Evaluation and comparison of autologous particulate dentin with demineralized freeze dried bone allograft in ridge preservation procedures - a prospective clinical study.

OBJECTIVES: To compare effectiveness of Autologous Particulate Dentin (APD) with Demineralized Freeze-Dried Bone Allograft (DFDBA) in ridge preservation, using radiographic and clinical parameters. MATERIALS AND METHODS: Thirty subjects with indication of mandibular posterior teeth extraction were randomly assigned to either test or control group. After atraumatic extraction, ridge preservation was performed using APD or DFDBA mixed with i-PRF in test and control groups respectively. Both groups had sockets sealed with A-PRF membrane. Clinical parameters (plaque, gingival and healing indices) and radiographic parameters (vertical ridge height, horizontal ridge width) were assessed at baseline and 6 months using CBCT. Statistical analysis was performed using an independent t-test to compare clinical and radiographic parameters between the groups. RESULTS: Both groups had significant decreases in ridge dimensions over 6 months (p < 0.001). The test group showed less reduction in ridge dimensions than control group at 6 months (p < 0.001). Mean change in vertical height was not significant (1.37 ± 1.32, 1.7311 ± 0.563), but in horizontal ridge width (1.3120 ± 1.13, 1.8093 ± 1.16) was significantly different between test and control groups respectively. There was no statistical difference in clinical parameters between the groups at 6 months (p > 0.001). CONCLUSIONS: APD grafts resulted in significant improvements in radiographic parameters, specifically in vertical ridge height and horizontal ridge width, compared to DFDBA group. CLINICAL RELEVANCE: Autologous particulate dentin is a promising, versatile substitute for regenerative procedures. While more research on its long-term efficacy and application is needed, current evidence suggests it could significantly improve patient care and outcomes.

Prevalence of tooth agenesis and supernumerary teeth related to different Thai cleft lip and cleft palate populations.

BACKGROUND: Pattern of dental anomalies encountered in cleft patients shows subtle signs of genetic involvement. This study aimed to evaluate the prevalence and pattern of tooth agenesis and supernumerary teeth in Thai cleft population according to the cleft type. METHODS: Data collected from patients with cleft lip and palate, who had been treated at Tawanchai Cleft Center, Khon Kaen University, Thailand, available during year 2012-2022, were investigated. Records from 194 patients with non-syndromic clefts met the inclusion criteria. Standard dental records, and at least either orthopantomogram (OPG) or cone beam computed tomography (CBCT), were examined. Statistical analysis was performed using chi-square and binominal test (p ≤ 0.05). RESULTS: Prevalence of tooth agenesis was higher (77.3%) than that of supernumerary teeth (5.7%) and was more common in bilateral cleft lip and palate (BCLP) (88.1%) than in unilateral cleft lip and palate (UCLP) (72.6%) (p = 0.017). The upper lateral incisor was more frequently affected (46.4%), followed by the upper second premolar. The number of missing teeth observed on the left side was significantly higher. Patients with left UCLP (ULCLP) had the highest prevalence of tooth agenesis. A total of 41 tooth agenesis code (TAC) patterns was found. The prevalence of supernumerary teeth was comparable with 6.6% of ULCLP, 5.1% of BCLP, and 4.5% of URCLP. Tooth-number anomalies were observed more often in the BCLP and were most likely to occur on the left side of the maxilla. Both types of anomalies could be featured in a small proportion of cleft patients. CONCLUSIONS: More than half of the patients with non-syndromic cleft lip and palate in this study, presented with tooth-number anomalies. Tooth agenesis was approximately 10-time more prevalent than supernumerary teeth. Tooth agenesis was likely to appear on the left-side of the maxilla regardless of the laterality of the cleft.

Comparative evaluation of the accuracy of electronic apex locators and cone-beam computed tomography in detection of root canal perforation and working length during endodontic retreatment.

BACKGROUND: To evaluate the accuracy of the electronic apex locators (EALs), and Cone-Beam Computed Tomography (CBCT) scanning, both in working length (WL) determination and in the detection of root canal perforations in retreatment cases. METHODS: Sixty human mandibular premolars were selected. After crown removal partially and canal access, root canals were instrumented and irrigated. The obturation process utilized gutta-percha and sealer with warm vertical compaction. Two groups were distinguished: one without perforation (Group 1) and the other with an apical third perforation (Group 2). Retreatment included filling removal, apical preparation, and irrigation. Actual working lengths (AWL) were determined using a stereomicroscope. CBCT images were used to measure CBCT working length (CWL), with adjustments for optimal views. Propex II and Dentaport ZX were used to measure electronic working length (EWL). Differences between EWL and AWL, as well as CWL, were analyzed to gauge accuracy. Data underwent Two-way ANOVA analysis. Measurements within ± 0.5 and ± 1 mm tolerance ranges were deemed successful for each device, followed by applying the Pearson Chi-square test. RESULTS: The study reveals no significant inter-group variations in device performance (p > .05). Dentaport ZX missed detecting perforation in two Group 2 (apical perforation) cases. For ± 1 mm tolerance, Propex II displayed the highest success in Group 2 (apical perforation). CONCLUSION: This study demonstrates the comparable performance of Propex II, Dentaport ZX, and CBCT in endodontic retreatment, providing insights into diagnostic reliability.

Comparative analysis of delivered and planned doses in target volumes for lung stereotactic ablative radiotherapy.

BACKGROUND: Adaptive therapy has been enormously improved based on the art of generating adaptive computed tomography (ACT) from planning CT (PCT) and the on-board image used for the patient setup. Exploiting the ACT, this study evaluated the dose delivered to patients with non-small-cell lung cancer (NSCLC) patients treated with stereotactic ablative radiotherapy (SABR) and derived relationship between the delivered dose and the parameters obtained through the evaluation procedure. METHODS: SABR treatment records of 72 patients with NSCLC who were prescribed a dose of 60 Gy (Dprescribed) to the 95% volume of the planning target volume (PTV) in four fractions were analysed in this retrospective study; 288 ACTs were generated by rigid and deformable registration of a PCT to a cone-beam computed tomography (CBCT) per fraction. Each ACT was sent to the treatment planning system (TPS) and treated as an individual PCT to calculate the dose. Delivered dose to a patient was estimated by averaging four doses calculated from four ACTs per treatment. Through the process, each ACT provided the geometric parameters, such as mean displacement of the deformed PTV voxels (Warpmean) and Dice similarity coefficient (DSC) from deformation vector field, and dosimetric parameters, e.g. difference of homogeneity index (ΔHI, HI defined as (D2%-D98%)/Dprescribed*100) and mean delivered dose to the PTV (Dmean), obtained from the dose statistics in the TPS. Those parameters were analyzed using multiple linear regression and one-way-ANOVA of SPSS® (version 27). RESULTS: The prescribed dose was confirmed to be fully delivered to internal target volume (ITV) within maximum difference of 1%, and the difference between the planned and delivered doses to the PTV was agreed within 6% for more than 95% of the ACT cases. Volume changes of the ITV during the treatment course were observed to be minor in comparison of their standard deviations. Multiple linear regression analysis between the obtained parameters and the dose delivered to 95% volume of the PTV (D95%) revealed four PTV parameters [Warpmean, DSC, ΔHI between the PCT and ACT, Dmean] and the PTV D95% to be significantly related with P-values < 0.05. The ACT cases of high ΔHI were caused by higher values of the Warpmean and DSC from the deformable image registration, resulting in lower PTV D95% delivered. The mean values of PTV D95% and Warpmean showed significant differences depending on the lung lobe where the tumour was located. CONCLUSIONS: Evaluation of the dose delivered to patients with NSCLC treated with SABR using ACTs confirmed that the prescribed dose was accurately delivered to the ITV. However, for the PTV, certain ACT cases characterised by high HI deviations from the original plan demonstrated variations in the delivered dose. These variations may potentially arise from factors such as patient setup during treatment, as suggested by the statistical analyses of the parameters obtained from the dose evaluation process.

Assessment of the Change in the Nasal Septum and Nasal Profile After Le Fort I With Cone Beam Computed Tomography.

OBJECTIVE: This study aimed to determine the relationship between nasal changes and the amount of advancement, impaction, and downward movement of the maxilla after Le Fort I osteotomy. METHODS: The study included 48 patients who underwent Le Fort I surgery and had pre- and postoperative cone-beam computed tomography records. Changes in the nasal septum were evaluated by measuring septal deviation angles and volumes. In addition, nasolabial angle and width of nasal and alar base were examined. Groups were determined according to the movement of point A (the deepest point on the curvature of the maxillary alveolar process), using a threshold of 1.5 mm for vertical movements and 4 mm for sagittal movements. This resulted in the comparison of 6 groups of 8 people each. Results are presented as mean and standard deviation or median and range depending on the data distribution. Significance level was accepted as P < 0.05. RESULT: There were no significant differences for each group on its own septal deviation volume or angle values pre/postoperatively. Groups 3 and 5, which both had at least 1.5 mm of impaction, showed significant changes in both deviation angle and volume between the preoperative and postoperative measurements. Nasolabial angle did not show significant changes between groups. Alar base width and nasal width increase was significantly highest in Group 1, which has more than 4 mm sagittal movement and less than 1.5 mm vertical movement. CONCLUSIONS: Le Fort I osteotomy may lead to undesirable changes in the spatial positioning of the nasal septum. The results of this study suggest that maxillary advancement does not significantly impact septal deviation, whereas maxillary impaction increases the amount of deviation. In addition, nasal width and alar base width tended to increase, and the nasolabial angle tended to decrease slightly, regardless of the direction of movement of the maxilla after orthognathic surgery. CLINICAL RELEVANCE: Surgeons should consider increased nasal septal deviation risks when planning impaction of the maxilla. The soft tissue changes in the nose vary according to different directions and amounts of Le Fort I surgery.

Competence of allogenic demineralized tooth matrix in socket seal surgery for alveolar ridge preservation: a randomized control clinical trial.

OBJECTIVES: To assess and compare the clinical, radiological, and histological outcomes of socket seal surgery between two protocols: deproteinized demineralized tooth matrix (dpDTM) and freeze-dried bone allograft (FDBA) each covered with a free gingival graft. MATERIALS AND METHODS: Twenty extraction sockets in the anterior or premolar region were randomly allocated to either the dpDTM or FDBA protocol (n = 10 per group). Measurements of the alveolar ridge changes were obtained using an intraoral scanner and cone-beam computed tomography at 3 months post-operation. Three-month post surgery, the dental implant was installed (n = 5 per group), bone biopsies were obtained for histomorphometrical and micro-computed tomography analyses. Implant stability quotients (ISQs) were determined and compared at 3 months post-implant. RESULTS: Lower significant reductions in buccal alveolar ridge height and hard tissue volume were observed in dpDTM group compared to FDBA group at 3 months (0.25 ± 0.35 mm vs. 1.60 ± 0.66 mm [p = .000] and 9.64 ± 15.39% mm3 vs. 31.45 ± 18.11% mm3 [p = .010], respectively). At the same time, lower soft tissue volume reduction was detected in the dpDTM group compared to FDBA group (4.21 ± 5.25% mm3 vs. 5.25 ± 5.79% mm3). No statistically significant difference in the percentage of mineralized tissue formation was found between dpDTM group (53.39 ± 11.16%) and FDBA group (49.90 ± 3.27%). Even though the ISQ in the dpDTM group showed a higher value than the FDBA group at 3 months post-implant, the results were without statistical significance. CONCLUSIONS: Alveolar ridge preservation using dpDTM is an efficacious procedure for providing the conditions for the development of functional and esthetic implants.

Distribution and influencing factors of pulp stones based on CBCT: a retrospective observational study from southwest China.

BACKGROUND: Pulp stones are a type of pulp calcification, the presence of which tends to hinder endodontic treatment. Thus, this retrospective study aimed to analyze the distribution of pulp stones in the population in southwest China and identify the influencing factors. MATERIALS: Cone-beam computed tomography (CBCT) scans of 5066 teeth of 200 patients (91 males and 109 females) aged 16-45 years were evaluated. Pulp stones were marked as either present or absent when distinct radiopaque masses were found in the pulp cavity, then evaluated the occurrence of pulp stones with regard to tooth type, sex, age group, and contact it with tooth status. The Pearson chi-square test and nonparametric test were used for statistical analysis. RESULTS: Pulp stones were detected in 49.0% of patients and 7.4% of teeth, respectively. The incidence in females was 1.9 times higher than in males (OR = 1.9, 95% CI = 1.1-3.3, p = 0.001). Pulp stones were most prevalent in patients 36-45 years of age. Furthermore, in the age range of 16-45 years, the likelihood of finding pulp stones increased 1.1 times per year with age (OR = 1.1, 95% CI = 1.0-1.1, p = 0.032). A higher incidence of pulp stones was observed in the maxilla and molars. Of the 5066 teeth studied, pulp stones were more common in non-intact teeth. CONCLUSION: Nearly half of the population in southwest China had pulp stones. Pulp stones were found significantly more often in females, maxilla, and non-intact teeth, and their frequency increased with age. For dentists, understanding the distribution of pulp stones is crucial for the proper design of root canal treatment (RCT). TRIAL REGISTRATION: This study was approved by the Ethics Committee of the Affiliated Hospital of Stomatology, Southwest Medical University (certificate number: 20220818001).

Combined biological effects of CBCT and therapeutic X-ray dose on chromosomal aberrations of lymphocytes.

BACKGROUND AND PURPOSE: Cone beam computed tomography (CBCT) is routinely used in radiotherapy to localize target volume. The aim of our study was to determine the biological effects of CBCT dose compared to subsequent therapeutic dose by using in vitro chromosome dosimetry. MATERIALS AND METHODS: Peripheral blood samples from five healthy volunteers were irradiated in two phantoms (water filled in-house made cylindrical, and Pure Image CTDI phantoms) with 6 MV FFF X-ray photons, the dose rate was 800 MU/min and the absorbed doses ranged from 0.5 to 8 Gy. Irradiation was performed with a 6 MV linear accelerator (LINAC) to generate a dose-response calibration curve. In the first part of the investigation, 1-5 CBCT imaging was used, in the second, only 2 Gy doses were delivered with a LINAC, and then, in the third part, a combination of CBCT and 2 Gy irradiation was performed mimicking online adapted radiotherapy treatment. Metaphases were prepared from lymphocyte cultures, using standard cytogenetic techniques, and chromosomal aberrations were evaluated. Estimate doses were calculated from chromosome aberrations using dose-response curves. RESULTS: Samples exposed to X-ray from CBCT imaging prior to treatment exhibited higher chromosomal aberrations and Estimate dose than the 2 Gy therapeutic (real) dose, and the magnitude of the increase depended on the number of CBCTs: 1-5 CBCT corresponded to 0.04-0.92 Gy, 1 CBCT + 2 Gy to 2.32 Gy, and 5 CBCTs + 2 Gy to 3.5 Gy. CONCLUSION: The estimated dose based on chromosomal aberrations is 24.8% higher than the physical dose, for the combination of 3 CBCTs and the therapeutic 2 Gy dose, which should be taken into account when calculating the total therapeutic dose that could increase the risk of a second cancer. The clinical implications of the combined radiation effect may require further investigation.

A new guide for enhancing dental implant placement: an in vitro assessment of accuracy.

This study aimed to design a new surgical guide for controlling the mesiodistal distance between implant osteotomies and adjacent teeth as well as the osteotomy depth in partially edentulous patients. The guide kit was designed with design software and milled with a CNC (computer numerical control) router. The guide consisted of 2 components-stoppers and crown guides-for determining the drilling depth and mesiodistal position, respectively. The stoppers were designed in 7.5-, 9.5-, and 11.5-mm lengths, and the crown guides were fabricated with outer diameters of 5.0, 6.0, 7.0, and 8.0 mm. The accuracy of the guide was assessed by preparing a total of 20 implant osteotomies in 4 partially edentulous models and comparing the dimensions of the actual osteotomies to the values that were predicted to occur with the use of the surgical guides. Osteotomies were prepared using the 7.5-mm stopper with either the 7.0- or 8.0-mm crown guide. Cone beam computed tomography (CBCT) was used to obtain images for analysis of osteotomy-tooth mesiodistal distances, which were predicted to be 3.0 or 5.5 mm, depending on position; interosteotomy mesiodistal distances, which were predicted to be 3.0 mm; and osteotomy depth, which was predicted to be 11.5 mm. A 1-sample t test was used to determine if there were significant differences between the predicted values and the measurements of the guided osteotomies on the CBCT images of the mandibular models, and an independent t test was conducted to compare the results of 3.0- and 5.5-mm osteotomy-tooth distances (α = 0.05). Differences between the predicted and actual values of the interosteotomy mesiodistal distance (P = 0.516) and osteotomy depth (P = 0.847) were not statistically significant. The actual osteotomy-tooth mesiodistal distances were significantly different from the predicted values of 3.0 (P = 0.000) and 5.5 mm (P = 0.001), with higher mean differences of 0.46 and 0.60 mm, respectively. The designed guide had a high accuracy in achieving optimal linear interosteotomy mesiodistal distances and osteotomy depths, and the obtained mean values were clinically acceptable.

Practical management recommendations for incidental otolaryngologic findings on cone beam computed tomography.

Cone beam computed tomography (CBCT) frequently captures unexpected structural abnormalities unrelated to the original intent of the diagnostic test. Once identified by dentists, these findings often require appropriate clinical referral for further investigation. This study reviewed recent literature using a comprehensive search to identify and curate common CBCT incidental findings (IFs). Studies were included if they reported CBCT IFs and included more than 10 cases. The review included 16 primary studies in addition to 4 studies described in recent relevant systematic reviews. A total of 51 descriptive terms used to describe key IFs across studies were identified, and terms were organized semantically into 15 core finding categories. Recommendations for management and referral acuity were derived from otolaryngologic clinical practice guidelines and input from practicing otolaryngologists, and the results were integrated into a clinical management algorithm for acuity of referral. This comprehensive review offers practical recommendations to facilitate appropriate clinical management of CBCT IFs via otolaryngologic referral.

[Study on fatigue resistance of mechanical nickel-titanium files by phase-locked infrared flaw detection method].

PURPOSE: The movement trend of the posterior teeth and the distribution of the periodontal membrane stress were studied by using three-dimensional digital technology. METHODS: CBCT data of 88 patients admitted to our hospital from June 2017 to June 2022 were selected, and input into Mimics20.0 software for preliminary extraction of all parts and stored with STL files; then the data were repaired and optimized through Geomagic Studio 2014 software. With the help of normal phase extension, the invisible appliance and periodontal membrane were constructed. Finally, the six FEM models were simulated and observed by the current teeth in different groups. Statistical analysis was performed with SPSS 21.0 software package. RESULTS: The effect force of the largest periodontal membrane was distributed in the neck of the tooth, followed by the apical area, with the maximum effect force value in the NA group. In all accessory groups, the periodontal membrane maximum paradigm isoeffect force values of all patients in the accessory vertical rectangular group were significantly smaller than the values obtained in the horizontal rectangular group. CONCLUSIONS: The design of orthodontic tooth accessories has a strong inhibition effect on the position movement of anterior teeth during recovery, which improves the accuracy of tooth three-dimensional movement to a certain extent. Meanwhile, the normal equivalent stress of the periodontal membrane of patients in the initial application of the invisible appliance without brackets is large.

[Evaluation of efficacy of denture occlusal plate combined with comprehensive physical therapy for temporomandibular joint disc displacement without reduction].

PURPOSE: To explore the efficacy of denture occlusal plate combined with comprehensive physical therapy for temporomandibular joint disc displacement without reduction(ADDwoR). METHODS: Sixty patients of ADDwoR and dentition defect or severely worn teeth who visited the Department of Orthodontics and Prosthodontics of Hengshui People's Hospital from January 2019 to December 2020 were selected and randomly divided into denture occlusal plate group (group A) and denture occlusal plate + comprehensive physical therapy group (group B) according to the treatment methods. Maximum mouth opening (MMO) and visual analog pain score(VAS) among all patients were recorded before treatment and every three weeks during three months of treatment. Cone-beam CT(CBCT) was taken before and 3 months after treatment. The changes in clinical efficacy indicators before and after treatment and CBCT data between the two groups were analyzed. Statistical analysis was performed with SPSS 26.0 software package. RESULTS: The differences of VAS of group A and B were statistically significant from before treatment to three weeks after treatment(P＜0.05), and group B decreases more. From 3 weeks after treatment, there was a significant difference of group B for MMO and VAS before treatment (P＜0.05). From 9 weeks after treatment, there was a significant difference of group A for MMO before treatment (P＜0.05), but there was no significant difference in MMO and VAS between group A and B(P＞0.05). CBCT showed narrowed anterior joint space, widened posterior joint space, enlarged superior joint space, decreased horizontal angle of the condyle and increased slope of joint nodules (P＜0.05). The difference between joint depth, anteroposterior diameter of the condyle, internal and external diameter was not significant (P＞0.05). There was significant differences in anterior, superior, and posterior joint space, condylar level angle, and slope of joint nodules of group B compared with group A(P＜0.05). CONCLUSIONS: Denture occlusal plate can effectively improve symptoms of ADDwoR, and denture occlusal plate combined with comprehensive physical therapy can quickly improve mouth opening and reduce pain in the joint area.

[Impact of GuttaFlow Bioseal sealer on the vertical fracture resistance of oval-shaped canals].

PURPOSE: To investigate the effect of GuttaFlow Bioseal root canal sealer on the vertical root fracture resistance of oval-shaped root canals. METHODS: Sixty orthodontically subtracted maxillary and mandibular single-rooted premolar teeth were scanned with CBCT. Oval canals were eligible when the buccolingual diameter of the canal was greater than or equal to two times the mesiodistal diameter at a distance of 5 mm from the root apex. Thirty single-rooted premolars with oval-shaped root canals were prepared to F2 using the Protaper system and then randomly divided into the GuttaFlow Bioseal filling group and iRoot SP filling group. Each group was further divided for root canal filling using warm vertical compression, cold lateral condensation and single cone techniques. Five single-rooted premolars was chosen as a negative control group. After 30 days of storage in a constant thermotank at 37 ℃ and 100% humidity, the filled roots were vertically placed into a cylindrical model of self-polymerizing acrylic resin. Subsequently, the samples were fixed on the lower plate of a universal testing machine, and a ball of 4 mm in diameter was applied vertically with a downward pressure at a speed of 1 mm/min until fracture occurred. The load values were recorded in Newtons. The data were analyzed using SPSS 29.0 software package. Fracture patterns were examined under microscope. RESULTS: T test results showed no significant difference between the GuttaFlow Bioseal-filled and iRoot SP-filled groups (P=0.321). One-way ANOVA showed a significant difference in vertical fracture resistance between the groups(P＜0.05), and LSD analysis showed that the GuttaFlow Bioseal-filled sample teeth were significantly more resistant to vertical fracture than the iRoot SP when using the thermal vertical compression filling method and the single-tip method(P＜0.05). In contrast, the GuttaFlow BIoseal-filled group was significantly less resistant to vertical fracture than the iRoot SP group when using the cold lateral compression filling method(P＜0.05). CONCLUISIONS: GuttaFlow Bioseal has the potential to improve root resistance to vertical fracture when filling root canals using the thermal vertical pressurization method and the single-tip method, but more clinical trials are needed to validate this result and its long-term prognosis.

[Transverse characteristics of normodivergent patients in different sagittal skeletal patterns].

PURPOSE: This study aimed to measure and analyze the transverse indicators of normodivergent patients with different sagittal skeletal malocclusions, to explore the transverse characteristics of different sagittal skeletal malocclusions. METHODS: Lateral cephalograms and CBCT of 90 normodivergent patients with skeletal Class Ⅰ, Ⅱ and Ⅲ in their permanent dentition were collected. Dolphin software was applied to measure the widths of the basal bone, alveolar bone, dental arch and buccolingual inclination angle of the corresponding teeth in the maxillary and mandibular canine, premolar and molar areas. SPSS 22.0 software package was applied for statistical analysis of the data. RESULTS: The widths of the mandibular basal bone in canine, premolar and molar areas of skeletal Class Ⅲ were (27.15±2.74), (39.30±2.82) and (59.97±2.93) mm, respectively. The widths of the mandibular alveolar bone of skeletal Class Ⅲ were (25.38±1.78), (34.51±2.28) and (47.72±2.73) mm, respectively. The dental arch widths of the maxillary premolar and mandibular canine areas of skeletal Class Ⅲ were (48.70±2.35) and (30.69±2.31)mm, respectively. The above data of skeletal Class Ⅲ were significantly larger than those of skeletal Class Ⅰ and Ⅱ(P＜0.01). The dental arch widths of the maxillary canine, maxillary molar and mandibular molar areas of skeletal Class Ⅲ were (38.88±1.90), (59.51±3.40) and (56.01±2.86)mm, respectively, which were significantly larger than those of skeletal Class Ⅱ(P＜0.05). The maxillomandibular width difference of basal bone in the canine, premolar and molar areas of skeletal Class Ⅲ were (4.69±2.84), (2.31±2.39) and (3.27±2.05) mm, respectively, which were significantly less than that of skeletal Class Ⅰ and Ⅱ(P＜0.01). Compared with skeletal Class Ⅰ, the maxillary canines and first molars of skeletal Class Ⅱ had larger lingual inclination level, while the maxillary first premolars and first molars of skeletal Class Ⅲ had larger buccal inclination level, the mandibular canines and the mandibular first premolars of skeletal Class Ⅲ had larger lingual inclination level(P＜0.01). CONCLUSIONS: For normodivergent patients, the width of the mandibular base bone, alveolar bone, and maxillary and mandibular dental arch in skeletal Class Ⅲ is the widest, which is more likely to have width discrepancy in basal bone. In skeletal Class Ⅲ, the maxillary teeth are buccally inclined, and the mandibular teeth are ingually inclined. In skeletal Class Ⅱ, the maxillary teeth are lingually inclined, and the mandibular teeth are compensatory upright.

[A correlation study between the occlusal cant and temporomandibular joint space in patients with mandibular lateral deviation].

PURPOSE: To investigate the correlation between the occlusal canting and the bilateral temporomandibular joint (TMJ) space in adult and juvenile mandibular deviation patients and study the mutual influence between the occlusal canting and mandibular position, in order to provide references for clinical treatment. METHODS: CBCT data of mandibular deviation patients（20 adults，20 juveniles）were selected. Inivo5 Dental Anatomage software was used to reconstruct the structures. The occlusal cant and vertical height of the bilateral maxillary from canines to first molars were measured, and the vertical heights difference between the same teeth on both sides was calculated. The anterior, superior and posterior space of temporomandibular joint were measured respectively in both groups. Pearson correlation analysis between the occlusal canting and bilateral condylar space was carried out by using SPSS 17.0 software package. RESULTS: In the juvenile group, negative correlations were found between the occlusal cant and the superior TMJ space on the deviated side (P＜0.05). Negative correlation was found between the vertical height difference of bilateral canines and the anterior TMJ space on the deviated side in the juvenile group(P＜0.05). In the adult group, no significant correlation was observed among those correlated examination (P＞0.05). CONCLUSONS: The occlusal canting is moderately correlated with mandibular position in the early stage of mandibular deviation patients. Early treatment of mandibular deviation is of great importance in preventing its progression into severe skeletal malocclusion, and more attention should be paid on the correction of the canted frontal occlusion plane.

In-house protocol for fully guided zygomatic implant surgery and prosthesis repositioning. A technical note

AIM: The present study aims to describe an in-house protocol for fully guided zygomatic implant surgery and prosthesis repositioning. MATERIALS AND METHODS: Four extramaxillary zygomatic dental implants (ZIs) were placed in one patient. The preoperative phase included digital planning, through which a surgical guide was designed and created. The analysis of the accuracy of guided surgery and the guided prosthesis repositioning was carried out by superimposing the digital planning with the final postsurgical implant positioning through CBCT. The radiologic evaluation included implant angular deviation, entrance and exit deviation, platform deviation, and apex apicocoronal and mesiodistal deviation. The prosthetic evaluation was performed in three directions: buccopalatal, apicocoronal, and mesiodistal. RESULTS: All the ZIs successfully osseointegrated after 3 months of healing, with no complications. The mean axial angular implant deviation was 0.52 ± 0.36 degrees, and the mean implant depth deviation was 0.47 ± 0.28 mm. The entrance and exit deviation of the implants was 0.74 ± 0.42 mm and 0.7 ± 0.43 mm, respectively. The virtual prosthesis was superimposed and compared with the standard tessellation language file of the provisional polymethyl methacrylate prosthesis at the level of the first molars and central incisors; the mean buccopalatal deviation was 0.6 ± 0.035 mm, the mean apicocoronal deviation was 0.65 ± 0.11 mm, and the mean mesiodistal deviation was 0.3 ± 0.07 mm. CONCLUSIONS: According to the results obtained in this first case of the present case series, careful and meticulous digital planning based on the correct prosthetic parameters can safely guide the performance of surgery.

Potential S1 Nerve Root Blocks Associated with Sacroiliac Joint Injections.

Background: Sacroiliac (SI) joint dysfunction is a common cause of lower back pain. The diagnosis of SI joint pain remains challenging. Sacroiliac joint injection remains the gold standard of diagnosis of SI joint pain as well as providing therapeutic effect. One complication related to SI joint injection is temporary numbness and weakness of the leg. Objectives: To evaluate the anatomy of the SI joint and the flow of the contrast in the sacroiliac joint and to understand how local anesthetic can affect the nerve roots and cause temporary weakness and numbness of the leg. Study Design. Retrospective case series. Setting. Academic medical center. Methods: Patients who underwent SI joint injection with three-dimensional cone beam computed tomography with fluoroscopy (3D-CBCT) imaging were identified through retrospective review of two providers' case log from the electronic medical record. The cone beam CT images were reviewed to study the contrast spread and flow in the SI joint. Results: 27/32 patients with the mean age of 56 years (range 39-87 years), 20 females, and 7 males were included in this study. After reviewing cone beam CT images, 4/27 (14.8%) patients showed contrast spread in the SI joint and spread into the S1 posterior neuroforamen. The remainder 23/27 (85.2%) patients had contrast localized in the SI joint. Limitations. Small population size, retrospective review of medical records. Conclusion: Our results indicate that the injection of lower concentration of local anesthetic with less volume may be necessary to decrease the risk of S1 nerve root block and epidural block. Furthermore, to improve the specificity of a diagnostic SI injection, an appropriate evaluation should be considered to rule out any S1 nerve pathology as a significant pain generator.

Antral membrane balloon technique versus Densah bur in crestal sinus lift with simultaneous implant placement: a randomized clinical trial.

BACKGROUND: The posterior maxilla presents challenges for implant insertion because of the poor bone quality as well as the loss of vertical bone height. Indirect transcrestal sinus lift techniques are advised when a few millimeters of additional height are needed. This study aimed to evaluate the clinical and radiographic outcomes of antral membrane balloon technique versus Densah burs for transcrestal maxillary sinus lifting with simultaneous implant placement. MATERIALS AND METHODS: This randomized clinical trial was conducted on 22 patients received 32 dental implants for replacement of missed maxillary posterior teeth after crestal maxillary sinus lifting. The patients were randomly divided into two groups. Group 1, patients underwent crestal sinus floor elevation with simultaneous implant placement using antral membrane balloon technique. Group 2, patients underwent crestal sinus floor elevation with simultaneous implant placement using Densah burs. Patients were evaluated clinically and radiographically using cone beam computed tomography (CBCT) at regular time intervals immediately, 6 months and 12 months after surgery. All clinical and radiographic parameters were statistically analyzed. RESULTS: All dental implants were successful for 12 months of follow up. Regarding implant primary stability, there was a statistical significant difference between the study groups in favor of Densah group (P = 0.004), while there was no significant difference after 6 months (P = 0.07). Radiographically, balloon group showed a statistically significant immediate postoperative vertical bone height (P < 0.0001), and significant reduction in vertical bone height after 6 months (P < 0.0001). Densah group showed significant increase in bone density (P ≤ 0.05). CONCLUSION: Both techniques demonstrated successful clinical and radiographic outcomes for crestal sinus lift. The antral membrane balloon group demonstrated better immediate postoperative vertical bone gain, while Densah burs had higher implant primary stability and bone density. TRIAL REGISTRATION: This study was registered in Clinical-Trials.gov PRS ( https://register. CLINICALTRIALS: gov ) under identification number NCT05922592 on 28/06/2023.

Evaluation of the accuracy of cone beam computed tomography (CBCT) in the detection of peri-implant fenestration.

BACKGROUND: Accurate assessment of the bone supporting the implant is crucial. Early detection of bone defects around the implant can prevent the loss of bone support that ultimately leads to the loss of the implant. Therefore, the purpose of this study is to check the accuracy of CBCT in detecting peri-implant fenestrations around the implant. MATERIALS & METHODS: In this laboratory study, healthy beef ribs were used. The ribs were divided into three groups of 12 (control group, 1-2 mm fenestration group, and 2-3 mm fenestration group). The blocks were cut to a length of 20 mm and 36 osteotomies with dimensions of 4 × 12 mm were made by the periodontist in order to place the implant in these bone blocks. Then the titanium implant was placed in the holes and the initial scan was performed with CBCT. In the second group, fenestration-like lesions were created on the same buccal side at a distance of 10 mm from the crest with a diameter of 1-2 mm and in the third group with a diameter of 2-3 mm, and the CBCT scan was performed again with the same parameters. Two radiologists evaluated the images twice for the presence and absence of fenestration. RESULTS: There was no statistically significant difference between direct measurements and CBCT in the fenestration group of 1-2 mm (p < 0.05), but there was a significant difference between direct measurements and CBCT in the fenestration group of 2-3 mm and underestimation was observed in CBCT measurements. CONCLUSION: The findings of this study showed that CBCT radiography has a higher accuracy in measuring the fenestration around the implant with a smaller diameter and has an acceptable diagnostic value in detecting bone loss around the implant.

Risk prediction model of impacted supernumerary tooth-associated root resorption in children based on cone-beam computed tomography analysis: a case control study.

BACKGROUND: External surface resorption is pressure-induced resorption and occurs on the external surface of the root, pressure exerted by impacted teeth, is common causes of external surface resorption. Predictive risk factors of impacted supernumerary tooth-associated root resorption (ISTARR) mentioned in this article include supernumerary teeth and patient factors. To investigate the risk factors of impacted supernumerary tooth-associated root resorption and predict the incidence of root resorption. METHODS: This restrospective study enrolled 324 patients with impacted supernumerary tooth. All Cone-Beam Computed Tomography (CBCT) data and patient information were divided into two groups (without tooth root resorption and with root resorption). CBCT images and patient information (age and gender) of 133 patients had adjacent tooth root resorption and 191 did not. seven variables were analysed using binary logistic regression. RESULTS: Individual analysis of potential risk factors showed that age, crown mesiodistal direction, root formation, and odontotheca of the impacted supernumerary tooth were associated significantly with ISTARR. Binary logistic regression showed that impacted supernumerary tooth with odontotheca (Odd Ratio = 2.926), the crown is in the middle (Odd Ratio = 1.446), located at the middle third of the adjacent tooth root (Odd Ratio = 1.614), complete root development (Odd Ratio = 1.334), and patient's age (Odd Ratio = 1.261) were significantly associated with ISTARR risk. CONCLUSIONS: The risk factors of root resorption can be detected and predicted early according to the features of supernumerary tooth and patient's age. Still, more prospective studies with larger sample size are needed to validate the result.