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Central giant cell granuloma (CGCG) is a bone lesion characterized by fibrous tissue containing areas of bleeding, giant cells with multiple nuclei, and trabeculae of woven bone. It is considered to be a local bone repair response, possibly triggered by inflammation, bleeding, or local injury. CGCG is more prevalent in females and can occur across a wide age range, typically diagnosed at a young age. Mandibular involvement is more common than maxillary involvement, with most lesions in the posterior region often extending into the ascending ramus. Management of aggressive CGCG can involve non-surgical (medical) and surgical treatment modalities. Surgical approaches vary from simple curettage to en bloc resection depending on various factors discussed in this case report.

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Background Monocortical mini-screw-type temporary anchorage devices (TADs), or mini-screws, have significantly impacted orthodontic treatment strategies, especially in severe crowding and protrusion cases. These devices offer flexibility in placement sites, but the chosen location can considerably influence tooth displacement patterns. Key factors include the 'line of force' and the biomechanical properties of orthodontic tools. By analyzing tension distribution and three-dimensional displacements, the finite element method (FEM) provides a thorough means to comprehend these patterns. The Curve of Spee (COS) is a crucial factor potentially affecting displacement. Objective This study aimed to leverage finite element analysis (FEA) to understand the impact of varying mini-implant heights (10 mm, 13 mm, and 16 mm) on the displacements of different tooth types under a consistent force of 150 gm and compare these displacements both in the presence and absence of the COS. Materials and methods A CAD model of the jaw and teeth was developed using CT scan data and a Rexcan III 3D White Light Scanner. This model was meshed in Altair HyperMesh using tetrahedral elements, resulting in a Finite Element Model. The model incorporated various components, including teeth, the periodontal ligament (PDL), alveolar bone, brackets, a titanium mini-screw, and an archwire measuring 0.019 x 0.025 inches. Unique material properties were assigned to the PDL, and the assembly accurately replicated the clinical alignment of the archwire and brackets. Subsequently, stress and strain analyses were conducted on the model using the FEM. Results The displacement patterns of various teeth at implant heights of 10 mm, 13 mm, and 16 mm under a 150-gm force were analyzed in relation to the COS. Notably, for the central incisor, the COS significantly affected displacements in the Y and Z directions. Similarly, the Lateral Incisor and Canine exhibited marked changes in the Z direction with the presence of the COS. The Second Premolar's apex displacement showed significant variation due to the COS, while the First Molar displayed notable changes in the X direction. Generally, the presence of the COS either maintained or slightly increased Z-directional displacements across teeth, particularly at the apices. Conclusion The presence of COS significantly influences tooth displacement patterns when using mini-screws at different implant heights. Central incisors, lateral incisors, and canines are particularly sensitive to changes in the Z direction with the COS. The biomechanical analysis emphasizes the importance of considering COS in treatment planning for optimal results with mini-implants in orthodontics.

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OBJECTIVE: To assess if the dental follicle volume of palatally impacted canines (PICs) affects the relative root position of the adjacent lateral incisors (LIs) and first premolars (FPs). MATERIALS AND METHODS: A retrospective cross-sectional study of 49 patients with unilaterally PICs with dental follicles who had CBCT imaging previously taken. Four orthodontic centers in different countries provided the sample. A mean difference of 5° between the angular measurements (mesiodistal tip, buccolingual inclination, or mesiodistal rotation) of the LI and FP adjacent to the PIC and the controls was considered clinically relevant. A value of 0.05 was set for significance level and a power of 80%. The minimum sample size was determined to be 26 patients. These patients were further assigned to an LI sample (n = 49) and an FP sample (n = 23), dependent on the direct contact of the dental follicle to that adjacent tooth. A manual segmentation technique was used to obtain the volumetric measurements of the dental follicle. Angular measurements of adjacent teeth were then compared to the contralateral nonimpacted side, which acted as the control. A multivariant regression analysis was performed using IBM SPSS software, and statistical significance was set at α = 0.05. RESULTS: Adequate intra-rater reliability was accomplished. The multivariant regression analysis implied that there is no difference in the mean change in the tip, torque, and rotation of the LI and FP between the impacted and control sides when dental follicle volumes are considered (P = .509 for the LI sample and P = .804 for the FP sample). LIMITATIONS: CBCT imaging of dental follicle border delimitations, partial volume effect, and scattering are limitations. This is a convenience sample where the FP subsample is small. CONCLUSION: The dental follicle volume of the PICs does not seem to influence the relative position of the adjacent LI and FP mesiodistal tip, buccolingual inclination, and mesiodistal rotation. Early intervention could have been suggested to avoid certain malocclusion traits if significant displacements were demonstrated.

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Objective: To evaluate the effects of periodontal initial therapy combined with orthodontic treatment on anterior tooth function and inflammatory factors in gingival crevicular fluid in patients with periodontal disease induced anterior tooth displacement. Methods: This was a clinical comparative study. A total of 140 patients with anterior teeth displacement caused by periodontal disease in Fujian University of Traditional Chinese Medicine from May 2020 to May 2022 were selected and randomly divided into two groups. Patients in the control group received periodontal initial therapy, and those in the study group were provided with orthodontic treatment on the basis of initial therapy. Further comparative analysis was performed focusing on the clinical effects of the two groups, the changes of probing depth, anterior overjet degree, oral function and inflammatory factors in gingival crevicular fluid before and after treatment. Results: The efficacy of the study group was significantly higher than that of the control group(p=0.00). After treatment, the probing depth, the anterior overjet degree and the rate of bleeding on probing in the study group were significantly lower than those in the control group(P=0.00). Furthermore, the proportion of tooth mobility degrees I, II and III in the study group was significantly lower than that in the control group after treatment(P<0.05). The levels of post-treatment inflammatory factors in the study group were significantly lower than those in the control group(p=0.00). Conclusion: Periodontal initial therapy combined with orthodontic treatment has a significant effect on anterior teeth displacement caused by periodontal disease, which deserves promotion clinically.

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The periodontium is a biological structure that supports the tooth in the jaw and behave as a developmental, biological, and functional unit. Teeth may be considered to be 'suspended' in their tooth sockets which provides teeth the ability to move in response to an applied load. In terms of the protection the suspension effect of the periodontal ligament may offer dental restorations, movement in an axial direction is of interest. No device or system to measure this movement is readily available, thus a novel approach had to be developed to address the questions of this research. The device developed allowed images to be taken of the participants teeth before, during and after a participant bit down on the tooth and used to measure the displacement of the tooth in image processing software. Average maximum tooth displacement from all participants of 73.8 µm (sd = 22.5 µm) were recorded. Longer application time of bite force was associated with greater cumulative tooth displacement, for a given level of force, and female participants experienced approximately 2 µm more displacement per Newton than males. The device and methods utilised in this study has shown good potential as a measurement protocol for measurement of vertical tooth movements in vivo. The response to load the teeth in this study has shown, highlighted the visco-elastic properties of the periodontal ligament and the amount of movement recorded supports the protection that controlled tooth movement offers teeth.

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Dental and dentoalveolar injuries are common in the pediatric population. Management is predicated on the type of tooth injured (primary or permanent), extent of injury, the dental and behavioral age of the patient, and ability of the patient to tolerate treatment. Although many dental injuries occur in isolation, a systematic evaluation of the patient is mandatory to confirm the absence of basal bone fractures of the maxilla or mandible, traumatic brain injury, cervical spine injury, and/or facial soft tissue injury. Long-term follow-up is paramount to achieving a functional occlusion and optimal dental health following injury.

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PURPOSE: This study aimed to clarify the effect of occlusal force on appropriate optical interocclusal registration in clinical practice, considering periodontal ligament and jawbone deformation. METHODS: Forty participants with natural, healthy dentition were enrolled (19 men and 21 women; mean age, 27.7 ± 2.0 years). A TRIOS3 intraoral scanner was used to scan the right lateral first premolar to the second molar areas of the upper and lower jaws. During scanning for interocclusal registration, participants were instructed to "bite normally," "bite lightly," and "bite strongly" to obtain data for the three occlusal patterns. The standard triangulated language (STL) data for each occlusion condition were superimposed using the appropriate software, following which the tooth displacement was calculated. The conventional method was also used to record the occlusal contact area for a silicone model using a dental contact analyzer. RESULTS: Tooth displacement was significantly lower for the strong-bite condition than for the weak-bite condition (0.018 mm vs. 0.028 mm, P<0.05). As the occlusal force increased, the occlusal contact area also increased, and significant differences were observed among the different occlusal conditions (P<0.05). CONCLUSIONS: Occlusal contact area changed depending on the bite force when using the silicone impression or optical intraoral scanning methods. Moreover, using optical impression methods in "strong bite force" may reduce the deviation and allow for stable interocclusal registration.

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OBJECTIVE: To identify tooth mobility (TM) by time-dependent tooth displacement using an electronic intra-oral loading device (ILD) in periodontally healthy and periodontally compromised patients. MATERIALS AND METHODS: Twenty-eight untreated periodontitis and 20 periodontally healthy patients [25 female and 26 male; ages: 20-81 years], contributing with 68 teeth (periodontitis: nteeth = 28; non-periodontitis: nteeth = 40), participated in the study. TM was measured in vivo by displacing central or lateral incisors to a maximum of 0.2 mm orally over durations of 0.5 s, 1 s, and 10 s with the ILD. The maximum force (Fmax) was extracted from the measured force/deflection curves for every single measurement. RESULTS: Differences in TM-ILD values were found for periodontitis as compared to non-periodontitis patients derived from the same loading durations (differences of 3.9 (0.5 s), 3.1 (1 s), 2.8 (10 s), (95% CI for 0.5 s (1.2-6.7), p = 0.024; 1 s (1.4-6.0), p = 0.067; 10 s (0.2-5.3), p = 0.001), rejecting the null hypothesis of no difference (T-test) for durations of 0.5 and 10 s. There was a significant correlation of TM-ILD (Fmax) with BOP at 0.5 s (- 0.52) and with attachment loss at all time durations (- 0.47 at 0.5 s; - 0.57 at 1 s; - 0.47 at 10 s). CONCLUSIONS: This clinical investigation could demonstrate that time-dependent tooth displacements using a new computerized electronic device were associated with attachment loss and bleeding on probing. CLINICAL RELEVANCE: ILD can improve the monitoring of tooth mobility, as TM-ILD values reflect qualitative (inflammatory status interpreted by BOP) and quantitative parameters (interpreted as the amount of CAL loss) of periodontal disease.

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PURPOSE: To compare the accuracy of occlusal wear facet morphology designed using different bite registration methods for mandibular first molar crowns. MATERIALS AND METHODS: The posterior teeth and intraoral intercuspal occlusions of 12 participants were scanned. The abutment shape of the mandibular first molars for complete crowns was virtually designed, and the anatomic coping design method was used to design crowns. In the anatomic coping design, digital wax patterns were constructed by elevating the wear facets on the original surface of the first molars and then adjusting the facets with 2 types of virtual occlusions determined by buccal bite registration (BBR) or segmented tooth registration (STR) methods, where the displacement of teeth under bite force was considered (STR) or not (BBR). The occlusal distance between the original wear facets and the antagonists as well as 3D deviations between the facets on the designed crowns and on the surfaces of the original teeth were measured. Paired-samples t-test was used to analyze the results (α = 0.05). RESULTS: Regarding occlusal distance, the mean 3D deviation and the root mean square (RMS) values of BBR were greater than those of the STR groups (p < 0.001 and p = 0.008). The mean 3D deviations of the crowns of the BBR and STR groups were 0.19 ±0.04 mm and 0.14 ±0.06 mm, respectively and the RMS values were 0.22 ±0.03 mm and 0.18 ±0.04 mm (p < 0.001), respectively. CONCLUSIONS: The morphology of occlusal wear facets of mandibular first molar crowns designed with the occlusion constructed using the segmented tooth registration method are more coincident with the original morphology.

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Cyclic neutropenia (CyN) is a rare, ELANE-related neutropenia. Oral manifestations are among the initial signs of CyN and an important reason that leads patients to seek professional help. This case report describes a 12-year-old girl with recurrent oral ulcers, severe chronic periodontitis, and pathological tooth migration as the initial and main clinical symptoms of CyN. Two novel mutations in ELANE, c.180T>G (p.I60M) and c.182C>G (p.A61G) associated with CyN were observed. Bioinformatics research indicated lower stability and impaired molecular linkages of the mutant neutrophil elastase (NE) encoded by ELANE. However, the enzyme affinity to the classic substrate Suc-Ala-Ala-Ala-pNA was not substantially changed, suggesting that the impaired integrity and stability of the mutant NE, rather than catalytic deficiency, might be the pathogenic mechanism of ELANE mutation-induced neutropenia. The patient was prescribed scaling and root planing (SRP) and monthly periodontal maintenance without systemic management. Although the routine periodontal treatment was occasionally interrupted by the 2019 coronavirus pandemic, her periodontal devastation remained well-remitted in the 5-year follow-up assessment. The results of this study confirmed the importance of plaque control and proper diagnosis in the periodontal management of such patients and provide better clinical references. In addition, the novel mutations identified in this study expand the spectrum of known ELANE mutations in CyN and further contribute to knowledge regarding its pathogenic mechanism.

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INTRODUCTION: This study aimed to determine if stress distribution from occlusal loads after targeted endodontic microsurgery (TEMS) differed for trephine-resected flat and curved root-ends, with and without bone graft. METHODS: Finite element analysis models were constructed from cone-beam computed tomography data of a TEMS-treated maxillary central incisor. Models included flat and curved resected root-ends, with and without apical bone graft, and normal or root canal filled controls. In centric occlusion, axial force was directed on mesial and distal lingual marginal ridges at 120° angle. For lateral excursion, additional mesiodistal forces were applied from centric occlusion. For edge biting, axial force was directed on the incisal edge. Under occlusal loads, stress distribution patterns on tooth and root-end circumference were analyzed. RESULTS: In normal and root filled controls, occlusal stress was distributed on labial and palatal root surfaces, concentrated in the labial cervical area, and maximized at the apex. For resected root-ends, occlusal loads concentrated stress on the labial cervical area. With bone graft, maximum stress concentration shifted to the apex, which implied stress relief and dispersion from the cervical root area. Stress patterns on the root-end were more widely spread in models with apical bone graft, whereas curved root-end showed stress concentrating arc especially when without apical bone support. The mean stress values on root-end circumference were significantly higher in curved than flat root-end (P < .05), especially with apical bone support (P < .05). CONCLUSIONS: Occlusal stress patterns on a maxillary central incisor were markedly affected by root-end resection configuration and apical bone support. Trephine-resected curved root-end had stress pattern concentrated on its circumference. Curved and flat root-ends had labial cervical stress that was relieved by bone graft. TEMS resected root-ends should be flattened and bone grafted to disperse stress from occlusal loads.

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Common impressions cannot accurately duplicate the dental occlusion under occlusal force due to tooth displacement and mandibular deformation. To establish new methods to construct virtual intercuspal occlusion and assess their construction accuracy. The intraoral occlusal contacts of posterior teeth of 15 subjects were recorded with 8 µm and 100 µm articulating paper, respectively, and the marked teeth and buccal bite data were scanned with an intraoral scanner. The virtual dental occlusions were separately determined by buccal bite registration (BBR) method, and 3 new methods, namely segmented tooth registration (STR), occlusal contact areas (marked by 8 µm articulating paper) registration (OCR) and mixing registration (MR) methods. With the intraoral contact areas marked by 100 µm articulating paper set as reference and contact areas of the 4 virtual occlusions as tests, sensitivity, positive predictive value (PPV) and the ratio of overlapping areas were calculated. Kruskal-Wallis test or 1-way ANOVA was used to analyse the difference among groups. The sensitivity ranged from 0.69 to 0.94 and the PPV from 0.67 to 0.90. Sensitivity of OCR group and PPV of STR and OCR groups were different from that of BBR group at overlapping threshold of 50% (P = .028, .028 and .006). There was statistical difference of the ratio of overlapping areas over reference areas, and the values of STR and OCR groups were higher than that of BBR group (P = .045 and .021). The ability of STR and OCR methods to construct virtual intercuspal occlusion was better than BBR method.

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This case could remind surgeons to consider the possibility of displacement of the impacted third molar in the fractured line to adjacent spaces, during open reduction and internal fixation of mandibular angle fracture.

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Tooth impaction is a pathological situation where a tooth is unable to achieve its normal functional position within the expected time span. The removal may be associated with intra-operative or post-operative complications. The Le Fort I osteotomy is a procedure used by maxillofacial surgeons to correct a wide range of dentofacial deformities. Due to its versatility and simplicity, it has gained popularity for a wide range of uses. This case report describes the location and surgical removal of a right maxillary third molar which was accidentally displaced into the infratemporal fossa in a 26-year-old female while performing Le Fort I osteotomy. The patient underwent a second surgery for the retrieval of tooth using modified Gillie's temporal approach. The important role of the cone beam computed tomography in determining the localization of the displaced tooth is demonstrated.

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BACKGROUND: There are certain reported cases of unusual displacements of teeth involved in a maxillofacial trauma to the maxillary sinus, nasal cavity, gastrointestinal tract or the airway, if worst. All these usually lead to complication the worst being death. So enquiring about them is a very essential part of surveying a maxillofacial trauma patient involving dentition. CASE: This patient was referred to our department for a dental consultation for his ill-defined firm, mildly tender, non-suppurative, submental swelling unresponsive to medication. He had undergone a polytrauma involving his face two months back. An orthopantomogram was ordered which showed a lower central incisor from the fracture site had slipped through the fracture gap into the submental space possibly missed by the CT scan. There was also a lower border splaying at the fracture site. A layer-wise dissection was done extra-orally to retrieve the tooth. CONCLUSION: This case envisages the importance of an OPG as an adjuvant to the basic radiographic study, in the emergency room, for a patient with oral and maxillofacial trauma. It also establishes the importance of a meticulous secondary survey, including counting the number of teeth and establishing a correct occlusion to avoid a complication and re-operation. Besides, a medical negligence lawsuit can also arise as some teeth may slip to lungs even.

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OBJECTIVES: The aim of the present work was set to explore the role of root diameter, root length, and thickness of periodontal ligament (PDL) and its material properties (linear and non-linear elastic material models) on the stress and strain distribution, tooth displacement and centre of resistance (CR) location. SETTING AND SAMPLE POPULATION: Both the bone and the tooth were considered as rigid bodies, and the PDL was modelled as a paraboloid with different geometric dimensions and material properties. MATERIALS AND METHODS: To achieve this goal, a horizontal force of 1 N was applied in the CR location and the stress and strain distribution and tooth displacement were quantified. Locations of CR were estimated through iterative finite element procedure. RESULTS: It was predicted that the position of CR is in the range of 34%-39% of the root length, slightly higher than one-third of the root length reported in the literature. The geometrical dimensions of the PDL had no significant effect on the position of CR, especially in the non-linear material model of the PDL, while the initial displacement of the tooth was found to be highly dependent on the geometrical and mechanical properties of the PDL. CONCLUSION: The simplified PDL modelling approach with non-linear material behaviour can be suggested for the estimation of initial tooth movement for individual clinical applications without the use of advanced 3D scans.

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BACKGROUND: Third molar extraction is one of the most common procedures performed by oral surgeons, however with rare complications. The accidental displacement of a maxillary third molar into the infratemporal fossa (ITF) is a rare complication that can occur even with experienced surgeons. CASE PRESENTATION: We describe the case of a 17-year-old patient whose right upper third molar was accidentally pushed to the ITF associated with a cellulitis and the late discovery of a textiloma (a surgical gauze). CONCLUSIONS: Extraction of third molars is a safe surgical procedure when performed in appropriate conditions. The diagnosis of textiloma following a maxillo-facial surgery is extremely rare. It is important to take into account this possibility in order to avoid delaying treatment when it occurs.

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PURPOSE: This study was conducted to investigate patterns of adjacent tooth displacement in the posterior implant with interproximal contact loss (ICL) by 3-D digital superimposition method. MATERIALS AND METHODS: Posterior partially edentulous patients, restored with implant fixed partial prostheses before 2011 and suffered from food impaction of ICL between 2009 and 2011, were included. Two dental casts, at the time of delivery and at the time of food impaction in a same patient, was converted into 3-D digital models through scanning and superimposition was performed to assess chronologic changes of the dentition. Directions of tooth displacement were evaluated and the amount of ICL was calculated. Correlations between the amount of ICL and elapsed time, or between the amount of ICL and age after function, were assessed at a significance level of P<.05. RESULTS: A total number of 13 patients (8 males, 5 females) with a mean age of 65.76 ± 9.94 years and 17 areas (4 maxillae, 13 mandibles) were included in this retrospective study. Teeth adjacent to the implant restoration showed complex displacements but characteristic tendency according to the location of the arch. The mean amount of ICL was 0.33 ± 0.14 mm. Elapsed time from function to ICL was 61.47 ± 31.27 months. There were no significant differences between the amount of ICL and elapsed time, or age (P>.05). CONCLUSION: Natural teeth showed various directional movements to result in occlusal change in the arch. The 3-D superimposition of chronologic digital models was a helpful method to analyze the changes of dentition and individual tooth displacement adjacent to implant restoration.

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OBJECTIVE: The purpose of this study was to compare the static (SFF) and kinetic frictional forces (KFF) of a computer-aided design and computer-aided manufacturing lingual bracket (CAD/CAM-LB) with those of conventional LB (Con-LB) and Con-LB with narrow bracket width (Con-LB-NBW) under 3 tooth displacement conditions. METHODS: The samples were divided into 9 groups according to combinations of 3 LB types (CAD/CAM-LB [Incognito], Con-LB [7th Generation, 7G], and Con-LB-NBW [STb]) with 3 displacement conditions (no displacement [control], maxillary right lateral incisor with 1-mm palatal displacement [MXLI-PD], and maxillary right canine with 1-mm gingival displacement [MXC-GD]; n = 6/group). While drawing a 0.016-inch copper or super-elastic nickel-titanium archwire with 0.5 mm/min for 5 minutes in a chamber maintained at 36.5℃, SFF and KFF were measured. The Kruskal-Wallis method with Bonferroni correction was performed. RESULTS: The Incognito group demonstrated the highest SFF, followed by the 7G and STb groups ([STb-control, STb-MXLI-PD, Stb-MXC-GD] < [7G-MXC-GD, 7G-MXLI-PD, 7G-control] < [Incognito-MXLI-PD, Incognito-control, Incognito-MXC-GD]; p < 0.001). However, there were no significant differences in SFF among the 3 displacement conditions within each bracket group. Within each displacement condition, the Incognito group demonstrated the highest KFF, followed by the 7G and STb groups ([STb-control, STb-MXLI-PD] < Stb-MXC-GD < 7G-MXLI-PD < [7G-control, 7G-MXC-GD] < [7G-MXC-GD, Incognito-MXLI-PD, Incognito-control] < [Incognito-control, Incognito-MXC-GD]; p < 0.001). MXC-GD exhibited higher KFFs than MXLI-PD in the same bracket group. CONCLUSIONS: The slot design and ligation method of the CAD/CAM-LB system should be modified to reduce SFF and KFF during the leveling/alignment stage.

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The aim of the present study was to use the scientific evidence found in a critical literature review as a basis to discuss the displacement of maxillary third molars to the infratemporal fossa in terms of anatomical and demographic characteristics and the treatment protocols used. In addition, this article reports a new clinical case of third molar displacement in a 19-year-old man. For the literature review, the Cochrane, Medline, Lilacs, and BBO databases were searched for relevant key words, and the selected articles were classified in accordance with their level of evidence according to the Oxford Centre for Evidence-Based Medicine criteria. Twenty-two articles were found, but only 13 were considered relevant and met the criteria for inclusion in this review. All of the articles were classified as Level 6b for scientific evidence (case reports). The maxillary left third molar was more commonly displaced to the infratemporal fossa (69.23%) than was the right third molar. Most of the molars exhibited complete root formation (53.84%), were multirooted (69.23%), and had fused roots (53.84%). During the procedures for removal of the displaced molars, either general or local anesthetic agents were used. Surgical access for molar removal was almost always intraoral, and no permanent postoperative complications were recorded. The time from tooth displacement until attempted surgical removal ranged from immediately to 24 years after the displacement. Both general dentists and oral and maxillofacial surgeons were responsible for the displacements.

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