Artifacts related to cone beam computed tomography technology (CBCT) and their significance for clinicians: illustrated review of medical literature.

Objective: to explain the meaning and to illustrate technical artifacts (aliasing as well as the ring artifact) and beam hardening (metal artifact) that can be present in the dentomaxillofacial cone beam computed tomography (CBCT), and to check the accessibility of free illustrations of these artifacts in medical publications. Material and methods: One observer applied five search equations using database PubMed. The exclusion criteria were: experimental studies, animal studies, studies not related to dentomaxillofacial area, and articles with closed access. There was no time limit for the search of articles. We limited our search to English and French language. Results: Only 3 articles out of 434 publications were retained after application of inclusion/exclusion criteria. In these articles only 4 annotated figures were freely accessible in medical publications from PubMed. In this paper we presented examples of aliasing, ring artifact, and beam artifacts from I-CAT, Carestream 9000 3D (Kodak), and Planmeca Promax 3D Mid CBCT. The intensity of beam hardening artifact varies from major degradation of image (i.e., subperiosteal implants, bridges, crowns, dental implants, and orthodontic fix appliances), through mean degradation (screws securing titanium mesh, head of mini-implant) to no beam hardening on metallic devices (orthodontic anchorage, orthodontic contention wire) or on dense objects (endodontic treatments, impression materials, Lego box). Some beam hardening artifacts arising from nasal piercing, hairs, or hearing aid device may be present on the image but they will not disturb the evaluation of the field of view. Conclusions: reduction of aliasing artifact is related with the improvement of detectors quality. The presence of ring artifact means that CBCT device has lost its calibration. The field of view (FOV) needs to be reduce in order to avoid scanning regions susceptible to beam hardening (e.g., metallic restorations, dental implants). Finally, the accessibility to open knowledge on technique -related CBCT artifacts seems extremely limited when searching at PubMed database.Objective: to explain the meaning and to illustrate technical artifacts (aliasing as well as the ring artifact) and beam hardening (metal artifact) that can be present in the dentomaxillofacial cone beam computed tomography (CBCT), and to check the accessibility of free illustrations of these artifacts in medical publications. Material and methods: One observer applied five search equations using database PubMed. The exclusion criteria were: experimental studies, animal studies, studies not related to dentomaxillofacial area, and articles with closed access. There was no time limit for the search of articles. We limited our search to English and French language.  Results: Only 3 articles out of 434 publications were retained after application of inclusion/exclusion criteria. In these articles only 4 annotated figures were freely accessible in medical publications from PubMed. In this paper we presented examples of aliasing, ring artifact, and beam artifacts from I-CAT, Carestream 9000 3D (Kodak), and Planmeca Promax 3D Mid CBCT. The intensity of beam hardening artifact varies from major degradation of image (i.e., subperiosteal implants, bridges, crowns, dental implants, and orthodontic fix appliances), through mean degradation (screws securing titanium mesh, head of mini-implant) to no beam hardening on metallic devices (orthodontic anchorage, orthodontic contention wire) or on dense objects (endodontic treatments, impression materials, Lego box). Some beam hardening artifacts arising from nasal piercing, hairs, or hearing aid device may be present on the image but they will not disturb the evaluation of the field of view. Conclusions: reduction of aliasing artifact is related with the improvement of detectors quality. The presence of ring artifact means that CBCT device has lost its calibration. The field of view (FOV) needs to be reduce in order to avoid scanning regions susceptible to beam hardening (e.g., metallic restorations, dental implants). Finally, the accessibility to open knowledge on technique -related CBCT artifacts seems extremely limited when searching at PubMed database

Open access resources on motion artifact in adult dentomaxillofacial CBCT: illustrated pictorial review of medical literature

Objective: to know how much open access/open knowledge reference figures were available on motion artifacts in CBCT dentomaxillofacial imaging, and to describe and to categorize clinical variation of motion artifacts related to diverse types of head motion retrospectively observed during CBCT scanning time. Material and methods: a search equation was performed on Pubmed database. We found 56 articles. The 45 articles were out of scope, and 7 articles were excluded after applying exclusion and inclusion criteria. Only 4 articles were finally freely accessible and selected for this review. Moreover, we retrospectively used our department CBCT database to search examinations with motion artifacts. We also checked retrospectively for radiological protocols as the type of motion artifact was described when occurred during the CBCT scanning time by the main observer. We had obtained the approval from the Ethical committee for this study. Results: The accessibility of free figures on motion artifact in dentomaxillofacial CBCT is limited to 13 figures not annotated, and to one annotated figure presenting a double contour around cortex of bony orbits. We proposed to categorize the motion artifacts into three levels: low, intermediary, and major. Each level was related to: 1) progressive image quality degradation, 2) distortion of anatomy, and 3) potential possibility of performing clinical diagnosis. All 45 figures were annotated. Conclusions: There exists a scarce open access literature on motion artifacts in CBCT. In our pictorial review we found that low level motion artifacts were more related to head rotation in axial plane (rolling). Rolling and lateral translation were responsible of intermediary level motion artifacts. Major level motion artifacts were created by complex motion with multiple rotation axes, multiple translation directions, and by anteroposterior translation. The main limitation of this study is related to retrospectively report empirical observation of patient motion during CBCT scanning and to compare these observations with motion artifacts found on clinical images. More robust methodology should be further developed using a virtual simulation of various types of head movements and associated parameters to consolidate the open knowledge on motion artifacts in dentomaxillofacial CBCT.  Objective: to know how much open access/open knowledge reference figures were available on motion artifacts in CBCT dentomaxillofacial imaging, and to describe and to categorize clinical variation of motion artifacts related to diverse types of head motion retrospectively observed during CBCT scanning time. Material and methods: a search equation was performed on Pubmed database. We found 56 articles. The 45 articles were out of scope, and 7 articles were excluded after applying exclusion and inclusion criteria. Only 4 articles were finally freely accessible and selected for this review. Moreover, we retrospectively used our department CBCT database to search examinations with motion artifacts. We also checked retrospectively for radiological protocols as the type of motion artifact was described when occurred during the CBCT scanning time by the main observer. We had obtained the approval from the Ethical committee for this study. Results: The accessibility of free figures on motion artifact in dentomaxillofacial CBCT is limited to 13 figures not annotated, and to one annotated figure presenting a double contour around cortex of bony orbits. We proposed to categorize the motion artifacts into three levels: low, intermediary, and major. Each level was related to: 1) progressive image quality degradation, 2) distortion of anatomy, and 3) potential possibility of performing clinical diagnosis. All 45 figures were annotated. Conclusions: There exists a scarce open access literature on motion artifacts in CBCT. In our pictorial review we found that low level motion artifacts were more related to head rotation in axial plane (rolling). Rolling and lateral translation were responsible of intermediary level motion artifacts. Major level motion artifacts were created by complex motion with multiple rotation axes, multiple translation directions, and by anteroposterior translation. The main limitation of this study is related to retrospectively report empirical observation of patient motion during CBCT scanning and to compare these observations with motion artifacts found on clinical images. More robust methodology should be further developed using a virtual simulation of various types of head movements and associated parameters to consolidate the open knowledge on motion artifacts in dentomaxillofacial CBCT. &nbsp

Paracondylar process and epitransverse process on cone beam computed tomography: a pictorial review based on a serie of 9 pa-tients

Objective: Paracondylar (PCP) and epitransverse processes (ETP) represent rare types of articulations that can occur between the occipital bone and the transverse process of atlas vertebra. Material and methods: Five systematic search strings were conducted on PubMed database on 14.01.2022. The search was conducted by one observer to identify studies on PCP, and on ETP in living patients. Open and close access articles were selected as this topic is infrequently described in the main medical literature. Results: We provided with a pictorial review of 1) Paracondylar tubercle, 2) Unilateral PCP with cylindrical shape, 3) Unilateral PCP with pyramidal shape, 4) Unilateral PCP with lateral joint with transverse process, 5) Unilateral PCP with superior joint and partial fusion with transverse process, 6) Unilateral ETP with neo-condyle and joint with occipital condyle, 7) Unilateral ETP with joint with occipital bone, 8) Unilateral ETP with a bony bridge with lateral mass (ponticulus lateralis), and 9) Bilateral variation: paracondylar mass and ETP. Conclusions: Six figures were found in the selected literature and belong only to articles published in closed access. We provided with additional 41 open access freely available figures. We were first to present CBCT reference figures of: 1) Unilateral paracondylar tubercle, 2) Fusion of PCP with the transverse process of C1, 3) Joint between ETP and the lateral side of occipital condyle, and 4) Presence of bony bridge (ponticulus lateralis) between ETP and the lateral mass of C1. We were also first to describe a bilateral mixt variation with paracondylar mass on one side and ETP on the other side of C1. An open and accessible knowledge support (such as Nemesis journal) is needed to easily find clinical reference CBCT figures of craniocervicofacial bone variations.  Objective: Paracondylar (PCP) and epitransverse processes (ETP) represent rare types of articulations that can occur between the occipital bone and the transverse process of atlas vertebra. Material and methods: Five systematic search strings were conducted on PubMed database on 14.01.2022. The search was conducted by one observer to identify studies on PCP, and on ETP in living patients. Open and close access articles were selected as this topic is infrequently described in the main medical literature. Results: We provided with a pictorial review of 1) Paracondylar tubercle, 2) Unilateral PCP with cylindrical shape, 3) Unilateral PCP with pyramidal shape, 4) Unilateral PCP with lateral joint with transverse process, 5) Unilateral PCP with superior joint and partial fusion with transverse process, 6) Unilateral ETP with neo-condyle and joint with occipital condyle, 7) Unilateral ETP with joint with occipital bone, 8) Unilateral ETP with a bony bridge with lateral mass (ponticulus lateralis), and 9) Bilateral variation: paracondylar mass and ETP. Conclusions: Six figures were found in the selected literature and belong only to articles published in closed access. We provided with additional 41 open access freely available figures. We were first to present CBCT reference figures of: 1) Unilateral paracondylar tubercle, 2) Fusion of PCP with the transverse process of C1, 3) Joint between ETP and the lateral side of occipital condyle, and 4) Presence of bony bridge (ponticulus lateralis) between ETP and the lateral mass of C1. We were also first to describe a bilateral mixt variation with paracondylar mass on one side and ETP on the other side of C1. An open and accessible knowledge support (such as Nemesis journal) is needed to easily find clinical reference CBCT figures of craniocervicofacial bone variations. &nbsp

Cone beam computed tomography (CBCT) in pediatric dentistry

Objective: The aims of this systematic review of the literature were to investigate the uses of cone beam computed tomography (CBCT) in pediatric dentistry and, if possible, identify the indications. Material and methods: A literature search was conducted using the PubMed and Scopus electronic databases and the keywords "CBCT and pediatric dentistry". This search provided us with 1518 references. The selected publications were all clinical articles written in French or English and referring to a pediatric population. After screening, 461 eligible full text articles remained. Results: In total, there were 169 references that met the inclusion criteria. Different topics, mainly relating to orthodontics, anatomy, and cleft lips and palate, were discussed. There was large variability in the information concerning the technical parameters. The radiographic protocols that we analyzed showed a large heterogeneity. Conclusions: The level of evidence provided by our work is limited because only two randomized double-blind controlled studies are included. Two indications can be distinguished: for orthodontics and for the rehabilitation of cleft lips and palate. There are a multitude of radiographic protocols. More research is needed to identify other potential clinical indications as well as to determine a standard CBCT protocol for children and adolescents.Objective: The aims of this systematic review of the literature were to investigate the uses of cone beam computed tomography (CBCT) in pediatric dentistry and, if possible, identify the indications. Material and methods: A literature search was conducted using the PubMed and Scopus electronic databases and the keywords "CBCT and pediatric dentistry". This search provided us with 1518 references. The selected publications were all clinical articles written in French or English and referring to a pediatric population. After screening, 461 eligible full text articles remained. Results: In total, there were 169 references that met the inclusion criteria. Different topics, mainly relating to orthodontics, anatomy, and cleft lips and palate, were discussed. There was large variability in the information concerning the technical parameters. The radiographic protocols that we analyzed showed a large heterogeneity. Conclusions: The level of evidence provided by our work is limited because only two randomized double-blind controlled studies are included. Two indications can be distinguished: for orthodontics and for the rehabilitation of cleft lips and palate. There are a multitude of radiographic protocols. More research is needed to identify other potential clinical indications as well as to determine a standard CBCT protocol for children and adolescents

Accessibility to the knowledge on anatomical variations from dentomaxillofacial CBCT

Objective: to investigate the accessibility of open access article on anatomical variations described on cone beam computed tomography (CBCT) using PubMed database. We wanted to investigate how many journals are sharing articles without pay-wall and how many are sharing articles without author publication charges. Material and methods: a search equation was designed with exclusion criteria limiting the search in PubMed to articles published in English and French. The search was performed by one observer. We had found 2228 articles; among them 709 were accessible as ‘full text’. After applying exclusion criteria and after full text reading only 50 articles remained for the review. Results: the 50 selected articles shared 306 annotated (visual marking, explanation like arrows) and 432 not annotated figures with the public. The 76% of articles were single studies on one specific topic. The main topic was endodontics with 22 articles. 28 journals from all continents participated in the effort of sharing of figures on anatomical variations from CBCT. However, only 2 journals were completely free of charges for authors and readers. Conclusions: we have found only 15 annotated and 3 not annotated figures in 2 articles published in 2 different open access journals (without reader pay-wall and without author publication charges). Sharing the knowledge on anatomical variations from dentomaxillofacial CBCT represents an exception in dental literature.  Objective: to investigate the accessibility of open access article on anatomical variations described on cone beam computed tomography (CBCT) using PubMed database. We wanted to investigate how many journals are sharing articles without pay-wall and how many are sharing articles without author publication charges. Material and methods: a search equation was designed with exclusion criteria limiting the search in PubMed to articles published in English and French. The search was performed by one observer. We had found 2228 articles; among them 709 were accessible as ‘full text’. After applying exclusion criteria and after full text reading only 50 articles remained for the review. Results: the 50 selected articles shared 306 annotated (visual marking, explanation like arrows) and 432 not annotated figures with the public. The 76% of articles were single studies on one specific topic. The main topic was endodontics with 22 articles. 28 journals from all continents participated in the effort of sharing of figures on anatomical variations from CBCT. However, only 2 journals were completely free of charges for authors and readers.  Conclusions: we have found only 15 annotated and 3 not annotated figures in 2 articles published in 2 different open access journals (without reader pay-wall and without author publication charges). Sharing the knowledge on anatomical variations from dentomaxillofacial CBCT represents an exception in dental literature. &nbsp

Dental use of cone beam computed tomography in pediatric embolized arteriovenous maxillofacial malformation

Objective: Pediatric facial arteriovenous malformations (AVMs) are rare but can cause potentially fatal hemorrhages during dental procedures and oral surgery. In this article we present a systematic review of the medical open access literature on pediatric facial AVM. Case report: We illustrate our purpose with clinical dental use of cone beam computed tomography (CBCT) in pediatric embolized facial AVM to define the presence and the position of the right upper impacted canine. Conclusions: We advocate the use of CBCT as additional imaging tool in the follow-up of pediatric dentomaxillofacial AVM, and for depiction of dentoalveolar structures that are inaccessible by conventional dental radiography.Objective: Pediatric facial arteriovenous malformations (AVMs) are rare but can cause potentially fatal hemorrhages during dental procedures and oral surgery. In this article we present a systematic review of the medical open access literature on pediatric facial AVM. Case report: We illustrate our purpose with clinical dental use of cone beam computed tomography (CBCT) in pediatric embolized facial AVM to define the presence and the position of the right upper impacted canine. Conclusions: We advocate the use of CBCT as additional imaging tool in the follow-up of pediatric dentomaxillofacial AVM, and for depiction of dentoalveolar structures that are inaccessible by conventional dental radiography

Central mucoepidermoid carcinoma of the maxilla, a challenging diagnosis

Objective: To present a pictorial review on central mucoepidermoid carcinoma. Case report: Central mucoepidermoid carcinoma (CMEC), also known as intraosseous mucoepidermoid carcinoma (IMEC), is an extremely rare disease (less than 2-4% of all MEC). However, CMEC is the most frequent malignant salivary gland tumour found in intraosseous locations. Due to this unusual location, diagnosis of CMEC can be challenging. Therefore, CMEC is often mistaken for other intraosseous or odontogenic pathologies. Radiological assessment shouldinclude panoramic X-Ray, CBCT  and thoracic CT, which should be performed after diagnosis. The recommended treatment includes radical resection surgery, followed by radiotherapy if indicated. A long-term follow-up is recommended for up to 10 years. Conclusion: The authors experienced the challenging diagnosis of CMEC through the case of a patient who presented with a slowly growing palatal mass.  Objective: To present a pictorial review on central mucoepidermoid carcinoma. Case report: Central mucoepidermoid carcinoma (CMEC), also known as intraosseous mucoepidermoid carcinoma (IMEC), is an extremely rare disease (less than 2-4% of all MEC). However, CMEC is the most frequent malignant salivary gland tumour found in intraosseous locations. Due to this unusual location, diagnosis of CMEC can be challenging. Therefore, CMEC is often mistaken for other intraosseous or odontogenic pathologies. Radiological assessment should include panoramic X-Ray, CBCT and thoracic CT, which should be performed after diagnosis. The recommended treatment includes radical resection surgery, followed by radiotherapy if indicated. A long-term follow-up is recommended for up to 10 years.  Conclusion: The authors experienced the challenging diagnosis of CMEC through the case of a patient who presented with a slowly growing palatal mass. &nbsp

Roadmap for daily practice of CBCT in cleft lip palate paediatric patients: a pictorial review.

Objective: to present and to illustrate a new methodology for daily practice in cone beam computed tomography (CBCT) interpretation and reporting in cleft lip palate (CLP) non syndromic paediatric patients. The proposed protocol is based on clinical experience and on systematic search of the literature. Material and methods: We performed two types of systematic search of articles: 1) articles related to the use of CBCT in CLP patients, and 2) articles related to the reporting and interpretation of the CBCT images by radiologists. We used two databases PubMed and Google scholar. Results: For indications of CBCT in CLP patients we found in PubMed 378 articles and 48 articles were selected for the review; in Google scholar we found 463 articles, and 9 articles were selected for the review. 2) For reporting in CBCT we found 956 articles in PubMed, and 9 articles were selected for the review. Conclusions: We presented the 6-steps system for interpretation and reporting information from CBCT of CLP paediatric patients: 1) Step 1 (axial view): presence or absence of bone bridge remnants of alveolar bone graft; Step 2 (3D dental tissue reconstruction): description of dental arch tooth by tooth, search for agenesis and supernumerary teeth, description of variation in the position of the tooth explaining the type of existing translation and rotation; Step 3 (coronal view): cleft palate pathway and its extension; anomaly in maxillary, ethmoid and sphenoid sinuses if existing; Step 4 (sagittal and coronal view): checking of the opening (calcification sites) of the sphenooccipital synchondrosis, and checking of anomalies of the occipital bone; Step 5 (3D bone tissue reconstruction): C1-C2 vertebra anomalies; Step 6 (3D soft tissue reconstruction): external ear anomalies. We illustrated our methodology with 46 figures from 5 CBCT of CLP patients.Objective: to present and to illustrate a new methodology for daily practice in cone beam computed tomography (CBCT) interpretation and reporting in cleft lip palate (CLP) non syndromic paediatric patients. The proposed protocol is based on clinical experience and on systematic search of the literature. Material and methods: We performed two types of systematic search of articles: 1) articles related to the use of CBCT in CLP patients, and 2) articles related to the reporting and interpretation of the CBCT images by radiologists. We used two databases PubMed and Google scholar. Results: For indications of CBCT in CLP patients we found in PubMed 378 articles and 48 articles were selected for the review; in Google scholar we found 463 articles, and 9 articles were selected for the review. 2) For reporting in CBCT we found 956 articles in PubMed, and 9 articles were selected for the review. Conclusions: We presented the 6-steps system for interpretation and reporting information from CBCT of CLP paediatric patients: 1) Step 1 (axial view): presence or absence of bone bridge remnants of alveolar bone graft; Step 2 (3D dental tissue reconstruction): description of dental arch tooth y tooth, search for agenesis and supernumerary teeth, description of variation in the position of the tooth explaining the type of existing translation and rotation; Step 3 (coronal view): cleft palate pathway and its extension; anomaly in maxillary, ethmoid and sphenoid sinuses if existing; Step 4 (sagittal and coronal view): checking of the opening (calcification sites) of the sphenooccipital synchondrosis, and checking of anomalies of the occipital bone; Step 5 (3D bone tissue reconstruction): C1-C2 vertebra anomalies; Step 6 (3D soft tissue reconstruction): external ear anomalies. We illustrated our methodology with 46 figures from 5 CBCT of CLP patients

Déplacement accidentel de la dent de sagesse maxillaire dans le vestibule jugal antérieur

Accidental displacements of the wisdom teeth of the upper jaw to various anatomical regions are rare. We systematically searched the literature on this issue using PubMed and DOAJ. There is no freely available illustration for the accidental displacement pathways of the upper wisdom teeth imaged by CT scan or by CBCT apart from displacement towards the infra-temporal, and the pterygopalatine fossa. We describe and illustrate by CBCT a unique case in the medical literature of accidental displacement of the wisdom tooth germ of the upper jaw into the anterior jugal space. The potential reasons, consequences and ways to prevent this rare complication of wisdom tooth extraction are also explained.Les déplacements accidentels des dents de sagesse du maxillaire supérieur dans divers régions anatomiques sont rares. Nous avons effectué la recherche de littérature sur ce sujet de manière systématique en utilisant PubMed et DOAJ. Il n’existe pas d’illustration accessible gratuitement pour les voies de déplacements accidentels des dents de sagesse supérieurs imagées par le CT scan ou par le CBCT à part le déplacement vers la fosse infra-temporale et vers la fosse ptérygopalatine. Nous décrivons et illustrons par CBCT un cas unique dans la littérature médicale de déplacement accidentel du germe de la dent de sagesse du maxillaire supérieur dans l’espace jugal antérieur. Les raisons potentielles, les conséquences ainsi que les moyens de prévention de cette rare complication d’extraction de dents de sagesse sont aussi expliquées