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Space analysis of the maxillary anterior bone geometry to understand anatomical limitation: and implant simulation study using cone-beam computed tomography (CBCT)Lee, Wongi 28 September 2016 (has links)
PURPOSE: The purpose of this study was to analyze anatomical spatial limitations of the existing bone for maxillary anterior implant placement in normal subjects.
MATERIALS AND METHODS: Fifty Two (52) Cone Beam Computed Tomography (CBCT) scans were selected. A 3i Osteotite (6 x 15mm) implant was superimposed on tooth positions from the right first premolar to left first premolar on reformatted cross sectional mages of maxillary anterior teeth. For the first trial, the implant was positioned following the alveolar bone axis. Utilizing Invivo 5 Software (Anatomage), the proximal overlaps between superimposed implants were evaluated at successive vertical steps of 2.5 mm. The prospective crown angulation or PCA (defined as the angulation between the crown axis and alveolar bone axis) was measured. The inter-canine distance across the arch, the palatal plane length and the palatal bony angulation (defined as the angulation between the palatal surface and the alveolar bone axis) were also measured. For the second trial, implant positioning followed a prosthetic driven position; the crown axis. The crown axis was defined as a line drawn from the midpoint of a line between the mid buccal/lingual CEJ to the incisal edge. The crest height and the apical height at which the implant's 1mm sleeve penetrated the buccal wall were calculated.
RESULTS: The implant position at the central incisor and lateral incisor presented the highest percentage of overlap in both the biologically and prosthetically driven positions. The prospective crown angulation was higher at the location of the lateral incisor compared to the central incisor and canine position. The association between the remaining anatomical parameters and the prevalence of overlap was analyzed with bi-serial correlation. There was no significant relationship among any of these parameters. When the implant was simulated in a prosthetically driven position, the lateral incisor implant position frequently showed perforation at 5mm apical to the buccal crest margin demonstrating this position as highly sensitive.
SUMMARY: The data demonstrated that the constriction of the alveolar bony volume in the anterior maxilla could affect implant placement. Understanding this bone morphology suggests a major limitation in the central/lateral positions which might require bone grafting. A new unique reference plane was utilized for this study. / 2018-09-28T00:00:00Z
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The Effect of Biologic Materials and Oral Steroids on Radiographic and Clinical Outcomes of Horizontal Alveolar Ridge Augmentation.Reichert, Amy 01 January 2018 (has links)
The purpose of this study was to investigate if the addition of biologic materials and/or oral steroids would affect horizontal bone gain, or the bone density of the grafted bone in horizontal alveolar ridge augmentations. A retrospective chart review was completed to assess the clinical and radiographic outcomes of 53 ridge augmentation patients. An average bone gain of 3.6mm of width was found in our study based on radiographic analysis. There were no statistically significant differences found in the linear bone gain with the addition of biologic materials and steroids. A marginally statistically significant difference was found in the bone density when biologics were added (p-value=0.0653). No statistically significant difference found in the bone density with the addition of oral steroids. The use of tenting screws and resorbable occlusive membranes and a combination of allograft and xenograft bone materials provides significant clinical and radiographic dimensional changes in alveolar ridge width.
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Relationship of human tongue volume with inter-dental maxillary and mandibular arch width, palatal axial cross-sectional perimeter, palatal index and root axial inclinationMandich, Marie-Alice 11 1900 (has links)
Objective : To determine the relationship of tongue volume as determined from Cone Beam Computed Tomography (CBCT) scan reconstructions with maxillary and mandibular arch width, axial cross-sectional palatal perimeter, palatal index and axial inclination of upper and lower first premolars and molars.
Method: Thirty subjects without prior orthodontic treatment swished barium sulfate to coat the tongue prior to CBCT imaging. The scan reconstructions were analyzed with three after-market softwares and intra-examiner reliability was assessed.
Results: Absolute agreement intra-class correlation coefficients were used to determine reliability of the measurements. Pearson correlation coefficients and regression analysis were used to determine relationships.
Conclusions: Tongue volume was strongly correlated with upper inter-molar width and palatal perimeter at the molar level, and least correlated with lower inter-molar width and axial inclination of the upper and lower first premolars and molars. The differences in measurements obtained from the three softwares were not statistically significant.
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Relationship of human tongue volume with inter-dental maxillary and mandibular arch width, palatal axial cross-sectional perimeter, palatal index and root axial inclinationMandich, Marie-Alice Unknown Date
No description available.
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Resolution of Maxillary Sinus Mucositis after Endodontic Treatment of Maxillary Teeth with Apical Periodontitis: A Cone-beam Computerized Tomography Pilot StudyNurbakhsh, Babak 15 December 2011 (has links)
This study characterized maxillary sinus mucositis (SIMS) adjacent to teeth with apical periodontitis (AP), and assessed its resolution three months after endodontic treatment. 29 subjects who maxillary posterior teeth with AP were imaged with cone-beam computed tomography (CBCT). Resolution of SIMS was assessed with CBCT three months after treatment, and periapical healing was assessed using the PAI after six months. Four non-compliant subjects were discontinued and SIMS was identified in 14/25 subjects (56%). Three months post-treatment, SIMS was resolved fully in 3/10 subjects (30%), and partially in 3/10 subjects (30%). Six months post-treatment, 6/10 subjects (60%) were classified as healed or healing. CBCT revealed a lower-than-expected prevalence of SIMS adjacent to teeth with AP. In specific cases SIMS might linger beyond three months after the elimination of the endodontic infection. Due to the low statistical power, association between the resolution of SIMS and periapical healing could not be explored.
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Resolution of Maxillary Sinus Mucositis after Endodontic Treatment of Maxillary Teeth with Apical Periodontitis: A Cone-beam Computerized Tomography Pilot StudyNurbakhsh, Babak 15 December 2011 (has links)
This study characterized maxillary sinus mucositis (SIMS) adjacent to teeth with apical periodontitis (AP), and assessed its resolution three months after endodontic treatment. 29 subjects who maxillary posterior teeth with AP were imaged with cone-beam computed tomography (CBCT). Resolution of SIMS was assessed with CBCT three months after treatment, and periapical healing was assessed using the PAI after six months. Four non-compliant subjects were discontinued and SIMS was identified in 14/25 subjects (56%). Three months post-treatment, SIMS was resolved fully in 3/10 subjects (30%), and partially in 3/10 subjects (30%). Six months post-treatment, 6/10 subjects (60%) were classified as healed or healing. CBCT revealed a lower-than-expected prevalence of SIMS adjacent to teeth with AP. In specific cases SIMS might linger beyond three months after the elimination of the endodontic infection. Due to the low statistical power, association between the resolution of SIMS and periapical healing could not be explored.
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Three-dimensional analysis of mandibular landmarks, planes and shape, and the symphyseal changes associated with growth and orthodontic treatmentDeller, Cecilia Mercedes 25 October 2017 (has links)
OBJECTIVE: To test reliability of 3D mandibular landmarks, planes of reference and surfaces and assess their correlation to conventional 2D cephalometric measurements. To analyze changes in three-dimensional shape of the symphysis due to growth and orthodontic treatment.
METHODS: This was a retrospective analysis of CBCTs of healthy orthodontic patients. 32 subjects were included, 16 males and 16 females. Mean ages of 10.6 ± 1.5 years and 15.0 ± 0.9 years before and after treatment, respectively. The mean follow up time was 4.3 years. Subjects free of any craniofacial anomalies, and no observable pathology on panoramic radiograph were. 15 subjects had CVM 1 and 17 subjects had CVM 2 before orthodontic treatment. All subjects had CVM 5 after orthodontic treatment. For the first phase, 3D mandibular landmark identifications were digitized. Planes and landmarks were constructed and compared with conventional 2D mandibular measurements. For the second phase, mandibles were isolated by removing surrounding structures. Pearson correlation and paired t-test were performed to test for correlation and differences between 2D and 3D measurements, respectively. Statistical analysis was performed using SAS 9.4. Software. MorphoJ software (Version 2.0, www.flywings.org.uk) was used for symphysis shape analysis; and Discriminant Function Analysis (DFA) between pre-treatment and post-treatment was used for statistical analysis of the symphysis.
RESULTS: We found statistical significant positive correlation between 2D and 3D pre-treatment ramus height (P-value =0.01), post-treatment ramus height (P-value < 0.0001), pre-treatment corpus length (P-value 0.0003), post-treatment corpus length (P-value 0.04), pre-treatment gonial angle (P-value <0.0001), and post-treatment gonial angle (P-value=0.05). Also, statistically significant differences in 2D ramus height (P=0.001), 3D ramus height (P-value=0.002), 2D corpus length (P-value <0.01), and 3D corpus length (P-value <0.01). For symphysis shape comparing between pre-treatment and post-treatment, we found that there is no statistically significant difference between them (P-value= 0.99).
CONCLUSION: These results demonstrated statistically significant positive correlation between certain 2D and 3D measurements, pre-treatment and post-treatment differences in 2D and 3D measurements showed consistent results. Symphysis shapes do break out as distinctly separate groups, but the differences between the means is small.
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CBCT analysis of the extension of the anterior loop of the mental nerve and its relation to age, gender, and dentate statusHussein, Omer Hani M A 14 April 2021 (has links)
INTRODUCTION: The mental foramen region is important in dental implant placement as it serves as essential neurovascular bed. Despite the belief that the interforaminal area is a safe area for implant placement, a detailed anatomical examination should be done before surgery to prevent injury to the nerve. The inferior alveolar nerve runs outward, upward and backward to the mental foramen and forms the anterior loop of the mental nerve. The anterior loop is the most mesial point of the mental foramen.
Methods to determine the extension of the anterior loop include surgical cadaver dissections, panoramic films of markers in dried skulls and cadaver mandibles, panoramic films of patients, periapical radiographs and CT scans of patients. These different methods and dissimilar diagnostic techniques have led to diverse results. The aim of this study was to measure the extension of the anterior loop of the mental foramen by using cone-beam computed tomography (CBCT).
METHODS: Randomly selected sagittal, axial, and coronal CBCT images of the maxillofacial region of 100 patients (50 males, and 50 females) aged between 18-80 were retrospectively screened to determine the extension of the anterior loop. Categorized into (1) younger males, (2) younger females aged (18-44), (3) older males, and (4) older females aged (45-80). Four groups based on dental status were added (1) fully edentulous males, (2) fully edentulous females, (3) dentated males, and (4) dentated females. Measurement tools provided by the software were used to determine the extension of the mental loop. Data was collected for statistical analysis to determine the association between CBCT findings and the patient's gender, age, and dentate status.
RESULTS: In this study, 50 male, and 50 female patients were included for anterior loop measurements. The median age of the sample population was 45 [range 33 to 59]. The mean anterior loop measurements for right and left side were 1.36 mm (0.80 SD) and 1.37 mm (0.79 SD) respectively. Eighty percent of our study participants were dentate and 20% were fully edentulous. Discussion
Prior to implant placement proper planning is necessary to avoid misplacement of dental fixtures and injury to the mental nerve. The anterior loop is one of the crucial anatomical structures that clinicians have to consider during the planning. CBCT proved to be the most reliable method of examining the maxillofacial region. No correlation was found between age, gender, and dentate status with changes in the anterior loop measurements. Even though there was no statistical difference among the groups, but there were variations in the anterior loop measurements. In some of the individual cases the anterior loop was 0 mm in one side and 2.5 mm on the other side. This is a big measurement variation of a clinical significance when it comes to implant placement. Looking to the results among groups statistically doesn’t give us the real measurement of the anterior loop. Instead every case should be examined individually to identify the extension of the anterior loop in both sides, even if it was not detected in one of the sides.
CONCLUSION: An implant placed in proximity to mental foramen requires planning to avoid complications or nerve injury. Because of possible variations in the anterior loop measurements should be done for each individual case. CBCT is the imaging method of choice to assess the anterior loop.
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COMPARISON OF SKELETAL AND DENTAL DIFFERENCES BETWEEN CLASS I AND CLASS II SIDES AND THEIR RELATIONSHIP WITH ASYMMETRIC MOLAR RELATIONSHIPS IN CLASS II SUBDIVISION MALOCCLUSIONS – A CBCT STUDYLo, Ivan, Suh, Heeyeon, Park, Joorok, Oh, Heesoo 25 September 2020 (has links)
Introduction: The purpose of this study is to compare dental and skeletal differences between Class I and Class II sides and their contributions to the degree of asymmetric molar relationship in Class II subdivision malocclusions using CBCT.
Methods: One hundred and eight patients presenting with Angle Class II subdivision malocclusions (mean age =21.05 years) were assessed with 3-dimensional cone-beam computed tomography scans. Paired t-tests were used to compare linear skeletal, angular and dental measurement differences between Class I and Class II sides. Correlations of linear skeletal, angular and dental measurement differences between Class I and Class II sides were made against the Asymmetric Molar Relationship measurement. Differences between Class I and Class II sides were correlated to the degree of skeletal asymmetry, as defined by defined as menton deviation from mid-sagittal plane.
Results: Maxillary first molar position was more mesially positioned on the Class II side and the mandibular first molar position was more distally positioned on the Class II side. No significant skeletal differences were found between Class I and Class II sides. Asymmetric Molar Relationship was correlated with a more mesially positioned maxillary first molar position and distally positioned mandibular first molar position on the Class II side. There were no significant skeletal differences that were correlated significantly with the Asymmetric Molar Relationship.
Conclusion: In a sample of one hundred and eight patients exhibiting Class II subdivision malocclusion with and without skeletal asymmetry, the Class I and Class II sides display differences that are mainly dentoalveolar in nature. The degree of molar relationship asymmetry was correlated with a more a mesially positioned maxillary molar and a more distally positioned mandibular molar on the Class II side. There were no significant skeletal differences between Class I and Class II sides and no significant skeletal contributions to molar asymmetry.
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PREVALENCE OF SHORT ROOT ANOMALY IN PATIENTS SEEKING ORTHODONTIC TREATMENTHowarth, Tim, Chen, James, Oh, Heesoo 25 September 2020 (has links)
Introduction: The purpose of this study was to investigate variance in prevalence and severity of short root anomaly (SRA) in patients seeking orthodontic treatment, stratified by ethnicity and sex. Materials and Methods: In this retrospective cross-sectional study, we evaluated 896 patients who had initial cone-beam computed tomographies (CBCTs) taken from July 1, 2014 to May 30, 2019. Panoramic radiographs and images from the CBCTs of each patient were extracted and placed in a database. The crown-to-root ratio of maxillary central incisors, lateral incisors, canines, and all pre-molars were evaluated to determine the presence, severity and associations of SRA. A Chi-square test and ordered logistic regression were used. Results: SRA was seen in 10.04% of the sample (90 patients). The maxillary central incisors are the most frequently and bilaterally affected. The severity of SRA among those with SRA showed statistically significant differences between the ethnic groups. Associations been SRA and Hispanic patients were found to be significant when evaluated by ordered logistic regression (P
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