Pre- and postoperative assessment of sinus grafting procedures using cone-beam computed tomography compared with panoramic radiographs.

OBJECTIVES: The present study evaluated the clinical validity of cone-beam computed tomography (CBCT) scans in comparison to panoramic radiographs regarding preoperative implant planning in combination with sinus grafting procedures. MATERIALS AND METHODS: Preoperative assessment of the maxillary sinuses and implant planning using panoramic radiographs and CBCT scans was performed on 16 sinuses (13 patients) and comprised choice of treatment, timing of implant placement, sinus morphology, level of confidence, complication prediction and graft volume assessment. Six examiners were involved in the study. RESULTS: In the majority of cases there was a concordance between the treatment type based on either panoramic radiographs or CBCT. If any difference was found, this was due to an overestimation of bone quantity and quality on panoramic radiographs. The assessment of sinus morphology showed a significantly higher detection rate of sinus mucosal hypertrophy on CBCT. The most appealing result is a significant increase in surgical confidence and a significantly better prediction of complications when using CBCT. CONCLUSIONS: A preoperative planning based on CBCT seems to improve sinus diagnostics and surgical confidence.

Inferior alveolar nerve sensory disturbance after impacted mandibular third molar evaluation using cone beam computed tomography and panoramic radiography: a pilot study.

PURPOSE: To measure sensory disturbances of the inferior alveolar nerve (IAN) after removal of impacted mandibular third molars using cone beam computed tomography (CBCT) and dental panoramic radiography (PAN) for preoperative assessment in a randomized controlled trial and to measure the efficacy of the observers' prediction of IAN exposure at surgery based on CBCT compared with PAN. MATERIALS AND METHODS: The sample consisted of 86 impacted third molars (from 79 consecutive patients) in close relation to the IAN as determined by PAN and judged as showing a "moderate" risk of IAN damage. Cases presenting with no close relation between the IAN and roots and extremely risky cases with an obvious interrelation were excluded. Potential neurosensory disturbances of the lip and chin were assessed before surgery and during the postoperative recall by measuring the function of the IAN with the light-touch sensation method. RESULTS: Postoperative sensory disturbances occurred in 1 patient in the CBCT group and 1 patient in the PAN group. The light-touch sensation test showed no significant differences at the lip (P = .10) and chin (P = .17) levels for CBCT- versus PAN-based surgery. Significant differences in making a correct diagnosis of neurovascular bundle exposure at the extraction of impacted teeth were found between the 2 modalities (P = .029). CONCLUSIONS: Within the limits of the present pilot study, CBCT was not superior to PAN in predicting postoperative sensory disturbances but was superior in predicting IAN exposure during third molar removal in cases judged as having "moderate" risk.

Analysis of intensity variability in multislice and cone beam computed tomography.

OBJECTIVES: The aim of this study was to evaluate the variability of intensity values in cone beam computed tomography (CBCT) imaging compared with multislice computed tomography Hounsfield units (MSCT HU) in order to assess the reliability of density assessments using CBCT images. MATERIAL AND METHODS: A quality control phantom was scanned with an MSCT scanner and five CBCT scanners. In one CBCT scanner, the phantom was scanned repeatedly in the same and in different positions. Images were analyzed using registration to a mathematical model. MSCT images were used as a reference. RESULTS: Density profiles of MSCT showed stable HU values, whereas in CBCT imaging the intensity values were variable over the profile. Repositioning of the phantom resulted in large fluctuations in intensity values. CONCLUSIONS: The use of intensity values in CBCT images is not reliable, because the values are influenced by device, imaging parameters and positioning.

Comparison of 6 cone-beam computed tomography systems for image quality and detection of simulated canine impaction-induced external root resorption in maxillary lateral incisors.

INTRODUCTION: The most frequent adverse effect of canine impaction is resorption of the adjacent incisors. The subjective image quality and the radiographic diagnostic accuracy for detection of simulated canine-induced external root resorption lesions in maxillary lateral incisors were compared among 6 cone-beam computed tomography (CBCT) systems in vitro. METHODS: A child cadaver skull in the early mixed dentition was obtained. This skull had an impacted maxillary left canine and allowed a reliable simulation. Simulated root resorption cavities were created in 8 extracted maxillary left lateral incisors by the sequential use of 0.16-mm diameter round burs in the distopalatal root surface. Cavities of varying depths were drilled in the middle or apical thirds of each tooth root according to 3 setups: slight (0.15, 0.20, and 0.30 mm), moderate (0.60 and 1.00 mm), and severe (1.50, 2.00, and 3.00 mm) resorption. The lateral incisors, including 2 intact teeth, were repositioned individually in the alveolus with approximal contacts to the impacted maxillary left canine. Six sets of radiographic images were obtained with 3D Accuitomo-XYZ Slice View Tomograph (J. Morita, Kyoto, Japan), Scanora 3D CBCT (Soredex, Tuusula, Finland), Galileos 3D Comfort (Sirona Dental Systems, Bensheim, Germany), Picasso Trio (E-WOO Technology, Giheung-gu, Republic of Korea), ProMax 3D (Planmeca OY, Helsinki, Finland), and Kodak 9000 3D (Trophy, Croissy-Beaubourg, France) for each tooth setup. The CBCT images were acquired and subsequently analyzed by 12 observers. Linear models for repeated measures were used to compare the CBCT systems for the image quality and the degree of agreement between the diagnosed severity of root resorption and the true severity. RESULTS: The differences in the image quality between CBCT systems were statistically significant (P <0.001). The root resorption scores between CBCT systems showed a significantly higher score for the ProMax when compared with the Galileos and the Kodak. However, the differences in agreement between the diagnosed severity of root resorption and the true severity for all resorption sizes were not significantly different (P >0.05) among the different CBCT systems. CONCLUSIONS: High image quality is important when detecting root resorption. The CBCT systems used in this study had high accuracy with no significant differences between them in the detection of the severity of root resorption.

Bone quality assessment based on cone beam computed tomography imaging.

OBJECTIVES: The aim of this in vitro study was to investigate the accuracy of fractal analysis and morphometry for bone quality assessment as measured with dual energy X-ray absorptiometry (DXA). MATERIAL AND METHODS: Nineteen mandibular bone samples were used for the creation of artificial bone lesions (n=5) or decalcification (n=12) to simulate osteoporosis; two samples were used as controls. Cone beam computed tomography (CBCT) and DXA scans were made before and after processing the samples. The image data obtained from the CBCT scans were used to calculate the mean fractal dimension (FD), bone area and density (morphometric analysis) of the samples. Bone mineral density (BMD) was obtained from the DXA scans and set as a reference value for bone quality. The correlation between BMD and FD and between BMD and morphometric results were calculated. RESULTS: A significant correlation between FD and BMD (rho=+0.71 to +0.75; P<0.05) was observed. Bone area and BMD of the specimens (rho=+0.69 to +0.85; P<0.05) were also significantly related, in contrast to the density analysis, for which no significant correlation to BMD was found. CONCLUSIONS: The results of this study suggest that fractal analysis and bone area measurement have potential to evaluate bone quality on CBCT images, while density measurement does not seem to be valid.

Is self-reported alcohol consumption associated with osteoporotic mandibular bone loss in women?

The aim of this study was to determine whether alcohol consumption would predict mandibular bone quality and quantity in a large European female population. In total, 672 middle-aged and elderly women (45-70 yr of age; standard deviation = 6) were recruited in the study. Alcohol consumption was recorded through a self-reported questionnaire. Mandibular cortical width was measured, by five observers, in the mental foramen region on panoramic radiographs. Mandibular bone density, expressed as aluminium thickness, was recorded on intra-oral radiographs. Alcohol consumption was associated with a reduction of mandibular bone density and cortical width. This association was higher in subjects with excessive alcohol consumption, defined in the present study as > 14 units consumed per week. This study showed reduced jaw-bone quality in older individuals and in those with increased alcohol consumption.

Replacement therapy for periodontitis: pilot radiographic evaluation in a dog model.

AIM: The aim of this study was to radiologically evaluate the impact of replacement therapy by monitoring bone density changes and alveolar bone level in periodontal pockets in a dog model. MATERIAL AND METHODS: Eight male beagle dogs with moderate periodontitis were enrolled in this split-mouth, double-blind randomized trial with ethical approval. Periodontal defects were surgically created bilaterally in the lower jaw. Four months later, the defects were randomly assigned to initial therapy (scaling and root planing) alone (control sites), or combined with multiple subgingival application of beneficial species. Intra-oral follow-up radiography was performed at this stage and 3 months later to verify the treatment effect. RESULTS: The bone density within periodontal pockets treated with beneficial bacteria improved significantly after 12 weeks, while this was non-significant for the control pockets, receiving a single root planing at baseline. There was a significant increase in the bone level at the end of the study for the pockets receiving beneficial bacteria. Again, no significance was noted for the control pockets. CONCLUSIONS: This pilot study indicates the potential effect of a subgingival application of beneficial species in periodontal pockets, and illustrates the strength of standardized follow-up radiography to evaluate the effects of different treatment strategies on bone re-modelling.

On Speech Problems with Fixed Restorations on Implants in the Edentulous Maxilla: Introduction of a Novel Management Concept.

BACKGROUND: Little attention has been paid to the effect of implant restorations on speech. PURPOSE: The aim of this study was threefold: (1) to find out if speech problems occur after inserting a fixed provisional restoration in the edentulous maxilla; (2) to explore speech adaptation in case articulation problems arise after rehabilitation; and (3) to describe the effect of changing the shape of the restoration on improving speech. MATERIALS AND METHODS: Ten patients with an edentulous maxilla were treated with fixed rehabilitation on implants. Speech evaluation was performed at four occasions: before implant surgery, immediately after restoration, and 3 weeks later before and after managing the speech problem by changing the shape of the restoration if speech problems occurred. Comparative three-dimensional-analysis of casts of the restoration before and after changing the shape of the restoration was carried out. RESULTS: The majority of patients (n = 7) experienced speech problems immediately after rehabilitation. Three weeks later, none of the seven patients with deteriorated speech returned to baseline speech. Then, volumetric reduction of the palatal aspects of the (pre)molars was performed, which allowed speech to return to baseline levels in five out of seven patients. In the two remaining patients, the intervention resulted in an improvement of speech without reaching their baseline levels. Three-dimensional-analysis showed that reducing the palatal volume of the premolars was effective in correcting speech. CONCLUSIONS: Speech problems may frequently occur after fixed rehabilitation of the completely edentulous maxilla. A novel speech management concept, consisting of reducing the palatal volume of the (pre)molars, is introduced, demonstrating to solve speech problems in most cases.

Segmentation of Trabecular Jaw Bone on Cone Beam CT Datasets.

BACKGROUND: The term bone quality is often used in a dentomaxillofacial context, for example in implant planning, as bone density and bone structure have been linked to primary implant success. PURPOSE: This research aimed to investigate the performance of adaptive thresholding of trabecular bone in cone beam CT (CBCT) images. The segmentation quality was assessed for different imaging devices and upper and lower jaws. MATERIALS AND METHODS: Four jaws were scanned with eight CBCT scanners and one micro-CT device. Images of the jaws were spatially aligned with the micro-CT images. Two volumes of interest for each jaw were manually delineated. Trabecular bone in the volumes of interest in the micro-CT images was segmented so that the micro-CT images could serve as high-resolution ground truth images. The volumes of interest in the CBCT images were segmented using both global and adaptive thresholding. RESULTS: Segmentation was significantly better for the lower jaw than for the upper jaw. Differences in performance between the scanners were significant for both jaws. Adaptive thresholding performed significantly better in segmenting the bone structure out of CBCT images. CONCLUSIONS: When assessing jaw bone structure, the observer should always choose adaptive thresholding. It remains a challenge to identify the optimal threshold selection for the structural assessment of jaw bone.

Clinical diagnosis of hyposalivation in hospitalized patients.

OBJECTIVE: The aim of this study was to evaluate the effectiveness of clinical criteria for the diagnosis of hyposalivation in hospitalized patients. MATERIAL AND METHODS: A clinical study was carried out on 145 subjects (48 males; 97 females; aged 20 to 90 years). Each subject was clinically examined, in the morning and in the afternoon, along 1 day. A focused anamnesis allowed identifying symptoms of hyposalivation, like xerostomia complaints (considered as a reference symptom), chewing difficulty, dysphagia and increased frequency of liquid intake. Afterwards, dryness of the mucosa of the cheeks and floor of the mouth, as well as salivary secretion during parotid gland stimulation were assessed during oral examination. RESULTS: Results obtained with Chi-square tests showed that 71 patients (48.9%) presented xerostomia complaints, with a significant correlation with all hyposalivation symptoms (p <0.05). Furthermore, xerostomia was also significantly correlated with all data obtained during oral examination in both periods of evaluation (p<0.05). CONCLUSION: Clinical diagnosis of hyposalivation in hospitalized patients is feasible and can provide an immediate and appropriate therapy avoiding further problems and improving their quality of life.

The relationship between the OSTEODENT index and hip fracture risk assessment using FRAX.

OBJECTIVES: The OSTEODENT index is a predicted probability of osteoporosis derived from a combination of an automated analysis of a dental panoramic radiograph and clinical information. This index has been proposed as a suitable case-finding tool for identification of subjects with osteoporosis in primary dental care; however, no data exist on the relationship between OSTEODENT index and fracture risk. The aims of this study were to assess the relationship between the OSTEODENT index and hip fracture risk as determined by FRAX and to compare the performance of the OSTEODENT index and FRAX (without femoral BMD data), in determining the need for intervention as recommended in UK national treatment guidance. STUDY DESIGN: The study was a retrospective analysis of data from 339 female subjects (mean age 55.3 years), from 2 centers: Manchester (UK) and Leuven (Belgium). Clinical information and femoral neck BMD were available for FRAX, and dental panoramic radiographic data and clinical information were available to calculate the OSTEODENT index. Subjects were classified into "treat" or "lifestyle advice and reassurance" categories using the National Osteoporosis Guideline Group (NOGG) threshold. RESULTS: The OSTEODENT index result was significantly related to the 10-year probability of hip fracture derived from the reference standard FRAX tool (Rs = 0.67, P < .0001); 84 patients (24.8%) were allocated to the "treat" category on the basis of FRAX and the UK national guidance. Using this "treatment/no treatment" classification as the reference standard, ROC analysis showed no significant difference between areas under the curves for the OSTEODENT index (0.815) and the 10-year probability of hip fracture derived from the FRAX index without BMD (0.825) when used as tests for determining therapeutic intervention. CONCLUSION: The results suggest that the OSTEODENT index has value in prediction of hip fracture risk. Prospective trials are needed to confirm this finding and to examine the feasibility for its use in primary dental care.

Is there a relation between local bone quality as assessed on panoramic radiographs and alveolar bone level?

The aim was to explore the relation between radiographic bone quality on panoramic radiographs and relative alveolar bone level. Digital panoramic radiographs of 94 female patients were analysed (mean age, 44.5; range, 35-74). Radiographic density of the alveolar bone in the premolar region was determined using Agfa Musica software. Alveolar bone level and bone quality index (BQI) were also assessed. Relationships between bone density and BQI on one hand and the relative loss of alveolar bone level on the other were assessed. Mandibular bone density and loss of alveolar bone level were weakly but significantly negatively correlated for the lower premolar area (r = -.27). The BQI did not show a statistically significant relation to alveolar bone level. Radiographic mandibular bone density on panoramic radiographs shows a weak but significant relation to alveolar bone level, with more periodontal breakdown for less dense alveolar bone.

Speech adaptation after treatment of full edentulism through immediate-loaded implant protocols.

OBJECTIVES: The objective of the present study was to evaluate the influence of immediate loading of implants on speech adaptation. MATERIAL AND METHODS: Ten patients (mean age 54, 6 females) were examined before surgery and 1, 3, 6 and 12 months afterwards. Articulation analysis was done using objective DAT-recoded data evaluated by two groups of speech and language therapists and a computer software program. Besides, patient VAS-scores, myofunctional problems and hearing impairment were recorded and analysed. RESULTS: In the present study only one patient suffered from deteriorated speech after immediate loading. Other patients showed unaffected or improved articulation 3 to 6 months after surgery with a strident and interdental pronunciation mostly becoming addental. Furthermore, myofunctional problems occurred in one patient, other patients adapted to the new situation after three months. Hearing impairment did not influence speech pathology in this study. CONCLUSION: Immediate loading of oral implants does not seem to compromise the normal 3-6 months speech adaptation period. Whether such procedure presents advantages to the conventional 2-stage rehabilitation remains to be investigated.

Clinical diagnosis of hyposalivation in hospitalized patients

OBJECTIVE: The aim of this study was to evaluate the effectiveness of clinical criteria for the diagnosis of hyposalivation in hospitalized patients. MATERIAL AND METHODS: A clinical study was carried out on 145 subjects (48 males; 97 females; aged 20 to 90 years). Each subject was clinically examined, in the morning and in the afternoon, along 1 day. A focused anamnesis allowed identifying symptoms of hyposalivation, like xerostomia complaints (considered as a reference symptom), chewing difficulty, dysphagia and increased frequency of liquid intake. Afterwards, dryness of the mucosa of the cheecks and floor of the mouth, as well as salivary secretion during parotid gland stimulation were assessed during oral examination. RESULTS: Results obtained with Chi-square tests showed that 71 patients (48.9%) presented xerostomia complaints, with a significant correlation with all hyposalivation symptoms (p <0.05). Furthermore, xerostomia was also significantly correlated with all data obtained during oral examination in both periods of evaluation (p<0.05). CONCLUSION: Clinical diagnosis of hyposalivation in hospitalized patients is feasible and can provide an immediate and appropriate therapy avoiding further problems and improving their quality of life.

Potential occupational health problems for dentists in Flanders, Belgium.

The aim of this study was to gather data on occupational health effects among Flemish dentists. A questionnaire on various potential health effects was sent out to randomly selected Flemish dentists. Pilot experimental studies were performed on hearing and sensory function of the fingers on small groups of dentists. Audiometric data of both ears, gathered with an interval of 10 years, were analysed. Sensory tests of the fingers were performed for dominant and non-dominant hands in relation to exposure time to (ultra)sonic equipment. Positive responses for the questionnaire were as follows: low back pain, 54% (stress-correlated); vision problems, 52.3% (age-correlated); infections, 9%; allergies, 22.5% (mainly latex); stress level was scored 7 on a scale from 0 to 10; diminished sensitivity of the fingertips, 6% and auditory disorders, 19.6%. Pilot audiometric data showed a hearing loss at 4,000 Hz for the left ear, presumably indicative of occupational noise trauma. The two-point discrimination ability of the dominant hand tended to diminish in line with the number of years of practice. Dentists in Flanders were found to suffer from various health-related problems. More elaborate studies are required to provide more details on the risks for occupational hearing impairment and vibration hand neuropathy and to determine whether the problems described were related to the practice of dentistry.