Differential diagnosis of cemento-osseous dysplasia and periapical cyst using texture analysis of CBCT.

BACKGROUND: Radiolucencies found at the root apex in patients with cemento-osseous dysplasia (COD) may be mistaken for periapical cysts (PC) of endodontic origin. The purpose of this study was to examine the utility of quantitative texture analysis using cone-beam computed tomography (CBCT) to differentiate between COD and PC. METHODS: Patients who underwent CBCT at Wonkwang University Daejeon Dental Hospital between January 2019 and December 2022 and were diagnosed with COD and PC by clinical, radiologic, and, if necessary, histopathologic examination were included. Twenty-five patients each were retrospectively enrolled in the COD and PC group. All lesions observed on axial CBCT images were manually segmented using the open-access software MaZda version 4.6 to establish the regions of interest, which were then subjected to texture analysis. Among the 279 texture features obtained, 10 texture features with the highest Fisher coefficients were selected. Statistical analysis was performed using the Mann-Whitney U-test, Welch's t-test, or Student's t-test. Texture features that showed significant differences were subjected to receiver operating characteristics (ROC) curve analysis to evaluate the differential diagnostic ability of COD and PC. RESULTS: The COD group consisted of 22 men and 3 women, while the PC group consisted of 14 men and 11 women, showing a significant difference between the two groups in terms of sex (p=0.003). The 10 selected texture features belonged to the gray level co-occurrence matrix and included the sum of average, sum of entropy, entropy, and difference of entropy. All 10 selected texture features showed statistically significant differences (p<0.05) when comparing patients with COD (n=25) versus those with PC (n=25), osteolytic-stage COD (n=11) versus PC (n=25), and osteolytic-stage COD (n=11) versus cementoblastic-stage COD (n=14). ROC curve analysis to determine the ability to differentiate between COD and PC showed a high area under the curve ranging from 0.96 to 0.98. CONCLUSION: Texture analysis of CBCT images has shown good diagnostic value in the differential diagnosis of COD and PC, which can help prevent unnecessary endodontic treatment, invasive biopsy, or surgical intervention associated with increased risk of infection.

Assessment of the correlation between supracrestal gingival tissue dimensions and other periodontal phenotypes components via the digital registration method: a cross­sectional study in a Chinese population.

BACKGROUND: Supracrestal gingival tissue dimensions (SGTDs) has been considered to be an essential element of periodontal phenotype (PP) components. This study aimed to explore the relationship between SGTDs and other PP components by digital superposition method that integrated cone beam computed tomography (CBCT) with intraoral scanning. METHODS: This cross-sectional study was conducted at the Stomatology Hospital of Fujian Medical University. Participants were recruited based on the inclusion and exclusion criteria. The data obtained from the digital scanner (TRIOS 3, 3Shape, Denmark) and CBCT images were imported into the TRIOS software (Implant Studio, 3Shape, Denmark) for computing relevant parameters. The significant level was set at 0.05. RESULTS: A total of 83 participants with 498 maxillary anterior teeth were finally included. The mean values of supracrestal gingival height (SGH) and the distance from the cementoenamel junction (CEJ) to the crest of the alveolar ridge (CEJ-ABC) on the buccal site were significantly higher than palatal SGH (SGH-p) and palatal CEJ-ABC (CEJ-ABC-p). Men exhibited taller CEJ-ABC and SGH-p than women. Additionally, tooth type was significantly associated with the SGH, SGH-p and CEJ-ABC-p. Taller SGH was associated with wider crown, smaller papilla height (PH), flatter gingival margin, thicker bone thickness (BT) and gingival thickness (GT) at CEJ, the alveolar bone crest (ABC), and 2 mm apical to the ABC. Smaller SGH-p displayed thicker BT and GT at CEJ, the ABC, and 2 and 4 mm apical to the ABC. Higher CEJ-ABC showed lower interproximal bone height, smaller PH, flatter gingival margin, thinner GT and BT at CEJ, and 2 mm apical to the ABC. Smaller CEJ-ABC-p displayed thicker BT at CEJ and 2 and 4 mm apical to the ABC. On the buccal, thicker GT was correlated with thicker BT at 2 and 4 mm below the ABC. CONCLUSION: SGTDs exhibited a correlation with other PP components, especially crown shape, gingival margin and interdental PH. The relationship between SGTDs and gingival and bone phenotypes depended on the apico-coronal level evaluated. TRIAL REGISTRATION: This study was approved by the Biomedical Research Ethics Committee of Stomatology Hospital of Fujian Medical University (approval no. 2023-24).

Site selection of micro-implant anchorages in the infrazygomatic crest in adult orthodontic patients.

OBJECTIVES: To determine the optimal placement of miniscrews, this study compared adult male and female patients in terms of cortical bone density, cortical bone thickness, and available bone width in the infrazygomatic crest region. METHODS: The cone beam computed tomography imaging data of 200 patients (20-30 years old; 100 males and 100 females) were collected. The right maxillary posterior teeth in the sagittal plane were divided into six levels from proximal to distal, and three measurement sites were positioned at vertical distances of 8, 10, and 12 mm from the cementum. Cortical bone density, cortical bone thickness, and available bone width were measured in 18 measurement sites in the infrazygomatic crest and analyzed statistically. RESULTS: The highest cortical bone density, cortical bone thickness, and available bone width in the infrazygomatic crest in adult male and female patients were at the level of the interradicular space between the maxillary second premolar and maxillary first molar. The bone cortical density and thickness increased with vertical height, whereas the available bone width decreased with increasing vertical height. Differences were observed in cortical bone density, cortical bone thickness, and available bone width between adult male and female patients. CONCLUSIONS: The optimal implantation sites of the micro-implant anchorages in the infrazygomatic crest were at the level of the interradicular space between the maxillary second premolar and the maxillary first molar, and the vertical height of the optimal implantation site in males was appropriately higher than that in females.

Biomechanical behavior of three maxillary expanders in cleft lip and palate: a finite element study.

This study evaluated the stress distribution in the dentoalveolar and palatal bone structures during maxillary expansion in a 17-year-old male patient with bilateral cleft lip and palate (BCLP) using expanders with dental (HYRAX) and skeletal anchorage (MARPE). For the generation of the specific finite element models, cone-beam computed tomography was used, and the DICOM files were exported to Mimics 3-Matic (Materialise) and Patran (MSC Software) software. Three specific three-dimensional models were generated: A) HYRAX: conventional four-banded hyrax screw (9 mm); B) MARPE-DS: 3 miniscrews (1.8 mm diameter - 5.4 mm length) and four-banded dental anchorage; and C) MARPE-NoDS: 3 miniscrews without dental anchorage. Maxillary expansion was simulated by activating the expanders transversely 1 mm on the "X" axis. HYRAX resulted in higher levels of deformation predominantly in the dentoalveolar region. MARPE-DS showed stress in the dentoalveolar region and mainly in the center of the palatal region, at approximately 4,000 µÎµ. MARPE-NoDS exhibited evident stress only in the palatal region. High stress levels in the root anchoring teeth were observed for HYRAX and MARPE-DS. In contrast, MARPE-NoDS cause stress on the tooth structure. The stress distribution from the expanders used in the BLCP showed asymmetric expansive behavior. During the initial activation phase of expansion, the HYRAX and MARPE-DS models produced similarly high strain at the dentoalveolar structures and upper posterior teeth displacement. The MARPE-NoDS model showed restricted strain on the palate.

Comparison of temporomandibular joints in relation to ages and vertical facial types in skeletal class II female patients: a multiple-cross-sectional study.

BACKGROUND: The temporomandibular joint (TMJ) is closely related to the dynamic balance and stability of mandibular function and orthodontic treatment. Skeletal class II female patients are thought to be at high risk for TMJ disease. The relationship between the TMJ and craniofacial structures is still controversial. This study compared the morphology and position of the TMJ in skeletal class II adolescents and adults with various vertical facial types using cone-beam computed tomography (CBCT). MATERIALS AND METHODS: A total of 117 skeletal class II patients were divided into three groups according to the FH-GoGn angle (hypodivergent, normodivergent and hyperdivergent), with 40 class I normodivergent patients serving as controls. Each group contained two age subgroups (adolescents: 11-14 years old, adults: 18-35 years old). The size (condylar length, height, long and short axis diameter, glenoid fossa width and depth) and shape (condylar neck inclination, condylar head angle and long axis angle, articular eminence inclination) of the condyle and fossa, joint space (anterior, superior, posterior, mesial and lateral), and position of the fossa (vertical, transverse, and anteroposterior distance) and condyle were measured and compared using CBCT. RESULTS: Class II hypodivergent patients exhibited the greatest condylar length, height, and long- and short-axis diameter; steepest articular eminence; deepest fossa depth; largest superior, mesial and lateral joint spaces; and highest fossa position in both age groups. The manifestations of class II hyperdivergent patients were mostly the opposite. In adults, except for the condylar long axis angle, the measurements of the condyle increased differently among skeletal patterns, while the measurements of the fossa decreased, as the joint spaces and fossa position remained approximately stable compared with those in adolescents. CONCLUSION: The vertical skeletal pattern, rather than the class II sagittal skeletal pattern, may be the main factor affecting the morphology and position of the TMJ. Attention should be given to the TMJ area in hyperdivergent patients with a relatively poor-fit condyle-fossa relationship. The changes in the TMJ with age were mainly morphological rather than positional and varied with skeletal pattern.

Assessment of maximal inspiratory and expiratory pressures in skeletal Class II patients with different growth patterns.

OBJECTIVES: To evaluate maximal inspiratory (MIP) and expiratory (MEP) pressures, which are reflective of respiratory muscle strength, in skeletal Class II patients with different growth patterns (horizontal, average, and vertical) and to correlate those with airway dimension. MATERIALS AND METHODS: Patients with a Class II skeletal base seeking orthodontic treatment were assigned to the following groups: average, horizontal, and vertical growth pattern. The control group (n = 14) comprised patients with a Class I skeletal base and average growth pattern. Airway dimensions were obtained using cone-beam computed tomography scans, and a spirometer with a pressure transducer was used for assessment of MIP and MEP. Routine spirometry for assessment of lung function was also performed. RESULTS: No significant differences were found in maximal inspiratory and expiratory pressures for the study groups in comparison with the control group. Class I patients had significantly greater oropharyngeal and nasopharyngeal airway volumes compared with the study groups. No significant difference in minimal cross-section area of the airway was observed among groups. A weak positive correlation between maximal inspiratory pressure and airway volume was observed. CONCLUSIONS: Although Class I patients displayed significantly greater oropharyngeal and nasopharyngeal airway volumes, there was no significant difference in respiratory muscle strength or airway function between Class II patients with different growth patterns and the Class I control group. The findings underscore the significance of exploring factors beyond craniofacial growth patterns that may contribute to sleep-related breathing disorders.

Pelvic target volume inter-fractional motion during radiotherapy for cervical cancer with daily iterative cone beam computed tomography.

BACKGROUND: Tumor regression and organ movements indicate that a large margin is used to ensure target volume coverage during radiotherapy. This study aimed to quantify inter-fractional movements of the uterus and cervix in patients with cervical cancer undergoing radiotherapy and to evaluate the clinical target volume (CTV) coverage. METHODS: This study analyzed 303 iterative cone beam computed tomography (iCBCT) scans from 15 cervical cancer patients undergoing external beam radiotherapy. CTVs of the uterus (CTV-U) and cervix (CTV-C) contours were delineated based on each iCBCT image. CTV-U encompassed the uterus, while CTV-C included the cervix, vagina, and adjacent parametrial regions. Compared with the planning CTV, the movement of CTV-U and CTV-C in the anterior-posterior, superior-inferior, and lateral directions between iCBCT scans was measured. Uniform expansions were applied to the planning CTV to assess target coverage. RESULTS: The motion (mean ± standard deviation) in the CTV-U position was 8.3 ± 4.1 mm in the left, 9.8 ± 4.4 mm in the right, 12.6 ± 4.0 mm in the anterior, 8.8 ± 5.1 mm in the posterior, 5.7 ± 5.4 mm in the superior, and 3.0 ± 3.2 mm in the inferior direction. The mean CTV-C displacement was 7.3 ± 3.2 mm in the left, 8.6 ± 3.8 mm in the right, 9.0 ± 6.1 mm in the anterior, 8.4 ± 3.6 mm in the posterior, 5.0 ± 5.0 mm in the superior, and 3.0 ± 2.5 mm in the inferior direction. Compared with the other tumor (T) stages, CTV-U and CTV-C motion in stage T1 was larger. A uniform CTV planning treatment volume margin of 15 mm failed to encompass the CTV-U and CTV-C in 11.1% and 2.2% of all fractions, respectively. The mean volume change of CTV-U and CTV-C were 150% and 51%, respectively, compared with the planning CTV. CONCLUSIONS: Movements of the uterine corpus are larger than those of the cervix. The likelihood of missing the CTV is significantly increased due to inter-fractional motion when utilizing traditional planning margins. Early T stage may require larger margins. Personal radiotherapy margining is needed to improve treatment accuracy.

Innovations in Orthodontics: Skeletal Versus Dentoalveolar Expansion Utilizing Clear Aligners and TAD-Assisted Expanders.

Hypoplastic maxilla is a common skeletal anomaly that compromises function and esthetics. Beyond just a narrow-appearing smile, this abnormality presents significant restorative challenges in adult patients as it is often associated with crowding, compromised axial inclination of the teeth, lack of alveolar bone support, root proximity, and occlusal trauma.1 Recent research also confirms association of maxillary deficiency with nasal stenosis and a predisposition to compromised nasal airflow and pharyngeal collapse during sleep.2,3 Maxillary transverse skeletal deficiency is often but not always associated with posterior dental cross-bite. In most cases, maxillary posterior teeth are flared buccally and mandibular posterior teeth are excessively lingually inclined masking the underlying skeletal problem.4 Advances in 3D imaging in dentistry, namely ultra-low radiation cone-beam imaging technology, have significantly enhanced clinicians' ability to diagnose and subsequently treat a maxillary transverse deficiency.5.

Influence of augmented reality technique on the accuracy of autotransplanted teeth in surgically created sockets.

BACKGROUND: The objective of the present study was to evaluate the reliability of an augmented reality drilling approach and a freehand drilling technique for the autotransplantation of single-rooted teeth. MATERIALS AND METHODS: Forty samples were assigned to the following surgical techniques for drilling guidance of the artificial sockets: A. augmented reality technique (AR) (n = 20) and B. conventional free-hand technique (FT) (n = 20). Then, two models with 10 teeth each were submitted to a preoperative cone-beam computed tomography (CBCT) scan and a digital impression by a 3D intraoral scan. Afterwards, the autotrasplanted teeth were planned in a 3D dental implant planning software and transferred to the augmented reality device. Then, a postoperative CBCT scan was performed. Data sets from postoperative CBCT scans were aligned to the planning in the 3D implant planning software to analize the coronal, apical and angular deviations. Student's t-test and Mann-Whitney non-parametric statistical analysis were used to analyze the results. RESULTS: No statistically significant differences were shown at coronal (p = 0.123) and angular (p = 0.340) level; however, apical deviations between AR and FT study groups (p = 0.008) were statistically significant different. CONCLUSION: The augmented reality appliance provides higher accuracy in the positioning of single-root autotransplanted teeth compared to the conventional free-hand technique.

Radiographic assessment of maxillary sinus membrane and lateral wall thickness using cone-beam CT in different facial types in southwestern Saudi Arabia.

The anatomy of the edentulous posterior maxilla and maxillary sinus possess unique challenges in implant dentistry. The purpose of this study was to assess maxillary sinus membrane thickness (MT) and lateral wall thickness (LWT) in different facial index profiles and to describe the clinical implications. A retrospective image analysis of 75 CBCT scans was done, which yielded a total of 150 sinus images. The facial index was calculated as per the formula given in the text and grouped as euryprosopic, mesoprosopic and leptoprosopic. The images obtained were of 36 women (48%) and 39 men (52%), with maximum subjects in 30-39 years age group. MT and LWT were measured at three different points on the radiograph at every 3mm from the base of the sinus floor in premolar and molar regions of each image. Results showed females had significant differences from males in LWT in both premolar and molar regions (p = 0.018 and 0.032 respectively). Subjects in 40-49 years of age had significant differences (p = 0.021) in MT in premolar region only. Also, difference in MT in premolar and molar regions were also statistically significant. Lastly, the present study did not find any statistically significant difference in MT and LWT in all three facial indices groups. It can be concluded that different facial indices have no positive correlation with maxillary sinus membrane thickness and lateral wall thickness. Hence, surgical complications are avoidable with proper detailed knowledge and appropriate identification of the anatomic structures characteristic to the maxillary sinus.

3D Digital Modeling of Dental Casts from Their 3D CT Images with Scatter and Beam-Hardening Correction.

Dental 3D modeling plays a pivotal role in digital dentistry, offering precise tools for treatment planning, implant placement, and prosthesis customization. Traditional methods rely on physical plaster casts, which pose challenges in storage, accessibility, and accuracy, fueling interest in digitization using 3D computed tomography (CT) imaging. We introduce a method that can reduce both artifacts simultaneously. To validate the proposed method, we carried out CT scan experiments using plaster dental casts created from dental impressions. After the artifact correction, the CT image quality was greatly improved in terms of image uniformity, contrast-to-noise ratio (CNR), and edge sharpness. We examined the correction effects on the accuracy of the 3D models generated from the CT images. As referenced to the 3D models derived from the optical scan data, the root mean square (RMS) errors were reduced by 8.8~71.7% for three dental casts of different sizes and shapes. Our method offers a solution to challenges posed by artifacts in CT scanning of plaster dental casts, leading to enhanced 3D model accuracy. This advancement holds promise for dental professionals seeking precise digital modeling for diverse applications in dentistry.

Cone-beam computed tomography (CBCT) dose optimization technique and image quality assessment scoring.

INTRODUCTION: Linear accelerator (LINAC) embedded with kV source-imager system is capable to do image-guided radiotherapy. The only disadvantage of cone-beam computed tomography image acquisition during treatment is the extra radiation dose to the patient. The aim of this study is to optimize the CBCT imaging doses likely to be received by the patient undergoing radiotherapy without affecting image quality. MATERIAL AND METHODS: The imaging dose to the patient was estimated on CTDI phantoms. The effect of additional filters of different materials (copper, brass, aluminum of thickness 0.1 mm each) was evaluated to find the optimized dose imaging technique. For the pelvis, a single imaging protocol available on the machine was used, whereas for the head and neck region, two protocols, high-quality head and standard-dose head were used. The image quality was assessed on CATPHAN-504 phantom using Owl CATPHAN® QA online tool. A new term "Image Assessment score" (IAS) was introduced to evaluate the image quality. RESULT: In the pelvis protocol, CBCT imaging doses with an additional 0.1-mm brass, copper, and aluminum filter were measured to be reduced by 7.1%, 4.7%, and 2.5%, respectively, whereas for high-quality head protocol, the dose reduction was 25.4% (with brass filter), 22% (with copper filter), and 3.1% (with aluminum filter). For the standard-dose head protocol, doses were reduced by 7.5%, 2.8%, and 2.1% with additional 0.1-mm brass copper and aluminum filters, respectively. Acceptable image quality was observed with all the filters. CONCLUSION: Although the reconstructed images were found somewhat noisier, they did not affect the purpose of imaging, that is, treatment position verification. It was observed that these extra filters further reduce the imaging dose without much affecting the image quality.

Immediate implant placement in the anterior mandible: a cone beam computed tomography study.

BACKGROUND: The placement of implants into the alveolar socket right after tooth extraction is called immediate implant placement (IIP). This approach has its particularities depending on which region of the jaws is involved. The anterior mandible region is peculiar due to the presence of mandibular incisors, which have the shortest roots among all permanent teeth. PURPOSE: This study aimed to investigate the factors that could be associated with the risk of either cortical bone wall perforation or invasion of the 2 mm secure distance from the surrounding anatomical structures (defined as unsafe implant placement), with IIP in the maxillary aesthetic zone, in a cone-beam computed tomography (CBCT) virtual study. MATERIALS AND METHODS: CBCT exams from 239 eligible subjects were investigated. Implants were virtually placed in two distinct positions: prosthetically-driven (along the long axis of the existing tooth) and bone-driven position (according to the available bone and with regard to nearby anatomical structures). Correlation between several variables was tested, and binary logistic regression analysis in order to assess of the possible associations between covariates and unsafe placement was performed. RESULTS: Safe placing implants was significantly higher for the bone-driven in comparison to the prosthetically-driven position (22.2% vs. 3.3%, respectively), and the 2-mm secure distance from anatomical structures was not possible to respect in the majority of cases (77.6% vs. 82.9%, respectively). Covariates associated with a higher risk of unsafe placement were tooth region (CI in relation to IL and CA), decrease of labial concavity angle (LCA), decrease of mandible basal bone height (MBBH), and decrease in mandibular bone thickness at the tooth apex level (MBT0). CONCLUSION: The possibility of safely placing immediate implants in the anterior mandible is significantly higher for bone-driven than in prosthetically driven position. Presurgical virtual planning with CBCT is a great tool for minimizing the risk of implant unsafe placement with regards to the anatomical conditions in the mandible.

3D evaluation of the maxillary sinus volumes in patients with bilateral cleft lip and palate.

One of the most common congenital anomalies of the head and neck region is a cleft lip and palate. This retrospective case-control research aimed to compare the maxillary sinus volumes in individuals with bilateral cleft lip and palate (BCLP) to a non-cleft control group. The study comprised 72 participants, including 36 patients with BCLP and 36 gender and age-matched control subjects. All topographies were obtained utilizing Cone Beam Computed Tomography (CBCT) for diagnostic purposes, and 3D Dolphin software was utilized for sinus segmentation. Volumetric measurements were taken in cubic millimeters. No significant differences were found between the sex and age distributions of both groups. Additionally, there was no statistically significant difference observed between the BCLP group and the control group on the right and left sides (p > 0.05). However, the mean maxillary sinus volumes of BCLP patients (8014.26 ± 2841.03 mm3) were significantly lower than those of the healthy control group (11,085.21 ± 3146.12 mm3) (p < 0.05). The findings of this study suggest that clinicians should be aware of the lower maxillary sinus volumes in BCLP patients when planning surgical interventions. The utilization of CBCT and sinus segmentation allowed for precise measurement of maxillary sinus volumes, contributing to the existing literature on anatomical variations in BCLP patients.

XTransCT: ultra-fast volumetric CT reconstruction using two orthogonal x-ray projections for image-guided radiation therapy via a transformer network.

Objective.The aim of this study was to reconstruct volumetric computed tomography (CT) images in real-time from ultra-sparse two-dimensional x-ray projections, facilitating easier navigation and positioning during image-guided radiation therapy.Approach.Our approach leverages a voxel-sapce-searching Transformer model to overcome the limitations of conventional CT reconstruction techniques, which require extensive x-ray projections and lead to high radiation doses and equipment constraints.Main results.The proposed XTransCT algorithm demonstrated superior performance in terms of image quality, structural accuracy, and generalizability across different datasets, including a hospital set of 50 patients, the large-scale public LIDC-IDRI dataset, and the LNDb dataset for cross-validation. Notably, the algorithm achieved an approximately 300% improvement in reconstruction speed, with a rate of 44 ms per 3D image reconstruction compared to former 3D convolution-based methods.Significance.The XTransCT architecture has the potential to impact clinical practice by providing high-quality CT images faster and with substantially reduced radiation exposure for patients. The model's generalizability suggests it has the potential applicable in various healthcare settings.

Performance of dental students, orthodontic residents, and orthodontists for classification of midpalatal suture maturation stages on cone-beam computed tomography scans - a preliminary study.

BACKGROUND: Assessment of midpalatal suture maturation on cone-beam computed tomography (CBCT) scans is performed by visual inspection and is therefore subjective. The extent to which the assessment of midpalatal suture maturation is affected by rater experience has not been adequately explored in the existing literature, thus limiting the availability of evidence-based findings. This study compared the outcomes of classification by dental students, orthodontic residents, and orthodontists. METHODS: Three different groups of students, orthodontic residents, and orthodontists evaluated 10 randomly chosen CBCT scans regarding midpalatal suture maturation from a pool of 179 patients (98 female and 81 male patients) aged 8 - 40 years which were previously classified by evaluating CBCT scans. The pool was set as benchmark utilizing midpalatal suture maturation classification by one examiner (OsiriX Lite version 11.0; Pixmeo SARL, Bernex, Switzerland). For assessment of intra-rater reliability of the examiners of each group the randomly chosen subjects were reclassified for midpalatal suture maturation after a wash-out period of two weeks by using the same software. Statistical analysis was performed to evaluate intra- and interrater reliability of the three groups with differing experience level. RESULTS: Groupwise intra-rater reliability assessment between the classification and reclassification was weak for examiners with a low level of experience (k = 0.59). Orthodontists had highest degree of agreement with regard to benchmark classification with an inter-rater reliability to be considered as moderate (k = 0.68). CONCLUSIONS: Assessment of midpalatal suture maturation on CBCT scans appears to be a subjective process and is considerably related to the experience level of the examiner. A high level of clinical experience seems to be favorable but does not necessarily ensure accurate results.

Outcome of nonsurgical management of large cyst-like periapical lesions using a modified apical negative pressure irrigation system: a case series study.

OBJECTIVE: To assess the effectiveness of a self-constructed modified apical negative pressure irrigation (ANPI) system employing commonly used clinical instruments in nonsurgical root canal therapy (NSRCT) for large cyst-like periapical lesions (LCPLs). METHODS: From 2017 to 2022, 35 patients diagnosed with LCPLs (5-15 mm) via preoperative clinical and radiographic evaluations of endodontic origin underwent NSRCT combined with ANPI. These patients were subjected to postoperative clinical and radiographic follow-up at 3 months, 6 months, 1 year, 2 years, 3 years, and 4 years, with a CBCT scan specifically conducted at 6-month follow-up. Through the reconstruction of three-dimensional cone beam computed tomography (CBCT) data, an early prognosis was facilitated by monitoring changes in lesion volume. Various treatment predictors-including sex, type of treatment, lesion size, preoperative pain, jaw, type of teeth involved, sealer extrusion, and the number of root canals-were meticulously analyzed. The evaluation of post-treatment outcomes leveraged both clinical observations and radiographic data collected during the follow-up periods. The Kruskal‒Wallis test and one-way ANOVA were also conducted to determine the independent factors influencing treatment outcomes. A significance level of 5% was established. RESULTS: Thirty-five teeth from 35 patients with a median age of 28 years (range 24-34) were treated; the median follow-up duration was 19 months (range 12-26). The overall success rate was 91.4%, with a median lesion reduction of 77.0% (range 54.2-96.4%) at 6 months. Patients under 30 years of age exhibited a significantly greater success rate than older patients did (100.0% vs. 80.0%, p = 0.037). Other factors, such as sex, jaw, treatment type, preoperative pain, cyst size, tooth location, sealer extrusion, and the number of roots, did not significantly impact treatment outcomes. CONCLUSIONS: Despite limitations related to the observational case-series study design and relatively small sample size, our findings suggest that utilizing the ANPI in the NSRCT for LCPLs may hold promise. The notably higher success rate in patients younger than 30 years is worth noting.

The implementation of an image-guided system at a proton therapy center facility.

PURPOSE: Pencil Beam Scanning (PBS) proton therapy has similar requirements on patient alignment to within 1 mm and 1-degree accuracy as photon radiosurgery. This study describes general workflow, acceptance, and commissioning test procedures and their respective results for an independent robotic arm used for Image Guided Radiotherapy (IGRT) for a Proton Therapy System. METHODS: The system is equipped with kV-imaging techniques capable of orthogonal and Cone-Beam Computed Tomography (CBCT) imaging modalities mounted on an independent robotic arm gantry attached to the ceiling. The imaging system is capable of 360-degree rotation around patients to produce CBCT and kilovoltage orthogonal images. The imaging hardware is controlled by Ehmet Health XIS software, and MIM Software handles the image fusion and registration to an acceptable accuracy of ≤1-mm shifts for patients' alignment. The system was tested according to the requirements outlined in the American Association of Physicists in Medicine (AAPM) Task Group (TG) 142 and TG 179. The system tests included (1) safety, functionality, and connectivity, (2) mechanical testing, (3) image quality, (4) image registration, and (5) imaging dose. Additional tests included imaging gantry isocentricity with a laser tracker and collision-avoiding system checks. RESULTS: The orthogonal and volumetric imaging are comparable in quality to other commercially available On-Board Imagers (OBI) systems. The resulting spatial resolution values were 1.8-, 0.8-, and 0.5-Line Pairs per Millimeter (lp/mm) for orthogonal, full-fan CBCT, and half-fan CBCT, respectively. The image registration is accurate to within 1 mm and 1 degree. The data shows consistent imaging-guided system performance with standard deviations in x, y, and z of 0.7, 0.8, and 0.7 mm, respectively. CONCLUSIONS: The system provides excellent image quality and performance, which can be used for IGRT. The proven accuracy of the x-ray imaging and positioning system at McLaren Proton Therapy Center (MPTC) is 1 mm, making it suitable for proton therapy.

BMP2 rs1005464 is associated with mandibular condyle size variation.

This study aimed to evaluate the association between single nucleotide polymorphisms (SNPs) in endochondral development-related genes and mandibular condyle shape, size, volume, and symmetry traits. Cone-beam Computed Tomographies and genomic DNA from 118 individuals were evaluated (age range: 15-66 years). Data from twelve 3D landmarks on mandibular condyles were submitted to morphometric analyses including Procrustes fit, principal component analysis, and estimation of centroid sizes and fluctuating asymmetry scores. Condylar volumes were additionally measured. Seven SNPs across BMP2, BMP4, RUNX2 and SMAD6 were genotyped. Linear models were fit to evaluate the effect of the SNPs on the mandibular condyles' quantitative traits. Only the association between BMP2 rs1005464 and centroid size remained significant after adjusting to account for the false discovery rate due to multiple testing. Individuals carrying at least one A allele for this SNP showed larger condylar size than common homozygotes GG (ß = 0.043; 95% CI: 0.014-0.071; P value = 0.028). The model including BMP2 rs1005464, age and sex of the participants explained 17% of the variation in condylar size. Shape, volume, and symmetry were not associated with the evaluated SNPs. These results suggest that BMP2 rs1005464 might be associated with variation in the mandibular condyles size.

Reliability of Artificial Intelligence-based Cone Beam Computed Tomography Integration with Digital Dental Images.

This study aimed to introduce cone-beam computed tomography (CBCT) digitization and integration of digital dental images (DDI) based on artificial intelligence (AI)-based registration (ABR) and to evaluate the reliability and reproducibility using this method compared with those of surface-based registration (SBR). This retrospective study consisted of CBCT images and DDI of 17 patients who had undergone computer-aided bimaxillary orthognathic surgery. The digitization of CBCT images and their integration with DDI were repeated using an AI-based program. CBCT images and DDI were integrated using a point-to-point registration. In contrast, with the SBR method, the three landmarks were identified manually on the CBCT and DDI, which were integrated with the iterative closest points method. After two repeated integrations of each method, the three-dimensional coordinate values of the first maxillary molars and central incisors and their differences were obtained. Intraclass coefficient (ICC) testing was performed to evaluate intra-observer reliability with each method's coordinates and compare their reliability between the ABR and SBR. The intra-observer reliability showed significant and almost perfect ICC in each method. There was no significance in the mean difference between the first and second registrations in each ABR and SBR and between both methods; however, their ranges were narrower with ABR than with the SBR method. This study shows that AI-based digitization and integration are reliable and reproducible.