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Alveolar ridge resorption following tooth extraction often renders a lateral bone augmentation inevitable. Some patients, however, suffer from severe early (during graft healing, EPatients who underwent a guided bone regeneration (GBR) were screened for inclusion according to the following criteria: (1) a relatively symmetrical maxillary arch, (2) an intact contra-lateral alveolar bone dimension, (3) the presence of a pre-operative cone-beam CT (CBCT), (4) a CBCT taken immediately after GBR, and (5) at least one CBCT scan ≥6 months after surgery. CBCT scans from different timepoints were registered and imported into Mimics software (Materialise, Leuven, Belgium). Bone dimensions of the contra-lateral site of the augmentation, representing the "individual phenotypical dimension of the alveolar crest" (IPD) were super-imposed on the augmented site and registered accordingly. As such, EA total of 17 patients (23 augmented sites) were included. After EWithin the limitations of this study the results indicate that the dimensions of a lateral bone augmentation are defined by the "individual phenotypic bone boundaries" of the patient. This article is protected by copyright. All rights reserved.

To report on zygomatic implant (ZI) survival rate and associated complications through a longitudinal retrospective cohort assessment.A total of 940 ZIs (rough: 781, machined: 159; immediate loading: 454, delayed loading: 486) and 451 standard implants (rough: 195, machined: 256; immediate loading: 58, delayed loading: 393) were placed in 302 adult patients with atrophic maxilla from December 1998 till September 2020. Following data collection reported complications were grouped based on their origin as infectious/ non-infectious biological and mechanical. Statistical analysis was performed to identify risk factors and preceding complications leading to implant loss (p0.05).The survival rate of ZI was found to be 89.9% and the average time between implant placement and an eventual loss was 4.8 years. The mean ZI follow-up period was 7.9±4.9 years. Amongst the infectious biological complications, sinusitis was the most reported (n=138) occurring at a mean follow-up time-point of 4.5 years, whereas infraorbital nerve hypoesthesia occurred more frequently in the non-infectious biological category (n=8, meantime: 0.3 years). The prosthetic screw fracture was the most reported complication of mechanical origin (n=29, meantime: 4 years). Furthermore, sinusitis, standard implant loss, zygomatic/peri-zygomatic region infection, and oroantral communication were significantly associated with ZI loss.ZI placement offered a high survival rate for the rehabilitation of severely atrophied maxilla with most losses occurring within the first five years at follow-up. The most frequently observed complication was sinusitis which tends to develop several years following implant placement.

To assess, in vitro, variables potentially influencing implant blooming using a human-like imaging phantom and 3D-printed mandibles.Sixty implants were inserted in 3D-printed mandibles in 26 different configurations in order to examine the impact of implant diameter, presence of a cover screw, implant design/material, implant position, and the presence of additional implants on implant blooming using two cone-beam computed tomography (CBCT) devices (Accuitomo [ACC] and NewTom [NWT]). Two observers measured the amount of implant blooming in both buccolingual and mesiodistal directions. Inter-rater agreement and descriptive statistics, grouped by implant characteristic and CBCT device, were calculated.Both CBCT devices increased implant diameter (a mean increase of 9.2% and 11.8% for titanium, 20.3% and 24.4% for zirconium, for ACC and NWT, respectively). An increase in implant diameter did not increase the amount of blooming, whereas placing a cover screw did (from 8.0% to 10.9% for ACC, and from 10.0% to 15.6% for NWT). Moreover, implant design, anatomical region, and the presence of another implant also affected the extent of the blooming.Dental implants show a clear diameter increase on CBCT, with the effect being more pronounced for zirconium than for titanium implants. Similar effects are likely to occur in the clinical setting, potentially masking nonosseointegration, reducing the dimensions of peri-implant defects, and/or causing underestimation of the buccal bone thickness.

The objective of this review was to assess the accuracy of available means of determining the BBT (buccal bone thickness) and/or BBL (buccal bone level). This was translated into the following research question: What is the accuracy of the available means of visualizing the BBP (buccal bone plate) to establish the BBT and/or the BBL, when compared to control measurements? As control measurements histomorphometric measurements, direct measurements and cone-beam computed tomography (CBCT) measurements in the absence of metal are accepted.METHODS: The literary search was performed by searching the databases of MEDLINE, Embase, and Web of Science, up to July 13, 2021. Types of studies included were clinical, in vitro and animal trials, specifically looking into the bone level and/or bone thickness of the buccal bone plate at oral implants. Reference lists were hand searched for relevant articles. Two reviewers performed the data extraction and analysis. Only studies using reliable control measurements to evaluate the accuracy of the tested means of visualizing BBT and/or BBL were included for analysis. The QUADAS-2 tool was used to perform bias analysis on the relevant studies. Extracted data was tabulated to show the differences between test and control measurements for BBT and BBL. For in vitro studies on CBCT measurements of BBT meta-analysis could be performed.A total of 1176 papers were identified in the search. Twenty-two articles were used for data extraction and qualitative analysis. Of these studies nine were animal studies, 9 were in vitro studies and four were human studies. Six animal studies and three human studies provided data on probing. CBCT and sonography as techniques for visualizing the buccal bone plate. Probing at implant sites seems to provide data that correlates with a consistent distance from the BBP. Meta-analysis for probing studies could not be performed due to heterogeneity in the setups of these studies. Eleven studies on CBCT were eligible for inclusion. Of these three were animal studies, the remaining 8 studies were all in vitro studies. Meta-analysis was performed on the accuracy of CBCT for in vitro studies, finding a significant underestimation of the BBT when compared to control measurements by a mean difference of -0.15 mm with 95%CI [-0.26,-0.03]. Three studies were identified on measurement of BBT and/or BBL by sonography. This included one human study and two in vitro studies. The identified studies show a low error when determining the buccal bone level or thickness using sonography. All included studies possess a high risk of bias according to risk of bias analysis, mostly due to selection of the patient.A strong limitation of this systematic review is the inclusion of different studies with heterogeneous designs. Within the limits of this analysis it cannot be concluded that probing is an accurate way of visualizing the BBP. CBCT cannot yet be recommended as a standard diagnostic tool for follow-up of the BBP at oral implants. The application of sonography as a diagnostic tool to visualize the BBP needs further scientific validation.

AIM To evaluate 3D accuracy and outcome of a dynamic navigation method for guided root canal treatment of severe pulp canal obliteration (PCO) in 3D printed jaws. METHODOLOGY Three operators with different levels of experience in Endodontics performed navigated access cavities, using the Navident system (ClaroNav), in two sets (maxillary and mandibular) of 3D-printed jaw models with teeth presenting severe PCO. Models were mounted on a phantom to mimic a real clinical situation. After treatment, a postoperative high resolution Cone-Beam Computer Tomography (CBCT) scan (NewTom) was taken for each model and registered to the preoperative model. All access cavities were then segmented using 3-Matic Medical software 15.0 (Materialise). Length and volume of each access cavity were measured, and a comparison was done by measuring the distance deviation in mm at the coronal entry point, apical point, vertical deviation, total deviation and angular deviation of the access cavity in comparison with the virtual planning. Additionally, all access cavities were scouted with a size 10 K-file and inspected on the CBCT to confirm that the canal was located. Descriptive statistics for each parameter were performed. Normality of the data was assessed; data were transformed if needed to make it normally distributed. One-way analysis of variance (anova) was applied to assess differences between parameters for tooth type, jaw, and operators and corrected for simultaneous hypothesis testing according to Tukey. Significance level was set at .05. RESULTS After training with the system (28 cavities per operator), a total of 132 teeth and 168 access cavities (56 per operator) were prepared. All operators located a total of 156 canals, obtaining an overall success of 93% without a difference between operator experience (p > .05). The mean deviation at the apical point was 0.63 mm (SD 0.35) and was significantly lower in anterior teeth in comparison with molars (p

OBJECTIVE: The aim of this study was to propose and validate a three-dimensional (3D) methodology for the assessment of canine eruption in patients born with unilateral cleft lip and palate (UCLP) following secondary alveolar bone graft (SABG). METHODS AND MATERIALS: A total of 10 patients (four females, six males; mean age: 8.8 years) with UCLP who underwent SABG were recruited. Pre- and 6-month post-operative cone-beam computed tomography (CBCT) was acquired for all patients. Post-operative data was registered onto pre-operative data utilizing voxel-based registration. Following superimposition, a segmentation process was applied to segment maxillary canine on both cleft and non-cleft side. Thereafter, translational and rotational changes in canine position were assessed for both cleft and non-cleft side by two observers. RESULTS: The intra-class correlation coefficient (ICC) indicated excellent reliability (≥0.90) with inter and intra-observer error of less than 0.05 mm. The overall ICC was found to be high for assessing both translational and rotational changes. The mean absolute inter- and intra-observer difference for translational and rotational changes was found to be less than 1 mm and 3°. CONCLUSION: The present method was found to be reliable proving to be clinically applicable for assessing maxillary canine eruption changes in both cleft and non-cleft bone. ispartof: CLINICAL AND EXPERIMENTAL DENTAL RESEARCH vol:7 issue:3 pages:285-292 ispartof: location:United States status: published

OBJECTIVES: Osseoperception is defined as the ability to perceive tactile sensation via mechanoreception in the peri-implant environment. The objective was to systematically review the available literature on the osseoperception phenomenon following dental implant placement and to explore potential factors which might improve the perception capacity. MATERIAL AND METHODS: A literature search was performed using PubMed, Cochrane, Embase, and Web of Science databases up to June 2021. Both human and animal studies assessing sensory capacity or innervation following implant placement were included in this review. Two reviewers independently performed the study selection, data extraction and quality assessment of the included studies. The methodological quality of the included papers was assessed using Cochrane risk of bias for human studies and SYRCLE's risk of bias tool for animal studies. RESULTS: The electronic search of databases yielded 1667 results. Following removal of duplicates, title and abstract screening and full-text reading, 22 publications were eligible to be included in the review. Psychophysical evidence from 14 studies indicated a lower tactile function of implants, where active and passive threshold levels were found to be 5 and 50 times higher for implants compared to natural teeth, respectively. The neurophysiological evidence from three studies indicated cortical plasticity following dental implant placement, measured via trigeminal nerve evoked potentials and functional magnetic resonance imaging. Histological evidence from five studies demonstrated the presence of myelinated nerve fibres in the peri-implant tissues. Additionally, immediate implant placement and loading showed beneficial effect on peri-implant tissue (re)innervation; however, no other biological or physiological factors could be identified influencing osseoperception. CONCLUSIONS: The reported evidence supported the existence of so-called osseoperception phenomenon for restoring the sensory feedback pathway following oral implant rehabilitation. Further studies are required to identify factors that might further assist physiological integration of the oral implants in the human body as such to approach natural oral function. ispartof: JOURNAL OF ORAL REHABILITATION vol:49 issue:5 pages:573-585 ispartof: location:England status: published

BACKGROUND: The objective of this review was to critically assess the existing literature on the relationship between the initial position of impacted canines and treatment outcomes. METHODS: We performed a systematic review of the available literature until February 2020 using the MEDLINE, Cochrane Central, Web of Science and PubMed databases. Prospective and retrospective studies (randomized controlled trials [RCTs], cohort studies, longitudinal follow-up studies) considering impacted maxillary canines that were orthodontically and/or surgically treated, and clearly reporting the initial position using 2D and/or 3D classifications, were included if they assessed at least one of the following: treatment success, treatment duration, number of treatment visits, radiographic outcome, periodontal health, esthetics and/or treatment complications. The included studies were assessed for risk of bias according to the Cochrane guidelines. RESULTS: Seventeen studies were reviewed (2 RCTs and 15 non-RCTs). The included studies enrolled a total of 1247 patients with an average age of 14.1 years and a total of 1597 impacted canines. Various causal relationships were detected between the success of treatment modalities and the initial state of the impacted canine (bucco-palatal position, vertical position, canine angulation, root development). DISCUSSION: Evidence, though limited, suggests that a higher alpha angle, higher vertical position and more mesial sector of the impacted canine are related to less successful interceptive and active treatment solutions, prolonged treatment time and inferior outcomes. ispartof: ORTHODONTICS & CRANIOFACIAL RESEARCH vol:24 issue:2 pages:180-193 ispartof: location:England status: published

OBJECTIVE AND BACKGROUND: Little is known about structural and mechanical properties of leukocyte- and platelet-rich fibrin (L-PRF) membranes and even less about the influence of antithrombotic drugs on L-PRF. The aim of this in vitro study is therefore to investigate mechanical properties, fibrin structure and cell content of L-PRF membranes and the impact of anticoagulant therapy on L-PRF. METHODS: Blood samples were obtained from 12 volunteers and supplemented with either no, 1.25 IU, 2.5 IU, 5 IU, or 10 IU enoxaparin. L-PRF membranes were characterized with tensile testing, scanning electron microscopy, and measurement of platelets and leukocytes. Control and enoxaparin-supplemented L-PRF membranes were compared. RESULTS: At 10 IU enoxaparin, no L-PRF membranes could be generated, whereas the low doses of 1.25 and 2.5 IU had no influence on L-PRF properties. The mechanical properties, fibrin networks, and number of platelets and leukocytes of 5 IU supplemented membranes were unlike the control membranes, but were not found to be significantly different because of limited sampling and inter- and intra-variability. CONCLUSION: Low doses of the anticoagulant enoxaparin do not affect mechanical properties, fibrin network, nor cellular content of L-PRF, whereas high doses impair L-PRF generation. ispartof: JOURNAL OF PERIODONTAL RESEARCH vol:55 issue:5 pages:686-693 ispartof: location:United States status: published

BACKGROUND/AIM: There is a lack of evidence regarding the radiological characteristics of a periapical radiolucency (PRL) fusion with the nasopalatine canal (NPC) following dentoalveolar trauma. The aim of this study was to assess the NPC enlargement resulting from fusion with a PRL and its relationship with the surrounding anatomical structures. MATERIAL AND METHODS: A total of 100 patients was retrospectively recruited and divided into two groups: case group and control group. The case group consisted of 50 cone-beam computed tomography scans of the maxilla of patients (32 males, 18 females; age range: 11-83 years) with a known history of dentoalveolar trauma in the maxillary anterior region and the presence of an undiagnosed and/or asymptomatic NPC and PRL fusion. An age- and gender-matched control group of 50 patients (32 males, 18 females; age range: 11-82 years) without trauma history to the upper anterior teeth, demonstrating normal maxillary scans, was recruited. A subjective scoring criterion was established for assessing the characteristics of the fused lesion and its relationship with the buccal/palatal alveolar cortex, nasal cavity cortex, NPC cortical border, and maxillary sinus floor. RESULTS: The fused NPC and PRL was mainly lobular in appearance (88%) with non-corticated well-defined margins (80%). Male patients showed larger (68%) dimensions compared with female patients (32%). The NPC cortical bone was the most commonly perforated structure in relation to fusion (72%), whereas maxillary sinus cortical bone was the least effected (2%). A statistically significant difference was observed between the NPC dimensions in the control and test groups, with fused lesions having larger mesiolateral, craniocaudal, and buccopalatal dimensions (P < .001). CONCLUSIONS: Periapical radiolucencies should be treated as soon as possible before they fuse with NPC. In case of fusion, surgical enucleation should be considered as the treatment of choice. ispartof: DENTAL TRAUMATOLOGY vol:36 issue:4 pages:438-445 ispartof: location:Denmark status: published

OBJECTIVE To investigate the relationship between preoperative trabecular bone structure and implant outcome based on bone morphometric bone parameters from CBCT scans. MATERIALS AND METHODS Twenty consecutive cases with early implant failure in the posterior region of the mandible were matched with 20 control patients with a successful implant osseointegration selected. All patients had taken a preoperative CBCT image according to a standardized acquisition protocol. On these CBCT scans, the trabecular bone of each implantation site was selected and segmented, after which 3D morphometric bone parameters were calculated and used in a cluster analysis to objectively differentiate trabecular bone patterns. Fisher's exact test was used to determine whether there is a significant association between trabecular pattern and implant outcome. RESULTS A sparse, intermediate, and dense trabecular bone pattern was distinguished by cluster analysis. The relationship between the trabecular bone pattern and early implant failure was significant (z = 9.6; p

Aim The aim of the study was to evaluate whether the use of a xenograft is not inferior to the use of xenograft and autogenous bone chips in treating dehiscences at implant placement. Materials and methods After implant placement, leaving a dehiscence, control sites were treated using a composite graft (autogenous bone chips and xenograft) and at the test sites 100% xenograft was used. Both sites were covered with a resorbable collagen membrane. Dehiscences were measured clinically at implant placement and at re-entry. CBCT was taken immediately after implant placement and after 4 months. Results In total, 28 GBR procedures were performed in 14 patients. On average, the change in vertical defect height was 2.07 mm (46.7%-test group) and 2.28 mm (50.9%-control group) (p > .05). The horizontal defect width at the implant shoulder change on average 1.85 mm (40.5%-test group) and 1.75 mm (40.9%-control group) (p > .05). On average, a loss in augmentation thickness of 0.45 mm (68.9%-test group) and 0.64 mm (55.5% control group) between implant placement and augmentation and abutment surgery was obtained at the implant shoulder. Conclusion Both treatment modalities seem to work to a certain extent. At implant shoulder level, the augmentation thickness seems to be disappeared after the healing phase. (NCT03946020).

Objectives To evaluate the peri-implant trabecular bone volume and architecture changes with 6-month follow-up after local application of platelet-rich plasma (PRP) and platelet-poor plasma (PPP) using high-resolution micro-CT. Material and methods Seventy-two dental implants were placed into healed mandibular sites of 9 beagle dogs. Implants were randomly divided into 4 groups following a split-mouth design: control I; control II; PPP; and PRP. Primary and secondary stabilities were assessed using resonance frequency analyses. At 1, 3, and 6 months after implant loading, trabecular structural parameters were evaluated at 0.5, 1, and 1.5 mm away from implants using micro-CT (voxel = 20 μm). Results Primary and secondary stabilities were equivalent in all conditions. PPP and PRP groups showed higher bone volume fraction (BV/TV) and trabecular thickness (Tb.Th) but lower trabecular separation (Tb.Sp) and total porosity percentage (Po (tot)) at all 3 time points. A significant decrease in BV/TV and Tb.Th was found for the control groups after 3 months of healing, while this was not observed in both the PPP and PRP groups. However, no distinct difference was found between the PRP and PPP groups over time. Moreover, as the investigated distance from the implant surface increased, BV/TV and Po (tot) within the same group and time point stayed the same, yet Tb.Th and Tb.Sp continued to increase. Conclusions Platelet-rich plasma and PPP with conventional implant placement lead to similar primary and secondary implant stability, but improved peri-implant bone volume and structural integration. The present research does not seem to suggest a different bone remodeling pattern when using PRP or PPP.

The aim of our study was to identify and predict patients at risk of impeded mandibular third molar eruption and potential relation between the third molar roots and the mandibular canal, based on molar angulations in an early development stage.A total of 1011 adolescent orthodontic patients were included in this longitudinal study.We analysed pre-eruptive rotational changes and root development of mandibular third molars on 2022 panoramic radiographs (two time-points). Five variables were evaluated: third molar eruption level, development stage, risk of relation between the third molar and the mandibular canal, the molar angulations and orthodontic treatment. The relation between early third molar angulation and mean annual angulation change was assessed using a linear mixed model. Logistic regression was applied to investigate a potential correlation of the radiographic variables with the eruption potential and risk of developing a relation between the third molar and the mandibular canal.Mandibular third molar follicles with an initial angulation exceeding 27.0° relative to the second molar tend to progressively increase their angulation during further development. A significant correlation was found between the hemimandibular molar angulations and the probability of eruption (P 0.0001). The second to first molar angulation was predictive for potential development of a relation with the mandibular canal (P = 0.005).From the present data, it appears that severely angulated mandibular third molars (27.0°) have a minimal chance of future eruption and a maximal risk of developing a relation with the mandibular canal.

Allergic rhinitis (AR) affects 23-30% of the European population with equal prevalence reported in Belgium. Despite guidelines on the correct use of effective treatment, up to 40% of AR patients remain uncontrolled. Allergen immunotherapy (AIT) has been shown to improve the level of control up to 84% of patients being controlled by AIT. Recently, new guidelines for AIT have been published, supporting the clinical evidence for effectiveness of various subcutaneous and sublingual products for AIT in patients who are allergic to airborne allergens. AIT in AR patients not only reduces nasal and/or ocular symptoms but also induces tolerance and has preventive potential. Adoption of AIT into daily clinical practice in Belgium and other European countries is hampered primarily by reimbursement issues of each of the single products but also by several patient- and physician-related factors. Patients need to be better informed about the effectiveness of AIT and the different routes of administration of AIT. Physicians dealing with AR patients should inform patients on tolerance-inducing effects of AIT and are in the need of a harmonized and practical guide that supports them in selecting eligible patients for AIT, in choosing evidence-based AIT products and in following treatment protocols with proven efficacy. Therefore, a stepwise and holistic approach is needed for better adoption of AIT in the real-life setting in Belgium. ispartof: CLINICAL AND TRANSLATIONAL ALLERGY vol:9 issue:1 ispartof: location:England status: published

BACKGROUND: Post-traumatic trigeminal neuropathy (PTN) is a disturbance of function or pathological change of the trigeminal nerve branches following trauma and has an important impact on patient's quality of life (QoL). OBJECTIVES: To provide diagnostic data on PTN and illustrate differences in aetiology, injured nerve, pain distribution, sensory profile and QoL between PTN subgroups. METHODS: 1331 patients with painful or non-painful PTN were retrospectively reviewed in two centres, extracting demographic data, time and cause of trauma, clinical findings including signs and symptoms, basic neurosensory testing, imaging modalities, treatments, and QoL or psychosocial assessment. RESULTS: More females were represented (70%) than males. The inferior alveolar nerve was most frequently damaged (60%) followed by the lingual nerve (28%). Wisdom teeth removal was considered the main cause (48%). Pain was reported in 63% of patients and pain frequency increased with age without clinically significant gender differences. Numbness was reported in 50% of PTN patients. Neurosensory testing showed larger affected dermatome involvement in persistent injuries, with no differences between the non-painful and painful PTN groups. Patient clustering indicated different sensory profile distributions when stratified according to aetiology or affected nerve branch. High interference with lifestyle was reported (78%), and patients suffering from painful PTN had worse QoL and psychosocial outcomes. CONCLUSION: Patients with painful PTN had different clinical profiles and lower QoL scores than those with non-painful PTN. Sensory profiles may provide important prognostic and therapeutic information; however, more research is needed to assess the clustering procedure and link these clusters to therapeutic guidelines. ispartof: JOURNAL OF ORAL REHABILITATION vol:47 issue:10 pages:1212-1221 ispartof: location:England status: published

Background and Objective While osseointegration following various dental implant placement protocols has been extensively investigated, the neurohistological integration has received little attention. The primary aim of this study was to compare the myelinated nerve fibers density in peri-implant bone tissue following various implant placement protocols. The secondary aim assessed the effect of follow-up on peri-implant nerve fibers density. Methods Ten beagle dogs randomly received 68 commercially pure titanium implants in the mandibular premolar or molar region bilaterally following extraction utilizing one of the six treatment protocols: (a) immediate implant placement (IIP) and immediate loading (IL); (b) IIP and delayed loading (DL); (c) IIP and left unloaded (UL); (d) delayed implant placement (DIP) and IL; (e) DIP and DL; and (f) DIP and UL. Histomorphometric analysis of the peri-implant myelinated nerve fibers was performed in a 300 mu m peri-implant zone at the cervical, middle, and apical level following implant placement. The follow-up assessment involved longitudinal observation at 3 months following each implant treatment protocol and at 6 months for IIP+IL and IIP+DL protocols. Results The influence of different treatment protocols, including the fixed effects of implant groups (IIP+IL, IIP+DL, IIP+UL, DIP+IL, DIP+DL, DIP+UL) and regions (cervical, middle, apical), was examined via a linear mixed model. The IIP+IL group showed a significantly higher myelinated nerve density compared to the IIP+UL and DIP+UL group. Peri-implant nerve re-innervation was significantly higher (P = .002) in the apical region compared to the cervical region. After immediate implant placement, the IL group showed a significantly (P = .03) higher density of myelinated nerve fibers compared to DL. No significant (P = .19) effect of follow-up on nerve density was observed. Conclusion The immediate implant placement and loading protocol showed most beneficial effect on peri-implant innervation with highest myelinated nerve density in the apical region. A longer loading time had no influence on the peri-implant nerve density. China Scholarship CouncilChina Scholarship Council [201708210187] Funding Source: Medline; Fonds Wetenschappelijk Onderzoek FWO[11.ZU.117N] Funding Source: Medline; National Natural Science [81370026] Funding Source: Medline Jacobs, R (corresponding author), Katholieke Univ Leuven, Dept Imaging & Pathol, OMFS IMPATH Res Grp, Campus Sint Rafael,Kapucijnenvoer 33, BE-3000 Leuven, Belgium. reinhilde.jacobs@kuleuven.be

Classification of impacted maxillary canines facilitates interdisciplinary communication. Cone beam computed tomography (CBCT) has proven to be superior for the localization of impacted maxillary canines compared with 2D imaging. The purpose of this study was to retrospectively classify a cohort of impacted maxillary canines, using a new developed 3D classification for impacted maxillary canines that is easy to use and does not require complex analysis of the 3D images. A retrospective cohort study was designed, containing CBCT data of 130 patients (male/female: 48/82; median age 16) with a total of 162 impacted maxillary canines. The proposed classification was based on four criteria: vertical crown position, mesiodistal tooth postion, bucco-lingual crown position, and associated pathology. For all included patients, classification criteria were identified and correlated to treatment selection using a newly developed 3D classification. The most common positions were vertical crown position at apical one third of neighboring teeth, mesiodistal tooth angulation, and palatal crown position. The most frequent associated pathologies were dilaceration of the root and resorption of a neighboring tooth. Significant associations among classification variables and treatment options were observed. Limitations of this study are the retrospective design. CBCT enabled 3D assessment of impacted maxillary canines allowing a classification system that may have an impact on further treatment strategies. ispartof: CLINICAL AND EXPERIMENTAL DENTAL RESEARCH vol:5 issue:1 pages:19-25 ispartof: location:United States status: published

Aesthetic appraisal is rarely included in the objective assessment of outcome studies of impacted maxillary canines treatment. The present study aimed to validate a new index for assessing the aesthetic appearance of maxillary canines and adjacent soft tissues. The Department of Oral and Maxillofacial Surgery at University Hospitals Leuven. Four oral-maxillofacial surgeons, two orthodontists, two prosthodontists, and two lay persons rated 11 maxillary canines and adjacent soft tissues according to the new index. Each of the examiners repeated the examination three times with a 2-week interval. Twelve relevant aesthetic variables were selected on the basis of the anatomic form, color, and surface characteristics of the canine crown and on the basis of the anatomic form, color, and surface characteristics of the adjacent soft tissues. Intraclass correlation (ICC) coefficient and Fleiss' kappa statistics were performed to analyze the intrarater and interrater agreement. The index proofed to be a reliable assessment tool. Considering the cumulative assessment of the Maxillary Canine Aesthetic Index (MCAI), the mean ICC value for the interrater agreement of the 10 examiners was 0.71, representing a good agreement. Intrarater agreement ranged from 0.10 to 0.91. Interrater agreement (Fleiss' kappa statistics) calculated for each variable ranged from 0.08 to 0.98. The MCAI is a tool in rating aesthetic outcome of impacted canine treatment and adjacent soft tissues. The MCAI can be used to evaluate the aesthetic outcome after surgical exposure or transalveolar transplantation of maxillary canines. ispartof: CLINICAL AND EXPERIMENTAL DENTAL RESEARCH vol:4 issue:5 pages:216-223 ispartof: location:United States status: published

Over the past decade, cone beam computed tomography (CBCT) has been increasingly used by endodontists. The aims of this study were to assess endodontic program directors', residents', and endodontists' considerations concerning CBCT-related graduate education, attitudes, and professional behavior. Survey data were collected from 31 of the 56 directors of U.S. endodontic graduate programs, 73 of 270 contacted residents, and 689 of 2,221 contacted endodontists (response rates 55%, 27%, and 31%, respectively). Ten of the 31 responding programs did not offer a CBCT-related class. Of the 21 programs that offered a CBCT class, 91% of the program directors and 85% of the residents agreed strongly that future endodontists need training to be able to use CBCT. Residents were less satisfied than directors with the way CBCT was taught (on a five-point scale with 1=most negative: 3.26 vs. 4.37; p

OBJECTIVES: To compare the trueness of 3D digital models derived from CBCT and IOS and to evaluate their accuracy for implementation in oral implant rehabilitation. MATERIALS AND METHODS: A dry human mandible with a full set of intact teeth was included in the study. The mandible was scanned using Trios IOS and four different CBCT machines with various protocols for generation of 3D digital models. A µCT was utilized to scan each tooth individually. Following registration and segmentation, the trueness evaluation of 3D digital models was carried out by part comparison analysis and color-coded mapping of the superimposed teeth surfaces. RESULTS: The four CBCT-derived 3D digital models with different protocols had better trueness than Trios IOS. NewTom VGi evo (110 KV), ProMax 3D (90 kV), 3D Accuitomo 170 (90 kV), Green 21 (110 kV), and Green 21 (90 kV) showed significantly better trueness than IOS. However, 3D Accuitomo 170 and ProMax 3D CBCT devices with 70 kV protocol showed better trueness without any significant difference with IOS. CONCLUSION: CBCT-derived 3D digital models showed better trueness when compared with IOS. When CBCT data are available for preoperative planning for oral implant rehabilitation, it may preclude the need for IOS for obtaining 3D study models. ispartof: CLINICAL ORAL IMPLANTS RESEARCH vol:30 issue:6 pages:498-504 ispartof: location:Denmark status: published

AIM: To describe a minimally invasive method to create a 3D-printed guide to gain access to obliterated root canals on the basis of CBCT data. SUMMARY: A 85-year-old female ASA III was referred for root canal treatment of tooth 22. Clinically, there were no complaints, no percussion pain or sinus tract. Radiologically, the tooth had an obliterated canal with an apical radiolucency. The tooth was diagnosed with asymptomatic apical periodontitis. Microguided Endodontic treatment was performed with the help of a 3D-printed guide. The root canal was localized initially with the aid of the 3D-printed guide using a round carbide bur with a head diameter of 0.8 mm. Then, the canal was shaped and cleaned using mechanical rotary files under copious irrigation with 5% NaOCl, 17% EDTA and passive ultrasonic activation. A completely healed apical area of tooth 22 was visible after 6 months on periapical radiographs and small field of view CBCT. KEY LEARNING POINTS: Using the Microguided Endodontics concept, a minimally invasive access was achieved up to the middle of the root, in a maxillary lateral incisor with pulp canal obliteration (PCO) and apical periodontitis. This technique is a valuable tool for the negotiation of PCO, reducing chair time and risk of iatrogenic damage to the root. ispartof: INTERNATIONAL ENDODONTIC JOURNAL vol:52 issue:4 pages:540-549 ispartof: location:NETHERLANDS, ACTA, Amsterdam status: published

Purpose To assess bone microarchitecture in maxillary sites grafted with autogenous or xenogenous grafts as well as to demonstrate the usefulness of microCT in dental implant research. Materials and Methods Samples (n = 12) consisting of titanium fixation screws covered by at least 0.5–1 mm of human bone were obtained from 17 sites grafted with autogenous or xenogenous materials and prepared for microCT scanning and conventional histology. Bone histomorphometric parameters were evaluated in three distinct regions (graft region, transitional region, and native bone region). Three-dimensional (3D) bone-to-implant contact (BIC) calculation was performed using microCT data. Histological sections were used to calculate two-dimensional (2D) BIC percentages, which were compared with values obtained from 2D microCT images. Results Histomorphometric parameters varied according to the type of graft used, but sites reconstructed with autogenous bone showed higher mean values in general. In autograft samples, indices for parameters such as Tb.Th and Tb.Sp were significantly different when the native bone region was compared to the graft region. While a higher mean 3D BIC was found in the native bone region for both graft materials, significant BIC differences were absent when graft types were compared. The 2D BIC percentages obtained from histological and microCT images were similar. Conclusions Autografts outperformed the xenogenous material used in this study concerning the histomorphometric parameters assessed. While graft type did not seem to influence 3D BIC, the native bone region showed the highest BIC percentages when compared to the other regions in both graft groups. In addition, 2D BIC ratios were similar regardless of graft material or image source (histological sections x microCT slices). Taken together, our findings suggest that microCT is an effective tool for 2D and 3D histomorphometric and BIC assessments in dental implant research.

The increasing storage of information, data, and forms of knowledge has led to the development of new technologies that can help to accomplish complex tasks in different areas, such as in dentistry. In this context, the role of computational methods, such as radiomics and Artificial Intelligence (AI) applications, has been progressing remarkably for dentomaxillofacial radiology (DMFR). These tools bring new perspectives for diagnosis, classification, and prediction of oral diseases, treatment planning, and for the evaluation and prediction of outcomes, minimizing the possibilities of human errors. A comprehensive review of the state-of-the-art of using radiomics and machine learning (ML) for imaging in oral healthcare is presented in this paper. Although the number of published studies is still relatively low, the preliminary results are very promising and in a near future, an augmented dentomaxillofacial radiology (ADMFR) will combine the use of radiomics-based and AI-based analyses with the radiologist's evaluation. In addition to the opportunities and possibilities, some challenges and limitations have also been discussed for further investigations. ispartof: PROTEOMICS CLINICAL APPLICATIONS vol:14 issue:3 ispartof: location:Germany status: published

The objective was to present an optimized imaging protocol for orofacial cleft (OFC) patients, which might be used as an international recommendation for OFC care programs. The present radiological protocol has been structured by the OFC team of the University Hospitals Leuven based on a combined approach of clinical experience and scientific evidence. The development was based on careful monitoring of the existing needs for radiological diagnosis by the involved disciplines. Needs were revised by expert consensus and radiological optimization. Effective doses were converted to panoramic equivalents (professional conversion) and background radiation (patient conversion). At the age of 6, a panoramic radiograph is taken for the evaluation of dental anomalies. For the preoperative planning of secondary alveolar bone, grafting a low-resolution cone beam computer tomography (CBCT) of a limited field of the maxilla is taken at the age of 7 to 9. At the age of 10, 15, and 20, a low-resolution CBCT of both jaws with the smallest possible field is taken serving as conventional, presurgical, and end of treatment records, respectively. Two-dimensional images are reconstructed out of 3D ones. There are currently no international guidelines concerning the imaging protocol for OFC patients. It is clear that a multidisciplinary approach plays a key role in radiation hygiene. In this article, we presented an optimized imaging protocol for OFC patients based on European guidelines to accomplish the concepts of justification and optimization, which might be used as an international recommendation for OFC care programs. ispartof: CLINICAL AND EXPERIMENTAL DENTAL RESEARCH vol:4 issue:5 pages:152-157 ispartof: location:United States status: published

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.

Aim To assess, in a randomized study, the implant (clinical and radiological) and patient outcomes of guided implant placement at 1-year follow-up, compared to conventional implant treatment. Material and Methods A total of 314 were placed in 59 patients, randomly assigned to one of the treatment groups. Radiographic and clinical parameters were recorded at the time of implant placement, prosthesis instalment (baseline) and at 1-year follow-up. Patient satisfaction was measured with the oral health-related quality of life instrument (OHIP-49). Results No implants were lost. The mean marginal bone loss after the first year of loading was 0.04 mm (SD 0.34) for the guided surgery and 0.01 mm (SD 0.38) for the control groups. In the guided surgery groups, the mean number of surfaces with BOP and plaque at 1-year follow-up was 1.41 (SD 1.25) and 1.10 (SD 1.22), for the control groups this was, respectively, 1.37 (SD 1.25) and 1.77 (SD 1.64). The mean pocket probing depth was 2.81 mm (SD 1.1) for the guided, and 2.50 mm (SD 0.94) for the control groups. For all treatment groups, a significant improvement in quality of life was observed at 1-year follow-up (p ≤ 0.01), no differences between groups were observed. Conclusion Within the limitations of this study, no difference could be found at 1-year follow-up between the implant and patient outcome variables of guided or conventional implant treatment.

Aim To assess the accuracy of guided surgery compared with mental navigation or the use of a pilot-drill template in fully edentulous patients. Material and methods Sixty consecutive patients (72 jaws), requiring four to six implants (maxilla or mandible), were randomly assigned to one of the following treatment modalities: Materialise Universal® mucosa, Materialise Universal® bone, Facilitate™ mucosa, Facilitate™ bone, mental navigation, or a pilot-drill template. Accuracy was assessed by matching the planning CT with a postoperative CBCT. Deviations were registered in a vertical (depth) and horizontal (lateral) plane. The latter further subdivided into BL (bucco-lingual) and MD (mesio-distal) deviations. Results The overall mean vertical deviation for the guided surgery groups was 0.9 mm ± 0.8 (range: 0.0–3.7) and 0.9 mm ± 0.6 (range: 0.0–2.9) in a horizontal direction. For the non-guided groups, this was 1.7 mm ± 1.3 (range: 0.0–6.4) and 2.1 mm ± 1.4 (range 0.0–8.5), respectively (P

Background Information regarding linear accuracy is necessary for efficient treatment evaluation, especially for maxillofacial reconstruction or implants. Purpose To investigate the accuracy of linear measurements from multiple cone beam computed tomography (CBCT) devices. Materials and Methods A RANDO® phantom was scanned with eight CBCT scanners (11 modes). The viewing software accompanying each scanner was employed for measurements in mediolateral, anteroposterior, and supero-inferior dimensions by two dentomaxillofacial radiologists. Digital caliper measurements were used as a “gold standard.” ANOVA with Scheffe post hoc analysis and intraclass correlation coefficient (ICC) were utilized for statistical analyses. The level of confidence was 95%. Results Differences from the gold standard among 11 acquisition modes were statistically significant (p

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.

Structured AbstractContext The scientific evidence of 3D cephalometry in orthodontics has not been well established. Objective The aim of this systematic review was to evaluate the evidence for the diagnostic efficacy of 3D cephalometry in orthdontics, focusing on measurement accuracy and reproducibility of landmark identification. Data Sources PubMed, EMBASE and the Cochrane library (from beginning to March 13, 2012) were searched. Search terms included: cone-beam computed tomography; tomography, spiral computed; imaging, three-dimensional; orthodontics. Study Selection Two reviewers read the retrieved articles and selected relevant publications based on pre-established inclusion criteria. The selected publications had to elucidate the hierarchical model of the efficacy of diagnostic imaging systems by Fryback and Thornbury. Data Extraction The data was then extracted according to two protocols, which were based on the Quality Assessment of Diagnostic Accuracy Studies (QUADAS) tool. Next, levels of evidence were categorized into 3 groups: low, moderate and high evidence. Data Synthesis 571 publications were found by database search strategies and 50 additional studies by hand search. A total of 35 publications were included in this review. Conclusions Limited evidence for the diagnostic efficacy of 3D cephalometry was found. Only 6 studies met the criteria for a moderate level of evidence. Accordingly, this systematic review reveals that there is still need for methodologically standardized studies on 3D cephalometric analysis.

Purpose To develop a method for characterizing trabecular bone microarchitecture using cone beam computed tomography (CBCT) and to evaluate trabecular bone changes after rehabilitation using immediate versus delayed implant protocols. Materials and Methods Six mongrel dogs randomly received 27 titanium implants in the maxillary incisor or mandibular premolar areas, following one of four protocols: (1) normal extraction socket healing; (2) immediate implant placement and immediate loading; (3) delayed implant placement and delayed loading; (4) delayed implant placement and immediate loading. The animals were euthanized at 8 weeks, and block biopsies were scanned using high resolution CBCT. Standard bone structural variables were assessed in coronal, middle, and apical levels. Results Coronal and middle regions had more compact, more platelike, and thicker trabeculae. Protocols (2), (3), and (4) had significantly higher values (p

OBJECTIVE: The predictability and simplicity of the Summers' technique for sinus floor elevation encouraged many clinicians to consider this new approach. The impact of such intervention on the sinus mucosa has, however, not been explored extensively. This pilot study followed the response of the Schneiderian membrane, longitudinally, via cone-beam CT images. MATERIAL AND METHODS: Ten consecutive patients (five women, mean age 58.7 years) referred for implant therapy in the posterior part of the maxilla, in combination with a trans-alveolar sinus floor elevation (13 sinuses involved), were enrolled. CBCT images were taken prior to and at 1 week and 1 month after surgery. The changes in thickness of the Schneiderian membrane were scored at nine standardized points per sinus using reformatted cross-sectional images. RESULTS: One week after sinus floor elevation, the Schneiderian membrane showed a significant swelling of 9.2 mm in the middle (SD 0.3; P

Aim To assess the accuracy of static computer-guided implant placement. Material and methods Electronic and manual literature searches were conducted to collect information on the accuracy of static computer-guided implant placement and meta-regression analyses were performed to summarize and analyse the overall accuracy. The latter included a search for correlations between factors such as: support (teeth/mucosa/bone), number of templates, use of fixation pins, jaw, template production, guiding system, guided implant placement. Results Nineteen accuracy studies met the inclusion criteria. Meta analysis revealed a mean error of 0.99 mm (ranging from 0 to 6.5 mm) at the entry point and of 1.24 mm (ranging from 0 to 6.9 mm) at the apex. The mean angular deviation was 3.81° (ranging from 0 to 24.9°). Significant differences for all deviation parameters was found for implant-guided placement compared to placement without guidance. Number of templates used was significant, influencing the apical and angular deviation in favour for the single template. Study design and jaw location had no significant effect. Less deviation was found when more fixation pins were used (significant for entry). Conclusion Computer-guided implant placement can be accurate, but significant deviations have to be taken into account. Randomized studies are needed to analyse the impact of individual parameters in order to allow optimization of this technique. Moreover, a clear overview on indications and benefits would help the clinicians to find the right candidates.

Objectives To quantify metal artifacts obtained from a wide range of cone beam computed tomography (CBCT) devices and exposure protocols, to compare their tolerance to metals of different densities, and to provide insights regarding the possible implementation of metal artifact analysis into a QC protocol for CBCT. Materials and methods A customized polymethyl methacrylate (PMMA) phantom, containing titanium and lead rods, was fabricated. It was scanned on 13 CBCT devices and one multi-slice computed tomography (MSCT) device, including high-dose and low-dose exposure protocols. Artifacts from the rods were assessed by two observers by measuring the standard deviation of voxel values in the vicinity of the rods, and normalizing this value to the percentage of the theoretical maximum standard deviation. Results For CBCT datasets, artifact values ranged between 6.1% and 27.4% for titanium, and between 10.% and 43.7% for lead. Most CBCT devices performed worse than MSCT for titanium artifacts, but all of them performed better for lead artifacts. In general, no clear improvement of metal artifacts was seen for high-dose protocols, although certain devices showed some artifact reduction for large FOV or high exposure protocols. Conclusions Regions in the vicinity of the metal rods were moderately or gravely affected, particularly in the area between the rods. In practice, the CBCT user has very limited possibilities to reduce artifacts. Researchers and manufacturers need to combine their efforts in optimizing exposure factors and implementing metal artifact reduction algorithms.

Summary This review aims to explore whether 3D imaging offers an added value in diagnosis of odontogenic sinusitis. Odontogenic maxillary sinusitis accounts for approximately 10–12% of maxillary sinusitis cases. Proper diagnosis of odontogenic sinusitis is based on a thorough dental and medical examination and crucial to ensure therapeutic efficacy. To establish the odontogenic cause of maxillary sinusitis, 2D and 3D imaging modalities may be considered, each presenting distinct advantages and drawbacks. The available research indicates that 2D imaging modalities may often mask the origin of odontogenic maxillary sinusitis. This limitation is particularly evident in the maxillary molar region, stressing the need for 3D cross-sectional imaging. The advent of low-dose cone beam computed tomography in dentistry may be particularly useful when odontogenic maxillary sinusitis is not responsive to therapy. Yet, it seems that more research is needed to validate its use in odontogenic maxillary sinusitis.

Cone‐beam CT (CBCT) has shown to be a useful imaging modality for various dentomaxillofacial applications. However, optimization and quality control of dental CBCT devices is hampered due to the lack of an appropriate tool for image quality assessment. To investigate the application of different image quality parameters for CBCT, a prototype polymethyl methacrylate (PMMA) cylindrical phantom with inserts for image quality analysis was developed. Applicability and reproducibility of the phantom were assessed using seven CBCT devices with different scanning protocols. Image quality parameters evaluated were: CT number correlation, contrast resolution, image homogeneity and uniformity, point spread function, and metal artifacts. Deviations of repeated measurements were between 0.0% and 3.3%. Correlation coefficients of CBCT voxel values with CT numbers ranged between 0.68 and 1.00. Contrast‐to‐noise ratio (CNR) values were much lower for hydroxyapatite (0