handling characteristics, increased stability, shorter surgical time and the preservation of bony perfusion is a viable alternative to conventional miniplates in the management of mandibular fractures.

Pierre Robin sequence: appearances and 25 years of experience with an innovative treatment protocol.

PURPOSE: The aim of the study was to evaluate the largest number of Pierre Robin sequence (PRS) cases to date and its treatment outcome. DESIGN: This is a retrospective study. SETTINGS: The study was conducted in a tertiary care university hospital. PATIENTS: One hundred eighty-eight patients with PRS have been subjected to analysis, defined by the clinical triad of glossoptosis, retro/micrognathia, and cleft or agenesis of the palate, for incidence, risk factors, associated syndromes, other concomitant abnormalities, airway and feeding difficulties, and outcome regarding the neonatal and perinatal surgical and nonsurgical management. RESULTS: The incidence of PRS was 6.02%. Risk factors were found in 41.5% of mothers with children with PRS. Eleven other syndromes/appearances were associated. Feeding difficulties were seen in 51.8% of the patients. Glossopexy (6.9%) and tracheotomy (2.13%) for airway management were performed very seldom. The suction and drinking plate as well as the surgical treatment protocol may be considered to be the reasons for reduced airway (up to 91.0%), feeding problems (up to 79.9%), and mortality rate (2.1%). CONCLUSION: The Pierre Robin sequence, as seen as a heterogeneous group, presents with variation of the cleft palate defects with glossoptosis and concomitant micrognathic mandible. The surgical management and certain prepalatal intervention as nonsurgical management with an innovative treatment strategy were evaluated.

A novel approach for the selection of human sperm using annexin V-binding and flow cytometry.

OBJECTIVE: To develop a method whereby sperm with phosphatidylserine externalization can be separated from those without this feature. Because annexin V binds phosphatidylserine, this study is using this feature to select functional spermatozoa. In addition, the relationship between annexin V binding in human spermatozoa and normal sperm morphology according to strict criteria was to be assessed. DESIGN: Prospective study. SETTING: Department of Obstetrics and Gynaecology of Stellenbosch University at Tygerberg Academic Hospital, Tygerberg, South Africa. PATIENT(S): Semen from 14 healthy sperm donors. Exclusion criterion was the presence of less than 20 x 10(6)/mL total motile spermatozoa in the original sample. MAIN OUTCOME MEASURE(S): Annexin V-negative sperm, annexin V-positive sperm, normal sperm morphology. INTERVENTION(S): An aliquot of a semen sample after double density gradient centrifugation was incubated with annexin V fluorescein isothiocyanate conjugate (FITC). Cell fluorescence signals were determined using a FACScalibur flow cytometer equipped with a FACSSort fluidic sorting module. The sorting procedure delivered two sperm subpopulations: annexin V-negative and annexin V-positive. Morphology slides were made and the sperm morphology was assessed according to strict criteria. RESULT(S): There was a significant enrichment of annexin V-negative sperm as well as morphologically normal sperm in the annexin V-negative subgroup after separation with flow cytometry. The percentage of morphologically normal sperm increased from 8.3% in the control to 11.9% in the annexin V-negative fraction, whereas the percentage of annexin V-positive sperm decreased to 5.7%. CONCLUSION(S): The annexin V-negative sperm subpopulation had morphologically superior quality sperm compared to annexin V-positive sperm. It is important to select morphologically normal sperm during intracytoplasmic sperm injection (ICSI) as it may contribute to increased implantation and pregnancy rates (PR).

Influence of deoxyribonucleic acid damage on fertilization and pregnancy.

OBJECTIVE: To investigate sperm DNA damage in relation to fertilization and pregnancy. DESIGN: Prospective study. SETTING: The Institute of Reproductive Medicine, Giessen, Germany. PATIENT(S): Semen collected from 249 patients attending the IVF program. MAIN OUTCOME MEASURE(S): The percentage of terminal deoxynucleotidyl transferase-mediated dUDP nick-end labeling- (TUNEL-), Fas-, and annexin-V-positive sperm and the proportion of green-fluorescing sperm in the acridine orange stain was determined and correlated with sperm concentration, motility, fertilization, and pregnancy. RESULT(S): Significant correlations with the concentration of motile sperm were only found for the acridine orange stain (before and after sperm separation) and for the TUNEL assay (after sperm separation). Moreover, patients whose sperm had a high percentage of DNA fragmentations showed significantly lower pregnancy rates (TUNEL assay: 19.05% vs. 34.65%; acridine orange stain: 24.58% vs. 37.93%). The apoptosis parameters (annexin V binding and Fas expression) showed no statistically significant differences. CONCLUSIONS: Our data clearly demonstrate that DNA fragmentation, as determined by the TUNEL assay, is predictive for pregnancy in IVF. This implies that spermatozoa with DNA fragmentation can still fertilize an oocyte but that when paternal genes are "switched on," further embryonic development stops, resulting in failed pregnancy. It seems that, at least in the patients we analyzed, apoptosis in the sperm does not play a role for fertilization. This would imply that DNA fragmentation in human spermatozoa is caused by external factors, such as reactive oxygen species, rather than by apoptosis.

DNA fragmentation of spermatozoa and assisted reproduction technology.

Despite the ever-increasing knowledge of the fertilization process, there is still a need for better understanding of the causes of sperm DNA fragmentation and its impact on fertilization and pregnancy. For this reason, human sperm DNA fragmentation was investigated by means of the terminal deoxynucleotidyl transferase-mediated dUDP nick-end labelling (TUNEL) assay and the production of reactive oxygen species (ROS) in the ejaculate and in the spermatozoa themselves. These data were correlated with fertilization and pregnancy data from IVF and intracytoplasmic sperm injection (ICSI) patients. Sperm DNA fragmentation did not correlate with fertilization rate, but there was a significantly reduced pregnancy rate in IVF patients inseminated with TUNEL-positive spermatozoa. ICSI patients exhibited the same tendency. This implies that spermatozoa with damaged DNA are able to fertilize an oocyte, but at the time the paternal genome is switched on, further development stops. The determination of ROS in the ejaculate and the percentage of ROS-producing spermatozoa revealed markedly stronger correlations between sperm functions (i.e. motility) and the percentage of ROS-producing spermatozoa. The influence of seminal leukocytes, known to produce large amounts of oxidants, on sperm DNA fragmentation should not be neglected.