Determining the reliability of diagnosis and treatment using artificial intelligence software with panoramic radiographs.

Purpose: The objective of this study was to evaluate the accuracy and effectiveness of an artificial intelligence (AI) program in identifying dental conditions using panoramic radiographs (PRs), as well as to assess the appropriateness of its treatment recommendations. Material and Methods: PRs from 100 patients (representing 4497 teeth) with known clinical examination findings were randomly selected from a university database. Three dentomaxillofacial radiologists and the Diagnocat AI software evaluated these PRs. The evaluations were focused on various dental conditions and treatments, including canal filling, caries, cast post and core, dental calculus, fillings, furcation lesions, implants, lack of interproximal tooth contact, open margins, overhangs, periapical lesions, periodontal bone loss, short fillings, voids in root fillings, overfillings, pontics, root fragments, impacted teeth, artificial crowns, missing teeth, and healthy teeth. Results: The AI demonstrated almost perfect agreement (exceeding 0.81) in most of the assessments when compared to the ground truth. The sensitivity was very high (above 0.8) for the evaluation of healthy teeth, artificial crowns, dental calculus, missing teeth, fillings, lack of interproximal contact, periodontal bone loss, and implants. However, the sensitivity was low for the assessment of caries, periapical lesions, pontic voids in the root canal, and overhangs. Conclusion: Despite the limitations of this study, the synthesized data suggest that AI-based decision support systems can serve as a valuable tool in detecting dental conditions, when used with PR for clinical dental applications.

Comparison of the effects of removable functional appliance therapy applied in pubertal and postpubertal periods: A retrospective cephalometric and fractal analyses study.

INTRODUCTION: In this study, we compared the effects of functional treatment with Twin-block appliance on the bony architectures of the maxilla and mandible by fractal dimension (FD) analysis, and the skeletal and dentoalveolar effects by cephalometric analysis, in pubertal and postpubertal patients with Class II malocclusion. METHODS: This study comprised 60 patients who underwent Twin-block treatment. Group 1 consisted of 30 patients in the pubertal period (6 boys and 24 girls; mean age 12.27 ± 1.35 years), whereas group 2 consisted of 30 patients in the postpubertal period (6 boys and 24 girls; mean age 13.73 ± 1.51 years). FD analysis was performed on the patients before and after Twin-block panoramic and lateral cephalometric radiographs. Cephalometric analysis was also conducted. Paired and Student t tests were used to compare the parametric data, and Wilcoxon signed rank and Mann-Whitney U tests were conducted to compare the nonparametric data. RESULTS: SNB, Pg-N, N-Me, ANS-Me, IMPA, L1/NB, Co-Gn, Go-Gn, S-Go, Co-Go, and Go-Me significantly increased in both groups after treatment. FD values of tuber, condyle, and molar regions significantly decreased in group 1, whereas no significant differences were observed in group 2 after treatment. CONCLUSIONS: In the pubertal period, the Twin-block appliance resulted in skeletal correction by causing bone remodeling and reshaping in both jaws along with the dentoalveolar correction. In the postpubertal period, Twin-block had no significant effect on the bone trabecular arrangement in the investigated areas but produced cephalometric improvement to a certain extent with lower skeletal and higher dental impact.

Effects of modified step Le Fort I advancement surgery on nostril area and inferior nasal structures volume in class III patients: a retrospective clinical study.

OBJECTIVE: The effect of the modified step Le Fort I osteotomy on the inferior nasal structures and the nostril area was evaluated. MATERIALS AND METHODS: This study included 24 patients who had modified step Le Fort I osteotomy. Inferior nasal concha volume (INCV), meatus nasi inferior volume (MNIV), the sum of both structures volume (TV), and nostril area (NA) were evaluated in pre- (T0) and postoperative (T1) periods. RESULTS: For all patients, NA increased both on the right side (p = 0.011) and left side (p = 0.050) after surgery. The INCV and TV values were lower in T1 than those in T0; however, a statistically significant decrease of INCV and TV was found only in the right side of males (p = 0.039 and p = 0.050, respectively). No significant difference was found in MNIV between T0 and T1 measurements (p > 0.05). CONCLUSION: Maxillary advancement with the modified step Le Fort I osteotomy technique increased the NA, which may have a positive effect on breathing function. On the other hand, although TV tended to decrease, MNIV did not change after surgery as the same decreasing tendency also existed in INCV. CLINICAL RELEVANCE: Step Le Fort I advancement surgery technique usually affects nasal structures positively regarding the nasal airway.

Evaluation of bony changes observed in mandibular osteotomy lines and mandibular condyles following bilateral sagittal ramus osteotomy by fractal analysis.

OBJECTIVES: This study aimed to evaluate the surgically impacted trabecular changes in mandibular osteotomy lines and mandibular condyles after bilateral sagittal split ramus osteotomy using the fractal analysis method. MATERIALS AND METHOD: The study population consisted of 30 patients (9 male, 21 female) diagnosed with mandibular prognathism and operated with bilateral sagittal split ramus osteotomy under general anesthesia. Fractal analyses observed the alterations on the trabecular structure of osteotomy lines, and mandibular condyles on panoramic radiographs obtained preoperatively, postoperatively, 1st week, 6th month, and 12th month. The box-counting method was used to evaluate the changes in trabecular structure by fractal analysis. P-values of less than 0.05 were considered significant. RESULTS: The fractal dimension values in both osteotomy lines and mandibular condyles were significantly decreased on postoperative 1st week regarding preoperative values. However, fractal dimension values commenced increasing in the following postoperative period. The fractal dimension values of the horizontal and vertical osteotomy lines reached their preoperative values on postoperative 6th and 12th month, respectively. The decreased fractal dimension values observed in the early postoperative period in the right and left condyles reached their preoperative values at the 6th postoperative month. CONCLUSION: Fractal analyses performed postoperatively can provide information about trabecular changes and bone healing of structures such as osteotomy lines directly affected by bilateral sagittal split ramus osteotomy and indirectly affected mandibular condyles. The results support that fractal analysis can be used together with clinical data in the evaluation of bone healing process.

Evaluation´ of mandibular alveolar bone in patients with different vertical facial patterns : A cross-sectional CBCT study.

PURPOSE: The study aimed to investigate the morphological and structural differences of mandibular alveolar bone between different vertical facial patterns (VFP). METHODS: In all, 66 CBCT scans of patients were selected for the study: 24 were designated as hyperdivergent, 25 as normodivergent, and 17 as hypodivergent. Fractal values of the interdental alveolus were measured at the incisor, canine, premolar, and molar regions. The minimum trabecular bone width (MTBW) of the alveolus, the buccal and lingual cortical bone thicknesses, and the total alveolar width (AW) at the minimum trabecular bone level were measured. One-way analysis of variance and Tukey test were used to compare the groups. The correlations between FMA (Frankfurt mandibular plane angle) and other measurements were analyzed by Pearson analysis. RESULTS: No significant differences were detected in fractal values and buccal and lingual cortical bone thicknesses between the groups. The MTBW and AW of the hypodivergent individuals were found to be higher in the anterior and premolar interdental sites. FMA was found to be significantly correlated with MTBW and AW. CONCLUSIONS: The patients with different VFPs did not exhibit significant differences in the trabecular complexity of the mandibular alveolus. Hypodivergent patients tend to have thicker trabecular and alveolar bone widths than normodivergent and hyperdivergent individuals.

Multiple Regression Modeling for Age Estimation by Assessment and Comparison of Spheno-Occipital Synchondrosis Fusion and Cervical Vertebral Maturation Stages.

Objectives The aim of this study was (1) to evaluate the relationship between spheno-occipital synchondrosis (SOS) fusion stages, cervical vertebral maturation (CVM) stages, and clivus sizes with chronological age on cone-beam computed tomography (CBCT) images, and (2) to compare these methods for accurate age estimation using regression analysis. Methods The CBCT images of 200 individuals (102 females and 98 males) were included in the study. The SOS fusion stages and CVM stages were evaluated. The width and length of the clivus were measured. The effects of SOS fusion stages, CVM stages, clivus width, and clivus length on age estimation were evaluated by univariate tests and the effects of coexistence with ANCOVA and regression model. Spearman rank correlation analysis was also used to investigate the relationship between the SOS fusion stage, CVM stage, clivus width, and clivus length. Results The SOS stages, CVM stages, and clivus width were not shown statistically significant differences between the sexes ( p -values = 0.205, 0.162, and 0.277, respectively), whereas clivus length was significantly longer in males (42.9 ± 4.26 mm) than in females (41.04 ± 3.74 mm). Multiple regression analysis showed 80% success when all parameters (SOS fusion stages, CVM stages, clivus width, and clivus length) were taken into consideration. Conclusion In conclusion, with the use of CVM stages and SOS fusion stages together, an accurate and reliable age estimation can be obtained in forensic medicine.

Three-dimensional verification of the radiographic visibility of the root pulp used for forensic age estimation in mandibular third molars.

OBJECTIVES: The aim of this study was to assess the reliability of panoramic radiography (OPG) using age estimation method using cone beam computed tomography (CBCT) verification in the evaluation of radiographic visibility of root pulp (RPV) of mandibular third molars for age estimation. METHODS: CBCT and OPG images of 429 mandibular third molars from 290 patients were evaluated. RPV of fully mineralized mandibular third molars was evaluated as stages 0, 1, 2, and 3 for both imaging methods. Descriptive statistics were performed separately for stages by age for both genders. The consistency of these scores with chronological age was evaluated for both imaging methods. The reliability of OPG evaluation was also analyzed with CBCT scores.Results Spearman's rho correlation demonstrated a positive correlation between RPV and chronological age for both genders and for OPG and CBCT evaluation. Considering the minimum ages of both imaging methods, all stages were above the age of 18 except for the female group of Stage 2 and all Stage 0. For the comparison of OPG and CBCT RPV Staging scores, the κ score was found to be 0.312 (p < 0.001), indicating a fair agreement. CONCLUSION: In conclusion, the absence of Stage 3 at age of 18 and under might have a forensic value for RPV age estimation method. Considering the fair agreement in the verification of OPG scores, it is not possible to determine the exact age with the RPV detected in OPG images, the use of CBCT for the RPV evaluation is recommended to available cases.

Evaluation of different Apexification treatments of teeth with immature apices and apical periodontitis on the fractal dimensions of trabecular bone.

The aim of the present study was to investigate in the fractal dimension (FD) time-dependent changes of periapical bone after two different apexification treatments in teeth with immature apices and apical periodontitis. This study included 55 cases treated with apexification. Cases were divided into two groups: a calcium hydroxide group and a mineral trioxide aggregate group. In each case, the lesion area was evaluated by fractal analysis on periapical radiographs obtained before and 1-year after treatment via Image-J program. The FD of each region of interest on the radiographs was calculated using the fractal analysis method. The data were statistically analysed. In both groups, the FD values increased compare to initial at 1-year follow-up after treatment (P < .05). There was no statistically significant difference between the groups in terms of the time-dependent increase in FD values (P = 0.118). In the present study, time-dependent changes in FD were independent of the apexification method.

Determination of alveolar bone height according to the relationship between molar teeth and maxillary sinus.

PURPOSE: This study aims to analyze alveolar bone height (ABH) in the maxillary molar area according to the anatomical relationship between maxillary sinus and maxillary molar teeth via cone beam computed tomography images. METHODS: In 330 patients, 660 maxillary first molar (M1) and 648 maxillary second molar (M2) were evaluated. ABH measurements were made as to the shortest distance between the furcation midpoints of maxillary molars and the lowest point of the sinus floor. After the measurement, the positions of the maxillary molar teeth relative to the maxillary sinus were classified into four categories as type 1, 2, 3, and 4. RESULTS: ABH measurements in males were significantly higher than females (p < 0.05), but there were no differences between sides (p > 0.05). There were significant differences between types of both M1 and M2 for ABH, and the longest ABH was measured in type 1 (p < 0.05). Type 3 was the most common among 1308 maxillary molars teeth followed by type 1, type 2, and type 4. CONCLUSION: Determination of the relationship between maxillary molar teeth and the maxillary sinus and analysis of ABH according to this relationship may help plan endodontic treatment, apical surgery, and immediate implant therapy and prevent their complications.

Evaluating the effects of functional orthodontic treatment on mandibular osseous structure using fractal dimension analysis of dental panoramic radiographs.

OBJECTIVE: To evaluate the effects of functional appliance treatment on mandibular trabecular structure using fractal dimension (FD) analysis of dental panoramic radiographs. MATERIALS AND METHODS: This study was conducted using digital panoramic radiographs of 45 patients with Class II malocclusion treated with functional appliances (treatment group, mean age: 11.39 ± 0.97 years; 23 girls, 22 boys) acquired before (T0) and after (T1) treatment and the panoramic radiographs of 45 control subjects who had undergone no orthodontic treatment (control group, mean age: 11.31 ± 0.87 years; 23 girls, 22 boys). FD values in the condylar process, mandibular corpus, and mandibular angle were analyzed from the panoramic radiographs of both groups. RESULTS: Analysis of changes in FD between T0 and T1 revealed significant increases in the FD values of the right and left condylar processes and right mandibular corpus in the treatment group (P < .001) and in the right condylar process in the control group (P < .05). Between-group comparisons demonstrated that the treatment group showed greater changes in the condylar process (right, P < .001; left, P < .05) and right mandibular corpus (P < .05) compared to controls. Correlation analysis between the cephalometric and FD changes in the treatment group showed the right condylar process changes were negatively correlated with GoGn/SN angle (P < .05) and positively correlated with Co-Go (P < .05), although these correlations were weak. CONCLUSIONS: FD analysis demonstrated significant changes in trabeculation of the condyle and mandibular corpus in the treatment group compared to the control group. Functional appliance treatment may lead to skeletal correction by altering skeletal form and trabeculation of the mandibular bone.

Contrast-to-noise ratios of different dental restorative materials: an in-vitro cone beam computed tomography study.

PURPOSE: In radiological views, strong beam hardening and streaking artifacts occur due to high-density structures and polyenergetic X-ray beams, and these lead to misdiagnosis. This study was performed in vitro to compare the contrast-to-noise ratio (CNR) of commonly used dental restorative materials by using Cone Beam Computed Tomography (CBCT) images with and without artifact reduction (AR) mode. MATERIALS AND METHODS: A total of 108 molar teeth were restored with nine different groups of restorative materials, with each group containing 12 teeth. Teeth were placed in a dry human mandible and scanned, one by one, via Planmeca 3D ProMax (Planmeca, Helsinki, Finland) with and without AR mode. Images were analyzed using ImageJ software (National Institutes of Health, Bethesda, MD) to calculate the CNR. RESULTS: CNR was calculated to be the highest in compomer (Glassiosite) images without AR mode (mean: 3.36) and with AR mode (mean: 3.61). CNR was calculated to be the lowest in amalgam (Tytin) images without AR mode (mean: 0.21) and with AR mode (mean: 0.23). A significant difference was found between materials in terms of CNR measurements (p ≤ 0.05). CNR measurements were increased after the AR mode application (p ≤ 0.05). CONCLUSION: AR mode was effective in reducing artifacts arising from dental materials on CBCT images, so it is necessary to use AR mode for correct diagnoses.

Assessment of Maxillary Sinus Changes After Le Fort I Osteotomy Surgery.

OBJECTIVE: The goal of this retrospective study is to examine the changes of maxillary sinus volume, sinus membrane thickness (SMT) and the distance between the floor of maxillary sinus and ostium after Le Fort I osteotomy. METHODS: A total of 30 patients who underwent Le Fort I osteotomy were evaluated just before and 1 year after the surgical operation. Linear and volumetric measurements were done via 3D-DOCTOR software on sectional and 3D images. RESULTS: Decrease in maxillary sinus volume, increase in SMT and no change in distance between the floor of the maxillary sinus and ostium were detected after surgery. After surgery, SMT was found higher in advancement + impaction group. CONCLUSION: This paper clarified that Le Fort I osteotomy affects the volume and thickness of the maxillary sinuses that may lead to deterioration of the ciliary activity and failure in the drainage which are predisposing factors for sinus pathologies. In maxillary osteotomies of later ages, maxillary sinus examination and follow-up should be performed regularly in order to maintain sinus health.

Prediction of rapid palatal expansion success via fractal analysis in hand-wrist radiographs.

INTRODUCTION: This study aimed to evaluate the efficacy of fractal analysis of hand-wrist radiography in the decision of conventional or surgery-assisted rapid palatal expansion (RPE). METHODS: The study included 48 patients who underwent the RPE procedure. Study groups were as follows: group 1 (successful conventional RPE [n = 24, 5 male and 19 female patients; mean age ± standard deviation, 15.85 ± 0.97 years]) and group 2 (failed conventional RPE [n = 24, 5 male and 19 female patients; mean age ± standard deviation, 15.96 ± 1.08 years]). Fractal dimension (FD) analysis was conducted on hand-wrist radiographs of the patients for 4 different regions: the epiphysis-diaphysis line of the radius bone and the proximal, medial (MP3), and distal (DP3) phalanxes of the middle finger. A Student t test was performed to compare fractal values between the groups. A receiver operating characteristic analysis was applied to determine the optimal cutoff value of FDs. In addition, a Pearson correlation coefficient was calculated to evaluate the relationship between the fractal values and either age or hand-wrist stage in a second sample group (n = 90; age range, 8.7-18.7 years). RESULTS: Fractal values of the radius, MP3, and DP3 were significantly increased in the failed conventional RPE group (P <0.05). The optimal cutoff value of the FD for predicting the success of conventional RPE was 1.16 in the radius, 1.18 in proximal phalanxes, 1.29 in MP3, and 1.08 in DP3. There was a positive correlation between fractal values of the radius and age or hand-wrist stages (P <0.05). CONCLUSIONS: Within the limits of this study, results revealed that fractal analysis of hand-wrist radiographs might be considered a significant tool in the prediction of RPE success.

Evaluation of a metal artifact reduction algorithm and an optimization filter in the estimation of peri-implant dehiscence defects by using cone beam computed tomography: an in-vitro study.

OBJECTIVES: The aim of this study was to assess the effect of a metal artifact reduction (MAR) algorithm and the adaptive image noise optimizer (AINO) optimization filter in the detection of peri-implant dehiscences with cone beam computed tomography (CBCT). STUDY DESIGN: Nine implants (3 zirconium, 3 titanium, and 3 zirconium-titanium) were placed in 3 sheep heads. Dehiscences were created on the buccal and lingual/palatal surfaces. A total of 9 defects and 9 controls with no defects were evaluated by 3 observers. Each sheep head was scanned 5 times with 4 scan modes; (1) without MAR/without AINO; (2) with MAR/without AINO; (3) without MAR/with AINO; and (4) with MAR/with AINO. Receiver operating characteristic analysis and weighted kappa coefficients were used to calculate diagnostic efficacy and intra- and interobserver agreements for each implant type and scan mode. RESULTS: For all implant types, dehiscences were most accurately detected when both MAR and AINO were applied (P ≤ .045). Detection of dehiscences was more accurate with titanium implants (P ≤ .040). There were no significant differences in agreement among and between the observers. CONCLUSIONS: The use of both MAR and AINO enhanced the detection accuracy of artificially created dehiscences in proximity to implants. Their combined use is recommended for detecting peri-implant dehiscences.

Evaluation of the Relationship Between Olfactory Fossa Measurements and Nasal Septum Deviation for Endoscopic Sinus Surgery.

INTRODUCTION: Endoscopic sinus surgeries (ESS) are frequently used in the treatment of optic nerve decompression, other intracranial lesions and sinonasal pathologies. The olfactory fossa can be localized on different levels in relation to the anterior cranial fossa. The aim of the present study was to evaluate the depth and width of the olfactory fossa (OF) in relation to nasal septum deviation (NSD). METHODS: A total of 225 patient (141 female and 84 male, age range between 15 to 56 years) of cone beam computed tomography (CBCT) data was used in this study. NSD, OF width, OF depth were measured. OF depth which was grouped according to the Keros classification as Type I, II, and III was calculated. All measurements were performed bilaterally except for NSD. RESULTS: In the right and left OF depth were found Keros Type I 32 (14.2%) and 30 (13.3%), Keros Type II 171 (76%) and 167 (74.2%), and Keros Type III 22 (9.8%) and 28 (12.4%) respectively. There was no statistically significant found between OF depth and NSD (P > 0.05). The mean angle of the NSD in men and women were 4.36 ±â€Š4.69 in women 4.11 ±â€Š4.36, respectively. The mean width of the right OF was 2.50 ±â€Š0.64 mm and 2.58 ±â€Š0.72 mm for the left side and there was no statistically significant association between OF width - NSD and OF width - OF depth (P > 0.05). CONCLUSION: The anatomy of the OF should be well established before surgical intervention increase of the length of the lateral lamella is also increases the risk of developing complications such as cerebral damage, hemorrhage, and cerebrospinal fluid fistula during endoscopic sinus surgery. Although there is no significant difference between OF measurement and NSD, with three-dimensional imaging detailed research is required before endoscopic sinus surgical operations.

Relationship between condyle cortication, sphenooccipital synchondrosis, and chronological age.

OBJECTIVE: To assess the relationship between chronologic age, mandibular condyle cortication, and sphenooccipital synchondrosis (SOS) fusion. METHODS: Cone Beam Computed Tomography data of 253 patients were retrospectively evaluated. Mandibular condyle cortication was divided into three classes as Types I, II, and III. SOS fusion grade was categorized using a four-stage system (0-3). These variables were evaluated in relation to age and sex. RESULTS: There were significant positive relationships between age and condyle cortication, and between age and SOS fusion stage and between cortication type and SOS fusion stage. CONCLUSION: Due to the positive correlation between the degree of SOS fusion stage, the condyle cortication type, and the chronological age, these indicators can be used for age estimation.

Evaluation of sphenoid sinus variations by using cone beam computed tomography in patients with cleft lip/palate.

OBJECTIVE: The purpose of this study is to evaluate the sphenoid sinus variations in patients with cleft lip/palate. METHODS: Sixty three (63) patient's cone beam computed tomography (CBCT) images, taken from the head and neck region, were evaluated. Images were divided into two groups; [Group 1; patients with cleft lip/palate (CLP Group) (n = 23) Group 2; patients without cleft lip/palate (control group) (n = 40)]. The main pneumatization types (conchal, sellar, and presellar) of sphenoid sinuses were assessed on sagittal sections of the CBCT images. The sphenoid body, lateral and lesserwing types were evaluated on coronal sections and anterior type pneumatization was evaluated on axial sections. RESULTS: The mean age ranged from 12 to 26 (16.57 ± 4.46) in Group 1 and 12 to 25 (16.58 ± 3.71) in Group 2. In both groups, the male and female distribution was found similar (P = 0.342). The sellar type was the most common pneumatization type of sphenoid sinus both for the Group 1 (91.3%) and Group 2 (80%). Any statistically significant difference was not found between the two groups in terms of the incidence of pneumatization types. Combined type pneumatization was detected in 65.6% of the Control group and 76.2% of the CLP group. CONCLUSIONS: In this study, the prevalence of sphenoid sinus pneumatization types in CLP patients was compared with the normal population. Any significant difference was not determined in the two groups.

Evaluation of osseous changes in dental panoramic radiography of thalassemia patients using mandibular indexes and fractal size analysis.

OBJECTIVE: This study aimed to evaluate the radiomorphometric indexes and fractal dimension (FD) on dental panoramic radiography (DPR) of Thalassemia Major (TM) patients. METHODS: In 59 TM patients and in 59 healthy control subjects, mandibular cortical index (MCI), mandibular cortical width (MCW), panoramic mandibular index (PMI), and FD of four different regions (FD1-4) were evaluated and compared using DPRs. RESULTS: The distribution of MCI in TM patients was similar to control subjects (p > 0.05). The mean MCW was significantly lower in TM patients (p = 0.001). There was no significant difference in PMI between TM patients and control subjects. The mean of FD measured in the supracortical area above the angle of mandible (FD2), in the anterior to the mental foramen (FD4) and mean FD of four different regions was significantly lower in TM patients (p = 0.003, p = 0.001, and p = 0.014, respectively). CONCLUSIONS: The radiomorphometric indices and fractal dimensions evaluated in the panoramic radiograph are capable of identifying thalassemia patients' jaw bone, and the results of DPR scanning can be used to refer these patients to appropriate medical investigation.

Assessment of signal-to-noise ratio and contrast-to-noise ratio in 3 T magnetic resonance imaging in the presence of zirconium, titanium, and titanium-zirconium alloy implants.

OBJECTIVE: We quantitatively compared the signal-to-noise ratio (SNR) and contrast-to-noise ratio (CNR) in T1 weighted imaging (WI) and T2 WI sequences in 3 Tesla (T) magnetic resonance imaging (MRI) using zirconium, titanium (grades 4 and 5), and titanium-zirconium alloy implants to evaluate the effect of implant type and imaging sequence. STUDY DESIGN: MRI was acquired using a 3 T magnet with a 16-channel head coil. Implants of each type were mounted in gel and scanned in axial, coronal, and sagittal planes using fast spin echo sequences in T1 WI (TR = 600, TE = 12 milliseconds) and T2 WI (TR = 3000, TE = 80 milliseconds) sequences. Data were transferred to Synapse 3-D software, and images were measured twice by an oral and maxillofacial radiologist blinded to the type of implants. RESULTS: Zirconium implants resulted in the lowest SNR and CNR values (P < .05). No significant differences were identified between titanium (grades 4 and 5) and titanium-zirconium implants. The T2 WI sequence had a significantly higher SNR and CNR than T1 WI. There was no difference in intraobserver agreement between T1 WI and T2 WI. CONCLUSIONS: CNR and SNR at 3 T MRI are dependent on implant type and imaging sequence. Titanium (grades 4 and 5) and titanium-zirconium implants and the T2 WI sequence produced higher SNR and CNR values.

Estimation of contrast-to-noise ratio in CT and CBCT images with varying scan settings in presence of different implant materials.

OBJECTIVES: To assess the contrast-to-noise ratio (CNR) of four different types of dental implant materials in CT and cone beam CT (CBCT) images with varying scan settings. METHODS: Four different types of implants: zirconium (Zr), titanium (Ti) Grade 4 and 5 and titanium-zirconium (Ti-ZrO2) alloy were placed in a 3% gelatin phantom in a cylindrical plastic container and scanned with two different CT machines (GE Medical systems and Toshiba Medical Systems) and one CBCT machine (I-CAT, Imaging Sciences International) with different voxel sizes of 0.2, 0.25, 0.3 and 0.4 mm. Images were analyzed using ImageJ software with the purpose of estimating the CNR. RESULTS: The CNR obtained from images acquired with CT was lower than the CBCT with all voxel sizes tested. 0.3 and 0.4 mm voxel sizes exhibited the highest CNR (p < 0.05) that gives the best image quality. Among the implant materials tested, titanium Grade 5 has the highest levels of CNR while Zirconium has the lowest (p < 0.05). CONCLUSIONS: The optimum protocol for radiographic follow-up in areas near implants on the I-CAT is low-resolution settings (0.3 and 0.4 mm voxel sizes) which gave the highest CNR thus image quality. In presence of Zr implants, an alternative imaging modality (i.e., MRI) may be considered to avoid low-quality images.