Evaluation of the surface damage of dental implants caused by different surgical protocols: an in vitro study.

The implant surface must withstand high insertion torque during implant insertion. The aim of this study was to investigate the damage to implant surfaces caused by two different insertion protocols in vitro. Fifteen titanium implants per group were inserted in standardized polyurethane foam models, group 1 according to a non-threaded surgical protocol and group 2 according to a threaded surgical protocol. Before and after insertion, the surfaces were visualized by scanning electron microscopy (SEM) and non-contact laser profilometry. Different surface area parameters were evaluated and maximum torque during insertion was determined. SEM detected topographical changes such as deposition of the test block and smoothening of the surface in the region of the thread crests in both groups. The laser profilometry analysis revealed significant changes in the surface topography of the implants in both groups, but no differences between the groups. Insertion torque was significantly decreased in the threaded group. Both types of surgical intervention resulted in surface damage. Less damage was detected to the thread crests with the use of a thread cutter, and most of the surface was not visibly affected by the surgical protocol at the microscopic level. The surgical protocol seems to have a minor influence on preservation of the implant surface.

Oral Squamous Carcinoma Cells Express B7-H1 and B7-DC Receptors in Vivo.

B7-H1 and B7-DC ligands are members of the B7 family with important regulatory functions in cell-mediated immune response. Both receptors are ligands of the programmed death receptor PD-1. B7-H1 expression has been detected in the majority of human carcinomas in vivo. B7-H1 mediated signals are able to negatively regulate activated T cell functions and survival, and enable tumor cells to overcome host response. The aim of this study was to investigate the expression of B7-H1 and B7-DC proteins in oral squamous cell carcinomas (OSCC) in vivo. Tissues from 15 samples were cryo-sected and following histological routine staining (HE), incubated with antibodies against human B7-H1 and B7-DC. Immuno-staining of pan-cytokeratin was performed to ascertain the epithelial origin of the tissue and CK 19 to demonstrate the proliferating stage. Confocal laser scanning microscopy confirmed the presence of both B7-H1 and B7-DC in all 15 OSCC. The B7-H1 and B7-DC staining was located in areas of the tissue that were identified as cancerous lesions in the previously stained HE sections before. Staining with Pan-CK and CK19 provided evidence for the epithelial origin and the proliferating stage of the tissue. The in vivo expression of the B7-H1 and B7-DC receptors in oral squamous cell carcinomas suggest that general mechanisms for immune evasion of tumors are also found in OSCC.

A retrospective analysis of preoperative staging modalities for oral squamous cell carcinoma.

BACKGROUND: An accurate preoperative assessment of cervical lymph node status is a prerequisite for individually tailored cancer therapies in patients with oral squamous cell carcinoma. The detection of malignant spread and its treatment crucially influence the prognosis. The aim of the present study was to analyze the different staging modalities used among patients with a diagnosis of primary oral squamous cell carcinoma between 2008 and 2015. MATERIAL AND METHODS: An analysis of preoperative staging findings, collected by clinical palpation, ultrasound, and computed tomography (CT), was performed. The results obtained were compared with the results of the final histopathological findings of the neck dissection specimens. A statistical analysis using McNemar's test was performed. RESULTS: The sensitivity of CT for the detection of malignant cervical tumor spread was 74.5%. The ultrasound obtained a sensitivity of 60.8%. Both CT and ultrasound demonstrated significantly enhanced sensitivity compared to the clinical palpation with a sensitivity of 37.1%. No significant difference was observed between CT and ultrasound. A combination of different staging modalities increased the sensitivity significantly compared with ultrasound staging alone. No significant difference in sensitivity was found between the combined use of different staging modalities and CT staging alone. The highest sensitivity, of 80.0%, was obtained by a combination of all three staging modalities: clinical palpation, ultrasound and CT. CONCLUSIONS: The present study indicates that CT has an essential role in the preoperative staging of patients with oral squamous cell carcinoma. Its use not only significantly increases the sensitivity of cervical lymph node metastasis detection but also offers a preoperative assessment of local tumor spread and resection borders. An additional non-invasive cervical lymph node examination increases the sensitivity of the tumor staging process and reduces the risk of occult metastasis.

Lethal cervical abscess following bisphosphonate related osteonecrosis of the jaw.

CONTEXT: Bisphosphonates are common drugs used in the management of bone metabolic diseases. Because of their recently increased use, their adverse effects, especially bisphosphonate-related osteonecrosis of the jaw (BRONJ), are monitored more frequently. BRONJ is a critical challenge in craniofacial surgery and is difficult to treat. Its occurrence is either spontaneous or follows dentoalveolar surgery. Typical complications of BRONJ are painful exposed bone, pathological fractures, extra-oral fistula, and local infections. OBJECTIVE: The aim of this paper is to report a rare case of bacterial embolism in the internal jugular vein after a BRONJ-induced submandibular abscess resulting in bacterial sepsis, multi-organ failure syndrome, and death. CASE ILLUSTRATION: A 59-year-old female patient developed severe BRONJ (stage II) with recurrent abscesses after oral osteoporosis therapy with alendronic acid. A subsequent submandibular abscess led to bacterial embolism of the left internal jugular vein, causing sepsis and death. DISCUSSION: Prevention, early detection and management of BRONJ remain a crucial challenge in craniofacial clinical practice. Despite several therapeutic approaches described in the current literature, none have undergone bedside application. CONCLUSION: Considering this report of death after recurrent abscesses following BRONJ, the use of bisphosphonates should be carefully monitored in order to prevent such severe complications.

Nonsynostotic cranial deformity: a six-month matched-pair photogrammetric comparison of treated and untreated infants.

Objective : To photogrammetrically objectify changes in nonsynostotic craniofacial deformity in orthotically treated versus untreated infants. Design : A statistical retrospective pairwise comparison of two respective three-dimensional (3D) photo scans of 80 children performed in a 6-month time lag. Patients : Two comparable samples of children (40 treated, 40 untreated) with nonsynostotic cranial deformity. Interventions : Respective 3D photo scans were matched using Cranioform Analytics 4.0 software. Main Outcome Measures : Median change of 30° Cranial Vault Asymmetry Index (CVAI), modified CVAI (CVAImod), Cranial Index (CI), and posterior symmetry ratio (PSR). Results : We found an improvement in Δ30° CVAI by 3.3% (treated) and by 1.31% (untreated), respectively. CVAImod improved by 3.46% in the treated group and by 1.55% in the untreated group. CI improved by 4.41% in the treated group and by 3.68% in the untreated group, and PSR improved by 0.71 in the treated group and 0.49 in the untreated group. Although improvement of cranial asymmetry was higher in those children treated with an individual molding orthosis, we could not document a statistically significant difference between the two groups. Conclusions : Helmet therapy may be less appropriate for the correction of brachycephaly than for cranial asymmetry. Nonsynostotic cranial deformity shows some spontaneous correction. Photogrammetry presents an accurate method to objectify craniofacial changes in early infancy.

Non-linear 3D evaluation of different oral implant-abutment connections.

Micro-gaps and osseous overload in the implant-abutment connection are the most common causes of peri-implant bone resorption and implant failure. These undesirable events can be visualized on standardized three-dimensional finite element models and by radiographic methods. The present study investigated the influence of 7 available implant systems (Ankylos, Astra, Bego, Brånemark, Camlog, Straumann, and Xive) with different implant-abutment connections on bone overload and the appearance of micro-gaps in vitro. The individual geometries of the implants were transferred to three-dimensional finite element models. In a non-linear analysis considering the pre-loading of the occlusion screw, friction between the implant and abutment, the influence of the cone angle on bone strain, and the appearance of micro-gaps were determined. Increased bone strains were correlated with small (< 15°) cone angles. Conical implant-abutment connections efficiently avoided micro-gaps but had a negative effect on peri-implant bone strain. Bone strain was reduced in implants with greater wall thickness (Ankylos) or a smaller cone angle (Bego). The results of our in silico study provide a solid basis for the reduction of peri-implant bone strain and micro-gaps in the implant-abutment connection to improve long-term stability.

Accuracy of three-dimensional photogrammetric images in non-synostotic cranial deformities.

OBJECTIVE: Given the increasing incidence of deformational plagiocephaly due to infants' supine sleeping position to prevent sudden infant death syndrome, reliable anthropometric diagnostics are needed. Besides the traditional method of measuring landmarks with callipers, three-dimensional (3D) photography has great potential. In this investigation the accuracy of 3D photogrammetry is studied. METHODS: The study included 100 randomly chosen children between the ages of 4 and 20 months with a non-synostotic cranial deformity in a retrospective analysis. Measurements of diagonals A and B on the infant's head were obtained once using callipers. 3D photographs of these children were measured 5 times by 5 clinicians separately. RESULTS: The inter- and intra-rater agreements of the 3D measurements had low variability in the variance component analysis. The standard deviations for reproducibility and repeatability were 0.117-0.283 cm for diagonals A and B. The intra-class correlation coefficients for the inter-rater reliability resulted in excellent agreement (0.97 for plagiocephaly, 0.98 for brachycephaly, 0.96 for combined deformity). The comparison of the 3D photographic and callipers measurements showed that 3D photography resulted in a slight over-estimation. CONCLUSION: 3D photogrammetry is potentially a reliable tool for treatment planning and follow-up of abnormal head shapes in infancy.

Topical use of platelet-rich plasma to influence bone volume in maxillary augmentation: a prospective randomized trial.

BACKGROUND AND OBJECTIVES: The atrophic posterior maxilla often requires restoration of the alveolar ridge due to a lack of bone quantity and quality before dental implant placement. The aim of this study was to verify the hypothesis that platelet-rich plasma (PRP) has an influence on bone density in the maxilla after sinus floor elevation in combination with autologous cancellous bone from the iliac crest. Therefore, a randomized, prospective, controlled trial was set up in two centres. STUDY DESIGN AND METHODS: Fifty-three patients who underwent osteoplastic bone grafting for sinus floor elevation were included. The intervention group was treated with defined concentrations of PRP in addition to transplanted bone. Bone biopsy was performed 4 months after augmentation. Bone volume was then measured using the histomorphometric parameter bone volume. RESULTS: The histomorphometric evaluation of the biopsies did not indicate superiority of any of the treatments in terms of bone volume. CONCLUSION: Topical use of PRP did not improve maxillary bone volume either clinically relevant or statistically significant compared to that in conventionally treated patients. The use of PRP to support bone regeneration cannot be recommended as a standard method for maxillary augmentation.

[Sonography in callus distraction of the hypoplastic mandible]. / Einsatz der Sonographie bei der Kallusdistraktion am hypoplastischen Unterkiefer.

OBJECTIVES: Since the early 1990's when callus distraction of hypoplastic mandibles was developed, surgeons have been looking for a reliable method to monitor distraction treatment. X-rays films resulted in insufficient quality of images of low calcified structures and are only of little support in follow-up. Therefore, a standardised protocol using ultrasound was introduced. METHODS: 24 patients were included (aged 4 - 29 years with hemifacial microsomy [19], mandibulary micrognathia [5]), 20 intraoral (Howmedica-Leibinger/Mühlheim) and 9 extraoral distractors (Normed/Tuttlingen). Standard procedures for intra- and extraoral distraction were carried out and all postsurgical treatment steps were monitored by ultrasound. RESULTS: The mineralisation of the neocallus shows the following sequence: echogenic dots, needles directed along the distraction direction, bands, plaques, and modulation of the neocompacta. Additional therapeutically relevant questions of distraction distance, inflammation or occurrence of pus, arising during treatment were answered by sonography. Distance measurements could be performed reliably. CAT scan and MRI cannot be carried out because of metal artefacts. X-ray pictures like orthopantomogram and Clementschisch projection cannot show the early mineralisation and do not allow an exact distance measurement. CONCLUSIONS: Sonography is a effective, method to investigate the callus field without using X-rays and supports monitoring and decision making in distraction treatment of hypoplastic mandibles.

[CleftData. Program for minimal documentation of lip-jaw-palate clefts]. / CleftData. Programm zur Minimaldokumentation der LKG-Spalten.

BACKGROUND: The aim of the German Study Group on Cleft Lip and Palate-Craniofacial Deformities is to develop a precise system for documentation of cleft lip and palate patients which is suitable for use in PC-databases. DOCUMENTATION: In cooperation with the medical disciplines involved in the therapy such as otolaryngology, oral and maxillofacial surgery, orthodontics and speech therapy a system of documentation was developed with regard to the international classification of diseases (ICD) and the operating procedures system (OPS). Malformations are classified with the LAHS coding system. In addition to this concept of minimal documentation photographic images in standardized projections are stored. Furthermore, each operative procedure is documented by its date and the anatomic region of malformation treated without details of operative methods or descriptions of other procedures. SOFTWARE: On behalf of the German Study Group on Cleft Lip and Palate a software to meet these purposes was developed called CleftData. Based on a relational Access database it is equipped with SQL connectivity enabling its use on all hard- and software-systems.

Surgical correction of scaphocephaly: experiences with a new procedure and follow-up investigations.

INTRODUCTION: Simple resection of the sagittal suture and the use of alloplastic material or extensive skull resections have long been proven to be unsatisfactory in the treatment of sagittal synostosis. In contrast to these experiences, the immediate correction of skull shape seems to yield the best results without significant morbidity. PATIENTS: Thirty-six scaphocephalic infants with an average age of 6.5 (3.5-14) months underwent operation by our craniofacial team since 1994. METHODS: Wide resection of the sagittal suture was used in combination with a bone-strip resection along the coronal and lambdoid sutures. Occasionally partial resection and reshaping of the frontal or occipital bone was necessary to correct an extremely bulging skull. The cranial growth and shape was monitored by anthropometric skull measurements in the last 20 patients. RESULTS: Except in two cases, in which the dura mater was minimally injured intraoperatively, no complications occurred in any patient. Craniofacial oedema always occurred but disappeared after 72 h. The immediate correction of the skull shape was successful in all cases and was completed within 6 months postoperatively. There was no iatrogenic bone defect one year after surgery. Postoperative skull shape and growth was normal. CONCLUSION: These procedures seem to be effective in the treatment of scaphocephalus. Further normalization of skull shape is achieved by unrestricted postoperative brain growth.

Standardized evaluation and documentation of findings in patients with craniosynostosis.

Surgical correction of craniosynostosis is usually performed according to standard procedures. However, a standard for clinical examination and report of findings for patients with craniosynostosis does not exist as yet. To compare findings from different hospitals, a documentation system was developed by a national craniosynostosis group. This system comprises a two-page document, clinical photographs, radiographs, CT scans, anthropometric measurements and molecular genetic findings. Data from craniosynostosis patients collected from participating hospitals are stored in a database, which facilitates online access. The documentation system was developed in cooperation with the group during 3 years since 1996. It was evaluated as being practicable and reliable and enables a comparability of findings reported in different hospitals. Molecular genetic analysis was found to support the investigation of patients with craniosynostosis and should therefore be integrated in the clinical evaluation.

The Giessen-Mainz-Frankfurt procedure: a new method for complex pelvic reconstruction for bladder exstrophy.

PURPOSE: In bladder exstrophy primary reconstruction remains the gold standard worldwide. Despite various types of osteotomies the permanent correction of pubic diastasis remains a challenge. In maxillofacial surgery callus distraction is a routine treatment for hypoplastic mandibles. Originally described by Ilizarov, this method provides stable and true bone lengthening after gradual distraction of an osteotomy site as long as the periosteum remains intact. In cooperation with the departments of maxillofacial surgery and orthopedics we used this technique to correct pubic diastasis and facilitate phallic reconstruction in a 4 1/2-year-old boy with bladder exstrophy who had previously undergone continent diversion. MATERIALS AND METHODS: Three-dimensional computerized tomography was used to create a stereolithography model and mock surgery was performed. Based on this model bilateral osteotomies of the superior and inferior segments of the pubic bones were done, preserving the periosteum. Pins were inserted and a multidirectional external fixation device was mounted. Distraction was started on day 5 postoperatively. The distraction rate was 1 mm. daily and immobilization time was 28 days. The distraction progress was monitored by sonography. The device was removed 6 weeks postoperatively. RESULTS: Radiography of the pelvis 2 years postoperatively revealed that the distance between the pubic bones had decreased from 6 to 3 cm. (50%). Simultaneously the slanting angle normalized from 24 to 35 degrees due to upward rotation of the inferior pubic rami. Mineralization in the newly formed bones was excellent. Visible penile length had increased significantly. CONCLUSIONS: To our knowledge we describe the first use of the basic Ilizarov principle of callus distraction for permanent complex pelvic reconstruction for bladder exstrophy in a 4 1/2-year-old boy. After subperiostial osteotomies approximation of the symphysis and rotation of the inferior pubic rami were achieved with a device commonly used in maxillofacial surgery. Approximation of 1 mm. daily for 28 days resulted in significant penile lengthening. At a followup of 2 years there were stable pelvic ring reconstruction and normal mineralization of the newly formed bones. In contrast to the standard techniques of osteotomies for correcting pubic diastasis, the Giessen-Mainz-Frankfurt procedure provides true bone growth with a stable decrease in diastasis. Successful penile reconstruction was facilitated 1 year postoperatively. This method may also be useful in primary and secondary bladder reconstruction.

[Osteoplasty of extensive jaw defects by protected bone regeneration using large pore resorbable implant]. / Osteoplastik ausgedehnter Kieferdefekte mittels geschützter Knochenregeneration unter Anwendung grossporiger resorbierbarer Folien.

This study was performed to demonstrate a protected bone regeneration method using macroporous resorbable sheets for the treatment of extended lower and upper jaw defects. By applying mechanical protection of bony defects with, e.g. membranes or titanium mesh, soft tissue prolapse as well as pressure on bone transplants which contributes to partial resorption can be avoided. The use of a pressure-resistant, resorbable, macroporous sheet combines the advantage of protected bone regeneration and complete resorption of the implanted sheet. The macroporous structure facilitates capillary ingrowth from the surrounding soft tissue. The sheet is made of 70:30 Poly(L-co-DL)-lactate with thermoplastic character and can be used as a container for autologous spongiosa or other osteoinductive and -conductive bone graft substitutes. In a pilot study, seven patients with lower jaw defects resulting from large cysts or tumor resections, some affecting the continuity of the mandible, were treated with this method. Following a protocol, X-rays were obtained to document the bony regeneration. The positive experience with this pilot study encouraged a multicenter project involving five university hospitals and 50 patients. The application of resorbable sheets in combination with transplantation of mersilized autologous spongiosa is currently being investigated. In future studies, fillings of sheets with osteoconductive and -inductive materials are planned.

[Results of the DOSAK tumor register]. / Ergebnisse aus dem DOSAK-Tumorregister.

The German-Swiss-Austrian Group on Maxillofacial Tumors (DOSAK) has been performing observational studies in oral cancer. Since 1989, approximately 1600 cases of tumor of the head and neck per years has been collected in a central tumor registry. The database consists of more than 16,000 patients from 71 clinics; almost two-thirds are primary cases of squamous cell carcinoma. The data show great differences in patho-anatomical findings, therapy concepts, and five-year survival rates among the hospitals.

The treatment of mandibular cysts associated with osteogenesis imperfecta.

A fifteen-year-old boy with osteogenesis imperfecta (OI) and dentinogenesis imperfecta also had a big cyst in the mandible and needed surgical therapy. Six months postoperatively we saw a complete regeneration of the bone-structures. We came to the conclusion that cysts which appear independently from the disease of OI can heal after surgical intervention.

Cephalometric assessment of sagittal jaw base relationship prior to orthognathic surgery: the role of anterior cranial base inclination.

In a cephalometric study, 71 presurgical lateral radiographs of patients suffering from malpositions of 1 or both jaws were analyzed to assess the influence of cranial base inclination on anteroposterior cephalometric angles. Angles SNA and SNB, as well as the angle between sella-nasion (SN) and Frankfort horizontal (FH), were measured. To verify the true sagittal position of the jaws, SNA and SNB were related to a corrected normal anterior cranial base inclination (mSNA, mSNB). Two geometric models were calculated and examined. The application of the first and second models for SNA and SNB resulted in different estimations of the sagittal jaw position in 46% and 38% of the presented patients, respectively. Linear regression analysis demonstrates that FH may not be substituted for SN as a reference line in anteroposterior measurements, but underlines that a correction with regard to anterior cranial base inclination is beneficial. According to the results of the second model, the most valuable reference line appears to be located approximately halfway between SN and FH. Considering the frequent coincidence of jaw malposition and cranial base dysmorphia, cranial base-related cephalometric parameters should be interpreted carefully.

Application of ultrasound in callus distraction of the hypoplastic mandible: an additional method for the follow-up.

Mandibular callus distraction was performed on 14 patients. In addition to established radiological methods, sonography was performed to monitor the clinical progress. Ultrasound shows a precise picture of all interesting items in distraction treatment. Although the value of radiographs is not obsolete completely, sonography was found to be a meaningful supplement in the clinical monitoring of callus distraction. Furthermore the method is capable of early recognition of complications and it can reduce X-ray exposure.