Maxillary Antral Pseudocyst Drift after Osteotome Sinus Floor Elevation with Simultaneous Implant Placement: A Case Report and Literature Review.

This report describes maxillary antral pseudocyst drift after maxillary sinus floor augmentation through osteotome sinus floor elevation with simultaneous implant placement. 3D Slicer was used to measure the pseudocyst and maxilla for the placement of the implants; follow-up visits were scheduled at 6, 12, and 22 months. No adverse effects were observed during or after surgery, and all implants exhibited osseointegration without mobility. At 6 months after surgery, the pseudocyst had moved posterolaterally from the preoperative position near the anterior medial maxillary sinus, then returned to its original position at 12 months. However, it had remigrated to the posterolateral position at 22 months. The preoperative volume of the pseudocyst was 3.795 mm3; it was 2.370, 3.439, and 2.930 mm3 at 6, 12, and 22 months after surgery, respectively. The changes in pseudocyst drift and volume did not have a substantial negative influence on the implants, presumably because of cystic attachment and the recurrence of multiple pseudocysts at different locations. The risks associated with changes in a pseudocyst can be avoided, if an appropriate treatment plan is selected.

Treatment effect analysis of curettage for jaw cysts based on volumetric assessment and image registration.

The study was conducted to develop a visual and intuitive quantitative evaluation method for maxillary cystic lesions after curettage. Mimics 16.0 and Geomagic Studio 2013 were used to form a precise reconstruction of the cystic lesion morphology of 60 cases; the average reduction rates and 95% confidence interval were calculated. Computed tomography (CT) registration was performed before and after surgery to observe morphology features of the bone regeneration of the cystic area. The average reduction rates (RR) of the cysts after curettage were (43.56 ± 16.79)%, (54.33 ± 17.15)% and (68.53 ± 15.99)% at 3 months, 6 months and 12 months after surgery, respectively. The average monthly reduction rates (MRR) were (12.07 ± 4.35)%, (8.16 ± 2.84)% and (5.35 ± 1.52)% at 3 months, 6 months and 12 months after surgery, respectively. Correlation analysis by comparing with each group showed that the effect of sex and age in the 3-month group and the initial size in the 12-month group on RR and MRR were statistically significant. Within the limitations of the study it seems that the chosen approach for quantitative evaluation of the therapeutic effect of curettage for jaw cystic lesions might facilitate visual and quantitative follow-up of cyst curettage and timely detection of recurrence.

Priming strategies for controlling stem cell fate: Applications and challenges in dental tissue regeneration.

Mesenchymal stromal cells (MSCs) have attracted intense interest in the field of dental tissue regeneration. Dental tissue is a popular source of MSCs because MSCs can be obtained with minimally invasive procedures. MSCs possess distinct inherent properties of self-renewal, immunomodulation, proangiogenic potential, and multilineage potency, as well as being readily available and easy to culture. However, major issues, including poor engraftment and low survival rates in vivo, remain to be resolved before large-scale application is feasible in clinical treatments. Thus, some recent investigations have sought ways to optimize MSC functions in vitro and in vivo. Currently, priming culture conditions, pretreatment with mechanical and physical stimuli, preconditioning with cytokines and growth factors, and genetic modification of MSCs are considered to be the main strategies; all of which could contribute to improving MSC efficacy in dental regenerative medicine. Research in this field has made tremendous progress and continues to gather interest and stimulate innovation. In this review, we summarize the priming approaches for enhancing the intrinsic biological properties of MSCs such as migration, antiapoptotic effect, proangiogenic potential, and regenerative properties. Challenges in current approaches associated with MSC modification and possible future solutions are also indicated. We aim to outline the present understanding of priming approaches to improve the therapeutic effects of MSCs on dental tissue regeneration.

CBCT evaluation of root canal morphology and anatomical relationship of root of maxillary second premolar to maxillary sinus in a western Chinese population.

BACKGROUND: To evaluate the root anatomy, root canal morphology and the anatomical relationship between the roots and maxillary sinus of maxillary second premolars by CBCT in a western Chinese population. METHODS: A total of 1118 CBCT scans of the maxillary second premolars were collected from West China Hospital of Stomatology, Sichuan University. Information below were measured on axial, coronal and sagittal sections, recorded and evaluated properly: the number of roots and canals, the morphology of canal system classified by Vertucci standard, the inter-orifice distance of canal orifices, the curvature of each canal and the distance from root tip to maxillary sinus floor. RESULTS: Among the 1118 teeth, 94.2% (1053) are single-rooted and 55.1% (616) have one canal. Type I (55.1%) is the commonest root canal morphology followed by Type II (31.9%). The mean inter-orifice distance (IOD) for multi-canal teeth ranging from 2.72 ± 0.32 to 3.41 ± 0.11 mm. Of 1622 canals, 38.8% (630) curvature are mesiodistal and 30.9% (501) are straight canals. The distance from root tip to maxillary sinus floor increased with age and the mean distance of single-rooted ones is 2.47 ± 3.45 mm. CONCLUSIONS: All kinds of canal morphology category can be detected in maxillary second premolars. The IOD might be a predictable factor for root canal morphology. Roots of maxillary second premolars are related to maxillary sinus which should be treated carefully.

Prevalence of middle mesial canal and radix entomolaris of mandibular first permanent molars in a western Chinese population: an in vivo cone-beam computed tomographic study.

BACKGROUND: The aim of this study was to investigate the prevalence of the middle mesial canal (MMC) and radix entomolaris (RE) in mandibular first permanent molars in a western Chinese population using cone-beam computed tomography (CBCT). METHODS: A total of 1174 CBCT images of the mandibular first molars were collected from West China Hospital of Stomatology, Sichuan University. The following information was recorded and evaluated: the detection rate and location of the MMC and RE, the curvature of the RE, the canal configuration and bilateral symmetry. RESULTS: The detection rates of the MMC and RE were 3.41 and 25.04%, respectively, as calculated by individuals, and 1.79 and 22.15%, respectively, as calculated by total teeth. The average curvature in the buccolingual (BL) orientation (40.63 ± 14.39°) was significantly larger than that in the mesiodistal (MD) orientation (17.64 ± 7.82°) (p < 0.05). Of 587 patients, 71.72% (421/587) had bilateral symmetry according to the root canal morphology. The prevalence of three-rooted mandibular first molars was higher in males than in females, while the prevalence of two-rooted mandibular first molars was higher in females than in males. CONCLUSIONS: Our results showed that the RE could be detected in almost 1/4 of the western Chinese population; thus, RE detection requires special attention and careful assessment in endodontic treatment.

Digital diagnosis and treatment of mandibular condylar fractures based on Extensible Neuro imaging Archive Toolkit (XNAT).

OBJECTIVES: The treatment of condylar fractures has long been controversial. In this paper, we established a database for accurate measurement, storage, management and analysis of patients' data, in order to help determine the best treatment plan. METHODS: First of all, the diagnosis and treatment database was established based on XNAT, including 339 cases of condylar fractures and their related information. Then image segmentation, registration and three-dimensional (3D) measurement were used to measure and analyze the condyle shapes. Statistical analysis was used to analyze the anatomical structure changes of condyle and the surrounding tissues at different stages before and after treatment. The processes of condylar fracture reestablishment at different stages were also dynamically monitored. Finally, based on all these information, the digital diagnosis and treatment plans for condylar fractures were developed. RESULTS: For the patients less than 18 years old with no significant dislocation, surgical treatment and conservative treatment were equally effective for intracapsular fracture, and had no significant difference for neck and basal fractures. For patients above 18 years old, there was no significant difference between the two treatment methods for intracapsular fractures; but for condylar neck and basal fractures, surgical treatment was better than conservative treatment. When condylar fracture shift angle was greater than 11 degrees, and mandibular ramus height reduction was greater than 4mm, the patients felt the strongest pain, and their mouths opening was severely restricted. There were 170 surgical cases with condylar fracture shift angel greater than 11 degrees, and 118 of them (69.4%) had good prognosis, 52 of them (30.6%) had complications such as limited mouth opening. There were 173 surgical cases with mandibular ramus height reduction more than 4mm, and 112 of them (64.7%) had good prognosis, 61 of them (35.3%) had complications such as limited mouth opening. CONCLUSIONS: The establishment of XNAT condylar fracture database is helpful for establishing a digital diagnosis and treatment workflow for mandibular condylar fractures, providing new theoretical foundation and application basis for diagnosis and treatment of condylar fractures.

Three-Dimensional Planning in Maxillofacial Fracture Surgery: Computer-Aided Design/Computer-Aided Manufacture Surgical Splints by Integrating Cone Beam Computerized Tomography Images Into Multislice Computerized Tomography Images.

This study aimed to evaluate an innovative workflow for maxillofacial fracture surgery planning and surgical splint designing. The maxillofacial multislice computerized tomography (MSCT) data and dental cone beam computerized tomography (CBCT) data both were obtained from 40 normal adults and 58 adults who suffered fractures. The each part of the CBCT dentition image was registered into MSCT image by the use of the iterative closest point algorithm. Volume evaluation of the virtual splints that were designed by the registered MSCT images and MSCT images of the same object was performed. Eighteen patients (group 1) were operated without any splint. Twenty-one (group 2) and 19 patients (group 3) used the splints designed according to the MSCT images and registered MSCT images, respectively. The authors' results showed that the mean errors between the 2 models ranged from 0.53 to 0.92 mm and the RMS errors ranged from 0.38 to 0.69 mm in fracture patients. The mean errors between the 2 models ranged from 0.47 to 0.85 mm and the RMS errors ranged from 0.33 to 0.71 mm in normal adults. 72.22% patients in group 1 recovered occlusion. 85.71% patients in group 2, and 94.73% patients in group 3 reconstructed occlusion. There was a statistically significant difference between the MSCT images based splints' volume and the registered MSCT splints' volume in patients (P <0.05). The MSCT images based splints' volume was statistically significantly distinct from the registered MSCT splints' volume in normal adults (P <0.05). There was a statistically significant difference between the MSCT images based splints' volume and the registered MSCT splints' volume in patients and normal adults (P <0.05). The occlusion recovery rate of group 3 was better than that of group 1 and group 2. The way of integrating CBCT images into MSCT images for splints designing was feasible. The volume of the splints designed by MSCT images tended to be smaller than the splints designed by the integrated MSCT images. The patients operated with splints tended to regain occlusion. The patients who were operated with the splints which were designed according to registered MSCT images tended to get occlusal recovered.

Virtual facial reconstruction based on accurate registration and fusion of 3D facial and MSCT scans.

OBJECTIVES: Accurate registration and feasible fusion of a three-dimensional (3D) photorealistic surface images (captured using the FaceSCAN3D® Scientific Photo Lab) from multislice spiral computed tomography (MSCT) images is important to achieve optimal craniomaxillofacial surgery outcomes; thus, the aim of this work was to optimize this process. METHODS: MSCT and 3D facial scans were acquired from 37 randomly selected patients. Using the Invesalius software package, skin and bone tissue models were reconstructed. The 3D photorealistic surface images were then constructed. Four image registration processes were performed using Geomagic Studio software: manual Procrustes and semi-automatic registration (global modified ICP) using both 7 and 15 anthropometric landmarks. The statistical differences were assessed using one-way ANOVA and LSD tests. P values <0.05 were considered significant. RESULTS: Average distances between these two surfaces measured 0.99 (SD 0.13 mm), 0.77 (SD 0.11 mm), 0.99 (SD 0.15 mm), and 0.77 mm (SD 0.10 mm) via the four image registration methods. Statistical differences were observed between the manual and semi-automatic registration groups (according to 7 and 15 anthropometric landmarks, respectively). Image registration errors for the entire virtual face were <0.8 mm in the semi-automatic registration groups. CONCLUSION: Employing the Procrustes registration system using seven anthropometric landmarks together with global registration allows accurate registration and feasible fusion of 3D facial scans with reconstructed 3D MSCT image data.

[Analysis of imaging findings in jaw bone islands].

OBJECTIVE: To provide reference data on frequency and distribution of bone islands (BIs) and investigate their relationship with age, gender, and localization. METHODS: A population who received a pretreatment and at least one follow-up panoramic radiograph in the Department of Oral Radiology, West China Hospital of Stomatology, Sichuan University, were selected for this retrospective study. A sample population of 29,556 patients (12,824 males and 16,732 females) with different dental complaints and ages ranging from 8 to 80 years (mean age: 23.95 years) were included. RESULTS: In the radiographic evaluation, BIs appeared as localized, well-defined, non-expansile, radiopaque masses which were round, elliptic, or irregular in shape. Their sizes varied from a few millimeters to about 2 cm in diameter. A total of 598 radiopacities were detected, and 545 patients of 29,556 patients (1.84%) had BIs. Among subjects with multiple lesions, 49 patients had 2 BIs and 2 patients had 3 BIs. The BIs had immense mandibular predilection, with presentation primarily in the premolar/molar region. The condition appeared to have no tendencies based on sex. CONCLUSION: Recognition of BIs variation is significant in dental examinations.

[Relationship of development between third molar and second molar, canine in aged 11].

OBJECTIVE: To analyze the imaging manifestations of third molar (M3) in aged 11, and to explore the relationship of development between M3 and second molar (M2), canine (C). METHODS: A total of 399 cases, aged 11, of West China School of Stomatology in June-August 2010 were selected as the imaging database. The M3, M2, C on the panoramic images were observed and the development degree in 399 was divided. And then the correlation analysis was done. RESULTS: 45.5% of M3 in aged 11 was in stage C. 30.8% of M2 was in stage F. 36.1% of C was in stage G. The development of M3 appeared earlier in girls than in boys, and earlier in the mandible than in the maxillary. There was no significant difference between the left and right side. The correlation coefficient between M3 and M2 was 0.437, and the correlation coefficient between M3 and C was 0.132. CONCLUSION: The general trends of the developments of M3 and M2, C were the same. The development of M3 can be used to describe the development of M2 and C, according to the close relationship in radiograph.

[Evaluation of cone-beam CT in diagnosis of supernumerary teeth in the anterior maxilla].

OBJECTIVE: To evaluate the value of cone-beam CT (CBCT) in the diagnosis and orientation of supernumerary teeth in the anterior maxilla. METHODS: 195 supernumerary teeth in the anterior maxilla of 146 patients were included, which were examined by CBCT. The number, shape, size, 3-dimensional position, growth direction of the supernumeraries and their relationship with the neighboring teeth were analyzed. RESULTS: The 146 patients aged from 5 to 39, and males were affected more than females in a ratio of 2.95:1. 102 (69.9%) patients had single supernumerary teeth. Of the 195 supernumerary teeth, 126 (64.6%) were near the middle line, 131 (67.2%) were conical, 51 (26.2%) were curved root, 98 (50.3%) were inverted and had a length of (11.97 +/- 2.40) mm. The supernumerary teeth often caused complications. CONCLUSION: The position of the supernumerary teeth is varied in the maxilla, and often causes permanent dentition complications. CBCT imaging yields accurate 3-dimensional pictures of supernumerary teeth, local dental and bony structures, which is helpful for diagnosis and orientation of supernumerary teeth.

Dental age estimation from the developmental stage of the third molars in western Chinese population.

The purpose of this study is to provide reference data about estimating dental age from third molars of the western Chinese population for comparing with other populations and being applied to the age estimation of western Chinese juveniles and adolescents. A total of 2078 digital panoramic radiographs of 989 male and 1089 female Chinese subjects aged between 5 and 23 years were examined. The mineralization status of the third molars was assessed using the formation stages described by Demirjian et al. with two modifications. The results showed that the development of third molars in the western Chinese population was likely to begin at age 5 in both males and females. The third molars 28 and 48 showed significantly higher frequency in females than in males. The third molars 18 in the stage 1, 38 in the stages 1, A and G, and 48 in the stage H showed significantly older average age in females than in males. The Demirjian's stages C and D could be used as a reference stage to determine dichotomously whether a western Chinese is more likely to be under or above age 14 or 16, respectively. This study provided reference data for the age estimation of western Chinese juveniles and adolescents by the mineralization stages of the third molar. Apart from forensic age determination in living subjects, the presented reference data can also be used for age estimations of unidentified corpses and skeletons.