The use of autologous bone for augmentation procedures leads to low prevalence of peri-implantitis-a retrospective study over a 20-year period

The aim of this study was to compare the prevalence of peri-implantitis in implants inserted into pristine bone (control) to implants where autologous bone was used for grafting procedures (study). All patients who underwent implant surgery during a 20 years interval by one maxillofacial implant surgeon and received a prosthodontic rehabilitation afterwards were eligible for inclusion in the study. Periimplant bone resorption and periimplant disease were assessed. Of 421 patients 384 (91.2%) patients responded to a recall after having been treated over a 20-year period by one maxillofacial surgeon and several dentists. A total of 110 patients had 239 implants in pristine bone, and 274 patients had 607 implants placed in combination with autologous bone grafting procedures. Mean time in function was 74 months (range 15-236 months). In all, 342 implants (34.8%) were in function for longer than 7 years. A total of 64 implant sites (7.6%) in 39 patients (10.2%) showed signs of peri-implant mucositis. In addition, 17 implants (2.0%) in 14 patients (3.6%) revealed signs of peri-implantitis, of which five implants were in the control group (2.09%) whereas 12 implants were in the study group (1.98%), with no statistically significant difference (p = 0.8405). More than half of the patients with peri-implantitis had a history of periodontitis. Three implants were lost due to peri-implantitis and four implants failed for other reasons, resulting in an overall success rate of 99.2% in 846 implants. CONCLUSIONS: Within the limitations of the study it seems that the use of autologous bone still is a relevant option when performing augmentation procedures because of the low prevalence of peri-implantitis.

Status report on dental implantology in Switzerland. An updated cross-sectional survey

A status report of dental implantology in Switzerland has already been performed in 1994 and 2006. The present study, based on these former surveys, aimed to update these results for the year 2016. To this end, a questionnaire was sent to all dentists in Switzerland who were members of the Swiss Dental Society (SSO) at the time of the survey. The questionnaire asked for personal background data and obtained information about the dentists' knowledge and concepts when using implants, the extent to which they used implants and about specific implant systems, which were selected based on the previous surveys. Out of 3,168 questionnaires, 1,446 were returned (return rate: 45.6%). Approximately 91% of the responding dentists had a practical involvement in implantology (implant placement only, superstructure insertion only, or both). Just over half of them (53%) placed more than twenty implants per year. Good handling was chosen by all dentists (100%) as a selection criterion for the implant system they used preferably. The current data suggested that the range of indications had widened, yet that the edentulous mandible was still the indication of choice. The percentage of dentists engaged in dental implantology doubled from 1994 to 2006 (1994: 42.2%, 2006: 82.2%). An increase of almost 10% in dentists involved in dental implantology was also apparent from 2006 to 2016 (2006: 82.2%, 2016: 91%). Our data show that, whilst the relative number of implant users had greatly increased among Swiss dentists, their rationale to place implants has remained similar.

[The Interdisciplinary Stomatology Service at the Department of Oral Surgery and Dental Imaging, University Center for Dental Medicine and the University Hospital Basel, Switzerland - Results from 2003 - 2013]

The Interdisciplinary Stomatology Service at the Department of Oral Surgery and Dental Imaging, University Center for Dental Medicine and the University Hospital Basel, Switzerland - Results from 2003 - 2013 Abstract. Stomatological problems are common, but rarely diagnosed in private dental practice. Even for oral surgeon's diagnosis and therapy of these disorders could be challenging. Stomatological problems can indicate general health problems. Hence, the oral cavity is also known as the «mirror of systemic diseases». To tackle this problem, an interdisciplinary stomatological service in a specialized dental clinic was established in 1999 at the Center for Dental Medicine, University of Basel, Switzerland. A board of specialists (Dermatologists, Otorhinolaryngologists, Oral- and Maxillofacial surgeons) was summoned monthly to perform interdisciplinary consultations of selected patients with complex oral and medical disorders. The specific knowledge of each specialist helped to ensure a diagnosis, even of rare systemic disorders and symptoms. Networking with a variety of specialists built the foundation for synoptic therapy approaches. Thus, the center was able to provide appropriate care for patients suffering from severe, chronic and complex stomatological findings. The results presented in this article are part of a dissertation based on the analysis of 154 patients who were seen in the interdisciplinary consultations in 2003 - 2013.

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Zusammenfassung. Die Beurteilung von Mundschleimhautbefunden ist selbst für das geschulte Auge auf den ersten Blick nicht immer einfach. Viele pathologische Befunde sind selten und werden von niedergelassenen Zahnärzten nur vereinzelt im Verlauf eines Berufslebens gesehen. Innerhalb der stomatologischen Sprechstunde an spezialisierten zahnmedizinischen Zentren können Mundschleimhautveränderungen aus diesem Grund oft schneller und sicherer diagnostiziert und therapiert werden. Dieser Artikel soll einen Überblick über häufige Veränderung der Mundschleimhaut innerhalb unserer stomatologischen Sprechstunde geben.

20 years of cleft lip and palate missions

Volunteer missions for cleft lip and palate (CLP) care in Indonesia (1991-1992), India (1994-2003), Bhutan (2005-2010), and Kenya (2011), took place always at the same Hospital in each country. Altogether over a thousand patients were operated using a conservative protocol: Safety first - no experiments. Five months and 5 kg were the basic rules. For the native doctors, training help for self-help was priority. In the announcements, patients with CLP were primarily addressed. Burns, contractions, tumors, and trauma-cases were the second priority. Fresh trauma was done in night shifts with the local surgeons in order not to interfere. Besides facial esthetics speech was the number one issue, following priorities fell into place. Cultural aspects played a certain role in the different countries and continents.

Antidepressants relevant to oral and maxillofacial surgical practice

Background:

Depression is commonly associated with a high-carbohydrate diet, lack of interest in proper oral hygiene and xerostomia connected to the use of antidepressants. Patients often consult their dentists as a result of changes affecting the hard dental substance and the soft-tissues.

Aim:

The aim of this study was to identify adverse drug interactions between the antidepressants and medications commonly administered in dentistry in order to give practicing dentists an overview of the scientific literature.

Objective:

The objective is to identify the adverse drug interactions between antidepressants and medication commonly administered in dentistry.

Study Design:

The literature search was performed using PubMed, Cochrane and the specific search items. The review (1984-2009) focused on medicines used in dental practice (vasoconstrictors, non-opioid analgesics, non-steroidal anti-inflammatory drugs, antibiotics, antifungals and benzodiazepines).

Results:

There are various drug interactions between antidepressants and medicines used in dentistry. When two or more drugs are co-administered, a drug interaction must always be anticipated though many of the interactions are potential problems, but do not seem to be real clinical issues.

Conclusion:

The probability of a drug interaction can be minimized by careful history-taking, skillful dose adjustment and safe administration of the therapeutic agent.

SADMFR guidelines for the use of Cone-Beam Computed Tomography/ Digital Volume Tomography

Cone-Beam Computed Tomography (CBCT) has been introduced in 1998. This radiological imaging procedure has been provided for dentistry and is comparable to computed tomography (CT) in medicine. It is expected that CBCT will have the same success in dental diagnostic imaging as computed tomography had in medicine. Just as CT is responsible for a significant rise in radiation dose to the population from medical X-ray diagnostics, CBCT studies will be accompanied by a significant increase of the dose to our patients by dentistry. Because of the growing concern for an uncritical and consequently rapidly increasing use of CBCT the Swiss Society of Dentomaxillofacial Radiology convened a first consensus conference in 2011 to formulate indications for CBCT, which can be used as guidelines. In this meeting, oral and maxillofacial surgery, orthodontics and temporomandibular joint disorders and diseases were treated and the most important and most experienced users of DVT in these areas were asked to participate. In general, a highly restrictive use of CBCT is required. Justifying main criterion for CBCT application is that additional, therapy-relevant information is expected that should lead to a significant benefit in patient care. All users of CBCT should have completed a structured, high-level training, just like that offered by the Swiss Society of Dentomaxillofacial Radiology.

Is the Schneiderian membrane thickness affected by periodontal disease? A cone beam computed tomography-based extended case series

OBJECTIVE

The aim was to assess the thickness of Schneiderian membranes (SM) in patients with advanced periodontal disease.

METHODS

17 dentate patients (DG) scheduled for periodontal surgery on maxillary molars were consecutively recruited and cone beam computed tomographies performed for preoperative diagnosis. Twenty-one patients (EG) requiring cone beam computed tomography-based planning of implant placement in the edentulous posterior maxilla served as controls.

RESULTS

Schneiderian membrane thickness measured from cone beam computed tomography was significantly greater in the dentate group compared to the edentulous group, both in the first (p = 0.028) and second (p < 0.001) molar position. In the dentate group, clinical signs of periodontal destruction (increased probing pocket depth or furcation involvement) were not associated with Schneiderian membrane thickness. Additional findings, such as periapical lesions (p = 0.008), and the distance between root tips and maxillary sinus revealed a significant association (p = 0.036) with Schneiderian membrane thickness.

CONCLUSION

In molar regions with periodontal destruction, Schneiderian membrane thickening occurred, particularly in combination with small bone layers above the root tips or periapical lesions.

Thermal conduction of titanium implants under CO2 laser irradiation in vitro

Objective:

The surgical exposure of dental implants can be performed by means of scalpel, punch, or, with less bleeding, by means of CO₂ laser. Possible overheating of the peri-implant bone tissue should be avoided. The goal of this study was to examine the temperature changes on implants under CO₂ laser irradiation (Luxar CO₂ 20 SP laser from POLYMED, Glattbrugg, Switzerland).

Study design:

Straumann^® implants were irradiated with continuous wave (cw), continuous wave with super-pulse (cw/sp), and pulsed wave (pw). The irradiation power was 4, 5, 6, 7, 8, 9, and 10 W and the irradiation times were 10, 20, 30, and 60 s. Similar temperature changes occurred in cw/sp mode and cw mode, but substantially higher temperatures appeared in pulsed wave mode.

Results:

The quickest temperature changes were observed with cw/sp irradiation (+0.5°C to +41.1°C, depending on the irradiation parameters). Beyond 20 s and 8 W irradiation, a rise exceeding 10°C on the implant surface was found.

Conclusions:

Implant diameter and length as well as the setting parameters of the CO₂ laser (irradiation power, irradiation time, and irradiation mode) are important factors to consider so that risk-free implant exposure can be accomplished. Ignoring these factors causes a risk of pathological heating of the irradiated implants and thus the surrounding tissue, which can result in the loss of an implant.

Cardiovascular monitoring and its consequences in oral surgery

Objective:

Higher life expectancy has lead to an increase of elderly patients in dental practices, thus also causing an increase in high-risk cardiovascular patients.

Study Design:

In all, 3012 patients had oral surgery with local anesthesia at the Department of Oral Surgery, Oral Radiology and Oral Medicine at the University of Basel. The Colin BP 306 compact monitor was used during these surgeries. The patient's heart rate, blood pressure, and oxygen saturation were routinely checked, both before and during the procedure.

Results:

The oral surgical procedure had to be discontinued 17 times, because the patient developed significantly elevated blood pressure. Twice, the procedure had to be discontinued due to cardiac arrhythmia. The average age of these 19 patients was 63.5 years.

Conclusions:

Pre-and intraoperative monitoring allows the dentist to identify patients with high-risk diagnostic findings and to reduce problematic cardiovascular situations.

Bisphosphonate-related osteonecrosis of the jaws--a review

The aim was to evaluate the knowledge about bisphosphonate-related osteonecrosis of the jaws (BRONJ). A bibliographic search in Medline, PubMed and the Cochrane Register of controlled clinical trials was performed between 2003 and 2010 by using the terms bisphosphonate and osteonecrosis of the jaw. The amount of publications per year, the type of journal for publication, and the evidence level of the trial were evaluated. Next to this the incidences and the success of treatment strategies for BRONJ were identified. A total of 671 publications were reviewed. Since 2006 more than 100 publications on BRONJ per year (with an upward trend) have been published, mostly in dental journals. The evidence level could be determined for 176 publications and only one grade Ia study was found. The studies showed a wide variety in design, most of them being retrospective. The incidence of BRONJ is strongly dependent on oral or intravenous application and varies between 0.0% and 27.5%. There is no scientific data to sufficiently support any specific treatment protocol for the management of BRONJ. Further clinical studies are needed to evaluate the incidence and treatment strategies at a higher level of evidence. Therefore uniform study protocols would be favourable.

Morphological Changes of Isolated Osteoclasts in Cell Culture Due to Different Biomaterials

Osteoclasts have been isolated in primary cell culture using femoral bone of laying hens being fed on an eight day calcium free diet. Placing these cells on the surface of fixed cortico-femoral chicken bone provoked the feature of resorption pits proving that they are able to resorb bone.

After placing osteoclasts on different biomaterials (Aluminumoxide ceramics, teflon, carbon fibre reinforced polysulphone, polymethylmethacrylate, polydioxanone) scanning electron microscopy was performed. Different materials provoke different morphological features of these cells, probably due to functional variations as a response to the changing surfaces. Adhesion was feasible on all the surfaces, uptake of small surface particles was possible and cell fusion took place on most materials suggesting acceptance of the tested biomaterials by the cells.

The results show that morphological changes of isolated osteoclasts in cell culture can be detected due to different functional challenges of the surfaces of different biomaterials.

Oral care

Adequate dental and oral hygiene may become a challenge for all users and especially for elderly people and young children because of their limited motor skills. The same holds true for patients undergoing/recovering from chemo-/radiotherapy with accompanying sensitive mucosal conditions. Poor dental hygiene can result in tooth decay, gingivitis, periodontitis, tooth loss, bad breath (halitosis), fungal infection and gum diseases. The use of a toothbrush is the most important measure for oral hygiene. Toothbrushes with soft bristles operated carefully by hand or via an electric device help to remove plaque and to avoid mucosal trauma. A handlebar with a grip cover can be helpful for manually disabled patients or for those with reduced motor skills. In case of oral hygiene at the bedside or of patients during/after chemo-/radiotherapy a gauze pad can be helpful for gently cleaning the teeth, gums and tongue. The use of fluoride toothpaste is imperative for the daily oral hygiene. Detergents such as sodium lauryl sulphate improve the cleaning action but may also dehydrate and irritate the mucous membrane. The use of products containing detergents and flavouring agents (peppermint, menthol, cinnamon) should therefore be avoided by bedridden patients or those with dry mouth and sensitive mucosa. Aids for suitable interdental cleaning, such as dental floss, interdental brushes or dental sticks, are often complicated to operate. Their correct use should be instructed by healthcare professionals. To support dental care, additional fluoridation with a fluoride gel or rinse can be useful. Products further containing antiseptics such as chlorhexidine or triclosan reduce the quantity of bacteria in the mouth. For patients undergoing or having undergone radio-/chemotherapy, a mouthwash that concomitantly moisturizes the oral mucosa is advisable.

[Immediately loaded MonoType implants in the edentulous mandible]

Results of immediately loaded implants are presented. 34 patients with 136 interforaminal MonoType implants (Straumann,Basel, Switzerland) were included in the study. The bar retention was manufactured fter the operation, inserted and covered with a hybrid prosthesis. 28 patients showed up for the follow-up study, the average time range was three years. Five implants were rated as failures, the cumulative six-year success rate being 94%. Interforaminal immediately loaded MonoType implants in edentulous patients showed very good results, comparable to similar studies with different systems.

[Status report on dental implantology in Switzerland]

PURPOSE

To present results of a survey on the status of implantology in Switzerland.

MATERIALS AND METHODS

A questionnaire was sent to all SSO (Swiss Dental Society) members asking for personal (anonymous) background data and their implantology concepts. Specific questions dealt with level of recognition of implants, use of implants, superstructures, success and failure rates, recall and training.

RESULTS

Straumann, Nobel Biocare, 3i, SPI and Frialit are the most commonly used implant systems in Switzerland. Almost two thirds (63.8%) of the dentists place more than 20 implants per year. Long-term prognosis is the crucial factor, whereas material costs play a minor role. The edentulous lower jaw is the indication of choice, whereas the edentulous upper jaw applies less. Almost every dentist active in implantology follows continuing education programs in the field.

CONCLUSION

Compared to a study undertaken twelve years ago the number of dentists engaged in implantology doubled, meaning at least one third of non-hospital dentists in Switzerland are involved in dental implantology. Overall the willingness to extend the therapeutic range has greatly increased.

Status report on dental implantology in Switzerland in 2006. A cross-sectional survey

PURPOSE

To present results of a survey on the status of implantology in Switzerland in 2006.

MATERIALS AND METHODS

A questionnaire was sent to all SSO (Swiss Dental Society) members asking for personal (anonymous) background data and their implantology concepts. Specific questions dealt with level of recognition of implants, use of implants, superstructures, success and failure rates, recall and training.

RESULTS

A total of 1568 (47.3%) of the 3315 questionnaires were returned. Straumann, Nobel Biocare, 3i, SPI and Frialit were the most commonly used implant systems in Switzerland. Almost two-thirds (63.8%) of the dentists placed more than 20 implants per year. Long-term prognosis was the crucial factor, whereas material costs played a minor role. The edentulous mandible was the indication of choice, whereas the edentulous maxilla applied less. Almost every dentist active in implantology followed continuing educations programs in the field.

CONCLUSIONS

Compared to a study undertaken 12 years ago, the number of dentists engaged in implantology doubled, meaning at least one-third of non-hospital dentists in Switzerland were involved in dental implantology. Overall, willingness to extend the therapeutic range has greatly increased.

[Cervicofacial actinomycosis: two case reports]

Infectious diseases transmitted by actinomycosis species cause severe destructive lesions. This rare and specific infection is mainly found in the orofacial regions. Causes of any hard tissue swelling in the jaw have, thus, to be assessed carefully. When actinomycosis is identified, a surgical intervention with curettement, draining and long-term antibiosis is required. The aim of the current article is to describe two clinical cases and to show the necessity of both, microbiological and histological laboratory diagnostics, to hedge the clinic diagnosis.

[Soft tissue calcifications in panoramic radiography. A risk factor for cerebrovascular accidents?]

Panoramic radiography is a basic diagnostic tool in the dental field where calcifications are seen occasionally in the lateral parts of the x-ray. The differential diagnosis are carotid artery atheromas, calcified submandibular lymphnodes and sialoliths of the submandibular gland. 4007 panoramic radiographs (100%) from patients >40 years were scanned retrospectively. Special emphasis was given to the carotid artery territory (CAT). 225 soft tissue calcifications were found (5.6%). 144 patients had calcifications in the CAT (3.6%), 73 showed calcified submandibular lymphnodes (1.8%), and 8 (0.2%) sialoliths. The female to male ratio was 54.7%:45.3%. Pneumatic diseases were beside hypertension and smoking a risk factor for CAT calcification. Carotid artery atheromas are the main risk for cerebrovascular insults. Dentists can help to detect patients at risk for stroke. Their patients can be referred for further diagnostics (ultrasound).

Vertical distraction osteogenesis of the alveolar process for implant therapy: two case reports

Rehabilitation of the chewing function of a patient depends on the quality and volume of the existing jawbone. Vertical augmentation of the jawbone is often a challenge for the dental surgeon. Various transplantation methods, from transplantation of autogenous bone to use of bone substitute material, have been described and discussed and are often controversial. Vertical distraction presents an alternative to preimplantation augmentation of vertically reduced bone. The technique offers certain advantages over conventional augmentative methods.

Antibiotic prophylaxis and therapy in oral surgery: a review

Antibiotics are used for prophylactic and therapeutic purposes. Since bacterial resistances constantly change the existing conditions, the patient's therapy needs to be monitored periodically and adjusted to the changed conditions. Clinicians should be very careful about prescribing antibiotics for prophylactic purposes. But with regard to risk patients--especially when there is a risk of endocarditis--antibiotic prophylaxis is essential. Antibiotic therapy is absolutely necessary as a supporting treatment for primary surgery if the patient has acute osteomyelitis, transmitted abscesses, or multiple space abscesses. It might also become necessary to refer the patient to an appropriately equipped center or clinic.

Long-term results of immediately loaded interforaminal implants

OBJECTIVE

To collect, retrospectively, long-term results from patients who received immediately loaded Straumann implants with bar-retained overdentures.

METHOD AND MATERIALS

The surgical and prosthetic treatment took place between 1981 and 1991 at the Department of Oral Surgery, Oral Radiology, and Oral Medicine, University of Basel. In each case on the day of the operation, the patients were fitted with a bar that was immediately loaded with a hybrid prosthesis. Patients who were available at the time of this study were clinically reexamined and statistically assessed.

RESULTS

Among the 44 patients who received 176 interforaminal Straumann implants (4 implants per patient), follow-up was possible in 23 patients, who had received a total of 89 implants. The mean observation time for the implants was 12.2 years (8 to 18 years). Three implants were lost. Five implants did not meet the predetermined success criteria. Using the definition by Cutler and Ederer, the probability of success was 83.3%.

CONCLUSIONS

The results show that the requisite 4-month healing time for immediately loaded interforaminal Straumann implants with bars does not have to be observed.

[Mefenamic acid and other non-steroidal anti-inflammatory agents in dental practice. A review of the literature]

There are no studies verifying that mefenamic acid is more effective than other NSAID (= non-steroidal anti-inflammatory drugs). However, there are several notions in the literature that this drug is less well-tolerated than other NSAID because over a prolonged period of application more lesions of the upper gastro-intestinal tract are induced as well as occasionally renal insufficiency. Compared to other NSAID the systemic toxicity starts already with relatively low doses above the maximal daily dose. Considering current knowledge there is no reason to prefer mefenamic acid to other NSAID.

Bacterial contamination of filtered intraoral bone chips

Intraoral bony defects can be filled with bony particles that are collected in a titanium filter. The aim of this study was to determine quantitatively and qualitatively the degree of this contamination. Over a period of 3 months, bony particles were collected from 50 patients undergoing oral surgery. The bony particles were scraped off the filter, resuspended, and incubated aerobically and anaerobically on human blood agar media. Colony forming units (CFU) were determined as well as the most common species of bacteria. All samples showed anaerobic and aerobic growth. After anaerobic incubation in 44 samples the number of bacteria was higher (38) or equal (six) to that after aerobic incubation. On average, 435,000 CFU (aerobic) and 1,013,000 CFU (anaerobic) per sample were found. The most frequently identified bacteria belonged to Veillonella spp. in the anaerobic and to Streptococcus oralis in the aerobic cultures. In 43 samples black-pigmented colonies were detected. Only bacteria common in the oral cavity were identified. Prophylactic antibiotic therapy may be indicated when using filtered bony particles for intraoral augmentation procedures.

Accuracy of treatment planning based on stereolithography in computer assisted surgerya)

Three-dimensional stereolithographic models (SL models), made of solid acrylic resin derived from computed-tomography (CT) data, are an established tool for preoperative treatment planning in numerous fields of medicine. An innovative approach, combining stereolithography with computer-assisted point-to-point navigation, can support the precise surgical realization of a plan that has been defined on an SL model preoperatively. The essential prerequisites for the application of such an approach are: (1) The accuracy of the SL models (including accuracy of the CT scan and correspondence of the model with the patient's anatomy) and (2) the registration method used for the transfer of the plan from the SL model to the patient (i.e., whether the applied registration markers can be added to the SL model corresponding to the markers at the patient with an accuracy that keeps the "cumulative error" at the end of the chain of errors, in the order of the accuracy of contemporary navigation systems). In this study, we focus on these two topics: By applying image-matching techniques, we fuse the original CT data of the patient with the corresponding CT data of the scanned SL model, and measure the deviations of defined parameter (e.g., distances between anatomical points). To evaluate the registration method used for the planning transfer, we apply a point-merge algorithm, using four marker points that should be located at exactly corresponding positions at the patient and at connective bars that are added to the surface of the SL model. Again, deviations at defined anatomical structures are measured and analyzed statistically. Our results prove sufficient correspondence of the two data sets and accuracy of the registration method for routine clinical application. The evaluation of the SL model accuracy revealed an arithmetic mean of the relative deviations from 0.8% to 5.4%, with an overall mean deviation of 2.2%. Mean deviations of the investigated anatomical structures ranged from 0.8 mm to 3.2 mm. An overall mean (comprising all structures) of 2.5 mm was found. The fiducial registration error of the point-merge algorithm ranged from 1.0 mm to 1.4 mm. The evaluated chain of errors showed a mean deviation of 2.5 mm. This study verifies that preoperative planning on SL models and intraoperative transfer of this plan with computer assisted navigation is a suitable and sufficiently reliable method for clinical applications.

[The "globulomaxillary cyst" a specific entity or a myth?]

The following review investigates the term and concept of the globulomaxillary cyst as a correct clinico-pathological diagnosis to describe a so-called fissural cyst said to be caused by epithelial entrapment between the nasal and maxillary process. After analyzing the available literature it has to be concluded that neither from an embryologic nor from a clinical or pathohistological standpoint the term globulomaxillary cyst represents a real entity by itself. Therefore, globulomaxillary cysts have to be diagnosed alternatively after a thorough clinical, radiological and histological examination as other odontogenic cysts like dentigerous cysts or odontogenic keratocysts, odontogenic tumors like ameloblastoma, central giant cell tumors, solitary bone cysts, etc.

[Periradicular surgery with endoscopy--a clinical prospective study]

Using an endoscope in periradicular surgery provides an impressive optical enlargement and may lead to better clinical diagnostics and a high rate of success. Aims of this investigation were examining this hypothesis as well as detecting influencing factors. In 2002 and 2003, 114 teeth of 91 patients were root-end resected using endoscope. Before surgery, the tooth, number of resected root-ends, content of root channels, clinical diagnosis and moment of surgery were recorded. Patients were controlled one year after surgery and success was evaluated as a summary of clinical and radiological findings. Four patients did not reappear for the control examination. Out of 110 teeth, treatment was successful in 91.8% and failed in 7.3%. 0.9% could not be classified. Statistically, more failures were noted after periradicular surgery in molars. The rate of success increased during the study by means of a learning curve. The results confirm the hypothesis that where using an endoscope periradicular surgery is highly successful.

[Sinus floor elevation and implantation--a retrospective study]

A retrospective analysis of sinusfloor elevation and implantation should evaluate in a sense of quality control the clinical results and complications during or after sinusfloor elevation. In our institution we performed 98 sinusfloor elevations in 80 patients (44 women, 36 men) between August 9, 1995 and November 18, 2002. In those elevated sinuses, 201 implants were inserted till October 16, 2003. Dates were sampled from the patient medical histories. Sinusfloor elevation and implantation in posterior maxillary bone have a good prognosis. Nevertheless implant survival depended on the chosen implant system (Kaplan-Meier-analysis). Implant survival was 98% for Straumann implants and 80% for Frialit-II implants after two years. A significant correlation between Frialit-II implants and Straumann implants (p=0.0119) was identifiable. There was no difference in healing between different augmentation materials (autogenous bone, Ceros 82, Algipore), but case numbers were too small for a relevant validity. In one-stage procedures implant loss was 8%, in two-stage procedures it was 18%. Implant losses in smokers were generally higher than in non-smokers. The period of consolidation of the augmentation's material introduced in two-stage procedures was about 10.3 months, healing time of implants 9.2 months. In one-stage procedures healing time of implants was about 7.7 months. Membrane perforations during surgery occurred in 11% and were not related to the development of postoperative sinusitis as described in literature.

[Diagnostic possibilities of digital volume tomography]

Cone beam computed tomography allows high quality 3D images of cranio-facial structures. Although detail resolution is increased, x-ray exposition is reduced compared to classic computer tomography. The volume is analysed in three orthogonal plains, which can be rotated independently without quality loss. Cone beam computed tomography seems to be a less expensive and less x-ray exposing alternative to classic computer tomography.

[Proliferative verrucous leukoplakia]

Proliferative verrucous leukoplakia (PVL) is a seldom form of oral leukoplakia (OL) with high transformation tendency. It starts as a bold hyperkeratosis changing into an exophytic verrucous form spreading in the oral cavity. The clinical diagnosis therefore is a retrospective one.

[Calcification of the falx cerebri. A pathognomonic symptom of Gorlin-Goltz syndrome]

BACKGROUND

Gorlin-Goltz syndrome is an autosomal dominant disorder with variable penetration characterized primarily by keratocysts of the jaws, multiple basal cell carcinomas, skeletal abnormalities and intracranial calcifications.

METHOD

In this study, 4787 radiographs with occipitomental x-rays from the hospital archives for oral and maxillofacial surgery of the Christian Albrechts University Kiel were examined for calcifications in the area of the falx cerebri.

RESULTS

Four characteristic alterations in the falx cerebri could be assigned to four groups of structures. Those in group 4 could be found only within Gorlin-Goltz syndrome patients, and differed significantly in form and extent from the remaining three groups.

CONCLUSION

The plurilamellar appearance of this group could be rated as a pathognomonic symptom of the Gorlin-Goltz syndrome.

[Vertical distraction osteogenesis of the alveolar process for implant treatment]

The rehabilitation of the chewing function of a patient is ultimately dependent on the quality and volume of the available jawbone. The vertical augmentation of the jawbone is often a challenge for the implanting dentist. Various methods, from transplanting autogenous bone through to the employment of bone substitute materials have been described and often controversially discussed. Vertical distraction offers an alternative to the pre-implantological augmentation of the vertically reduced bone. A technique which shows certain advantages over conventional augmentative methods.

[The odontogenic keratocyst--odontogenic cyst or benign tumor?]

The odontogenic keratocyst is the third most common cyst of the jaws, after the follicular and radicular cyst. Keratocysts most commonly occur as single lesions in the jaw of otherwise healthy persons. Multiple odontogenic keratocysts are a well-recognized feature of the nevoid basal cell carcinoma syndrome. The mandible, especially the third molar region, the angle of the mandible and the ascending ramus are involved far more frequently than the maxilla. Clinically, the cysts often remain asymptomatic and there are two specific histological entities: the orthokeratinized and the parakeratinized odontogenic keratocyst. Different surgical treatment options like marsupialization, enucleation with curettage or peripheral ostectomy, and osseous resection (marginal or segmental) have been discussed in the literature with variable rates of recurrence. Besides a predilection for recurrence, the keratocysts, in contrast to other odontogenic cysts, show a more aggressive clinical behavior and demonstrate a high mitotic count and higher turnover rate of the epithelium. This led to the tentative suggestion that the keratocyst might be a benign cystic neoplasm rather than simply an odontogenic cyst.

[Knowledge and re-evaluation of the prevention of endocarditis in dentistry]

Physicians, dentists and patients were questioned as to their knowledge of endocarditis prophylaxis. about three quarters of the physicians and about half of the dentists were able to judge the risk of endocarditis correctly. Removal of calculus was underestimated as a risk for bacteriemia by physicians and patients alike. dentists overestimated the risk for endocarditis in the group of "non-risk-patients" (bypass), a fact resulting in an overdose/overuse of antibiotics. patients with lower education had less knowledge about the relation between their own personal risk and the necessary dental treatment.

[Cardiovascular monitoring and its consequences in oral surgery]

The increasing number of high-risk patients in oral surgery makes it necessary to monitor the patient's general condition while operating. The surgeon needs a simple technical procedure to detect an impending clinical incident in time. From June 2002 to June 2004, 3012 patients underwent surgery in local anesthesia and were monitored with Colin BP 306 compact monitor. Heart rate, blood pressure, and oxygen saturation were checked non invasively during surgery. 17 times the operation was cancelled due to blood pressure problems. The treatment was cancelled twice due to cardiac arrhythmia. The average of the 19 patients' age was 63.5. Monitoring patients during surgery enables the surgeon to recognize high-risk situations immediately before the operation, to detect problem situations early and to avoid them, to work more calmly because of the enhanced security factor.

[Controlled orthodontic extrusion with subsequent implantation]

Controlled orthodontic extrusion constitutes a non-surgical technique to increase alveolar bone material. Prosthetic reconstruction alone frequently does not achieve sufficient long-term aesthetics. An adequate implantation bed is indispensable to meet aesthetic demands. Controlled orthodontic extrusion represents an alternative to pre-implantological augmentation of the vertically reduced alveolar process and its soft tissue.

[Antibiotic prophylaxis and therapy in dental surgery]

Antibiotics are used for prophylactic and therapeutic indications. Since the conditions caused by bacteria resistance are in constant modification the regime has to be verified at regular intervals and adapted to the new conditions. The prescription of antibiotics in oral surgery and medicine should be administrated with reservation. The use of antibiotic prophylaxis is imperatively required during treatment of high-risk patients, especially in cases of endocarditis. An antibiotic therapy is absolutely indicated in acute osteomyelitis as well as in spreading and multispacial abscesses.

[Treatment of intraoral hemangiomas with the CO2 laser]

Intra-oral haemangiomas can lead to intra-operative bleeding while being excised conventionally with a scalpel. Therefore excision with CO2-Laser using coagulating effects and vaporisation of soft-tissues has been introduced. 52 intra-oral haemangiomas were excised minimal invasively and without relapse. With CO2-Laser no complications were seen postoperatively but the healing period was prolonged.

[Dose exposure from analog and digital full mouth radiography and panoramic radiography]

The present study investigated the dose exposition in the head and neck region by use of analog and digital radiographic dental systems. Four radiographic devices were tested: panoramic radiography (analog and digital) and 14-image full-mouth-survey (FMS, analog and digital). Organ doses were measured on a Rando-phantom by use of CaF2-dosimeters according to the IRCP-guidelines and the effective doses calculated. The results were the following: the value of E was lowest in digital FMS (41 microSv) and highest in analog FMS (78 microSv), i.e. dose was reduced by 47% by using a digital device. In panoramic radiography, doses were 17% lower using digital technique (digital 45 microSv vs. analog 54 pSv). Thus, FMS is no longer associated with higher doses than orthopantomography when conventional films are replaced by digital techniques.

[Complications during and after third molar extraction]

A retrospective analysis of intra- and postoperative complications with special regard to infections should give information about the success rate of our antiseptic treatment procedure when removing third molars. 3,980 third molars were surgically removed between July 1, 1992 and June 30, 1999. Dates were sampled from the patient medical histories (963 men, 935 women) and statistically analyzed. Intraoral complications arose in 188 cases: 153 perforations (3.8%) of the maxillary sinus and additional 35 complications (0.9%) arose from ruptured tuber maxillae, intraoperative bleedings, dislocations of teeth into the maxillary sinus and primary not removable root fragments. In 159 cases there were postoperative complications: 102 common simple infections were mainly respresented (2.6%). Persistent oroantral fistulae, odontogenous sinusitis, sensitivity disturbances, mandibular fractures, after-bleedings and osteomyelitis had to be treated postoperatively in 1.4%. Further a significant correlation between smoking and pericoronal infection (p = 0.0001 regio 38 / p = 0.012 regio 48) was identifiable. Based on our results we recommend to remove third molars for prophylactic reasons before the age of 25 because the intra- and postoperative complications will rise significantly afterwards.

[Intraoral piezo-surgery]

The Piezo "effect"describes a physical interaction, which is used in different fields of clinical medicine. An ultrasound technology results in the power of a surgical cut technique, which is able to distinguish between hard and soft tissue. With the presented instruments it is possible to treat bone mechanically in a piezo-surgical manner without hurting the surrounding soft tissues when touching them. Four examples: Tooth extraction before implantation under minimal grinding of bone, Gaining bone for peri-implant transplantation, Preparation of Sinus Lift, Exposing the inferior alveolar nerve demonstrate the use of Piezo-Surgery in the intraoral area. This method shows a remarkable addition to the intraoral operation techniques.

[Cleft lip and palate surgery in India]

10 cleft lip and palate temporary facilities were set up 1994-2003 in a Christian Hospital in Central India. 725 patients were operated upon. An analysis of the operations in regard to lip closure, closure of the soft and the hard palate, secondary cleft operations and cleft-related surgery is given. Differing therapy concepts in developed countries are discussed and compared to experiences of other third world volunteer medical groups.

[Bacterial contamination of bony particles from the bone collection trap]

Intraoral bony defects can be filled with bony particles that are collected in a titanium filter while drilling. The rinsing liquid is contaminated with blood and saliva which implies that the bony particles are also contaminated with bacteria. The aim of this study was to determine quantitatively and qualitatively the degree of this contamination. Over a period of three months bony particles were collected from 50 patients undergoing surgery. The bony particles were scraped off the filter, resuspended and incubated aerobically and anaerobically on human blood agar media. Colony forming units (CFU) were determined as well as the most common species of bacteria. All samples showed anaerobic and aerobic growth. After anaerobic incubation in 44 samples the number of bacteria was higher (38) or equal (six) to that after aerobic incubation. On average 435,000 CFU (aerobic) and 1,013,000 CFU (anaerobic) per sample were found. The most frequently identified bacteria belonged to Veillonella spp. in the anaerobic and to Streptococcus oralis in the aerobic cultures. In 43 samples black pigmented colonies were detected. There were only bacteria identified which are common in the oral cavity.

[Guided bone regeneration beneath titanium foils]

The aim of this study was to examine the clinical and histological bony healing process beneath titanium foils used for guided tissue regeneration as well as of the Frios Algipore graft which was applied with autologous bone. 66 sinus floor elevations were carried out and examined over a period of three years and eight months. A success rate of 64% was recorded with foil incorporation. Complications occurred in form of primary and secondary disturbances in the healing process caused by exposure of the foil. 12 of the 66 foils had to be removed early. In all but one case, the augmented bone material was macroscopically well integrated despite the loss of the foil. Primary stability of the inserted dental implants into the ossified augmented site after operations of the sinus maxillaris was reached in all cases with absence of post-operative complications, and in 94% when there was postoperative exposure of the membrane. Histologically, a thin layer of connective tissue poor in cells but rich in collagen fibers appeared underneath the titanium foil. This was followed by newly-formed bony tissue transforming into osseous lamella parallel to the membrane underneath the new periost. In 65 out of 66 cases a sufficient amount of stable bone was built up locally suggesting good bio-compatibility and barrier function. Further, the foil also provided mechanical rest and supporting function for the space underneath. However, the occurrence of healing complications in 36% of the cases showed a need to improve on the titanium foils.

Long-term evaluation of submerged and nonsubmerged ITI solid-screw titanium implants: a 10-year life table analysis of 468 implants

PURPOSE

Submerged and nonsubmerged ITI solid-screw titanium implants were followed retrospectively from 1989 to 1993 and prospectively from 1994 on to analyze long-term prognosis in partially and fully edentulous patients.

MATERIAL AND METHODS

A total of 468 implants were consecutively inserted in 191 patients from 1989 to 1998. Two hundred twenty-eight successfully integrated fixed-restoration implants and 238 with removable restorations were restored following a healing period of 4 to 6 months (9 months in sinus floor elevation sites). From 1994 on all implants inserted were documented annually up to 9 years. During examination the clinical status of the implants was analyzed and evaluated according to predefined criteria of success and this allowed the calculation of 10-year cumulative survival and success rates for 468 implants.

RESULTS

Two implants (0.43%) did not successfully integrate during the healing period, and 8 implants (1.7%) were classified as failures during follow-up (1 late failure under load, 7 with a progressive bone loss from 1 to 3 threads). Including 68 implants in subjects who dropped out (with a dropout rate of 14.4%), the 10-year cumulative survival and success rates were 99.2% and 96.4%, respectively.

DISCUSSION

Over the course of this long-term study, osseointegrated implants, once used as a last possible solution, became nearly standard in cases of single-tooth implants because of the high rate of long-term success. Life table analysis not only determines whether an implant is functioning, it also makes a statement about its clinical status according to strict success criteria.

CONCLUSION

The study demonstrated that ITI solid-screw titanium implants achieved success rates above 95% in a clinical center for an observation period of up to 10 years.

[Torque of endosseous dental screw type implants]

The success of osseous and oral implants is partially dependent on the design and on the mechanical way of insertion. The torque moments during manual and machine-insertion and the correlation between torque and design of the implants were topics of this paper. The experiments were separated in two parts using pork-ribs in vitro. The first experiment was done with manual and machine insertion of implants. The second trial dealt with machine overloading of correctly inserted implants. The cylindrical implants showed an initial insertion curve followed by a linear phase which ended in a peak when insertion depth was reached. The conical formed implants did not show an initial curve while being inserted but a steeper linear phase and a defined peak when reaching the insertion depth. The torque moments at deep insertion (normal drilling depth) differed about 80% to the torque moments at normal insertion. The torques of continual machine insertion are 15 to 20% lower than those of discontinual manual insertion. According to these findings the design parameters for an optimal enossal oral dental implant should be of a cylindrical form with step like design, a cylindrical neck and a self cutting function of the symmetrical thread in combination with a blunt implant tip.

Three-dimensional cephalometry using individual skeletal laser technology models

When planning operations on the facial skull, transversal asymmetries of the maxillo-mandibular complex cannot be adequately assessed using conventional two-dimensional (2D) x-ray cephalometry. On eight patients who presented with facial skull asymmetries, a three-dimensional (3D) laser technology model (LTM) using CT data was fabricated. Five sagittal plane points and six symmetry points were marked on the LTM, measured with the FlashPoint 3-D Digitizer and then geometrically converted, such that using the sagittal plane points, sella, basion, and nasion, a method could be developed that allowed the localization of each spatial point in the three symmetry planes. Thus one could quantitatively record a patient's specific facial skull asymmetry in all three planes and a 3D measurement became feasible. Based on the measurements, the asymmetry could be assessed with respect to the sagittal, vertical, and horizontal planes. With the 3-D LTM Digitizer measuring system, the surgeon now had precise numerical information regarding the symmetry ratios of the skull at his disposal, information that would have been difficult to evaluate solely using a model analysis. The results from this study show that our measuring system is applicable and useful for complex maxillofacial asymmetries. The planning of surgical interventions was optimized because precise numerical values regarding the degree of the asymmetry were available. With the 3-D LTM Digitizer measuring system, cephalometric analysis of complex asymmetries in the three spatial planes can be pragmatically supported.