Postoperative Cone Beam Computed Tomography Research Articles

Accuracy analysis of robotic-assisted immediate implant placement: A retrospective case series

ObjectivesThis study aimed to investigate the accuracy of a robotic computer-assisted implant surgery (r-CAIS) for immediate implant placement. MethodsPatients requiring immediate implant placement in the maxillary anterior region were enrolled for r-CAIS. Before surgery, the patients underwent a cone beam computed tomography (CBCT) scan with a positioning marker. Virtual implant placement position and drilling sequences were planned. Following spatial registration and calibration, the implants were placed with the robotic system under supervision. A postoperative CBCT was taken to control the actual implant positions. The DICOM data of the virtually planned and the actually placed implant were superimposed and registered through the accuracy verification software of the robotic system. The accuracy was calculated automatically. The deviation at the mesial–distal, labial–palatal, and apico-coronal directions were recorded. ResultsFifteen patients with 20 implants were included. No adverse surgical events or postoperative complications were reported. The global platform, apex, and angular deviation were 0.75 ± 0.20 mm (95 % CI: 0.65 to 0.84 mm), 0.70 ± 0.27 mm (95 % CI: 0.57 to 0.82 mm), and 1.17 ± 0.73° (95 % CI: 0.83 to 1.51°), respectively. Moreover, the vertical platform and apex deviation were 0.50 ± 0.31 mm, (95 % CI: 0.35 to 0.64 mm) and 0.48 ± 0.32 mm, (95 % CI: 0.33 to 0.63 mm), respectively. All the placed implant positions were further labial and apical than the planned ones, respectively. ConclusionsHigh accuracy of immediate implant placement was achieved with the robotic system. Clinical significanceOur study provided evidence to support the potential of the robotic system in implant placement, even in challenging scenarios.

Accuracy comparison of single- and double-sleeve endodontic guides for fiber post removal

BackgroundThis study aimed to assess the accuracy of two different endodontic guides for fiber post removal.MethodsIn this in vitro study, 54 maxillary canine fiber posts were mounted on 36 maxillary stone casts; 18 teeth were mounted unilaterally, and 36 teeth were mounted bilaterally. Static endodontic guides were fabricated according to baseline cone-beam computed tomography (CBCT) and intraoral optical scans using Blue Sky software. In the single-sleeve endodontic guides group (SSG), two anterior and two posterior teeth were included in a 5-unit guide. In the double-sleeve endodontic guides group (DSG) group, the guide was passed through the midline to include both canine teeth and extended by 2 teeth posterior to the canine teeth bilaterally (a 10-unit guide). After drilling, postoperative CBCT scans were taken and superimposed on the virtually designed path, and the maximum coronal deviation (MCD) at the marginal entry point of the tooth, maximum apical deviation (MAD) at 10 mm apical to the tooth margin, and maximum angular deflection (MAnD) of the drill were calculated.ResultsThe mean MCD, MAD, and MAnD were 0.34 mm, 0.6 mm, and 2.32 degrees, respectively, in the SSG and 0.31 mm, 0.7 mm, and 2.37 degrees, respectively, in the DSG. The two groups were not significantly different from each other in terms of MCD (P = 0.573), MAD (P = 0.290), or MAnD (P = 0.896).ConclusionsThe accuracies of the two techniques, the extended double sleeve guide and the single sleeve guide, were comparable and thus DSG may be used for removal of fiber posts in adjacent or distant teeth.

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

BackgroundThe 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 methodsForty 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.ResultsNo 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.ConclusionThe augmented reality appliance provides higher accuracy in the positioning of single-root autotransplanted teeth compared to the conventional free-hand technique.

Cortical Block Grafting Successfully Augments Alveolar Cleft Sites for Dental Implant Placement

BackgroundSupplemental bone grafting is regularly required before dental implant placement in patients with cleft lip and palate (CLP). PurposeThe study purpose was to measure and compare implant osseointegration and changes in graft dimensions following lateral incisor onlay cortical bone grafting in CLP and non-CLP patients. Study design, setting, sampleRetrospective cohort study composed of patients who presented to Boston Children’s Hospital and underwent autogenous onlay cortical block bone grafting at lateral incisor sites from 2015 through 2023. Patients were excluded if the cone beam computed tomography (CBCT) quality was insufficient for accurate measurements. Predictor variableThe predictor variable was CLP status coded as CLP or non-CLP. Main outcome variableThe primary outcome variable was successful implant osseointegration confirmed by a torque of 35 N/cm or more after 3 months of implant healing. Secondary outcomes were change in bone width between pre- and post-operative CBCT scans at lateral incisor sites and the need for additional bone augmentation prior to or during implant placement. CovariatesCovariates were age, sex, cleft location, and time from bone graft to postoperative CBCT and implant placement. AnalysesData analyses were performed using T-tests, Fisher’s Exact Tests, Mann-Whitney U Tests, and Pearson’s correlation. P<0.05 was considered statistically significant. ResultsA total of 22 subjects (16 with CLP) were evaluated. The mean age at the time of graft was 19.3 ± 2.4 years with 52.6% males. Implants osseointegrated at 20 of 22 lateral incisor sites (one CLP failure, one non-CLP failure). There was significant change in bone width after grafting for patients with CLP (p<0.001). Patients with CLP experienced a 3.32 (± 1.80) mm and 2.99 (± 1.61) mm increase in bone width at two different levels. Patients with CLP achieved greater boney changes near the alveolar crest than non-cleft patients (p=0.008) but the change was not significantly different more apically (p=0.86). One subject with CLP required additional grafting during implant placement. Conclusions and RelevanceCortical block onlay bone grafting is a predictable technique to augment lateral incisor sites in patients with cleft lip and palate for placement of a dental implant.

Volumetric Analysis of Various Pediatric Rotary Files in the Preparation of Primary Root Canals Using Cone-beam Computed Tomography.

This study was planned to evaluate and compare the cleaning efficacy of three pediatric rotary files with the standard Protaper adult file system in primary teeth using cone-beam computed tomography (CBCT). A total of 40 extracted deciduous second molars, with palatal/mesial roots having at least two-thirds of root length and an intact furcation area, were distributed randomly among four groups, with each group containing 10 teeth. Canal preparation of group I (Pro AF Baby Gold), group II (Kedo SG Blue), group III (Prime Pedo), and group IV (Protaper) was done. Pre- and postoperative CBCT images were taken. The volumetric changes of the root canals were assessed and subjected to statistical analysis using Statistical Package for the Social Sciences (SPSS) version 16 and R Studio 3.1.1. Volumetric changes within the groups were analyzed using paired t-tests and between the groups using analysis of variance (ANOVA). The comparison of mean volume difference between groups using ANOVA was statistically significant with F = 4.467, p = 0.002. A Tukey post hoc test revealed that group IV was statistically significant compared with groups I (p = 0.033) and III (p = 0.008) but was not statistically significant with group II (p = 0.170). There was no statistically significant difference in volumetric changes within the three pediatric rotary file systems. Protaper removed more dentin than all the pediatric rotary files, but it was not statistically significant over Kedo SG Blue. Among the pediatric rotary files, Kedo SG Blue removed more dentin than Pro AF Baby Gold and Prime Pedo, but they were not statistically significant. Nainer Chidambaram JV, Jayaprakash J, Arangannal P. Volumetric Analysis of Various Pediatric Rotary Files in the Preparation of Primary Root Canals Using Cone-beam Computed Tomography. Int J Clin Pediatr Dent 2024;17(1):15-20.

Comparative Analysis of the Efficacy of Various Retreatment File Systems in the Removal of Gutta-Percha in Retreatment Cases and Time Taken During the Procedure: An In Vitro Cone Beam CT Study.

Background Removing gutta-percha manually can be a challenging task, especially when addressing densely packed root-filling material, particularly in cases where resin-based sealers are employed for obturation. The use of nickel-titanium (NiTi) rotary instruments not only effectively shapes the root canal but also efficiently removes the endodontic filling from the curved canal during retreatment. Hence, incorporating rotary NiTi instruments in retreatment cases can alleviate fatigue for both patients and operators. Objectives This study aims to compare the efficacy of Neo-Endo retreatment files, R-Endo retreatment files, and K and H files in the removal of endodontic filling material. Additionally, the remnants of gutta-percha in root canals are evaluated using cone beam computed tomography (CBCT). Materials and methods A total of 60 extracted first maxillary molar teeth were selected for this study. Canal preparation was conducted using the step-back method up to an apical size of 40 K-file. The obturation process involved the use of gutta-percha points and AH Plus sealer in a lateral compaction technique. Post-operative CBCT scans were taken. The samples were randomly divided according to the retreatment files used: group I included Neo-Endo retreatment files, group II included R-Endo retreatment files, and group III included conventional K-files and Hedstroem files (H-Files). The retreatment procedure was considered complete when the last instrument easily reached the working-length range and was physically clean. A stopwatch was used to record the time taken by each file to remove the obturating material. T1 represented the total time (including irrigation and change of file) required to reach the apex, while T2 indicated the complete removal of materials from the canal with the last instrument. The overall time recorded (TT) was calculated as T1 + T2. The removal process was analyzed with CBCT scans. Results The Neo-Endo retreatment files removed the filling materials better and more quickly than the other files. Conclusions Despite the presence of residual filling material in all samples, the Neo-Endo retreatment files left the least amount of residual filling material and achieved the shortest completion time.

Digital registration versus cone-beam computed tomography for evaluating implant position: a prospective cohort study

BackgroundPostoperative cone-beam computed tomography (CBCT) examination is considered a reliable method for clinicians to assess the positions of implants. Nevertheless, CBCT has drawbacks involving radiation exposure and high costs. Moreover, the image quality can be affected by artifacts. Recently, some literature has mentioned a digital registration method (DRM) as an alternative to CBCT for evaluating implant positions. The aim of this clinical study was to verify the accuracy of the DRM compared to CBCT scans in postoperative implant positioning.Materials and methodsA total of 36 patients who received anterior maxillary implants were included in this clinical study, involving a total of 48 implants. The study included 24 patients in the single implant group and 12 patients in the dual implant group. The postoperative three-dimensional (3D) positions of implants were obtained using both CBCT and DRM. The DRM included three main steps. Firstly, the postoperative 3D data of the dentition and intraoral scan body (ISB) was obtained through the intraoral scan (IOS). Secondly, a virtual model named registration unit which comprised an implant replica and a matching ISB was created with the help of a lab scanner and reverse engineering software. Thirdly, by superimposing the registration unit and IOS data, the postoperative position of the implant was determined. The accuracy of DRM was evaluated by calculating the Root Mean Square (RMS) values after superimposing the implant positions obtained from DRM with those from postoperative CBCT. The accuracy of DRM was compared between the single implant group and the dual implant group using independent sample t-tests. The superimposition deviations of CBCT and IOS were also evaluated.ResultsThe overall mean RMS was 0.29 ± 0.05 mm. The mean RMS was 0.30 ± 0.03 mm in the single implant group and 0.29 ± 0.06 mm in the dual implant group, with no significant difference (p = 0.27). The overall registration accuracy of the IOS and CBCT data ranged from 0.14 ± 0.05 mm to 0.21 ± 0.08 mm.ConclusionIn comparison with the 3D implant positions obtained by CBCT, the implant positions located by the DRM showed clinically acceptable deviation ranges. This method can be used in single and dual implant treatments to assess the implant positions.

Arthroscopic reduction and rigid fixation of the anteriorly displaced temporomandibular joint disc without reduction using titanium screw: a case series.

To evaluate the effectiveness of arthroscopic reduction and rigid fixation (ARRF) using a suture-free titanium screw as a treatment approach to temporomandibular joint's (TMJ) anterior disc displacement without reduction (ADDwoR) and assess its impact on clinical outcomes, including improvements in symptoms related to TMJ disorders. A series of twenty patients presented to the Department of Orthognathic and Temporomandibular Surgery at West China Hospital of Stomatology between September 2022 and January 2023, complaining of symptoms such as pain, clicking, and limited mouth opening. Standard magnetic resonance image (MRI) imaging T1 and T2 sequences in both sagittal and coronal views study with closed and maximal open mouth positions were taken preoperatively to assess the disc's position, integrity, and shape. Also, cone-beam computed tomography (CBCT) scans images to find any degenerative changes and evaluate the condylar bone's features and volume. Additionally, the clinical examination assesses limited oral opening, mechanical pain, and the presence of any noises such as clicking and crepitus. All cases were treated under general anesthesia using the arthroscopic release, reduction, and rigid fixation of the TMJ's ADDwoR to establish a normal disc-condyle relationship and to restore the functional position. Patients' symptoms, such as pain and mouth opening, improved significantly following the arthroscopic treatment. Postoperative MRI and CBCT imaging follow-up conducted at 6 months demonstrated the stable position of the reduced TMJ disc and the fixation screw. Notably, none of the patients exhibited signs of relapse during this follow-up period. Overall, the ARRF of TMJ's ADDwoR using a suture-free titanium screw proved to be safe and provides satisfactory results, in addition to the several advantages of using suture-free titanium screws, such as biocompatibility, strong fixation, and durability. However, it is a technically demanding procedure requiring extensive, long-term training. ARRF using a cost-effective fixation titanium screw to treat ADDwoR emerges as a clinically effective minimally invasive approach.

Insertion Results and Hearing Outcomes of a Slim Lateral Wall Electrode.

The clinical outcomes of cochlear implantation vary for several reasons. It is necessary to study the different electrodes and variables for further development. The aim of this study is to report the clinical outcomes of a new slim lateral wall electrode (SlimJ). Data of 25 cochlear implantations in 23 patients with the SlimJ electrode were retrospectively collected. The insertion results were assessed by image fusion of the preoperative computed tomography (CT), magnetic resonance imaging (MRI), and postoperative cone-beam CT. The hearing outcomes were evaluated by the improvement of speech recognition in noise, measured preoperatively and at follow-up. Postoperative pure-tone thresholds were obtained in cases with preoperative functional low frequency hearing [PTA (0.125-0.5 kHz) ≤ 80 dB HL]. The preoperative mean speech reception threshold (SRT) was +0.6 dB signal-to-noise ratio (SNR) (SD ± 4.2 dB) and the postoperative -3.5 dB SNR (SD ± 2.3 dB). The improvements between the preoperative and postoperative SRT levels ranged from 0.0 to 15.1 dB, with a mean improvement of 4.2 dB (SD ± 3.6 dB). Residual hearing in low frequencies (mean PTA(125-500 Hz)) was preserved within 30 dB HL in 70% and within 15 dB HL in 40% of patients who had preoperatively functional low frequency hearing. Mean insertion depth angle (IDA) was 401° (SD ± 41°). We observed scalar translocations from scala tympani to scala vestibuli in 2 ears (9%). The relatively atraumatic insertion characteristics make the SlimJ array feasible for hearing preservation cochlear implantation. The hearing outcomes are comparable to those reported for other electrodes and devices.

An evaluation of the sources and extent of error in the position of implants placed using 3D-printed stereolithographic surgical guides.

Introduction/Background. Errors can be introduced in implant placement when using stereolithographically manufactured fully limiting surgical guides due to various factors, such as discrepancies in designing and manufacturing of surgical guides (intrinsic error), built-in variations in design of mechanical components of guide systems and implant dimensions (inherent error) or due to placement error by the operator (operator error). Aim. The aim of this study was to evaluate influence of various factors on implant position when using these guides. Materials and Methods. Prosthetically-driven implant positions were planned with pre-operative cone beam computed tomography (CBCT) data and digital scans using a computer aided designing (CAD) software. Static guided implant surgery was performed under local anaesthesia using fully limiting mucosa-supported surgical guide. Pre-operative and post-operative CBCTs were superimposed using surgical sleeve as a reference to evaluate the placement error by operator (N=12). To evaluate intrinsic error, standard tessellation language (STL) files of the virtual design of the surgical guides and the STL file obtained after scanning the 3D printed stereolithographic surgical guides were superimposed. Inherent error was calculated using a geometric model. Results. Intrinsic error was observed to be a major contributing factor in angular deviation of implant, linear deviation observed at implant shoulder as well as at implant apex. Operator error was observed to be a major contributing factor for mean vertical deviation observed at apex of implant. Conclusion. This study showed that accuracy of implant placement was largely influenced by discrepancies introduced during designing and manufacturing of stereolithographic surgical guides as compared to other sources.

An evaluation of the sources and extent of error in the position of implants placed using 3D-printed stereolithographic surgical guides.

Introduction/Background. Errors can be introduced in implant placement when using stereolithographically manufactured fully limiting surgical guides due to various factors, such as discrepancies in designing and manufacturing of surgical guides (intrinsic error), built-in variations in design of mechanical components of guide systems and implant dimensions (inherent error) or due to placement error by the operator (operator error). Aim. The aim of this study was to evaluate influence of various factors on implant position when using these guides. Materials and Methods. Prosthetically-driven implant positions were planned with pre-operative cone beam computed tomography (CBCT) data and digital scans using a computer aided designing (CAD) software. Static guided implant surgery was performed under local anaesthesia using fully limiting mucosa-supported surgical guide. Pre-operative and post-operative CBCTs were superimposed using surgical sleeve as a reference to evaluate the placement error by operator (N=12). To evaluate intrinsic error, standard tessellation language (STL) files of the virtual design of the surgical guides and the STL file obtained after scanning the 3D printed stereolithographic surgical guides were superimposed. Inherent error was calculated using a geometric model. Results. Intrinsic error was observed to be a major contributing factor in angular deviation of implant, linear deviation observed at implant shoulder as well as at implant apex. Operator error was observed to be a major contributing factor for mean vertical deviation observed at apex of implant. Conclusion. This study showed that accuracy of implant placement was largely influenced by discrepancies introduced during designing and manufacturing of stereolithographic surgical guides as compared to other sources.

Nasal and maxillary sinus volume change in patients with obstructive sleep apnea after bimaxillary advancement surgery

The airway complex is modified by bimaxillary advancement surgery performed in patients suffering from obstructive sleep apnea (OSA). The aim of the present study is to analyse the volume of nasal and maxillary sinus after bimaxillary advancement surgery in patients suffering from OSA. The maxillary sinus and nasal complex of eighteen patients with OSA was measured through cone-beam computed tomography (CBCT) before and after they were treated with bimaxillary advancement surgery. Digital planning software was used to effectively measure the upper volume changes, as well as, statistical analysis of the results was performed.Methods Eighteen patients were diagnosed with OSA the severity of which was measured by the apnea hypopnea index and were selected and submitted to preoperative and postoperative CBCT scans. Afterwards, datasets were uploaded into therapeutic digital planning software (Dolphin Imaging) to measure the volume of the right and left maxillary sinus and nasal and maxillary sinus complex. Statistically analysis between preoperative and postoperative measures was performed by Student t-test statistical analysis.Results The paired t-test showed statistically significant volumetric reductions in the left maxillary sinus (p = 0.0004), right maxillary sinus (p < 0.0001) and nasal and maxillary sinus complex (p = 0.0009) after bimaxillary advancement surgery performed in patients suffering from OSA.Conclusion The results showed that bimaxillary advancement surgery reduces the maxillary sinus volume as well as, the fossa nasal and sinus complex volume.

Clinical Effect of Platelet-Rich Fibrin Combined with BIO-GENE Artificial Bone Meal in Bone Defects After Jaw Cyst Surgery.

To compare the clinical repair effects of leaving the defect empty and using Platelet-Rich Fibrin (PRF) combined with BIO-GENE artificial bone powder in patients with bone defects 6 months after jaw cystectomy. From June 2021 to June 2022, 70 patients who were admitted to the Department of Stomatology, Affiliated Hospital of Yanbian University, and were diagnosed with jaw cysts postoperatively were selected. All of the patients were divided into two groups according to random method, among which 35 patients who underwent cystectomy alone were recorded as group A, which served as blank control; 35 patients who underwent cystectomy and PRF combined with BIO-GENE artificial bone meal repaired bone defects during the same period were recorded as group B. 3D Slicer 5.0.3 software was used to reconstruct Cone Beam Computed Tomography (CBCT) after operation. In this study, the preoperative and postoperative CBCT data of the patients were analyzed using 3D Slicer 5.0.3 software in DICOM format to calculate the cleft volume before surgery and the newly formed bone volume after surgery. The osteogenesis rate was measured based on these calculations.The bone formation percentage in the bone defect area was recorded at 6 months, and the clinical curative effects of the two groups were compared. After 6 months of surgery, the patients showed varying degrees of restoration in the jaw cyst area.The osteogenesis rate at 6 months in group A was 76.06±13.38%, while group B had a rate of 92.87±5.72%.The CBCT values in group B were higher than those in group A at 6 months post-surgery (P<0.05), t=-6.84.Group A and Group B showed a statistically significant difference. Compared with simple cystectomy, PRF combined with BIO-GENE artificial bone powder has a better effect on the speed of bone repair after cystectomy within 6 months and provides more favorable effects for the repair of postoperative dentition defects, and provides support to repair teeth after defects such as dental implants.

Feasibility and accuracy of a task-autonomous robot for zygomatic implant placement

Zygomatic implants (ZIs) should be placed accurately as planned preoperatively to minimize complications and maximize the use of the remaining bone. Current digital techniques such as static guides and dynamic navigation are affected by human error; therefore, new techniques are required to improve the accuracy of ZI placement. The purpose of this clinical study was to assess the feasibility and accuracy of a task-autonomous robot for ZI placement. Patients indicated for ZI placement were enrolled, and an appropriate surgical positioning piece was selected based on the presence of natural teeth in the maxilla. Preoperative cone beam computed tomography (CBCT) scanning was performed with the surgical positioning piece, and virtual implant design and socket preparation procedures were initiated. Implant socket preparation and placement were automatically performed by the robot according to the preoperative plan under the supervision of the surgeon. Postoperative CBCT scanning was performed to evaluate deviations between the virtual and actual implants. All quantitative data were expressed as standardized descriptive statistics (mean, standard deviation, minimum, maximum, and 95% confidence interval [CI]). The Shapiro-Wilk test was used to assess the normal distribution of all variables (α=.05). Six participants were enrolled, and 8 ZIs were inserted. No intraoperative or postoperative complications were observed. Robotic ZI placement showed a global coronal deviation of 0.97mm (95% CI: 0.55 to 1.39 mm), a global apical deviation of 1.27mm (95% CI: 0.71 to 1.83 mm), and an angular deviation of 1.48 degrees (95% CI: 0.97 to 2.00 degrees). Task-autonomous robots can be used for ZI placement with satisfactory accuracy. Robotic ZI surgery can be an alternative to static guidance and dynamic navigation to improve the accuracy of implant placement.

LeFort I Horizontal Osteotomy: Defining the Feasibility of the "High Osteotomy".

To define "high osteotomy" and determine the feasibility of performing this procedure. Single institution, retrospective review. Academic tertiary referral hospital. 34 skeletally mature, nonsyndromic patients with unilateral CLP who underwent Le Fort I osteotomy between 2013 and 2020. Patients with cone-beam computed tomography (CBCT) scans completed both pre- (T1) and post-operatively (T2) were included. Patients with bilateral clefts and rhinoplasty prior to post-operative imaging were excluded. Single jaw one-piece Le Fort I advancement surgery. Measurements of the superior ala and inferior turbinates were taken from the post-operative CBCT. The sample included 26 males and 8 females, 12 right- and 22 left-sided clefts. The inferior turbinates are above the superior alar crease at a rate of 73.53% and 76.48% on the cleft and non-cleft sides, respectively. One (2.9%) osteotomy cut was above the level of the cleft superior alar crease, and no cuts were above the level of the non-cleft superior ala. On average, the superior ala was 2.63 mm below the inferior turbinates. The average vertical distances from the superior alar crease and the inferior turbinates to the base of the non-cleft side pyriform aperture were 12.17 mm (95% CI 4.00-20.34) and 14.80 mm (95% CI 4.61-24.98), respectively. To complete a "high osteotomy," with 95% confidence, the cut should be 20.36 mm from the base of the pyriform aperture. A "high" osteotomy is not consistently possible due to the relationship between the superior alar crease and the inferior turbinate.

Accuracy of Palatal Orthodontic Mini-Implants Placed Using Fully Digital Planned Insertion Guides: A Cadaver Study.

Digital workflows have become integral in orthodontic diagnosis and therapy, reducing risk factors and chair time with one-visit protocols. This study assessed the transfer accuracy of fully digital planned insertion guides for orthodontic mini-implants (OMIs) compared with freehanded insertion. Cone-beam computed tomography (CBCT) datasets and intraoral surface scans of 32 cadaver maxillae were used to place 64 miniscrews in the anterior palate. Three groups were formed, two using printed insertion guides (A and B) and one with freehand insertion (C). Group A used commercially available customized surgical templates and Group B in-house planned and fabricated insertion guides. Postoperative CBCT datasets were superimposed with the planning model, and accuracy measurements were performed using orthodontic software. Statistical differences were found for transverse angular deviations (4.81° in A vs. 12.66° in B and 5.02° in C, p = 0.003) and sagittal angular deviations (2.26° in A vs. 2.20° in B and 5.34° in C, p = 0.007). However, accurate insertion depth was not achieved in either guide group; Group A insertion was too shallow (-0.17 mm), whereas Group B insertion was deeper (+0.65 mm) than planned. Outsourcing the planning and fabrication of computer-aided design and computer-aided manufacturing insertion guides may be beneficial for certain indications; particularly, in this study, commercial templates demonstrated superior accuracy than our in-house-fabricated insertion guides.

Accuracy of computer-assisted dynamic navigation when performing coronectomy of the mandibular third molar: A pilot study

ObjectivesThe study represents a preliminary evaluation of the accuracy of the dynamic navigation system (DNS) in coronectomy of the mandibular third molar (M3M). MethodsThe study included participants with an impacted M3M near the inferior alveolar canal. The coronectomy planes were designed before the surgery using cone-beam computed tomography (CBCT) imaging data and then loaded into the DNS program. Intraoperatively, the navigation system was used to guide the complete removal of the target crown. Postoperative CBCT imaging was used to assess any three-dimensional deviations of the actual postoperative from the planned preoperative section planes for each patient. ResultsA total of 12 patients (13 teeth) were included. The root mean square (RMS) deviation of the preoperatively designed plane from the actual postoperative surface was 0.69 ± 0.21 mm, with a maximum of 1.45 ± 0.83/-1.87 ± 0.63 mm deviation. The areas with distance deviations < 1 mm, 1–2 mm, and 2–3 mm were 71.97 ± 5.72 %, 22.96 ± 6.57 %, and 4.52 ± 2.28 %, respectively. Most patients showed extremely high convexity of the surface area located in the mesial region adjacent to the base of the extraction socket. There was no observable evidence of scratching of the buccolingual bone plate at the base of the extraction socket by the handpiece drill. ConclusionsThese results provide preliminary support for the use of DNS-based techniques when extracting M3M using a buccal approach. This would improve the accuracy of coronectomy and reduce the potiential damage to the surrounding tissue. Clinical significanceDNS is effective for guiding coronectomy.

Assessment of Surgical Accuracy in Maxillomandibular Advancement Surgery for Obstructive Sleep Apnea: A Preliminary Analysis.

This retrospective study aimed to: (1) investigate the surgical accuracy of maxillomandibular advancement (MMA) in obstructive sleep apnea (OSA) patients, with a specific focus on maxillary and mandibular advancement and counter-clockwise rotation and (2) investigate the correlation between the amount of achieved advancement and the reduction in the relative apnea hypopnea index (AHI). Sixteen patients, for whom a three-dimensional virtual surgical plan was generated preoperatively and a computed tomography scan (CT) or cone-beam computer tomography (CBCT) was acquired postoperatively, were included. The postoperative CT or CBCT was compared to the virtual surgical plan, and differences in the mandibular and maxillary advancement and counter-clockwise rotation were assessed. Maxillary and mandibular advancement (median 3.1 mm, p = 0.002 and 2.3 mm, p = 0.03, respectively) and counter-clockwise rotation (median 3.7°, p = 0.006 and 4.7°, p = 0.001, respectively) were notably less than intended. A significant correlation was found between the planned maxillary advancement and the difference between the planned and actual maxillary advancement (p = 0.048; adjusted R2 = 0.1979) and also between the planned counter-clockwise rotation and the difference between the planned and actual counter-clockwise rotation for the mandible (p = 0.012; adjusted R2 = 0.3261). Neither the maxilla-first nor the mandible-first surgical sequence proved to be superior in terms of the ability to achieve the intended movements (p > 0.45). Despite a significant reduction (p = 0.001) in the apnea hypopnea index (AHI) from a median of 62.6 events/h to 19.4 events/h following MMA, no relationship was found between the extent of maxillary or mandibular advancement and AHI improvement in this small cohort (p = 0.389 and p = 0.387, respectively). This study underlines the necessity for surgeons and future research projects to be aware of surgical inaccuracies in MMA procedures for OSA patients. Additionally, further research is required to investigate if sufficient advancement is an important factor associated with MMA treatment outcome.

Accuracy of autonomous robotic surgery for dental implant placement in fully edentulous patients: A retrospective case series study.

This study evaluated the accuracy of dental implant placement using the robotic computer-assisted implant surgery (r-CAIS) technology in fully edentulous patients. Fully edentulous and terminal dentition patients were enrolled for r-CAIS technology. Based on the cone-beam computed tomography (CBCT) examination, a customized positioning marker and a preoperative surgical plan were created before surgery. During the implant surgery, the implant osteotomy and placement were automatically performed using an autonomous robotic surgery system under the surgeon's supervision. A postoperative CBCT scan was used to determine the discrepancies between the planned and placed implants. Ten patients with 59 implants underwent autonomous robotic surgery. No adverse surgical events occurred. The deviations of global coronal, global apical, and angular were 0.67 ± 0.37 mm (95% CI: 0.58-0.77 mm), 0.69 ± 0.37 mm (95% CI: 0.59-0.78 mm), and 1.27° ± 0.59° (95% CI: 1.42°-1.11°), respectively. The autonomous r-CAIS technology proved an accurate surgical approach for implant placement in fully edentulous patients due to the control of the angular deviation. Autonomous robotic surgery seems promising as an accurate technology for treating fully edentulous patients. However, further trials are required to provide more hard clinical evidence.

Treatment-Related Factors Affecting the Success of Endodontic Microsurgery and the Influence of GTR on Radiographic Healing-A Cone-Beam Computed Tomography Study.

The primary objective of this retrospective study was to assess the correlation between treatment-related factors (resection angle, depth of retrograde filling, length of resected root and use of guided tissue regeneration-GTR) evaluated using cone-beam computed tomography (CBCT) scans and the treatment outcomes of endodontic microsurgery (EMS). The secondary purpose of this research was to evaluate the influence of the GTR technique on the radiographic healing state, taking into account the initial parameters of periapical lesions. In 161 cases, the local factors (volume of a lesion, bone destruction pattern, presence/absence of cortical bone destruction) were measured using preoperative CBCT images before undergoing EMS. At least one year after surgery, the outcome of EMS was classified as a success or a failure (based on radiographic and clinical criteria). Using postoperative CBCT, treatment-related factors (resection angle, depth of retrograde filling, and length of resected root) were measured. Additionally, the status of radiographic healing was evaluated (in accordance with modified PENN 3D criteria). Eighteen cases (11.18%) were classified as failures, and 143 were classified as successes (88.82%). Univariate analysis showed that there was no statistically significant influence of treatment-related factors on the healing outcome of EMS. An exact Fischer's test showed the significant impact of GTR on radiographic healing (P < 0.001) in apical lesions (P < 0.001), lesions with a volume between 100 mm3 and 450 mm3 (P < 0.009) and over 450 mm3 (P < 0.001), lesions with the destruction of one plate (P < 0.001), and lesions with the destruction of two plates (through and through) (P = 0.022). The use of GTR in apical lesions, lesions with volumes over 100 mm3, and lesions with the destruction of at least one plate is significantly associated with better radiographic healing.