Daniel van Steenberghe

State-of-the-art on cone beam CT imaging for preoperative planning of implant placement

Orofacial diagnostic imaging has grown dramatically in recent years. As the use of endosseous implants has revolutionized oral rehabilitation, a specialized technique has become available for the preoperative planning of oral implant placement: cone beam computed tomography (CT). This imaging technology provides 3D and cross-sectional views of the jaws. It is obvious that this hardware is not in the same class as CT machines in cost, size, weight, complexity, and radiation dose. It is thus considered to be the examination of choice when making a risk–benefit assessment. The present review deals with imaging modalities available for preoperative planning purposes with a specific focus on the use of the cone beam CT and software for planning of oral implant surgery. It is apparent that cone beam CT is the medium of the future, thus, many changes will be performed to improve these. Any adaptation of the future systems should go hand in hand with a further dose optimalization.

GC–MS analysis of breath odor compounds in liver patients

BACKGROUND Liver diseases can cause a sweet, musty aroma of the breath, called fetor hepaticus. Even in a stage of cirrhosis, the disease can be asymptomatic for many years. Breath analysis might be helpful to detect occult liver pathology. STUDY OBJECTIVE This study examined whether specific breath odor compounds can be found in liver patients, suffering from cirrhosis, which might be useful for diagnosis. MATERIALS AND METHODS Fifty-two liver patients and 50 healthy volunteers were enrolled. Alveolar air was analyzed by gas chromatography-mass spectrometry. Using discriminant analysis a model for liver disease was built. RESULTS Dimethyl sulfide, acetone, 2-butanone and 2-pentanone were increased in breath of liver patients, while indole and dimethyl selenide were decreased. Sensitivity and specificity of the model were respectively 100% and 70%. CONCLUSIONS Fetor hepaticus is caused by dimethyl sulfide and to a lower extent by ketones in alveolar air. Breath analysis by GC-MS makes it possible to discriminate patients with breath malodor related to hepatic pathologies.

Impact of local and systemic factors on the incidence of late oral implant loss

BACKGROUND This retrospective study was set to assess the influence of systemic and local bone and intra-oral factors on the occurrence of implant loss from abutment connection up to 2 years. MATERIALS AND METHODS The files of 700 patients, have been collected randomly from the total patient group treated by means of endosseous Brånemark system implants (Nobel Biocare, Gothenburg, Sweden) at the Department of Periodontology of the University Hospital of the Catholic University of Leuven. The end point observation was evaluating the loss of the implants 2 years after abutment installation. The study involved all implants that did not encounter early loss and implants for which it was possible to evaluate its status 2 years after abutment surgery. Thus, data of 412 patients (240 females) provided with 1514 implants were analyzed. For each patient, the medical history was carefully checked. Data collection and analysis were mainly focused on endogenous factors such as hypertension, coagulation problems, osteoporosis, hypo- hyperthyroidism, chemotherapy, diabetes type I or II, Crohns disease, some local factors [e.g. bone quality and quantity, implant (length, diameter, location), type of edentulism, PTV, radiotherapy], smoking habits, and breach of sterility during surgery. RESULTS Radiotherapy, implant (diameter and location), and higher PTV at implant insertion and abutment connection, all affected significantly the implant loss. CONCLUSION Implant location in the oral cavity and radiotherapy seem predominant to explain the occurrence of implant loss. On the other hand, smoking and systemic health factors do not seem to be prominent players in the etiology of late implant loss.

Immediately loaded CAD-CAM manufactured fixed complete dentures using flapless implant placement procedures: a cohort study of consecutive patients.

STATEMENT OF PROBLEM Data available regarding the treatment outcome for completely edentulous jaws by means of a prefabricated fixed complete denture placed immediately after flapless implant insertion using a surgical guide are only short term. PURPOSE The purpose of this study was to follow the survival of implants inserted in completely edentulous jaws using a flapless procedure and immediately loaded with prefabricated fixed complete dentures for several years. A second purpose was to investigate whether there is a difference in marginal bone remodeling in smoking (S) and nonsmoking (NS) patients. MATERIAL AND METHODS During a 5-year period (mean time of follow-up 2.2 years), 30 consecutive patients, 12 women, 38-74 years of age (average 56 years) were treated for complete edentulism in 1 arch in the Department of Periodontology at the University Hospitals in Leuven. The S group included 13 and the NS group 17 patients. Descriptive statistics were used to analyze the data. Two outcome parameters were analyzed: the cumulative survival rate (CSR) of individual implants and the marginal bone remodeling for up to 5 years in the 2 groups. RESULTS Nine (4.9%) implants failed. Eight of the failures occurred in 3 smoking patients. The absolute survival rate for all patients was 95%, while the cumulative survival rate (CSR) after 5 years was 91.5%. For the NS group, the CSR was 98.9%, while for the S it was 81.2%. The mean marginal bone resorption was - 2.6 and - 1.2 mm in the S and NS groups, respectively. CONCLUSIONS The present findings indicate that the treatment protocol described results in good implant survival rate even after several years. Smoking may eventually compromise the efficacy of this treatment concept.

Review of the treatment strategies for oral malodour

Abstract. Breath malodour, a significant social and/or psychological handicap, may be caused by several intra- and extraoral factors. Malodour of intraoral origin is the result of microbial putrefaction, during which volatile sulphur compounds (VSC) and other volatile compounds are produced. The treatment of oral malodour can therefore be focused on the reduction of the intraoral bacterial load and/or the conversion of VSC to nonvolatile substrates. This article outlines the efficacy and mechanisms of different antimalodour approaches. Most approaches were found to be inefficient and/or short lasting. The most successful treatment involves mechanical debridement (including toothbrushing, flossing, and tongue cleaning), possibly combined with the use of an antimicrobial mouthrinse.

Radiographic planning and assessment of endosseous oral implants

General Introduction.- I. Radiographic Evaluation of the Areas to Be Implanted.- 1. Imaging Procedures for Pre-Operative Assessment.- 1.1 Introduction.- 1.2 Analogue Intra-Oral Radiography.- 1.3 Digital Intra-Oral Radiography.- 1.4 Lateral Cephalography.- 1.5 Panoramic Radiography.- 1.6 Conventional Tomograph.- 1.7 Computer Tomography (CT).- 1.8 Recent Developments in Pre-Operative Treatment Planning.- 1.9 Concluding Remarks.- 2. Jaw Bone Quality and Quantity.- 2.1 Introduction.- 2.2 The Mandible.- 2.3 The Maxilla.- 3. Radiographic Indications and Contra-Indications for Implant Placement.- 3.1 Introduction.- 3.2 Radiographic Indications.- 3.3 Radiographic Contra-Indications.- 3.4 A Practical Guide for Pre-Operative Planning.- II. Radiographic Follow-Up of Endosseous Implants.- 4. Bone Quantity.- 4.1 Methodologies for Assessment of Alveolar Bone Quantity.- 4.2 Methodologies for Assessment of Peri-Implant Bone Quantity.- 4.3 Peri-Implant Bone Height Changes.- 5. Bone Quality.- 5.1 Methodologies for Assessment of Alveolar Bone Quality.- 5.2 Methodologies for Assessment of Peri-Implant Bone Quality.- 5.3 Peri-Implant Bone Density Changes.- 6. Radiographic Assessment of Implant Complications and/or Failures.- 6.1 Introduction.- 6.2 Assessment of Bone-to-Implant Interface.- 6.3 Assessment of Marginal Bone Level Stability.- 6.4 CT-Scan Images.- Summary.- References.

Oral pressure receptors mediate a series of inhibitory and excitatory periods in the masseteric poststimulus EMG complex following tapping of a tooth in man

Abstract Poststimulus EMG complexes (PSECs), consisting of a series of inhibitory and excitatory waves in full-wave rectified and averaged electromyogram (EMG), were elicited in the masseter muscles of 7 subjects following controlled tapping of a tooth, at a controlled clenching level. Applying local anaesthesia to this tooth decreased the total surface of the waves, on average by 89%. The excitatory and the inhibitory waves were similarly affected, indicating that mainly pressure receptors in the periodontium mediate the entire PSEC. In 4 subjects, who were exposed to acoustic noise to exclude a contribution of acoustic receptors, the recovery of the PSEC waves from local anaesthesia was tracked. In 3 subjects, one wave (the first inhibitory or the first excitatory one, respectively) recovered differently from the other waves, indicating that they are not necessarily mediated by one type of afferent axons. The evidence, nevertheless, suggests that the different PSEC waves in man reflect the projection of the periodontal afferents upon several brain structures, involved in the control of the activity of the masseteric motorneurones, as: (1) inhibitory and excitatory control requires different groups of interneurones; and (2) a mediation of the first inhibitory wave by slower conducting axons than the second inhibitory wave, or a mediation of both waves by axons of similar type, is not compatible with common interneurones.

A split-mouth comparative study up to 16 years of two screw-shaped titanium implant systems.

INTRODUCTION Many studies have dealt with the clinical outcome of oral implants, yet none applied a randomized split-mouth design for a long-term follow-up of similar implant systems. AIM To evaluate two oral implant systems with different surface characteristics in a randomized split-mouth design and to radiologically analyse peri-implant bone level and density over an up to 16-year period. MATERIALS AND METHODS The study comprised clinical and radiographic records of 18 partially edentulous patients treated with both implant types randomly placed in either left or right jaw sides. Outcome was evaluated over time. RESULTS Clinical and radiographic parameters showed no significant differences over time for both systems. Ten years after implant placement, a significantly increasing peri-implant bone density was noted, while Periotest values were found to be significantly decreasing. Fifteen years after implant loading, mean bone loss was 0.02 mm (range -1.15 to 1.51; SD 0.45) for Astra Tech® implants (n=24) and 0.31 mm (range -0.98 to 2.31; SD 0.69) for Brånemark® implants (n=23). CONCLUSIONS The study failed to demonstrate significant differences in the outcome of the peri-implant bone for two implant systems with different surface characteristics. The marginal bone level around oral implants changed <0.5 mm after 15 years of loading.

From Osseointegration to Osseoperception

Periodontology has broadened its scope by the research and clinical use of osseointegrated implants. Since tactile and reflex functions have been associated with periodontal ligament neural receptors, osseoperception could be associated with endosseous and/or periosteal innervation.Periodontology has broadened its scope by the research and clinical use of osseointegrated implants. Since tactile and reflex functions have been associated with periodontal ligament neural receptors, osseoperception could be associated with endosseous and/or periosteal innervation.

Interactive periodontal and acoustic influences on the masseteric post-stimulus electromyographic complex in man.

Post-stimulus electromyogram (EMG) complexes (PSECs) were studied in the full-wave rectified and averaged EMGs of the masseter muscles in 15 subjects, who clenched at a controlled level. The PSECs, a series of downward- and upward-going waves reflecting inhibitory and excitatory influences upon the masseteric motoneurones, were elicited by mechanical stimulation of a tooth. The stimuli selectively activated mechanoreceptors in the periodontium and, by bone-conduction, acoustic receptors. Application of acoustic masking during the periods of stimulation revealed a series of inhibitory and excitatory acoustic influences in the PSEC, which were absent after local electrical stimulation of receptors in the periodontium or their afferents. By applying local anaesthesia to the periodontium of a mechanically stimulated tooth, the durations of the acoustic influences were on the average reduced by 76%. In subjects whose PSECs consistently included a second inhibitory period, the duration of the acoustic influences with respect to that of the PSEC (30%) was larger than otherwise (13%), suggesting a central gating of periodontal pathways which can block both periodontal and acoustic influences. The acoustic influences, of which the appearance in the PSEC largely depends upon activated periodontal pathways, represent a new finding of audio-motor reflexes.