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Cleft lip and palate belong to the most frequent craniofacial anomalies. Secondary osteoplasty is usually performed between 7 and 11 years with the closure of the osseus defect by autologous bone. Due to widespread occurrence of the defect in conjunction with its social significance due to possible esthetic impairments, the outcome of treatment is of substantial interest. The success of the treatment is determined by the precise rebuilding of the dental arch using autologous bone from the iliac crest. A detailed analysis of retrospective data disclosed a lack of essential and structured information to identify success factors for fast regeneration and specify the treatment. Moreover, according to the current status, no comparable process monitoring is possible during osteoplasty due to the lack of sensory systems. Therefore, a holistic approach was developed to determine the parameters for a successful treatment via the incorporation of patient data, the treatment sequences and sensor data gained by an attachable sensor module into a developed Dental Tech Space (DTS). This approach enables heterogeneous data sets to be linked inside of DTS, archiving and analysis, and is also for future considerations of respective patient-specific treatment plans.

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 DOSAK 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.

The clinical standard for alveolar cleft osteoplasty is augmentation with autologous bone being available in limited amounts and might be associated with donor site morbidity. The aim of the present study was the creation of tissue-engineered bone grafts and their in vivo evaluation regarding their potential to promote osteogenesis in an alveolar cleft model. Artificial bone defects with a diameter of 3.3 mm were created surgically in the palate of 84 adult Lewis rats. Four experimental groups (n = 21) were examined: bovine hydroxyl apatite/collagen (bHA) without cells, bHA with undifferentiated mesenchymal stromal cells (MSC), bHA with osteogenically differentiated MSC. In a control group, the defect remained empty. After 6, 9 and 12 weeks, the remaining defect volume was assessed by cone beam computed tomography. Histologically, the remaining defect width and percentage of bone formation was quantified. After 12 weeks, the remaining defect width was 60.1% for bHA, 74.7% for bHA with undifferentiated MSC and 81.8% for bHA with osteogenically differentiated MSC. For the control group, the remaining defect width measured 46.2% which was a statistically significant difference (p

The current surgical techniques used in cleft repair are well established, but different centers use different approaches. To determine the best treatment for patients, a multi-center comparative study is required. In this study, we surveyed all craniofacial departments registered with the German Society of Maxillofacial Surgery to determine which cleft repair techniques are currently in use. Our findings revealed much variation in cleft repair between different centers. Although most centers did use a two-stage approach, the operative techniques and timing of lip and palate closure were different in every center. This shows that a retrospective comparative analysis of patient outcome between the participating centers is not possible and illustrates the need for prospective comparative studies to establish the optimal technique for reconstructive cleft surgery.

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.

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.

Alveolar bone grafting is an integral part of the treatment concept in cleft palate patients. As an alternative to autogenous bone, tissue-engineered grafts have found some clinical application. The aim of the present study has been to compare ossification in the cleft area using tissue-engineered grafts in a case series of patients with ossification after transplantation of autogenous spongious bone as the gold standard in alveoloplasty. Eight children with complete cleft lips and cleft palates were included in the study. In four children (group A), the cleft defect was filled with tissue-engineered bone (autogenous osteoblasts cultured on demineralized bone matrix Osteovit(®)); as control in another 4 children (group B), the alveoloplasty was performed using spongious iliac bone. Preoperative and 6 months postoperative cone-beam computed tomography was performed, and volumes of the remaining cleft defects were calculated using 3D navigation software. Wound healing was uneventful in both groups. Six months postoperatively the mean volume of the cleft was 0.55±0.24cm(3) after grafting of tissue-engineered bone (group A) and 0.59±0.23cm(3) after transplantation of autogenous spongiosa. In group A, 40.9% of the cleft defect was ossified; in the control group (group B), 36.6%. Tissue-engineered bone is a promising alternative in alveolar bone grafting and no disadvantages were observed in comparison to the gold standard.

Background. Primary reconstruction of the man- dible is the golden standard of surgical treatment after abla- tive tumor surgery. Many different microvascular bone grafts are used to reduce wound healing complications at the severely compromised recipient site. The loss of primary grafts due to radiotherapy or osteoradionecrosis can make secondary mandibular reconstruction necessary. To address this problem, we developed the technique of the prefabrica- tion of a radial forearm flap with cancellous bone. The aims were to establish these techniques into the clinical routine and to create a safe and reliable flap with low donor site morbidity. Methods. In patients who had undergone ablative tumor surgery radiochemotherapy, and primary reconstruction, pre- fabricated bony radial forearm flaps (PBRFFs) were applied for secondary reconstruction of the mandible. Cylinders of cancel- lous bone taken from the iliac crest were implanted in the lower forearm to allow the necessary vascularization. After a healing period of 4 weeks, the PBRFF was elevated and grafted into the mandibular defect. Results. All grafts healed uneventfully. However, 1 case required revision of the venous anastomosis after 2 days. The transplants improved the contour of the lower face enabling a good correction of the facial asymmetry. During the follow-up of up to 4 years, the radiographic controls showed good bony consolidation between the graft and the stumps of the mandi- ble as well as formation of cortical bone around the cancellous bone cylinders. Conclusion. These results demonstrate that the PBRFF is a safe and reliable graft which provides alternate solution in which other microvascular bone grafts have already failed. In the future, the iliac bone graft may be replaced with scaffold seeded with stem cells for further reduction of donor site mor- bidity. V C 2009 Wiley Periodicals, Inc. Head Neck 31: 1579- 1587, 2009

Purpose: In the Pierre Robin sequence, retrognathia and glossoptosis lead to airway obstruction in infants with or without cleft palate. Mandibular distraction has gained acceptance for the treatment of airway obstruction. However, surgical interventions can result in complications. In our institution, mandibular traction is the standard treatment in cases of severe respiratory distress. Patients and Methods: A retrospective study was performed of all infants treated for Pierre Robin sequence at our institution from 1979 to 2007. The diagnosis and type of treatment (positioning/palatal plate or mandibular traction) were evaluated. The palatal plate had several knobs at the anterior alveolar ridge to direct the tongue forward. Mandibular traction was applied using weights transmitted onto the mandible by a custom-made plate fixed at the mandible with circumferential wiring. Results: Nineteen children required airway treatment because of repeated cyanotic episodes and respiratory adaptation disorders. Of these 19 children, 8 had been diagnosed with pure Pierre Robin sequence and 11 also had other congenital abnormalities. Of the 19 patients, 10 (56%) were treated nonoperatively by lateral or prone positioning and/or wearing a palatal plate to stimulate the tongue. In 8 patients, conservative management was not sufficient, and continuous mandibular traction was performed for 2 to 5 weeks using weights of 50 to 200 g. One patient required a tracheostomy because of tracheomalacia. Conclusions: Surgical therapy using mandibular traction is a minimally invasive alternative to more invasive procedures because no serious complications such as scars or damage to the nerves were encountered.

To bridge the cleft in the alveolar bone and to allow for physiologic eruption of the canine teeth, alveolar bone grafting is often necessary in patients with cleft lips and palates. Instead of autogenous bone, biomaterial seeded with autogenous osteogenic cells has found some clinical application. However, so far no real functional proof has been available to demonstrate that this technique also allows further physiologic features such as tooth eruption to occur. This report describes the results of grafting tissue-engineered bone into the alveolar cleft of a 10-year-old boy. Immediate postoperative healing was uneventful. Eight months after grafting, erupting teeth had moved into the newly formed bone. Eighteen months postoperatively at the site where the tissue-engineered graft had been inserted, the canine had erupted spontaneously in its proper place. The data suggest that tissue-engineered bone can lead to the ossification of the alveolar cleft and allow for physiologic spontaneous tooth eruption.

Bone substitution materials are seen as an alternative to autogenous bone transplants in the reconstruction of human bone structures. The aim of the present animal study was to evaluate the clinical handling and the conditions of bone healing after the application of a phosphoserine and collagen-I-modified calcium-phosphate cement (Biozement D). The application of phosphoserine is supposed to influence the texture of the extracellular matrix. Standardised bone defects were created in the lower jaw of 10 adult minipigs. These defects were reconstructed with a pasty calcium-phosphate cement mixture. After a healing time of 4 months, the animals were sacrificed. The mandibles of all animals were resected and non-decalcified histological sections of the areas of interest were prepared. The experiment was evaluated by means of qualitative histology and histomorphometry. The hydroxyapatite cement entirely hardened intraoperatively. Modelling and handling of the cement was facile and the margin fit to the host bone was excellent. Histology showed that resorption started in the periphery and proceeded exceptionally fast. The bony substitution, especially in phosphoserine-endowed cements, was very promising. After a healing period of 4 months, phosphoserine cements showed a bone regeneration of nearly two-thirds of the defect sizes. In the applied animal experiment, the newly developed hydroxyapatite collagen-I cement is well suited for bone substitution due to its easy handling, its excellent integration and good resorption characteristics. The addition of phosphoserine is very promising in terms of influencing resorption features and bone regeneration.

The expansion of biodegradable osteosynthesis systems in clinical application correlates well to the progress in development of new materials as to the improvement of application methods. One of those new application methods is the ultrasound-aided insertion of Resorb-X pins. The aim of this study was the histological evaluation of possible thermal damage to bone due to the ultrasound insertion. For this purpose, condylar neck fractures in 12 sheep were produced, repositioned and fixed by Resorb-X plates and pins. The animals were sacrificed in two groups, one after 2 weeks and one after 9 weeks. The bone-pin interlinkage and the structure of the bone were histologically evaluated. After 2 weeks a tight bone-polymer interlinkage was seen. Neither a pronounced foreign body reaction nor an interposition of fibrous tissue at the interface or a thermally induced necrosis was observed. The late phase of wound healing after 9 weeks showed pathomorphological characteristics within the normal range of bone healing. The bone seemed to be free of any alteration caused by process engineering. We conclude that thermal stress caused by ultrasound-aided pin insertion does not lead to cellular reaction in the bone. The fast and easy application of this improved biodegradable osteosynthesis system will bring a clear advantage in clinical use.

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.

Ziel der retrospektiven Untersuchung war es, die Ergebnisse nach Verwendung verschiedener Operationsverfahren und dem Einsatz der computergestutzten Chirurgie bei der sekundaren Rekonstruktion nach schweren Mittelgesichtsschadelfrakturen einzuschatzen. Es sollen die Erfahrungen mitgeteilt und funktionelle sowie asthetische Aspekte betrachtet werden. 18 Patienten wurden in Bezug auf Diplopie, Enophthalmus und Asthetik uber einen Nachbeobachtungszeitraum von bis zu 2,5 Jahren beurteilt. Ca. 40% der Patienten erhielten mehrere rekonstruktive Verfahren. Bei 5 der 9 betroffenen Patienten hatte sich die Diplopie gebessert; bei 4 Patienten war der praoperative Befund unverandert. Ein signifikanter Enophthalmus konnte bei 8 der 12 Patienten korrigiert werden. Nach weiteren Tertiareingriffen hatten 6 Patienten ein gutes Resultat, 7 ein befriedigendes und bei 5 Patienten lag ein schlechtes asthetisches Ergebnis vor. Zur sekundaren Mittelgesichtsrekonstruktion ist meist die Kombination verschiedener operativer Verfahren notwendig. Knocherne Asymmetrien und Enophthalmus lassen sich erfolgreich korrigieren; funktionelle Einschrankungen und asthetische Beeintrachtigungen, bedingt durch schlechte Weichgewebsverhaltnisse, konnen nur schwer behoben werden. Die computergestutzte Chirurgie ist hilfreich bei der Praparation in den Weichgeweben der Orbita und bei der Platzierung von Transplantaten und osteotomierten Segmenten.

Der transorale Zugang reduziert das Risiko einer Schadigung des N. facialis, aber das Anbringen von zwei Osteosyntheseplatten am proximalen Fragment zur Erzielung einer ausreichenden Stabilitat ist oft nicht moglich. Um eine stabile Osteosynthese auch hoher gelegener Frakturen zu ermoglichen, wurde eine neue deltaformige Osteosyntheseplatte entwickelt, die den Belastungsverhaltnissen am Kiefergelenk gerecht wird. Diese Platte wurde klinisch getestet. Insgesamt 11 Patienten mit 13 Kiefergelenkfrakturen (Spiessl I: n = 2, Spiessl II: n = 10, Spiessl III: n = 1, davon 3 beidseitige Frakturen) wurden uber einen transoralen Zugangsweg operiert und klinisch sowie rontgenologisch nachkontrolliert. Beurteilt wurden funktionelle Parameter sowie die Frakturstellung im Rontgenbild. Nach mehr als 6 Monaten hatte sich die Funktion mit einer maximalen Schneidekantendistanz von 42 mm sowie Pro- und Laterotrusion von uber 5 mm normalisiert. Die Rontgenkontrollen zeigten postoperativ bei 7 der 8 Patienten bzw. nach 6 Monaten bei 6 der 8 Patienten eine vollstandige Wiederherstellung der Ramushohe im Orthopantogramm. Die Clementschitsch-Aufnahme zeigte bei 12 der 13 Frakturen postoperativ bzw. bei 10 der 13 Frakturen nach 6 Monaten eine anatomisch korrekte Position. Plattenbruche oder Plattendeformierungen traten nicht auf. Bei 2 Patienten wurden zum Zeitpunkt der Materialentfernung gelockerte Schrauben gefunden. Die neu entwickelte 3D-Platte lies sich gut handhaben und war zur Versorgung von Kiefergelenkfrakturen ausreichend stabil. Zur operativen Therapie uber einen transoralen Zugang unter Vermeidung extraoraler Narben und einer Schadigung des N. facialis kann die Platte empfohlen werden.

The development of sufficient tissue engineered bone grafts for alveolar cleft osteoplasty could reduce the necessity of autogenous bone grafts and its donor site morbidity. The aim of the study was to evaluate tissue engineered bone grafts in an artificially created bone defect. Bone grafts were created in vitro colonizing a synthetic hydroxyapatite–tricalciumphosphate scaffold (BONITmatrix ® ) with either undifferentiated mesenchymal stromal cells (group 1) or osteogenic differentiated mesenchymal stromal cells (group 2). Cells were multiplied from bone marrow of donor rats. Unmodified scaffolds (group 3) and the tissue engineered bone grafts were inserted into artificial maxillary defects of 54 Lewis rats. In 18 animals the defects remained unfilled (control). After one, three and six weeks the rats were sacrificed. The defect was evaluated radiologically and histologically with regard to the remaining defect volume and diameter. Statistical analysis followed. The bone grafts led to a specific bone formation at the defect margin. No complete reunion of any defect was observed within the healing time. After six weeks, the remaining defect volume was 6.86 ± 3.21 mm 3 (control), 4.08 ± 1.36 mm 3 (group 1), 5.00 ± 0.84 mm 3 (group 2) 5.50 ± 1.05 mm 3 (group 3). The remaining defect diameter measured 2.63 ± 0.52 mm (control), 2.39 ± 0.23 mm (group 1), 2.53 ± 0.22 mm (group 2) and 2.70 ± 0.66 mm (group 3). In all experimental groups the defect volume and diameter decreased over time, which was significant for group 1 ( p = 0.014), group 2 ( p = 0.025) and group 3 ( p = 0.048). The defect volume and width was significantly reduced for bone grafts containing undifferentiated cells compared to control ( p = 0.035) or scaffolds only ( p = 0.05). Conclusion Tissue engineered bone grafts induce a pronounced bone formation in artificial bone defects compared to unfilled controls or scaffolds only.

Untersuchungen zum Zusammenhang zwischen kephalometrischen und polysomnographischen Befunden wurden bisher von mehreren Autoren uberwiegen mit linearen statistischen Methoden durchgefuhrt. Die eigene Arbeitsgruppe interessiete, ob durch den Einsatz mehrdimensionaler stati stischer Verfahren der Informationsgehalt der Radiokephalometrie starker ausgeschopft werden kann. 77 Patienten mit OSAS (Alter 25–69 Jahre, RDI 3,6–90, 1/h) wurden polysomnographisch und kephalometrisch untersucht. Die Vermessung der knochernen Parameter erfolgte mit dem Computerprogramm WinCeph und die Pharynxweichteile in Anlehnung an Hochban et al. (Dtsch Zahnarztl Z 49: 777–782, 1994). Mittels logistischer Regressionen wurde gepruft, ob polysomnographische RDI-Werte >20 aus dem Rontgenbild vorhergesagt werden konnen. Die Kopplung der 10 knochernen Parameter ergab bezuglich der Erkennung erhohter RDI-Werte eine Sensitivitat von 93% bei einer Spezifitat von 44%. Vier Parameter fielen durch besonders hohe relative Risiken auf. Die alleinige Verwendung der Weichteilparameter zeigte eine Sensitivitat von 98% bei einer Spezifitat von 13%. Die gleichzeitige Betrachtung von Weichteil- und knochernen Parametern erbrachte eine Sensitivitat von 96% bei einer Spezifitat von 40% in der Erkennung erhohter RDI-Werte. Die Radiokephalometrie gehort nicht zur Basisdiagnostik des OSAS, sie kann aber bei kieferchirurgischen Operationsentscheidungen einen Beitrag leisten.

OFD1, now recognized as a ciliopathy, is characterized by malformations of the face, oral cavity and digits, and is transmitted as an X-linked condition with lethality in males. Mutations in OFD1 also cause X-linked Joubert syndrome (JBTS10) and Simpson-Golabi-Behmel syndrome type 2 (SGBS2). We have studied 55 sporadic and six familial cases of suspected OFD1. Comprehensive mutation analysis in OFD1 revealed mutations in 37 female patients from 30 families; 22 mutations have not been previously described including two heterozygous deletions spanning OFD1 and neighbouring genes. Analysis of clinical findings in patients with mutations revealed that oral features are the most reliable diagnostic criteria. A first, detailed evaluation of brain MRIs from seven patients with cognitive defects illustrated extensive variability with the complete brain phenotype consisting of complete agenesis of the corpus callosum, large single or multiple interhemispheric cysts, striking cortical infolding of gyri, ventriculomegaly, mild molar tooth malformation and moderate to severe cerebellar vermis hypoplasia. Although the OFD1 gene apparently escapes X-inactivation, skewed inactivation was observed in seven of 14 patients. The direction of skewing did not correlate with disease severity, reinforcing the hypothesis that additional factors contribute to the extensive intrafamilial variability.

We describe a new design of resorbable plate for use in the treatment of fractures of the condylar neck, and report the outcome of initial treatment in two patients.

Sinus floor elevation is the standard procedure that allows dental implant insertion in the atrophic posterior maxilla. Instead of autogenous bone, tissue-engineered bone grafts can be used, but clear comparative clinical studies also assessing the influence of the biomaterial are missing. In six patients, tissue-engineered bone grafts were used in eight sinus floor elevations. After culturing osteoblast-like cells from biopsies of the maxilla, they were seeded on scaffolds made either from demineralised bovine bone matrix (DBBM) or from solvent-dehydrated mineralised bone (SDBB), and grafted. In all patients primary wound healing was without complications, except for one patient in the SDBB group. After 12 months, implant insertion was possible only in the SDBB group; in the DBBM group, fibrous connective tissue was found in an attempt of implant insertion. After 5 months, implant placement was performed in one patient of each group. However, the two implants inserted in the DBBM group were lost after 6 weeks. Histology of the bone cores in the DBBM group at 5 months showed lamellar bone and osteoid, and at 12 months showed fibrous connective tissue. Inflammation and some resorption of the scaffold was found 5 months after SDBB grafting, and after 12 months cancellous bone formation encapsulating SDBB remnants were observed. These preliminary data suggest that the preparation method of the bovine bone matrix, in particular the mineral content, and therefore the mechanical stability may have some influence on the generation of new bone.

The finite element (FE) method was originally developed on a physical basis for the computation of structure-mechanical problems. Meanwhile, it has been widely applied to medical issues. This study sought a suitable method to build a FE model for remodelling processes in osseous defects supplemented with bone substitute material. For this purpose, the second right premolars were extracted from four pig mandibles (Sus scrofa domesticus) and the extraction alveoli were provided with synthetic bone substitute material. After 70 days, a segmented osteotomy of this area was performed for specimen collection. Radiographs of the specimens were taken in defined planes before and after fixation and embedded with Technovit 9100. Fixation-related shrinkage was quantified from the radiographs using reference lines. Computer tomographic (CT) and microCT images of the fixed and embedded specimens were obtained. From these data, a FE model was built. The construction of a FE model is sufficient to represent bone remodelling after supply of bone substitute material. The use of microCT data permits building a clearly more precise model.

The aim of this study is to evaluate and compare the biomechanical stability of various osteosynthesis materials for mandible condylar-process fractures. On 160 porcine mandibles, four different monocortical plating techniques (40 per group) were investigated. Condyles were fractured at a defined location from the incisure to the posterior border. After correct anatomical reduction the fractures were plated, using four different techniques. Osteosynthesis materials used were the delta plate, the trapezoid plate, the dynamic compression plate and double mini-plates. Each group was subjected to linear loading in lateral to medial, medial to lateral, anterior to posterior and posterior to anterior directions by a universal mechanical testing machine TIRAtest 2720. Yield load, yield displacement were measured for the different plates. Statistically significant differences were noted between the fixation groups in all four directions. Rigid internal fixation with double mini plates showed the best stability in all directions except posterior to anterior. In this direction, the delta-plate resisted the highest loads. In the three other directions, the delta plate was second best with data similar to double miniplates but lower in magnitude.

SUMMARY Purpose Gingival hyperplasia is a well known side effect of Cyclosporine A therapy. The aetiology of this is not totally understood and there is debate whether it is hyperplasia of the gingival epithelium or of the submucosal connective tissue, or both, and what roles play factors like age and gender of the patients, duration and dosage of the drug. Material and methods The influence of different Cyclosporine A concentrations (10 −6 g/ml; 5 × 10 −7 g/ml; 10 −9 g/ml) and of no medication (controls) on growth and proliferation of cultured human gingival keratinocytes was investigated after a culture period of 3, 6 and 9 days. Cell proliferation was assessed by counting anti Ki-67 stained nuclei, cell growth by counting total number of nuclei and by the EZ4U-assay. Results There was no significant correlation of the cell proliferation rate and cellular growth with either gender ( p > 0.568) or duration of medication ( p > 0.876); but Cyclosporine A concentration showed a highly significant influence on cellular growth ( p = 0.0001). Inhibition of cell growth was dependent on drug dosage, but a low concentration of 10 −9 g/ml even stimulated cell growth. Conclusions There is evidence that Cyclosporine A in low concentrations (10 −9 g/ml as applied in long-term therapy) stimulates gingival keratinocyte growth and therefore might be related to hyperplasia of the gingiva. However, high Cyclosporine A concentrations may inhibit cell growths and factors like gender of the patient did not show any influence in-vitro.

Aim of this retrospective study was to assess the outcome after secondary midfacial reconstruction using different operation techniques and computer assisted surgery. Functional and aesthetic aspects as well as experiences are reported.18 patients were assessed for enophthalmos, diplopia, and aesthetics during a follow-up period of up to 2.5 years.In 40% of the patients several techniques for soft and hard tissue reconstruction were used. In 5 of the 9 patients diplopia was improved; in 4 patients there was no change. A significant enophthalmos was corrected in 8 out of 12 patients. After additional surgery 6 patients had a good aesthetic result, 7 a satisfactory and 5 a poor.For secondary midfacial reconstruction often a combination of different surgical techniques is necessary. Bony asymmetries and enophthalmos were successfully corrected, however, functional and aesthetic impairment due to bad soft tissue condition are difficult to correct. Computer assisted surgery is helpful for dissection within the orbit, for graft placement, and for positioning of osteotomized segments.

Purpose Transoral surgical treatment of condylar neck fractures minimizes the risk of damaging the facial nerve. But fracture reduction and plate osteosynthesis remain challenging, especially when using 2 plates, although endoscopic assistance has proven helpful. To further improve and simplify osteosynthesis at the condylar neck, a new delta-shaped osteosynthesis plate that mimics the function of 2 plates has been developed. The present clinical follow-up study was conducted to evaluate this new plate. Patients and Methods A total of 16 patients with 19 condylar neck fractures (3 Spiessl I, 13 Spiessl II, 1 Spiessl III, 2 Spiessl IV) and 3 bilateral fractures were treated through an endoscopic-assisted transoral approach. After reduction, the plate was applied, with the screws inserted either transcutaneously or with angulated instruments. Results The operation time ranged between 55 and 120 minutes. More than 6 months after the operation, functional parameters returned to normal, with an average mouth opening of 41 mm, protrusion of 5 mm, and laterotrusion of 6 mm. Radiographic controls showed good fracture alignment in 15 of 19 cases immediately after the operation, and in 14 of 19 cases 6 months after the operation. No plate fracture or bending was observed. In 3 patients, loose screws were found on plate removal. Conclusions The clinical data and the engineering and biomechanical background suggest that the new delta-shaped plate can be regarded as 2 miniplates. The new plate is suitable for treatment of condylar neck fractures, particularly when used in an endoscopic-assisted transoral approach.

Donor morbidity is minimized when tissue engineering is applied to produce osteogenic grafts by growing osteoblasts on biomaterials. However, limiting factors are the origin, proliferation, and differentiation of osteoblasts. Therefore, the aim of this study was to evaluate the efficacy of growing osteoblasts from different types of bone samples and to assess the influence of the donor site.From 28 patients 37 bone specimens were obtained during removal of third molars in the maxilla and mandible. Seventeen specimens were bone chips and 20 were bone sludge. After subculturing primary cultures, histochemical and immunhistochemical tests (EZ4U test, BrdU labeling, ALP histochemistry, type I collagen immunohistochemistry, osteocalcin ELISA) were performed to determine cell proliferation, viability, and differentiation.Both bone chips and bone sludge from the mandible and maxilla are suitable for culturing human osteoblastlike cells. However, bone chips were superior to bone sludge with respect to ability to grow cells, and maxillary bone was superior to mandibular bone in this regard. Harvesting technique had only little influence on the expression of cell differentiation markers (ALP, type I collagen, osteocalcin).Chips from human membrane bone, especially from the maxilla, are suitable for culturing high numbers of differentiated osteoblastlike cells. These cells may be used to tissue engineer bone grafts, which may be used to enhance the implant placement site.

Objective The aim of this study was to compare bone regeneration after grafting enucleated mandibular cyst cavities using either autogenous osteoblasts cultured on a biomaterial or autogenous spongiose iliac bone. Study design Twenty patients with 22 mandibular cysts were assessed. Eleven cysts were filled in with tissue-engineered bone (autogenous osteblasts cultured on demineralized bone matrix Osteovit) and 11 with spongiose iliac bone as controls. Panoramic radiographs were taken preoperatively, immediately postoperatively, and 3, 6, and 12 months after surgery. Radiolucency was computer analyzed using gray-level histograms. Results In both groups bone regeneration took place in a similar fashion. After 3 and 6 months there were few differences in bone density between the groups. However, in radiographic controls after 12 months ossification was considerably stronger in cysts grafted with tissue-engineered bone. Conclusion These results advocate for the clinical application of tissue-engineered bone as an alternative viable filling material for cysts.

Summary Purpose In this study the efficacy of computer-assisted surgery (CAS) used for secondary orbital reconstruction after midfacial fractures was evaluated, comparing the clinical outcome with that after conventional surgery (CS). Special consideration was given to whether CAS can reduce the number of secondary corrections. Patients and methods Twenty consecutive patients (24 orbits; 12 in each group) were assessed for enophthalmos, diplopia, and aesthetics during a follow-up period of up to 3 years. Results After CAS, enophthalmos was fully corrected in 8 of 11 orbits but after CS in only 6 of 10 orbits. Improvement of diplopia was achieved in 1 of 7 (CAS) and in 3 of 4 (CS) patients. The aesthetic result after secondary reconstruction and additional surgery was better in the CAS group. Additional surgery to correct bony structures was only necessary in 3 patients of the CS group. Additional soft tissue surgery was necessary in both groups. Conclusion CAS can improve the clinical outcome of reconstructive bone surgery reducing the amount of additional hard tissue procedures. It was helpful during dissection of the scarred orbital tissue and placement of a graft. However, it had no impact on soft tissue correction especially with respect to function.