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Maxillary ameloblastomas can extensively expand into the paranasal sinuses or even the nasal cavity due to a slow growth pattern. Sinusitis is rarely the first tumor-related complaint. Due to the various growth forms of ameloblastomas the challenging histological differential diagnosis includes several other odontogenic as well as benign and malignant non-odontogenic tumors, e.g. tumors from the mucosa of the paranasal sinuses, salivary glands and Rathke's pouch. Despite the radical surgical approach a complete resection with wide margins cannot always be achieved. Maxillary ameloblastomas show the highest recurrence rates.

Aim: The aim of this experimental study was to histomorphometrically evaluate the effects of vitamin C administration on bone formation in response to expansion of the rat inter-premaxillary suture., Materials and Methods: A total of 30 50- to 60-day old Wistar male rats were divided into three groups of equal number. The inter-premaxillary suture in each animal was expanded with a 0.49 N force applied to the upper incisors. At 24 h after appliance placement, control animals received saline solution (group I) and two groups were given a single dose of vitamin C using two different methods [locally into the suture (group II) and systemically via intramuscular injection (group III)]. The area of new bone (µm(2)), the perimeter around the new bone (µm), Feret's diameter (µm), and the percentage of new bone to non-ossified tissue (%) were measured and compared. Kruskal-Wallis and Tukey tests were used for statistical evaluation at the p<0.05 level., Results: We observed significant differences among the groups in all histomorphometric parameters. New bone area, bone perimeter, Feret's diameter, and percentage of new bone dimensions were significantly higher in group III than the others (p<0.001). Histomorphometric measurements of bone architecture revealed that this improved in the group administered with vitamin C systemically, while local injection revealed significantly less bone growth than the control group., Conclusion: The systemic administration of vitamin C during the early stages of inter-premaxillary suture expansion may stimulate bone growth. However, local injection of this antioxidant into an orthopedically-expanded suture area has negative effects on bone formation.

The group of odontogenic ectomesenchymal tumors consists of odontogenic fibroma (epithelium-rich and epithelium-poor types), odontogenic myxoma, and cementoblastoma. Whereas odontogenic fibromas and cementoblastomas are very rare lesions, odontogenic myxoma is the fourth common odontogenic tumor, preceded only by keratocystic odontogenic tumor, the odontomas, and ameloblastoma. The diagnosis of cementoblastoma rests on its connection to the root of a tooth. The differentiation of odontogenic fibroma and myxoma from other lesions, especially from normal structures such as dental follicles and papillae, may be challenging if the X-ray appearance (localized osteolysis containing a tooth) is not appreciated and subtle histological clues (remainders of inner enamel epithelium at the surface of the lesion, dentin fragments) are not properly recognized. While odontogenic fibromas have almost no tendency for recurrence and are treated by enucleation or local excision, cementoblastomas and especially odontogenic myxomas have a high percentage of recurrence if intralesional procedures are applied. Hence, complete resection with free margins is recommended--at least for larger odontogenic myxomas and, especially, lesions in the maxilla--to prevent further extension to the orbita or base of the skull.

Background and Aim: The use of mini-implants for skeletal anchorage has greatly broadened the therapeutic spectrum in orthodontics over the last few years. The alveolar ridge is the most frequent insertion site, which however is associated with tooth injury, a risk not to be underestimated. The objective of this study was to examine the quantitative parameters of pre-drilling and implant insertion in association with the degree of a root contact., Material and Methods: Eleven lower jaw bones of adult pigs were prepared and embedded in resin. At 320 sites in the toothbearing alveolar ridge a 1.3 mm pre-drilling was carried out up to the complete implant length. The vertical force exerted against the pre-drilling upon penetration of the different bone layers and at a root contact was measured at a drift-speed of 0.5 mm/s. Dual Top screws (1.6 x 8 mm) were then inserted into the prepared implant sites, the insertion torques were measured, and recorded as a function of the rotation angle. After explantation, we prepared histological slides from the level of the implant's maximum diameter. The implant's contact with cortical and cancellous bone and to the roots was measured and correlated to vertical pre-drilling forces and insertion torques., Results: Vertical pre-drilling forces and insertion torques of orthodontic mini-implants varied in relation to the type of tissue penetrated and the degree of root contact. The insertion torques ranged from 32 to 345 Nmm and pre-drilling forces up to 6 N overall., Conclusion: Root contact can be recognized during pre-drilling by a distinct increase in resistance, and during mini-implant insertion by higher torques.

Malignant melanoma of the oral cavity is a rare disease with high lethality, rapid progression and frequently seen lymph node metastases. The clinical appearance of the mucosal melanoma is mostly irregular in shape and dark blue, brown or black in colour. During early stages the lesions are painless with a tendency to spontaneous bleeding. Mucosal melanoma shows expansive and infiltrative growth into neighbouring structures, with the result of bone destruction and loss of teeth. We present a case of a female patient with a primary mucosal melanoma. A local infiltration and invasion of a tooth could be seen. Although many publications deal with oral mucosal melanoma with local destruction of bone, there are no reports on an infiltration into dental roots. Aspects of this unusual infiltration of hard tissues are discussed.

To date, CAD/CAM technology has made no noteworthy inroads into removable dentures. We want to present a new area of application for this in our study. Models of the maxilla and edentulous mandible were 3D scanned. The software detects and automatically reconstructs the reference structures that are anatomically important for the set-up of artificial teeth, such as the alveolar ridge centerlines and the interalveolar relations between the alveolar ridges. In a further step, the occlusal plane is semiautomatically defined and the front dental arch is designed. After these design features have been determined, artificial teeth are selected from a database and set up automatically. The dental technician can assess the esthetics and function of the suggested dental set-up on the computer screen and make slight corrections if necessary. Summarizing: The interplay of hardware and software components within on integrated solution including conversion of the "virtual" into a real positioning of prosthetic teeth is presented.

Background: Bisphosphonates (BP) are widely used in patients with osteoporosis or malignant tumors with bony metastases such as breast cancer and plasmocytoma because of their potency to affect osteoclasts and bone resorption. Osteonecrosis of the jaw (ONJ) has been described as a potential side effect since 2003. After a review of the literature we present results of a questionnaire, which was sent to departments of oral and maxillofacial surgery (OMFS) in German-speaking countries., Material and Methods: We present 349 patients from the literature, 54 patients from the departments of OMFS and 19 cases from our own department. These patients ware analyzed depending on their disease, their medication, localization of the affected area, histological signs and therapeutic outcome., Results: Of 73 patients, 68 (93%) were treated with pamidronate or zoledronate; 69 (94%) patients suffered from malignant diseases, 3 (5%) had osteoporosis, and 1 (1%) had Paget's disease. In 57 (78%) patients the ONJ affected the mandible, in 12 (16%) the maxilla and in 4 (5%) both jaws. A previous tooth extraction was reported in 38 (52%) patients, and in 35 (48%) ONJ occurred spontaneously. Histological findings were similar to osteomyelitis with a high number of actinomyces colonies. Nine (12%) patients received non-surgical treatment only, 52 (71%) patients underwent minor surgical procedures (e. g. decortication) and 19 (26%) patients underwent marginal or segmental resection of the jaw. Considering all treatment modalities, healing was achieved in 55; the most effective was marginal and segmental resection (88%)., Discussion: Though millions of patients receive BP treatment only a few suffer from ONJ. The incidence in cancer patients with pamidronate and zoledronate therapy is 4%-10%. Because of the similarity to "phossy jaw", seen in patients dealing with white phosphorus in the nineteenth century, some authors call the new entity "bis-phossy jaw". As the pathogenesis of ONJ is not clear we recommend that the descriptive term bisphosphonate-associated osteonecrosis should be used. Bone resection and safe soft tissue closure is the treatment of choice. We recommend systematic dental care for patients receiving BP medication. Information exchange between oncologists, oral and maxillofacial surgeons and dentists is important.

Background: Bone metastases in the upper jaw are relatively rare but not unusual in oral and maxillofacial surgery. In many cases finding the primary tumour is difficult because of its occult location., Case Report: We describe a 53-year-old female patient who suffered from a tumor in the oral cavity. The first histological and clinical diagnosis revealed a granuloma pyogenicum. Because of the delayed healing process another biopsy became necessary showing a metastasis of an unknown primary tumor. Diagnostic procedures detected an adenocarcinoma of the left kidney with pelvic metastases. Appropriate surgical intervention and chemotherapy were subsequently initiated., Conclusion: The present case report demonstrates how difficult it can be to provide the right pathological diagnosis in biopsy material even regarding obvious malignancy. Therefore thorough diagnostic efforts are indispensable to facilitate the causal treatment of an unknown primary tumor.

Purpose: This paper describes a surgical and prosthetic procedure for treating the extremely atrophic maxilla. It explains a two-staged surgical technique, donor and recipient site morbidity, implant survival, and the implant-retained prosthetic rehabilitation of the patients., Patients and Methods: A total of 57 consecutive patients were treated with a sinus lifting procedure and a simultaneous lateral augmentation using autogenous corticocancellous block and particulate bone grafts from the iliac crest. After a 6-month bone healing period, a total of 284 endosteal Titanium screw implants were inserted. Following a 3-month osseointegration period, the implants were exposed and loaded with either fixed or removable prostheses., Results: In three cases a partial bone graft loss was observed; however, enosseous implantation was possible as planned. During the observation period none of the 284 implants was lost; 3 implants exhibited treatable peri-implant infection. Complications at the donor and recipient sites were minimal and did not negatively influence the overall clinical result of the treatment., Conclusion: The combination of sinus lift procedure and lateral augmentation for the treatment of the extremely atrophied maxilla proved to be a safe method that produces good and reliable clinical results.

Aim: The aim of this retrospective trial was to investigate differences in mesiodistal and vestibulo-oral crown sizes of naturally, fully-erupted permanent maxillary teeth between patients with and without palatal canine displacement., Patients and Method: 115 patients (mean age: 14 years 10 months; females: 77 males: 38) treated in the Department of Orthodontics, University of Munich were included in the study. 65 of the patients showed at least one palatally-displaced canine. Diagnosis and the location of the displacement were determined on the basis of standardized radiographs and confirmed by surgical documentation. Each maxillary tooth's mesiodistal and vestibulo-oral width was measured using a dial caliper on each dental cast. Excluded were partially-erupted teeth and surfaces with caries or restorations that had to be measured. An analysis of available space was made by evaluating the pre-treatment dental casts of all patients included in the study., Results: Comparing the tooth widths of patients with unilateral canine displacement with the corresponding contralateral quadrants, we noted a statistically significant difference, namely that the central and lateral incisors and the canines of the affected side were narrower than those of the non-affected side in the same patient. Moreover, the displaced upper canines showed an increase in vestibulo-oral dimension. Overall tooth width (including all tooth groups) in patients with palatally-displaced canines was significantly less than that in the control group. However, when comparing the crown diameters of unilaterally- and bilaterally-affected patients, no differences in tooth-size were observed. The space-analysis showed excessive dental-arch space in patients with a palatally-displaced canine., Conclusion: Patients affected by palatal canine displacement showed significantly smaller maxillary tooth size.

The case of a 36-year-old male and former patient is presented who died for initially unknown reasons, with intermaxillary wire fixation for the treatment of an infected mandibular fracture still in place. The combined investigation of forensic experts and maxillofacial surgeons excluded aspiration and asphyxia as cause of death. Evidence was found for lethal methadone concentrations after intravenous drug abuse and a broncho pneumonia. Despite the clear evidence of a fatal intoxication in this case, caution must be exercised when dealing with individuals carrying intermaxillary fixation.

Background: Up to now hydroxyapatite (HA) and beta-tricalciumphosphate (beta-TCP) ceramics have been routinely sintered at temperatures between 1100 degrees and 1500 degrees C. Our new calcium ceramic is fabricated by a sol-gel process at 200 degrees C. The aim of this investigation was to test the biodegradation of and the induction of bone formation by this material., Material and Methods: Eighteen 1-year-old Goettingen minipigs were divided into three groups. Critical size defects (>5 cm(3)) in the mandible were treated differently in all three animals (group 1: filling with 40% beta-TCP plus 60% HA, group 2: pure HA was applied, group 3 served as controls: only gelatinous material was given). Macroscopic and microscopic investigations of the former defects were made 8 months postoperatively. RESULTS. In groups 1 and 2 biodegradation of more than 93% of the new calcium phosphate formula was found 8 months postoperatively and considered to be very good. No difference was observed between pure HA (group 2) and the combination of HA and beta-TCP (group 1). In both groups complete bone formation was seen macroscopically in the former defects. In the control group only incomplete bone formation with 48.4% of the defect area was noted. This difference was significant ( p<0.001)., Discussion: The new calcium phosphate formula made by a sol-gel method at 120 degrees C seems to be suitable for filling bone defects and is of interest for orthopedic surgery, traumatology, craniomaxillofacial surgery, and dentistry.

Background: Giant cell lesions of the bone present similar histological features. The differential diagnosis comprises central giant cell granuloma, giant cell tumor of bone, and osteitis fibrosa cystica (brown tumor) in combination with hyperparathyroidism. Since these lesions may mimic metastatic bone disease in patients with a history of cancer, a malignant process has to be considered. Since the treatment and prognosis of these entities-benign versus malignant osteolytic bone processes-differ greatly, definitive differential diagnosis is of utmost importance., Case Report: Two patients presenting with osteolytic lesions of the maxilla are reported here. In both cases a history of cancer (breast and prostate) suggested bone spreading of these malignant tumors. The clinical and histological findings were similar in both patients. One lesion was diagnosed as central giant cell granuloma, the other was found to be brown tumour in osteitis fibrosa cystica as an initial manifestation of hyperparathyroidism., Discussion: The presented cases demonstrate the difficulties in establishing the correct diagnosis of patients found to have osteolytic lesions of the jawbones which is critical for the appropriate management of these patients. The article discusses the different entities of osteolytic lesions of the jawbones and the necessary diagnostic and therapeutic approach.

This case report deals with the case history of a 45-year-old male patient who presented with an unusual case of a central odontogenic fibroma which destroyed and replaced the bone mass of the right maxilla. After clinical examination a biopsy was performed and histopathology was consistent with a central odontogenic fibroma with destructive growth. The treatment plan consisted of a surgical resection of the right maxilla. The histopathological evaluation showed a subtotal destruction of the maxillary bone mass by the odontogenic fibroma. Obvious problems concerning the differential diagnosis of odontogenic fibromas as well as current concepts regarding their exact designation and classification are discussed.

Brown tumors are focal bone lesions caused by an increased osteoclastic activity and fibroblastic proliferation within a primary or more rarely secondary hyperparathyroidism. They are named after their typical brown hemorrhagic stroma with its also typical giant cell formations. We report the case of a 31-year-old pregnant patient with a rapidly growing tumor of her left maxilla whose first symptoms during pregnancy mimicked chronic sinusitis. After swelling of the cheek, diplopia, and recurrent epistaxis appeared, she was referred to our Department for further diagnostics. After CT scan, biopsy was performed under the presumption of a malignant process with the surprising histological result of a reparative giant cell granuloma. At the same time, hyperthyroidism and nodular goiter were diagnosed and further endocrinological examinations were planned. Not until a parathyroid adenoma was diagnosed after urgent operation of the maxillary process (loose molar teeth and displacement of the left bulbus) could the tumor be interpreted and detected within this context of primary hyperparathyroidism as a brown tumor. The brown tumor should be taken into consideration as a rare differential diagnosis of a bone-destroying process of the facial bones. We discuss the clinical signs, diagnostics, and therapy for this case as well as the relevant literature. The reparative giant cell granuloma represents an important differential diagnosis and cannot be distinguished from a brown tumor by histological examination or radiological findings without complete information about the clinical signs and the endocrinological status of the patient.

A 13-year-old girl suffered from a mesenchymal chondrosarcoma of the left maxilla. The therapeutic options and the prognosis for this disease are described with respect to the currently known 72 cases in the literature. Mesenchymal chondrosarcomas are rare tumors of the bone and soft tissue. The first clinical symptom is a painless swelling of the facial skull. They occur largely in the 2nd and 3rd decades of life, preferentially in males. Radiological criteria for the identification of this type of tumor include focal ossification areas which are accompanied by non-calcified regions. Complete surgical removal of the tumor is the therapy of choice. Pre- and postoperative chemotherapy can have a beneficial effect. The final outcome of the disease is difficult to evaluate since late complications (e.g., reoccurrence and/or metastases) appear even after 20 years and only a small number of cases have been reported. At present, the 5-year survival rate is reported to be 54-82% and the 10-year rate 28-56%.

Background: The melanotic neuroectodermal tumor of infancy is a rare and so far as being classified neoplasm with a high rate of recurrence for one year after diagnosis. Since Krompecher described 1918 the tumor at first, only about 200 cases are reported until today, mostly with manifestation in the maxillary region., Case-Reports: The authors present two infants at the age of six and eight weeks with first clinical manifestation of the tumor in the maxillary region. Although there were no other common signs, the tumor destroyed wide areas of the mid-face. In spite of a treatment with radical surgery, recurrences occur rapidly in the first living year., Conclusions: Our clinical and histological findings show characteristics of local malignant growth. For these facts the radical resections of the primary tumor and its recurrences are individually the therapeutical consequences. A follow up of seven years of one infant shows a hypoplasm of the mid-face as a result of the inhibition of further growth by the loss of germs after maxillary hemisection.

Case Report: We report the case of a 9-year-old female patient with a moderate swelling of the right maxilla. A tumor was diagnosed by conventional X-ray within the region of tooth 17 in the right tuber maxillae. The histological diagnosis after biopsy of the lesion was "fibrous dysplasia Jaffe-Lichtenstein". One year later, the tumor was still growing, and computed tomography was carried out. The first histological diagnosis was confirmed by another biopsy; the differential diagnosis was "ossifying fibroma". In the following years, the tumor grew and expanded into the right orbit and maxilla. Four years after the first diagnosis the tumor was removed operatively., Differential Diagnosis of the Operative Specimen: The histology showed round, partially trabecular or calcified bodies, known as psammoma-like ossicles. Therefore, in light of the clinical course and the radiographic appearance, the correct diagnosis was "psammous desmo-osteoblastoma"., Discussion: The psammous desmo-osteoblastoma and its differential diagnosis are discussed in this article.

Purpose: The development of fibrous nonunions following orthognathic surgery is thought to result from an interaction of biomechanical stress and the differential and more rapid migration of fibroblasts compared to osteoblasts into the wound site during healing. The present study was designed to test this hypothesis through the manipulation of guided tissue regeneration and osteotomy fixation techniques in an experimental rabbit model., Materials and Methods: Bilateral critical size (4 mm) defects (n = 24) were produced in the maxillae of 12 adult New Zealand White rabbits. The maxillary segments were rigidly or nonrigidly fixed using bone microplates and screws or osteosynthetic wires. The defects were then covered with a resorbable collagen membrane or left uncovered. The rabbits were followed for 4 weeks with serial dorsoventral and lateral oblique cephalographs and the maxillae were then harvested for histological analysis., Results: Radiographic and histomorphometric analysis revealed that rigidly fixed defects, covered with membrane, showed the most rapid and organized new bone formation. The rigidly fixed defects with membrane averaged approximately 40% more new bone in the osteotomy site than the rigidly fixed defects with no membrane. Nonrigidly fixed defects with no membrane also showed an ingrowth of fibroblasts and fibrous nonunions., Conclusion: These results suggest that an interaction between the decreased fibrous tissue ingrowth through guided tissue regeneration and osteotomy segment stability from rigid fixation prevented postoperative fibrous nonunions and facilitated new bone regeneration and osteotomy site healing in this rabbit model.

Within this chapter, tumors which produce bone matrix (osteoid) or other bone-forming tissues, like cartilage, connective tissue, and cementum or originate within the bone marrow are described. In addition, those lesions are mentioned which, according to the WHO, are typical for the jawbones and are therefore included within the 1992 WHO classification of odontogenic tumors. Vascular and epithelial tumors which may also be observed in the jaws are not described. All the lesions and tumors reported have in common a more or less similar clinical and radiological appearance. A precise diagnosis, therefore, can only be established by a sufficient biopsy which should be seen by a pathologist with experience in this field. In addition to clinical, radiological, and histological appearances, therapeutic necessities are described. The data from recent publications are taken into account. This presentation is based on the data collected within the reference registry of the German-Austrian-Swiss Study Group of Tumors of the Face and Jaws (DOSAK) in Basel.

The histopathologic diagnosis of odontogenic cysts is based mainly on the morphological nature of the epithelial lining of cysts and their origin. We used the international histologic classification set up by the World Health Organisation in 1992. The aim of this study was to investigate the differentiation of various types of cyst using an immunohistochemical technique rather than by conventional morphological assessment. A standard immunocytochemical method (APAAP method), applying anticytokeratin monoclonal antibodies and a p53 antibody, was used for the diagnosis of odontogenic cysts. A total of 57 jaw cysts were diagnosed according to clinical, radiological and pathological criteria as radicular cysts (20), dentigerous cysts (20) and keratocysts (17). The results proved that cyst type can be distinguished by the pattern of staining using the monoclonal antibodies CK7, CK19, CK20 for cytokeratins and the clone DO-7 for the p53 protein. Staining with the monoclonal antibodies CK7 and CK20 did not distinguish type. CK19 was not detected in keratocysts and p53 was only expressed in keratocysts. This may prove to be diagnostically useful for the more precise distinction between different cyst types.

Rehabilitation in patients with severe alveolar ridge atrophy of the maxilla or mandible is problematic and can often only be achieved by long-term treatment. In most cases, autologous bone grafting with iliac crest bone has been used to augment severely atrophied upper jaws. In our experience, iliac bone grafts are less useful, since iliac bone appears to be of inferior quality; in elderly osteoporotic women, the bone is soft, indentable, and of poor osteogenic potency. In our department, we have been using only autologous calvarial bone grafts for augmentation of alveolar ridge atrophy since 1993. The bone is removed from the outer table of the skull only, trimmed to the alveolar ridge, und fixed with titanium lag scews. The skull defect created is covered with crushed bone or a titanium mesh to avoid aesthetic problems. Insertion of dental implants follows after a healing period of the bone grafts of 5-6 months. A total of 63 patients underwent calvarial split-graft augmentation; augmentation of the maxilla and mandible was carried out in 15 of these patients, of the maxilla only in eight, and of the mandible only in 40. The investigations 1 year later showed a resorption rate of approximately 10%. This is lower than when using iliac bone grafting. The resorption results were stable between 6 and 12 months after augmentation. Using dental implants (12 patients with 32 implants), the resorption rate was low and constant. We have never seen total loss of bone grafts or intracranial complications. All patients were pleased with the treatment. In our opinion, severe alveolar atrophy of the maxilla or mandible should be compensated for by augmentation with autologous calvarial bone grafts to obtain good long-term results.

In the severely resorbed maxilla, a 10-year success rate of only 49-74% of implants in combination with autogenous bone grafts has been reported. We developed a modified technique of antral inlay grafting and lateral and vertical onlay grafting of the severely resorbed maxilla for inserting implants to retain dentures. The clinical and radiologic results are presented. In 21 patients with severely resorbed edentulous maxillae, a total of 20 bilateral and one unilateral antral inlay graftings and lateral and vertical onlay graftings were performed after a prosthodontic setup. We opened the maxillary sinus by removing a bony window from the anterolateral wall and, after elevation of the sinus lining, grafted the sinus floor with corticocancellous iliac crest bone grafts. The maxilla was also augmented in the lateral and vertical direction. The bone grafts were fixed by osteosynthesis. After a median of 5 months, a total of 134 implants (Brånemark) were placed and later loaded by prosthodontic rehabilitation. Computed tomography (CT) scans were taken before the grafting procedure, immediately after grafting, after 4 months, and every year thereafter. A total of 94.8% of the implants were successful at the time of the abutment operation. After loading, two additional failures were seen in an average follow-up period of 2.5 years. Most patients were provided with implant-borne dentures. CT scans showed an average initial gain of vertical bone height of 3.7-17.7 mm. One year after grafting, a loss of 1.3 mm or 7% occurred. In the following 2 years, no major atrophy was observed. Statistical analysis showed no correlation between sex, bone height before augmentation, augmented bone height, and resorption of the grafted bone. We observed undisturbed healing and obtained large vertical bone heights, a high success rate, minimal resorption, and fully satisfactory prosthodontic rehabilitation; we can thus recommend our modified technique of reconstruction of the severely resorbed maxilla for routine use.

Twenty-three patients with class VI atrophy of the maxilla were treated with horseshoe Le Fort I osteotomy. In ten patients, simultaneous placement of the implants was carried out, and in 12 the implantation was done in a second procedure 6-9 months later. A total of 178 implants were placed, and 15 were lost. In one patient, five implants were lost due to an oronasal fistula, leading to loss of part of the bone graft. The implant survival rate for all the implants was 89.0-88.2% in the one-step procedure and 90.0% in the two-step procedure. There was no difference between the one-step and the two-step procedure with respect to the peri-implant soft tissues in follow-up of least 2 years after implantation. We favor the two-step procedure because it allows more precise positioning of implants.

In 63 patients, 82 elevations of the maxillary sinus were performed. As augmentation, materials autografts from the iliac crest (combined with alveolar ridge augmentations in 16 sinus lifts) were transplanted in 39 cases and osteoinductive, allogeneic bone powder (AAA bone (autolyzed, antigen-extracted, allogeneic bone): n = 8, DFDBA (demineralized freeze-dried bone allograft) and/or Grafton (demineralized bone matrix gel): n = 35) were used in 43 cases. Some 4-6 months after implantation, osteoinductive, allogeneic (demineralized) bone implants showed radio-opaque areas as an equivalent of bone formation. Histological examinations revealed that osteoinductive implants were completely transformed into patients' own bone tissue. The average augmentation height after autograft transplantations was 14 (+/- 3) mm in comparison with 9 (+/- 3) mm after allograft implantations. Histologically as well as radiologically no differences of the bone quality could be determined between the two augmentation materials. Endoscopic controls showed, in both groups, nonirritated mucous membranes. On an average 2 endosseous implants (Bone Lock or ITI-screw implants) were inserted into the augmentated maxillary sinus floors in both groups. No osseointegration was achieved in 4 out of 67 dental implants when bone autografts were used and in 2 out of 74 dental implants of the allogeneic bone group. Patients with bone autografts suffered from postoperative complaints on an average of 19 (+/- 9) days (without consideration of 2 patients with postoperative complaints persisting for more than 90 days). The average postoperative complaints of recipients of allogeneic bone implants continued for 3 (+/- 5) days. The 13 patients who underwent an ambulant sinus lift procedure with allogeneic bone powder were already symptom-free several hours after the operation. Under critical consideration of all investigated parameters, osteoinductive bone implants are preferable to iliac bone autografts for maxillary sinus augmentations in those cases in which no additional alveolar ridge augmentation is required.

Postoperative cosmetic results in soft tissue after combined surgical and prosthetic treatment of the extremely atrophic edentulous maxilla by maxillary advancement, sinus lift, and insertion of enosseous implants are rarely considered during preoperative planning. In a prospective study that began in 1993 in 23 patients, the treatment concept was determined by a medical rapid prototyping model and video imaging to predict the soft tissue profile, taking into consideration the appearance of the front teeth. In eight patients, the surgical and/or the prosthetic concept was modified according to the treatment plan decided on with the patient. All patients were highly satisfied with the aesthetic and functional result achieved. Profile prediction using video imaging is a useful tool in planning rehabilitation of the atrophic maxilla and takes into account the interplay of various factors--the amount of maxillary advancement, the direction of insertion of enosseous implants, and the type of supraconstruction. This procedure shows a very high level of acceptance by patients.

Purpose: The aim of this retrospective study was to evaluate the long-term survival rate of dental implants in edentulous patients suffering from severe atrophy of the alveolar ridges in the upper jaw., Patients and Methods: In total, 964 implants were inserted in 140 patients. A total of 481 implants were combined with an osteoplastic augmentation of the maxilla, and 483 implants were inserted directly in the atrophic bone. The success rate was determined using survival analysis, log rank tests and a Cox regression analysis., Results: The overall survival rate for all implants was 42.2% during an observation period of 11 years. Between implants combined with an osteoplasty and implants inserted in local bone tissue there were no significant differences in the survival rate. The survival rate of implants combined with an osteoplasty was significantly reduced in women and in the case of repeated insertion or augmentation. Interestingly, a few of the patients treated with an osteoplasty demonstrated high numbers of individual implant failures. Those patients were postmenopausal women exclusively. Among them there is probably a certain group with a very high risk of implant failures., Conclusion: This study shows that oral rehabilitation with osteointegrated implants in patients with severely atrophic alveolar ridges in the upper jaw is still problematic.

A total of 27 vascularized iliac crest segments and four vascularized scapula transplants were transferred to achieve masticatory rehabilitation in 31 patients suffering from extensive maxillary defects; 83 Brånemark implants and 16 IMZ implants were inserted 4-8 months after the bone transplantation. The implants were uncovered 6-8 months after insertion. All patients were provided with a bar-fixed, removable prosthesis. At an average insertion period of 4.5 years, the implant loss rate was 18.8%. The effectiveness of a combination of microsurgical bone transplantation and implantation in treating serious maxillary defects is thus demonstrated.

In the maxilla, it is sometimes necessary to use implants to achieve a good prosthetic result. However, an increased failure rate of maxillary implants seems to be a common clinical experience. This experience was investigated in a retrospective statistical analysis. In a retrospective study of 665 patients between 1987 and 1997, 2484 implants were examined. The implants in the upper jaw were compared to those in the lower jaw. Implants with and without autogenous bone grafts and fixtures in patients with alveolar ridge atrophy, tumor, or trauma were explored. In particular, the data obtained from the orthopantomograms after completion of the prosthetic superstructures were controlled for peri-implantary bone loss evaluation. A total of 40% of the fixtures were placed in the maxilla, and 30% of these implants were combined with a local or an iliac bone graft. Out of 2484 implants, 207 were lost, largely during the healing period. The failure rates in the groups of patients with alveolar ridge atrophy, tumor, and trauma were between 6 and 27.5%, and the differences between these groups were higher than the difference between the upper and the lower jaw. Especially in the maxilla and after osteoplasty, horizontal peri-implantary bone loss was increased, with some cases of dramatic bone loss and decrease of the osseous integration of the fixtures. There was no statistic evidence of a significantly higher failure rate in the upper jaw than in the lower jaw. However, besides the rate of implant loss, additional markers should also be considered for adequate evaluation of implant prognosis in the maxilla.

Consideration of alveolar profiles and clinical experience demonstrate that the transversal dimension has been neglected in dental implantology so far. For a comprehensive evaluation of the impact of alveolar bone height and width, 95 edentulous bony maxillae with standardized, measured, and classified cross-sections were analyzed. With four types of implants (minimum length, 10 mm), 1076 insertions were simulated at 269 cross-sections and evaluated with regard to type of implant, position of cross-section, and class of atrophy. Similar evaluation was carried out in the clinical part of the study on 24 consecutive patients with edentulous maxillae. Implant insertion could only be simulated in 35% of the cadaver cross-sections, but had been expected in an additional 4.5% based on their sufficient bone height; length reductions were necessary in another 6%. These results depended largely on the class of atrophy. Anterior cross-sections offered better conditions than posterior ones. In contrast, implant insertion was impossible in all 24 patients. Height was primarily inadequate in 22 patients, and in two patients with sufficient bone height inadequate transversal dimensions were only recognised intraoperatively. These results allow a quantification of the impact of vertical and transversal maxillary alveolar bone dimensions. This impact primarily depends on bone height, but even with sufficient height, reductions of implant length often become necessary. Both for the cadaver maxillae (12% of the cross-sections with expected implant insertion) and for the patients (8%), alveolar profiles remain in which height measurement alone leads to incorrect assessment and may even result in the interruption of precisely planned surgical procedures. The complexity and expense of implant-borne rehabilitation and the consequences resulting from incorrect preoperative planning therefore generally justify extended cross-sectional diagnostic measuring.

The aim of this study was to investigate experimentally the effect of long-term orthodontic loading on the activity and location of osteodynamic changes around short titanium screw implants. For this purpose 6 maxillary premolars (1P1, 2P2, 3P3) were extracted from each of 2 foxhounds. After a 16-week healing period, 8 implants (4 per dog) were inserted in the edentulous areas. Simultaneously 2 implants (1 per dog) were positioned in the palatal suture. After an 8-week implant healing period the fixtures in the P1/P2 areas (n = 4) and the palate (n = 2) were loaded (test implants) by means of Sentalloy traction springs (approximately 2 N continuous force). The fixtures in the P2/P3 areas served as controls (n = 4). The osteodynamic changes during the force application period (26 weeks) were recorded with bone labeling fluorochromes. Histological evaluation revealed a tendency towards higher remodeling activity within the peri-implant bone (up to 500 microns from the implant surface) of the loaded compared with the unloaded sample. This higher activity was found on both sides facing the loading direction as well as on the opposite sides. Furthermore, within the bone adjacent to the marginal halves of the implants on the loading direction sides, this higher remodeling activity extended more than 1000 microns from the respective implant surfaces. The results suggest that long-term orthodontic loading of short maxillary implants may increase the remodeling activity within the peri-implant bone.

Purpose: To establish a new method for dental imaging using magnetic resonance tomography named Dental-MRT and to demonstrate its usefulness in diagnosing dentogen pathologies of the mandible and maxilla., Methods: Seven healthy volunteers, three patients with pulpitis, two patients with dentigerous cysts, two patients after tooth transplantation, and three patients with atrophic mandibles have been evaluated. Optimized axial T1- and T2-weighted gradient echo and spin echo sequences in 2D and 3D technique have been established to perform studies of the jaws. The acquired images were reconstructed with a standard dental software package on a work-station as panorama and cross-sectional views of the mandible or maxilla., Results: The entire maxillo-mandibular bone, teeth, dental pulp, and the content of the mandibular canal were well depicted. Patients with pulpitis demonstrate bone marrow edema in the periapical region. Dentigerous cysts and their relation to the surrounding structures are clearly shown. After contrast media administration marked enhancement of the dental pulp can be demonstrated., Conclusion: Dental-MRT promises to provide a new tool for visualization and detection of dental diseases.

An adenomatoid odontogenic tumor has been reported which was not connected with any impacted or displaced tooth. The clinical and radiographical results were consistent with a non-odontogenic cyst, but in this case the pathohistological examination revealed string-like and partly cross-linked cells of odontogenic epithelium as well as solid aggregates of epithelia, possessing gland-like structures at their centers. Furthermore, small deposits of PAS-positive materials could be seen which could be interpreted as non-mineralized dentine with a tubular basic structure. The therapy consisted of completely enucleating the tumor. Any recurrence of malignant degeneration has not yet been reported.

Ameloblastic fibromas are rare benign odontogenic tumours, which appear preferentially in adolescents and young adults. They are most often found in the mandible. The present case report describes a 40-year-old patient with an ameloblastic fibroma in the upper jaw, an extremely rare site. The diagnosis, differential diagnosis, histology and therapeutic procedure are described.

The aim of this study was to evaluate treatment results after extraction of maxillary second molars. Since this therapy was chosen in patients with class II malocclusion, deep overbite and counterclockwise growth pattern, its effects on overbite and correction of the malocclusion were examined. For this purpose pre- and post-treatment models of 25 patients with 48 extracted upper second molars were measured and lateral cephalograms were appropriately superimposed in order to determine maxillary and mandibular skeletal and dentoalveolar changes. Our results indicate an average overbite reduction from 4.7 mm to 2.7 mm. None of the patients showed a posttreatment overbite increase. Despite the considerable initial Class II relation in many cases, a Class I occlusion was achieved in 92% of the patients. Primarily, the correction was achieved by distalization of the upper first molars. Furthermore, the mesial migration of the lower first molars, skeletal changes in the lower jaw, and the growth inhibition in the upper jaw contributed to the correction of the class II malocclusion.

Mesenchymal chondrosarcoma is a variant that shows some peculiarities in comparison with classical chondrosarcomas. On the basis of a case report on a young man with a mesenchymal chondrosarcoma of the maxilla, the clinical symptomatology and diagnostics, morphological findings and actual therapy are discussed. In addition, problems of differential diagnosis are also discussed.

The existence of the alveolar process depends on the development of teeth. In edentulous maxillae, the alveolar process disappears in general in the region of incisives, canines and eventually premolars, but it persists in over 80% of cases in the region of molars. The persistence of the alveolar process correlates with the pneumatisation of the alveolar process by the alveolar recess of the maxillary sinus. The sinus may invade the whole alveolar process or only part of it so that in its lower part a thicker bone layer persists. Very rarely the alveolar process disappears completely with the loss of teeth. The deepest recess of the maxillary sinus corresponds to the level of the zygomatic process i.e. to the region of the first and second molar teeth.

A case of a rare subtype of midfacial ossifying fibroma in a 5-year old child is presented. Fibro-osseous lesions represent a variety of bone proliferations each characterised by different morphological patterns of osteoid production. Psammomatoid ossifying fibroma is characterised histologically by numerous small round ossicles resembling psammoma bodies and is a locally invasive lesion of facial and cranial bones. The histopathology is described. The surgical treatment includes complete resection of the tumour as well as involved bones by means of midfacial degloving. Two years after surgical treatment the child is free from symptoms and tumour recurrence.

A longitudinal study of 39 casts of pre-operative orthodontically treated unilateral cleft lip and palate children from birth to palate operation was carried out with a special coordinate measuring technique to quantify changes in the maxilla. A significant reduction in width of the alveolar cleft was found. The anterior alveolar arch width remained constant, while the posterior region slightly increased. These results seem to justify treatment with the infant appliance. After measuring casts from 39 preoperatively treated and casts from 62 untreated patients prior to lip operation, a comparison of the mathematical average values between the two groups revealed few differences. This can be explained by referring to the original morphological findings and the different measurements during the preoperative orthodontic treatment, which lead to different changes in segment position prior to lip operation. In a cross section examination this difference could not be found. A sub-classification of the subject matter in primary and secondary clefts revealed that between both types clear differences in the resulting parameters can be observed. This leaves the question, whether the width of the cleft palate is caused by tissue deficiency or by an embedded tongue. Furthermore, how will the orthodontic appliance therapy influence the growth? A greater dislocation of the segments in secondary clefts may be expected in cases where the rest position of the tongue appears caudal. Improved measuring methods to record cleft morphology and more emphasis on the study of soft tissue reactions may help to understand the differing results after preoperative or orthodontic treatment.

The in-vivo bone ablation characteristics of a pulsed solid-state erbium:YAG laser were compared to those of a pulsed solid-state holmium:YAG laser. Partial osteotomies in the maxillary, the mandibulary, and the nasal bones of white rats were performed. The tissue response was examined by light microscopy. Thermal gradients following the laser application were also measured. Over all energy levels tested the erbium:YAG laser produced ablation of bone with minimal thermal damage to the adjacent tissue. The results of this study are promising for future application of the infrared holmium- and erbium:YAG lasers in otorhinolaryngology.

The authors report a case of a melanotic neuroectodermal tumor of infancy occurring in the maxilla of a 6-month-old female infant. The tumor displayed a biphasic cellular pattern with small neuroblast-like cells and large melanocytic cells showing a highly characteristic immunophenotype. Both tumor cell types immunostained for neuron specific enolase (NSE) and vimentin. The melanocytoid cells reacted additionally with the anti-keratin antibody Kl 1 and with HMB 45, an antibody specific for melanocytic antigens. The melanotic neuroectodermal tumor of infancy usually runs a benign course, however, local recurrence and metastasis may occur. The course of the disease cannot be predicted from morphological findings.

The problem of 'Gundu' in primates is discussed. Cases of so-called 'Gundu' in the literature, two cases in Gorilla and one in Lagothrix, are dealt with. Histological and X-ray techniques are used. One case (Lagothrix) represents the so-called simian bone disease, which is metabolic disorder and is due to a secondary nutritional hyperparathyroidism. The other two cases (Gorilla) show symmetrical bony tumors of the maxilla. The origin is uncertain. Gundu, Paget's disease and primary hyperparathyroidism Recklinghausen have not been observed in primates so far.