Cone beam computed tomography (CBCT) for diagnosis and treatment planning in periodontology: systematic review update.

OBJECTIVES: To update the findings of a systematic review from the year 2016 on the evidence for the accuracy and potential benefits of cone beam computed tomography (CBCT) in periodontal diagnostics. MATERIAL AND METHODS: A systematic literature search was performed and the criteria for PICO, PRISMA and risk of bias assessment were applied. Only clinical trials (> 10 patients) conducted in humans on periodontal bone loss, i.e. vertical and/or horizontal or furcation involvement, in CBCT compared with clinical and/or conventional radiographic measures were included. RESULTS: From 1152 articles identified, 11 case series on furcations and eight on vertical and/or horizontal bone loss were included. The studies showed moderate risk of bias and heterogeneous study designs. The agreement between non-surgical clinical or two-dimensional radiographic assessments of horizontal, vertical or interfurcal bone loss and CBCT measurements was analysed in 11 studies and was low in six studies with comparable study designs. A high accuracy (80-84%) of CBCT measurements compared with intra-surgical findings of furcation involvement was observed in four studies. Comparing CBCT with intra-surgical measurements of vertical or horizontal bone loss, an accuracy between 58 and 93% was found in four out of six studies. Three studies were analysed and indicated benefits of CBCT in decision making and/or a reduction of treatment costs and time in teeth of interest. CONCLUSIONS: The findings provide additional evidence for the accuracy of CBCT in assessing periodontal bone loss. CLINICAL RELEVANCE: CBCT is an accurate diagnostic tool in periodontology, which needs to be carefully considered in certain situations.

Establishment of national diagnostic reference levels in dental cone beam computed tomography in Switzerland.

OBJECTIVES: The aim of this study was to establish diagnostic reference levels (DRLs) in the field of dental maxillofacial and ear-nose-throat (ENT) practices using cone beam CT (CBCT) in Switzerland. METHODS: A questionnaire was sent to owners of CBCTs in Switzerland; to a total of 612 institutions. The answers were analyzed for each indication, provided that enough data were available. The DRLs were defined as the 75th percentile of air kerma product distribution (PKA). RESULTS: 227 answers were collected (38% of all centers). Third quartile of PKA values were obtained for five dental indications: 662 mGy cm² for wisdom tooth, 683 mGy cm² for single tooth implant treatment, 542 mGy cm² for tooth position anomalies, 569 mGy cm² for pathological dentoalveolar modifications, and 639 mGy cm² for endodontics. The standard field of view (FOV) size of 5 cm in diameter x 5 cm in height was proposed. CONCLUSIONS: Large ranges of FOV and PKA were found for a given indication, demonstrating the importance of establishing DRLs as well as FOV recommendations in view of optimizing the present practice. For now, only DRLs for dental and maxillofacial could be defined; because of a lack of ENT data, no DRL values for ENT practices could be derived from this survey.

Pediatric cleft palate patients show a 3- to 5-fold increase in cumulative radiation exposure from dental radiology compared with an age- and gender-matched population: a retrospective cohort study.

OBJECTIVE: The objective of the study was to compare estimates of pediatric cumulative exposure and lifetime attributable risk (LAR) of radiation-induced cancer from dental radiology between cleft palate (CP) subjects and age- and gender-matched controls (non-CP), with and without orthodontic treatment. MATERIALS AND METHODS: The radiation exposure frequency of CP subjects and non-CP controls with and without orthodontic treatment was compared for two-dimensional radiography (intra-oral, panoramic and cephalometric radiography), computed tomography (CT), and cone-beam CT (CBCT) using cumulative radiation dose as an estimate. From this dose estimate, the age- and gender-dependent risk for radiation-induced stochastic effects was calculated for each patient group. RESULTS: CP patients received more radiographic examinations than non-CP controls, with the exception of intra-oral radiographs. The cumulative dose to CP patients was considerably higher (1963 µSv at the age of 20 years) than non-CP patients with (597 µSv) and without (383 µSv) orthodontic treatment, primarily due to the higher frequency of CT scanning. Accordingly, CP patients had a three to five times higher LAR than non-CP patients. CONCLUSIONS: This study suggests a significantly higher lifetime radiation exposure to CP patients than non-CP controls from dental radiographic procedures. Diagnostic benefits from the use of CT and CBCT in children must be justified and appropriate dose optimization strategies implemented. CLINICAL RELEVANCE: The present study indicates the need for proper justification and optimization of pediatric exposures in dentistry, with a special focus on high-risk groups.

Diagnosis of tooth ankylosis using panoramic views, cone beam computed tomography, and histological data: a retrospective observational case series study.

Objectives: The aim of this study was to determine whether cone beam computed tomography is a reliable radiological method to diagnose tooth ankylosis. Materials and methods: A series of teeth clinically diagnosed as ankylosed were collected after extraction in a private practice from 2009 to 2015 and analyzed retrospectively. Inclusion criteria comprised permanent molars extracted due to failed tooth eruption in the absence of any visible mechanical obstruction, existing panoramic view (PV), and cone beam computed tomography (CBCT) and histological sections of sufficient quality. The CBCT scans and PVs were evaluated twice for signs of ankylosis by two independent observers using the following score: clear signs, possible signs, and no signs. The histological sections were evaluated and graded similarly to the radiographs by a specialist blinded to the radiographs and treatment. Results: Out of an initial group of 22 patients, 9 subjects with 10 affected teeth were included for final evaluation. The age ranged from 8.3 to 17 years. No agreement was seen in comparing the PV scores to the histological sections. Fair to moderate agreement was seen in comparing the CBCT scores to the histological sections. All histologically confirmed ankylosis were detected in CBCT by both observers but some false positive results were found. Limitation: Only a small sample size was available as the disorder is rare. It is difficult to distinguish ankylosis from primary failure of eruption. Conclusion: CBCT images can be a useful adjunctive diagnostic tool to diagnose ankylosed teeth, but cannot be recommended as a single diagnostic modality as false positive results were found.

TLD measurements and Monte Carlo calculations of head and neck organ and effective doses for cone beam computed tomography using 3D Accuitomo 170.

OBJECTIVES: In dentistry, the use of cone beam CT has steadily increased over the last few years. The aim of this study was to measure organ doses and to perform dose calculations based on Monte Carlo (MC) simulations to work out a basis for full three-dimensional (3D) dose calculations for any patient examination performed with the machine used in this study. METHODS: TLD-100 LiF detectors were placed at 71 measurement positions on the surface and within a RT-Humanoid phantom to cover all relevant radiosensitive organs and tissues. Three examinations with different protocols were performed with the 3D Accuitomo® and dose calculations with MC simulations were carried out for the same three protocols using the EGSnrc MC transport code system. RESULTS: Field of views of 140 × 100, 80 × 50 and 40 × 40 mm2 were selected, the mean organ doses were measured as 5.2, 2.75 and 1.5 mGy and the effective doses were determined as 250, 97 and 48 µSv. For the MC simulation of organ doses and the thermoluminescent dosemeter measurements, an overall agreement within ±10.1% (two standard deviations) was achieved. The measured dose values for 3D Accuitomo® were about a factor 2 lower when compared with conventional CT examinations. CONCLUSIONS: Reliable results for the organ doses as well as effective dose values were achieved with thermoluminescent dosemeter measurements in the RT-Humanoid phantom. This study provides the basis for the application of MC simulations for further dose determinations of cone beam CT machines. The MC calculation may therefore be a valuable tool to support the dentists in the evaluation of the trade-off between additional information that may be relevant to the choice of therapy and the additional dose given to the patient.

Cone beam computed tomography (CBCT) for diagnosis and treatment planning in periodontology: A systematic review.

OBJECTIVE: The improvement in diagnostic accuracy and optimization of treatment planning in periodontology through the use of three-dimensional imaging with cone beam computed tomography (CBCT) is discussed controversially in the literature. The objective was to identify the best available external evidence for the indications of CBCT for periodontal diagnosis and treatment planning in specific clinical situations. DATA SOURCES: A systematic literature search was performed for articles published by 2 March 2015 using electronic databases and hand search. Two reviewers performed the study selection, data collection, and validity assessment. PICO and PRISMA criteria were applied. From the combined search, seven studies were finally included. CONCLUSION: The case series were published from the years 2009 to 2014. Five of the included publications refer to maxillary and/or mandibular molars and two to aspects related to vertical bony defects. Two studies show a high accuracy of CBCT in detecting intrabony defect morphology when compared to periapical radiographs. Particularly, in maxillary molars, CBCT provides high accuracy for detecting furcation involvement and morphology of surrounding periodontal tissues. CBCT has demonstrated advantages, when more invasive treatment approaches were considered in terms of decision making and cost benefit. Within their limits, the available data suggest that CBCT may improve diagnostic accuracy and optimize treatment planning in periodontal defects, particularly in maxillary molars with furcation involvement, and that the higher irradiation doses and cost-benefit ratio should be carefully analyzed before using CBCT for periodontal diagnosis and treatment planning.

SADMFR Guidelines for the Use of Cone-Beam Computed Tomography/Digital Volume Tomography.

In 2011, the first consensus conference on guidelines for the use of cone-beam computed tomography (CBCT) was convened by the Swiss Society of Dentomaxillofacial Radiology (SGDMFR). This conference covered topics of oral and maxillofacial surgery, temporomandibular joint dysfunctions and disorders, and orthodontics. In 2014, a second consensus conference was convened on guidelines for the use of CBCT in endodontics, periodontology, reconstructive dentistry and pediatric dentistry. The guidelines are intended for all dentists in order to facilitate the decision as to when the use of CBCT is justified. As a rule, the use of CBCT is considered restrictive, since radiation protection reasons do not allow its routine use. CBCT should therefore be reserved for complex cases where its application can be expected to provide further information that is relevant to the choice of therapy. In periodontology, sufficient information is usually available from clinical examination and periapical radiographs; in endodontics alternative methods can often be used instead of CBCT; and for implant patients undergoing reconstructive dentistry, CT is of interest for the workflow from implant planning to the superstructure. For pediatric dentistry no application of CBCT is seen for caries diagnosis.

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

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

[Focal osteosclerotic lesions of the jaws--a review focusing on diagnostic and therpeutic aspects]. / Fokale Osteosklerosen im Kiefer. Eine Uebersichtsarbeit zur Diagnostik und Therapie.

The diagnosis of osteosclerotic lesions is sometimes quite challenging for the general dental practitioner. When having no clear reason for a sclerotic process in the jaw bone, the dentist is often left without a definite diagnosis and treatment plan. Additionally, the literature often mixes terms for sclerotic bone lesions in the mandible or maxilla, causing further confusion about classification, therapy and prognosis of these entities. Although osteosclerotic jaw lesions can arise in every decade of life, they often are encountered by chance on routine radiographic examinations. For further diagnosis these lesions are even referred for invasive procedures such as bone biopsies. Nevertheless, accurate knowledge about the pathogenesis, radiographic and clinical appearance of these lesions could already lead to a diagnosis without the need for further biopsies. The present review focuses on the focal osteosclerosis of the jaws, discussing diagnosis, treatment and important differential diagnoses.

Comparison of periapical radiography and limited cone-beam tomography in posterior maxillary teeth referred for apical surgery.

This study compared periapical (PA) radiography and cone-beam tomography (CBT) for preoperative diagnosis in posterior maxillary teeth of consecutive patients referred for possible apical surgery. Images were concurrently analyzed by an oral radiologist and an endodontist to reach consensus in interpretation of the radiographic findings. The final material included 37 premolars and 37 molars with a total of 156 roots. CBT showed significantly more lesions (34%, p < 0.001) than PA radiography. Detecting lesions with PA radiography alone was most difficult in second molars or in roots in close proximity to the maxillary sinus floor. Additional findings were seen significantly more frequently in CBT compared with PA radiography including expansion of lesions into the maxillary sinus (p < 0.001), sinus membrane thickening (p < 0.001), and missed canals (p < 0.05). The present study highlights the advantages of using CBT for preoperative treatment planning in maxillary posterior teeth with apical pathology.

Postoperative tomographic assessment of veneer bone grafting with implant placement in the maxillary anterior region.

Various ridge augmentation and sinus lift procedures were performed in severely resorbed alveolar crests of a maxilla to provide some volume for implant treatment. It was reported that the outcome of maxillary sinus lift procedures was evaluated with conventional tomography or computerized tomography, and that grafted bone around implants markedly progressed in resorption, particularly at the implant apex. However, veneer bone grafting with implant placement has not been evaluated after treatment with imaging techniques. Therefore, the purpose of this study was to assess veneer bone grafting after maxillary anterior implant treatment. Seven patients with a mean age of 24 years, with implants placed in the maxillary anterior region with or without autogenous veneer bone grafting were postoperatively examined using conventional tomography. On tomograms, the ratio of bone-to-implant contact and the area of bone were measured in labial bones with bone grafts, and they were compared with the values without bone grafts. In cases with bone grafting, the average ratio of bone-to-implant contact was 63.6%, whereas 81.8% was formed in cases without bone grafting. The average area of bone was 12.9 mm and 23.4 mm in patients with and without bone grafting, respectively. No significant difference was found between the implants with and without bone grafts. Resorbed labial bone was observed in the maxillary anterior region with and without veneer bone grafting.

Study on the necessity for cross-section imaging of the posterior mandible for treatment planning of standard cases in implant dentistry.

OBJECTIVE: To investigate whether cross-section imaging influences the planning and therapy of standard implant cases in the posterior mandible. MATERIAL AND METHODS: In a prospective study conducted over 16 months, the planned treatment (standard implant therapy without bone augmentation procedures in the premolar and molar regions of the mandible) was compared with the postoperative result in 50 randomly selected patients. Clinical examinations and panoramic radiographs were performed pre- and postoperatively, whereas cross-sectional tomography was performed only preoperatively. RESULTS: The vertical magnification factor in the panoramic radiographs was very constant pre- and postoperatively with 1 : 1.27 and in the spiral tomograms with 1 : 1.52. In 11 of 77 implant sites, the mandibular canal could not be evaluated in the spiral tomograms. The additional information from cross-sectional spiral tomography did not influence the original planning in 74 of 77 (96.1%) implant sites. Based on the postoperative panoramic radiograph, the average distance from the tip of the implants to the mandibular canal was 3.04+/-2.06 mm. In two cases (2.6%), transient postoperative altered tactile sensation of the mental nerve was found. CONCLUSION: The information from preoperative cross-sectional spiral tomography has minor impact on treatment planning in standard implant cases in mandibular premolar and molar regions. The clinical examination provides sufficient information for selecting implant diameter and the panoramic radiograph provides sufficient information for implant length selection.

Long-term stability of osseointegrated implants in augmented bone: a 5-year prospective study in partially edentulous patients.

This prospective clinical study evaluated the 5-year survival and success rates of 66 titanium implants placed in bone that had been previously augmented with autografts and nonresorbable barrier membranes. During the observation period, three patients with five implants dropped out of the study. None of the remaining 61 implants were lost during the follow-up period (implant survival rate of 100%). One implant exhibited a periimplant infection, whereas 60 implants were considered clinically successful at the 5-year examination, resulting in a 5-year success rate of 98.3%. It can be concluded that the clinical results of implants in regenerated bone are comparable to those of implants in nonregenerated bone.