Prescription of panoramic radiographs in children using age-based prevalence of dental anomalies and pathologies.

BACKGROUND: Panoramic radiographs (PRs) are used in the detection and diagnosis of developmental dental anomalies and pathologies (DDAPs) in children. AIM: The primary objective of this observational cohort study was to evaluate the age-based prevalence of DDAP on PRs, whereas the secondary objective was to determine a threshold age for the detection of DDAP to provide supportive evidence for the prescription of PR in paediatric dental practice. DESIGN: The study examined diagnostic PRs from 581 subjects aged 6 to 19 years. All PRs were reviewed by experienced, calibrated, masked examiners for the identification or presence of anomalies in size, shape, position, structure, and other developmental anomalies and pathologies (ODAP) of the face-neck region in a standardized condition. The data were statistically analyzed for interpretation. RESULTS: Overall, 74% (n = 411) of the cohort had at least one anomaly (shape anomaly: 12%, number anomaly: 17%, positional anomaly: 28%, structural anomaly: 0%, and ODAP: 63%). The optimal Youden index cutoff for any anomaly was 9 years. Twelve and 15 years also showed predictive ability. CONCLUSION: The results suggest that PRs should be prescribed at ages 9, 12, and 15 years for the diagnosis of DDAP.

Estimating the 3-D location of impacted maxillary canines: A CBCT-based analysis of severity of impaction.

OBJECTIVES: The objective of the study was to quantify the 3-D location of impacted canines by measuring their linear and angular deviations in relation to adjacent structures and further evaluate impaction severity. METHODS: CBCT images of 314 impacted canines were analysed in the sagittal, coronal and axial planes. Linear and angular measurements were recorded. Canine inclination was identified in coronal and sagittal planes. An evaluation system was constructed for analysis. Upright canine was considered as the appropriate position for fully erupted maxillary canine. Outcomes were compared between right and left sides and by gender. For categorical variables, chi-square tests were used while Mann-Whitney U test was used for continuous variables. Regression models were used to measure severity. RESULTS: Impactions were greater in females (119/207; 57.5%). No significant differences between unilateral (100/207; 49.3%) and bilateral (107/207; 51.7%) (P > 0.05). Out of 314 impactions, 105 (33.4%) were mild, 118 (37.58%) moderate and 91 (28.98%) severe. Severe impactions were primarily buccal (44/ 91; 48.3%), in the occlusal ½ of the adjacent incisor root (38/ 91, 41.7%), mesial to the distal border of central incisor (47/91, 51.6%), with sagittal angle value + >45 ̊ (46/ 91, 50.5%) and mesial tip + >30 ̊ (86/ 91, 94.5%). CONCLUSIONS: Severely impacted canines had their crowns buccal, closer to occlusal plane and mesial to the distal border of the central incisor with greater than 45-degree buccal inclination and greater than 30-degree mesial tip. The sagittal angle can have a significant impact on the severity of impaction. A new classification system was proposed to quantify severity.

Short-term and long-term effects of miniscrew-assisted and conventional rapid palatal expansion on the cranial and circummaxillary sutures.

INTRODUCTION: The objective of this study was to analyze the short-term and long-term effects of miniscrew-assisted rapid palatal expansion (MARPE) and conventional rapid palatal expansion (RPE) appliances on cranial and circummaxillary sutures as compared with a matched control group. METHODS: One hundred and eighty cone-beam computed tomography scans for 60 subjects were evaluated for the 3 groups: (1) MARPE (n = 20; aged 13.7 ± 1.74 years), (2) RPE (n = 21; age 13.9 ± 1.14 years), and (3) control (n = 19; age 13.3 ± 1.49 years) at pretreatment (T1), postexpansion (T2), and posttreatment (T3) (T1 to T3: MARPE, 2 years 8 months; RPE, 2 years 9 months; control, 2 years 7 months). Frontonasal suture, frontomaxillary suture, zygomaticomaxillary suture, zygomaticofrontal suture, intermaxillary suture, pterygomaxillary suture, nasomaxillary suture, and zygomaticotemporal suture were measured on the right and left sides for all 3 time labels. In addition, midpalatal suture was measured at the incisor, canine, and molar levels. RESULTS: Within-group analysis showed that MARPE and RPE led to a significant increase in the widths of frontonasal, frontomaxillary, intermaxillary, nasomaxillary, and midpalatal suture at incisor, canine, and molar levels at T2 compared with T1. Between-group analysis showed that MARPE and RPE significantly increased the width of the intermaxillary and midpalatal suture at the incisor, canine, and molar compared with controls at T2. In the long term, between-group comparisons showed no significant difference among the 3 groups except that MARPE led to a significant increase in the width of midpalatal suture at incisor, canine, and molar levels compared with RPE and controls at T3. CONCLUSIONS: MARPE led to a significant increase in the width of the midpalatal suture at incisor, canine, and molar levels compared with RPE and controls in the long term. There was no difference in the width of other cranial and circummaxillary sutures among the 3 groups in the long term.

Comparative evaluation of a lower dose CBCT acquisition protocol for preoperative implant site assessment in dry human skulls.

Restoration of edentulous sites with dental implants is increasingly becoming a popular choice. Cross-sectional 3D imaging using CBCT provides a superior view of the implant site to help the clinician plan the procedure better. In spite of the advantages, radiation dose remains a concern. The evolution of lower dose protocols is ongoing but whether those acquisition protocols yield comparable diagnostic information is still not well established. The objective of this study was to evaluate the diagnostic efficacy of a low dose, 180˚ rotational CBCT acquisition protocol for evaluating a potential implant site in comparison with a conventional 360˚ rotational acquisition. Ten dentate and partially edentulous dry human skulls were chosen for this study. Each skull was imaged using a 360˚ and a 180˚ rotational acquisition on a J. Morita's Accuitomo CBCT scanner. 82 randomized implant sites, 40 in the maxilla and 42 in the mandible were analyzed. Evaluation of cortical and trabecular bone, proximity to crucial structures such as the inferior alveolar nerve canal and the maxillary sinus, and width of the potential placement site were measured. An oral surgeon and an oral radiologist rated the diagnostic efficacy of the scans by evaluating the above characteristics. Statistical evaluation of the data with linear regression showed significant agreement between both protocol measurements. Kappa analyses yielded a good inter-observer agreement. In this ex-vivo study, there was no significant difference in both the qualitative and quantitate evaluation between the conventional 36 0˚ acquisition protocol and  the modified lower dose 180˚ rotational protocol.

Comparative Evaluation of a Lower-Dose CBCT Acquisition Protocol for Preoperative Implant Site Assessment in Dry Human Skulls: A Proof-of-Concept Study.

Restoration of edentulous sites with dental implants is increasingly becoming a popular choice. Cross-sectional 3-dimensional imaging using cone-beam computed tomography (CBCT) provides a better depiction of the implant site to help the clinician plan the procedure better. In spite of the advantages, radiation dose will always remain a concern. The evolution of lower-dose protocols is ongoing, but whether those acquisition protocols yield comparable diagnostic information is still not well established. The objective of this study was to evaluate the diagnostic efficacy of a low-dose, 180° rotational CBCT acquisition protocol for evaluating a potential implant site in comparison with a conventional 360° rotational acquisition. Ten dentate and partially edentulous dry human skulls providing 82 randomized implant sites-40 in the maxilla and 42 in the mandible-were chosen for this study. Each skull was imaged using a 360° and a 180° rotational acquisition on a J. Morita Accuitomo CBCT scanner. Evaluation of cortical and trabecular bone, height, width, and proximity to critical structures, such as the inferior alveolar nerve canal and the maxillary sinus, were measured. An oral surgeon and an oral radiologist rated the diagnostic efficacy of the scans by evaluating the above characteristics. Statistical evaluation of the data with linear regression showed significant agreement between both protocol measurements. Kappa analyses yielded a good interobserver agreement. In this proof-of-concept study, CBCT imaging using the lower-dose, modified arc, and 180° acquisition protocol shows comparable results to the conventional 360° protocol for preoperative implant assessment.

Variability associated with mandibular ramus area thickness and depth in subjects with different growth patterns, gender, and growth status.

INTRODUCTION: The purpose of this study was to quantitatively evaluate the ramus bone parameters (ramus thickness and ramus depth) for miniscrew placement. An additional aim was to compare and contrast the ramus bone parameters in growing and nongrowing male and female subjects with hyperdivergent, normodivergent, hypodivergent facial types. METHODS: Cone-beam computed tomography scans of 690 subjects were evaluated. They were classified in terms of growth status, gender, and facial type. Ramus thickness was measured as the distance from the outer (buccal) to the inner (lingual) aspects of the mandibular ramus. Ramus depth was measured as the distance from the anterior border of the ramus to the inferior alveolar nerve canal. The measurements for ramus thickness and ramus depth were performed at 3 different levels bilaterally: (1) occlusal plane (OP), (2) 5 mm above the occlusal plane (5OP), and (3) 10 mm above the occlusal plane (10OP). RESULTS: Males showed a significantly higher ramus thickness than females (P <0.05). Ramus thickness decreased significantly (P <0.05) as we moved superior from the level of OP to 5OP and 10OP in all 3 facial types in both females (growing and nongrowing) and males (growing and nongrowing). Growing females and growing males had significantly higher ramus thickness than nongrowing females and nongrowing males, respectively. Ramus depth increased as we moved higher from the OP to 10OP. Hyperdivergent facial type showed a significantly reduced ramus depth compared with hypodivergent and normodivergent facial type in growing and nongrowing males and females at all 3 locations, namely OP, 5OP, and 10OP (P <0.05). CONCLUSIONS: Because of adequate ramus depth and ramus thickness, 5OP was considered the optimal insertion site for the placement of miniscrews. Patients with a hyperdivergent facial type showed significantly reduced ramus depth than hypodivergent and normodivergent facial types. Ramus thickness in males was significantly higher than in females in all facial types.

Long-term effects of conventional and miniscrew-assisted rapid palatal expansion on root resorption.

INTRODUCTION: The purpose of this study was to use cone-beam computed tomography to compare immediate and long-term effects of conventional and miniscrew-assisted rapid palatal expansion (MARPE) appliances on root resorption in 2 treatment groups and a control group. METHODS: One hundred eighty cone-beam computed tomography images of 60 patients at 3 time points were assessed: initial, postexpansion, and debond. The patients were divided into 3 groups: control (n = 19), rapid palatal expansion (RPE) appliance (n = 21), and MARPE (n = 20). The period of initial to debond varied for the 3 groups: 2 years, 7 months for controls; 2 years, 9 months for RPE; and 2 years, 8 months for MARPE. The length of mesiobuccal, distobuccal, and palatal root of the maxillary first molar (1M); the buccal root of maxillary first premolar; and second premolar were measured. The inclination of the 1M, intercuspal width (ICW), interroot width (IRW), ICW/IRW ratio, maxillary skeletal width were measured in all 3 groups at different time points. RESULTS: Immediately after expansion, RPE and MARPE groups showed a significant increase in the molar inclination, ICW, ICW/IRW ratio, and maxillary skeletal width compared with controls at postexpansion. However, the long-term comparison did not show any significant difference for root resorption and expansion parameters between the 3 groups, except the ICW/IRW ratio, which was higher in MARPE than controls at debond. A significant negative association was observed between the length of the mesiobuccal root of 1M and molar inclination (ß = -0.025; 95% confidence interval, -0.050 to 0.0008; P <0.05). The expansion of ICW and IRW did not show a significant association with root resorption. CONCLUSIONS: The long-term outcomes showed no difference in the amount of root resorption between the RPE, MARPE, and control groups. Molar inclination showed a significant negative association with the length of the mesiobuccal root of the 1M.

Variability of the maxillary suture maturation and density in the subjects with different sex and growth status.

INTRODUCTION: The objective of this study was to classify median palatine suture (MPS) maturation type in young and adult patients. Additionally, we compared MPS maturity type and density based on sex and growth status. MATERIALS AND METHODS: In this retrospective cone beam computed tomography study, we included a total of 221 subjects, grouped based on sex and growth status. Once scans were aligned and oriented in the sagittal view, we conducted our evaluations on the axial sections. Based on interdigitation and shape, the MPS were categorized into Maturation Types A through E. Additionally, MPS density was measured as Hounsfield unit equivalent pixel intensity value scale for anterior and posterior sutural regions. RESULTS: The majority of male (39%) and female (42%) subjects had MPS Maturation Type C. A maximum number of growing (42%) patients had Type C and nongrowing subjects (39%) had Type E sutures. The sex comparison showed significantly lower (p < .001) MPS density for both anterior and posterior regions in males when compared to females. Additionally, for the posterior region, nongrowing males had significantly lower (p < .001) MPS density when compared to nongrowing females. Subgroup comparisons of the MPS densities between growing and nongrowing males and growing and nongrowing females showed a significant difference (p < .001). CONCLUSION: Classification of the MPS based on the maturation types provides a reliable predictor for orthodontic treatment planning. MPS density is significantly higher in females as compared to males. Similarly, nongrowing individuals have significantly higher MPS density compared to growing individuals for both anterior and posterior locations.

Variability associated with mandibular buccal shelf area width and height in subjects with different growth pattern, sex, and growth status.

INTRODUCTION: The primary objective of the study was to quantitatively analyze the width and height of the mandibular buccal shelf area (MBS) at 3 different potential locations for mini-implant placement. In addition, we aimed to compare and contrast the bone parameters of the MBS to study the correlation between different growth status (growing or nongrowing), facial types (hypodivergent, normodivergent, and hyperdivergent), and sex differences (male or female). METHODS: In this retrospective cone-beam computed tomography study, 678 subjects were included. They were divided into groups according to growth status, facial type, and sex. Scans were imported into the reconstruction program and were aligned in 3 different steps. Measurements were made at 6 different coronal sections: mandibular first molar distal root, second molar mesial root, and second molar distal root (bilaterally). The roots of mandibular molars were used as a reference to measure the width and the roof of the inferior alveolar canal to measure the height of the buccal shelf area. Intraobserver reliability was assessed by measuring the width and height of MBS in 20 randomly selected subjects. RESULTS: No significant difference (P > 0.05) was found in the width of MBS between males and females. MBS width increased, and height decreased (P < 0.0001) as moved distally from the first molar distal root to the second molar distal root in all 3 facial types irrespective of age or sex. The hypodivergent facial type had significantly greater bone width than the hyperdivergent facial type at all the 3 locations in both males and females. The hypodivergent facial type had significantly less (P < 0.0001) bone height than the hyperdivergent group at all the 3 locations irrespective of age or sex. CONCLUSIONS: The optimal site for MBS mini-implant is the buccal region of the distal root of mandibular second molars. Hypodivergent patients have more width and less height of MBS compared with hyperdivergent patients. MBS mini-implants are not advised for growing patients because of proximity to developing roots.

Effect of multiple injections of botulinum toxin into painful masticatory muscles on bone density in the temporomandibular complex.

BACKGROUND: Adverse effects of masticatory muscle injections of Botulinum Toxin (Btx) have been noted in animal and, less dramatically, human studies. OBJECTIVE: Among women treated in multiple community-based private practices, to compare TMJ bone density and mandibular condylar volume between patients with myofascial TMJD receiving multiple masticatory muscle Btx treatments and similarly diagnosed women not receiving such treatment. METHODS: Cohorts consisted of women whose treatment charts indicated a diagnosis of myofascial TMJD: 35 received at least 2 Btx treatment cycles; 44 received none. Bone density at pre-specified regions of interest (ROI) was defined by grey scale values from Cone Beam CT, adjusting for a fixed density phantom included in each scan. Mean bone density and mandibular condyle volume were compared between groups. Dose-response effects were tested within the Btx-exposed group. RESULTS: The mean density of primary and secondary ROIs was similar between exposure groups, as was condylar volume. Among Btx-exposed women, increasing dose of Btx to the temporalis muscle was inversely proportional to the density of the trabecular area of the mandible body. Many Btx-exposed women received smaller doses of Btx to the masseter muscles than in most TMJD Btx clinical trials. CONCLUSION: Masticatory muscle injections of Btx failed to produce clinically significant TMJ bone-related changes. Should Btx receive regulatory approval for treatment of myofascial TMJD, a phase IV study is recommended to evaluate potential adverse effects of Btx on bone and muscle when administered at higher doses and/or for more treatment cycles.

Influence of type of radiograph and levels of experience and training on reproducibility of the cervical vertebral maturation method.

INTRODUCTION: The objective of this study was to assess the reproducibility of cervical vertebral maturation (CVM) method based on the type of radiographic image and the level of experience and level of training of the evaluator. METHODS: Ten evaluators (5 orthodontic residents and 5 faculty members) were randomly divided into 2 groups: trained and untrained. All participants evaluated 80 radiographic images previously acquired in 4 different formats: (1) 2-dimensional (2D) digital (2D-digital), (2) 2D digitized hard copy from the Iowa Facial Growth Study (American Association of Orthodontists Foundation Craniofacial Growth Legacy Collection), (3) 2D digital reconstructed from a 3-dimensional (3D) radiograph (2D-from 3D), and (4) 3D cone-beam computerized tomographic (3D-CBCT) images. Agreement among evaluators on the morphology of the cervical vertebrae (CV) and the CVM stage of each radiographic image was assessed using Randolph's kappa statistic and Kendall's W coefficient of concordance. RESULTS: Interobserver agreement on the determination of a curvature on the inferior border of the CV was substantial to perfect, whereas agreement on shape was fair to moderate. Overall, the level training in all image types, except 3D-CBCTs, but not the level of experience affected the agreement for shape and curvature of the CVs. Interobserver agreement on CVM staging for all combined images was substantial at 0.72. Faculty had a higher level of agreement than residents except for 2D-digital and 3D-CBCT images, whereas trained evaluators had an overall higher level of agreement than untrained evaluators except for 3D-CBCT images. CONCLUSIONS: Interobserver agreement in determining CVM stage was substantial for all images evaluated; experience and training resulted in higher level of agreement for some image types. The 3D-CBCT images did not provide increased interobserver agreement over current 2D-digital lateral cephalograms in determining CVM staging or shape of the CV. The highest agreement in CVM staging was obtained on 2D-digital lateral cephalograms with training.

Loading of the Condylar Cartilage Can Rescue the Effects of Botox on TMJ.

The purpose of this study is to evaluate whether the effects of botulinum neurotoxin (botox) injection into the masseter in the mandibular condylar cartilage (MCC) and subchondral bone could be rescued by compressive loading of the temporomandibular joint (TMJ). Twenty-four 6-week-old female mice (C57BL/6J) were used. Mice were divided in three groups: (1) Botox (n = 8); (2) Botox plus loading (n = 8); (3) Pure control (n = 8). Bone labels (3 and 1 day before sacrifice) and the proliferation marker EdU (2 and 1 day before sacrifice) were intraperitoneally injected into all groups of mice. Condyles were dissected and examined by micro-CT and histology. Sagittal sections of condyles were stained for TRAP, alkaline phosphatase, EdU, TUNEL, and toluidine blue. In addition, immunostaining for pSmad, VEGF, and Runx2 was performed. Bone volume fraction, tissue density, and trabecular thickness were significantly decreased on the subchondral bone of botox-injected side when compared to control side and control mice, 4 weeks after injection. Furthermore, histological analysis revealed decrease in mineralization, matrix deposition, TRAP activity, EdU, and TUNEL-positive cells in the MCC of the botox-injected side, 4 weeks after injection. However, compressive loading reversed the reduced bone volume and density and the cellular changes in the MCC caused by Botox injection. TMJ compressive loading rescues the negative effects of botox injection into the masseter in the MCC and subchondral bone.

Analyzing Dental Implant Sites From Cone Beam Computed Tomography Scans on a Tablet Computer: A Comparative Study Between iPad and 3 Display Systems.

PURPOSE: The aim of this study was to compare a medical-grade PACS (picture archiving and communication system) monitor, a consumer-grade monitor, a laptop computer, and a tablet computer for linear measurements of height and width for specific implant sites in the posterior maxilla and mandible, along with visualization of the associated anatomical structures. MATERIAL AND METHODS: Cone beam computed tomography (CBCT) scans were evaluated. The images were reviewed using PACS-LCD monitor, consumer-grade LCD monitor using CB-Works software, a 13″ MacBook Pro, and an iPad 4 using OsiriX DICOM reader software. The operators had to identify anatomical structures in each display using a 2-point scale. User experience between PACS and iPad was also evaluated by means of a questionnaire. RESULTS: The measurements were very similar for each device. P-values were all greater than 0.05, indicating no significant difference between the monitors for each measurement. The intraoperator reliability was very high. The user experience was similar in each category with the most significant difference regarding the portability where the PACS display received the lowest score and the iPad received the highest score. CONCLUSIONS: The iPad with retina display was comparable with the medical-grade monitor, producing similar measurements and image visualization, and thus providing an inexpensive, portable, and reliable screen to analyze CBCT images in the operating room during the implant surgery.

Cone Beam CT Analysis of Tempora Bone Pneumatizatioi in Subjects with Unilateral Cleft Lip and Palate.

OBJECTIVES: To evaluate the pneumatization pattern in the temporal bone in patients with cleft lip and palate. METHODS: A retrospective observational analysis of cone beam computed tomography (CBCT) scans of patients with cleft lip and palate was done. The patients were referred for orthodontic treatment and had a unilateral cleft lip and palate and anterior maxillary constriction. Four reference structures were identified to evaluate the extension of pneumatization in the cleft vs non-cleft side temporal bones. RESULTS: Twenty patients had cleft on the left side and nine patients had cleft on the right side, This study found reduced temporal bone pneumatization on the side of the cleft. The mean score of temporal bone pneumatization on the cleft side was 4.7±1.47 while mean score of pneumatization on the non-cleft side was 6.7±1.80 (P<0.001). CONCLUSIONS: Pneumatization of the temporal bone was significantly lower on the side of the cleft and an identification of this change can help in early diagnosis and management of any ear-related conditions in this vulnerable group of patients to make appropriate referrals for specialized care.

CBCT evaluation of buccal bone regeneration in postmenopausal women with and without osteopenia or osteoporosis undergoing dental implant therapy.

STATEMENT OF PROBLEM: Because alveolar bone augmentation in women with osteoporosis/osteopenia has an uncertain prognosis, objective and reliable methods should be used to study standard surgical approaches. PURPOSE: The purpose of this clinical study was to evaluate bone regeneration 9 months after bone augmentation and implant placement in postmenopausal women with different levels of systemic bone health by using cone beam computed tomography (CBCT) and to test proof of concept for this measurement approach. MATERIAL AND METHODS: A subset of 14 participants was analyzed in a best practice study of postmenopausal women receiving dental implants and simultaneous horizontal ridge augmentation. Women were categorized as osteopenic/osteoporotic or normal based on the results of preoperative dual-energy x-ray absorptiometry. All implant study sites received a particulate graft and/or buccal plate expansion. The study sites were evaluated with CBCT preoperatively, immediately postoperatively, and 9 months postoperatively. Nonparametric statistics were used for all analyses. The related samples Wilcoxon signed rank test was used to assess the differences in bone width between time points (α=.05 for all tests). RESULTS: After 9 months, 13 out of 14 participants showed increased bone width compared to the preoperative baseline measurements. The increase was statistically significant for the participants with osteoporosis/osteopenia (P=.007), but not for those with normal bone health (P=.066). The CBCT scans showed that mineralized tissue buccal to the implant surface had the radiographic appearance of mature bone. CONCLUSIONS: CBCT showed evidence of bone regeneration, with an increase in alveolar ridge width in postmenopausal osteopenic/osteoporotic women subsequent to surgical reconstruction.

Diagnostic accuracy of 2 cone-beam computed tomography protocols for detecting arthritic changes in temporomandibular joints.

INTRODUCTION: The temporomandibular joint (TMJ) is a complex joint that often develops degenerative joint disease. Clinical examination alone cannot usually diagnose this accurately, and a radiographic examination complements and aids in diagnosis and treatment. The osseous components of the TMJ complex are best imaged using computed tomography. The evolution of cone-beam computed tomography (CBCT) offers a low radiation dose and a high spatial resolution alternative and is becoming the imaging modality of choice for the TMJ. To further reduce the dose and yet not compromise the diagnostic task at hand, some alternative rotation acquisition protocols are available but have not been adequately evaluated. The aim of this study was to evaluate the diagnostic efficacy of 2 CBCT acquisition protocols to detect degenerative changes associated with the TMJ complex. METHODS: Thirty-four TMJs, from 17 dry human skulls, were obtained from the anatomy department at the School of Dental Medicine of the University of Connecticut. The sample consisted of complete dentate and partially dentate skulls with no identifiable markers such as age, sex, or ethnicity. Small and large lesions simulating early and established arthritic changes were created on the mandibular condyle. Each defect was randomly created on the medial pole, articulating surface, or lateral pole. After simulating the articular disc with rubber dam material, the condyle and the glenoid fossa were articulated and positioned in place by a rubber band. The skulls were scanned by using an Accuitomo CBCT scanner (J. Morita Corp, Kyoto, Japan) with 180° and 360° rotation protocols. Two operators scored the lesions and compared the results to the gold standard, which was the master list of where the lesions were made on the condyles. RESULTS: On the 102 randomly selected sites, 39 large and 33 small lesions were made, and the rest of the sites had no lesions. The detection rates for areas with large lesions and areas with no lesions were 100% between the examiners. However, of the 33 small lesions, each examiner was able to identify 32 of them with the 360° scans: a 97.4% detection rate when compared with the gold standard. With the 180° scan, 94.9% of the small lesions were detected when compared with the gold standard, and 96.9% were detected with the 360° scan. The overall interexaminer reliability was over 90% for both imaging protocols (Cronbach's alpha, 92.4% for 180° and 97% for 360°). CONCLUSIONS: Based on the results of this study, the 180° CBCT acquisition protocol can detect small and large arthritic lesions with high reliability and is comparable with the 360° spin acquisition.

Evaluation of alveolar bone dimensions in unilateral palatally impacted canine: a cone-beam computed tomographic analyses.

INTRODUCTION: The purpose of this study was to evaluate the alveolar bone dimensions and arch perimeter discrepancy in unilateral palatally impacted canines. METHODS: This retrospective split-mouth study reviewed 207 cone-beam computed tomography (CBCT) scans of patients with unilateral or bilateral impacted canines referred for orthodontic treatment. Out of 207 CBCT scans, only 39 scans in which canines were unilaterally palatally impacted were approved for the study based on our inclusion and exclusion criteria. Two fiducial lines were used to orient the examiners and standardize the measurements. Arch perimeter, buccopalatal (BP) width, and alveolar height were measured both on the impacted and non-impacted side. Two different examiners measured all the parameters. A one-sample Kolmogorov-Smirnov test was used to examine normality of distribution of outcomes. Wilcoxon Signed Rank tests were used for comparing arch width and alveolar bone height between the impacted and non-impacted sides. For arch perimeter, the paired-sample t-test was used. RESULTS: The arch perimeter, BP width, and alveolar bone height was significantly decreased on the impacted side (P < 0.05). The mean arch perimeter on the impacted side was 41.7 ± 2.5mm compared to 43.5 ± 2.37 on the non-impacted side. Similarly, BP width and alveolar bone height on the impacted side was 6.87 ± 1.08 mm and 18.12 ± 2.28 mm, respectively, whereas on the non-impacted side was 8.70 ± 1.13 mm and 19.49 ± 2.09 mm, respectively. CONCLUSION: There was a significant decrease in the arch perimeter and alveolar bone dimensions (BP width and alveolar bone height) on the impacted side.

Artifacts in Cone Beam Computed Tomography Image Volumes: An Illustrative Depiction.

INTRODUCTION: The evolution of cone beam computed tomography (CBCT) has brought about a paradigm shift in radiographic evaluation of the maxillofacial skeleton. Because of its low cost, high resolution, and relatively low-radiation dose, CBCT is fast becoming the 3-D imaging modality of choice in dentistry. The ubiquitous availability of this new imaging modality poses unique challenges in understanding this technology and recognizing the associated artifacts that present themselves in the acquired image volumes. There are several artifacts that are inherent to CBCT scans by virtue of the physics behind their acquisition and image reconstruction algorithms. BACKGROUND: An image artifact may be defined as a visualized structure in the reconstructed data that was not originally present in the object or the imaged area of interest. It can be explained as any distortion or error in the image that is unrelated to the subject being studied. Artifacts are induced by discrepancies between the physical conditions of the measuring setup, which is usually the CBCT scanner's technical composition and position of the object under investigation. OBJECTIVE: The objective of this study is to present an illustrative depiction of the most commonly encountered CBCT artifacts with an explanation of how each artifact is caused and how it presents itself in CBCT image volumes. CONCLUSION: Because these artifacts cause significant image degradation and often misrepresent the region of interest, they should be recognized, understood, and taught along with normal CBCT anatomy to facilitate accurate evaluation of the image volumes and prevent inaccurate diagnoses.

Calcification of the stylohyoid ligament in panoramic radiography and cone beam computed tomography among patients referred for dental implant treatment planning.

BACKGROUND: Calcification of the stylohyoid ligament (SHL) is a common condition noted as an incidental finding in routine radiographic examination. Due to proximity with important neurovascular structures, elongation and calcification may sometimes lead to dysphagia and pain. The objective of this study was to evaluate the incidence of calcified SHL detected on cone beam computed tomography (CBCT) scans and panoramic radiographs (PR) in patients referred for dental implant therapy. METHODS: Retrospective analysis of 30 patients referred for dental implants to the Department of Oral and Maxillofacial Radiology at the University of Connecticut School of Dental Medicine was done. Patients were imaged using Hitachi CB MercuRay CBCT machine, and PRs were obtained using Planmeca panoramic machine. CBCT reconstructions and panoramic images were evaluated for the incidence and pattern of SHL calcification. RESULTS: Nineteen patients (63.3%) had calcified SHLs, 16 of whom were reported to have bilateral involvement. PR was unable to show complete calcification of the ligament in any of the cases, whereas CBCT showed evidence of complete calcification when present (14 cases). CONCLUSION: CBCT was more accurate in determining the pattern and extent of calcification of the SHL in patients undergoing implant treatment planning.

The Utility of Cone Beam Computed Tomography Scans in Diagnosing and Treating Anterior Lesions of the Maxilla and Mandible.

BACKGROUND: The standard screening protocol for radiographic examination in dentistry as per the American Dental Association recommendations is a panoramic radiograph (PAN) and four horizontal bitewings. PAN inherently suffers from several shortcomings like the superimposition of anatomic structures, especially of the cervical spine that obscures a significant portion of the anterior maxilla and mandible. This region has a significant amount of pathology that is not adequately imaged. Three-dimensional (3D) imaging provides circumferential information on the area of interest and adds value to the diagnosis and treatment planning of pathology, especially in the anterior maxilla and mandible. However, there is not an adequate number of well-designed studies that articulate the true value addition of 3D imaging for the evaluation of this region. OBJECTIVES: The objective of this study is to evaluate the value addition of 3D imaging in diagnosing pathologies in the anterior maxilla and mandible when compared to two-dimensional PAN. MATERIALS AND METHODS: A total of 25 cases that had a diagnosis of anterior pathology and had both a PAN and a cone beam computed tomography (CBCT) scan were collected for this study. An institutional review board approval to retrospectively evaluate these data was obtained. The PAN and CBCT scans were randomly evaluated by a second-year dental student, an oral and maxillofacial radiology resident in training, and a board-certified oral radiologist. The scans were evaluated using a three-point modified Likert scale, where 1 represents "not visible or clear," 2 represents "visible but not clear," and 3 represents "visible and clear." The lesions were evaluated for characteristics like lesion location, size & shape, internal contents, borders of the lesion, cortical integrity, locularity, and effect on adjacent structures like root resorption. After the evaluation was completed, a comparison of the lesion diagnosis was done with histopathology to confirm the diagnosis. The evaluators were also asked to comment on the specific feature that 3D imaging provided that added value to the case. Kappa analysis was done to evaluate inter-operator reliability. RESULTS: PAN demonstrated significantly lower efficacy in identifying and diagnosing lesions. Only 56% of cases were analyzed using PAN, with 44% deemed undetectable or poorly visualized. These challenging cases necessitated CBCT scans for accurate diagnosis, which successfully diagnosed all 25 cases. The p-value of 0.0002 for PAN implies a highly significant difference from histopathology, suggesting the distinctions are not due to chance. Conversely, the p-value of 0.3273 for CBCT implies that observed differences may be random, lacking sufficient evidence to reject the null hypothesis. CBCT scans consistently outperformed PAN in visualizing various lesion characteristics, underscoring their superior diagnostic capabilities. CONCLUSIONS: In this study, with a small sample size, 3D imaging provided a significant value addition to the diagnosis and treatment planning by providing additional information regarding the location, extent, internal content, and effect on adjacent structures. The practical implications for clinical settings, along with comparisons to current literature, underscore the study's distinctiveness.