Maxillary incisors mesiodistal angulation changes in patients with orthodontically treated anterior superior diastemas

OBJECTIVE: The aims of this study were to describe the patterns of maxillary incisor angulation in patients with upper interincisive diastemas, to evaluate angulation changes with treatment and posttreatment period, and to assess whether there are association between incisor angulation and interincisive diastema relapse. METHODS: The sample comprised 30 Class I or Class II patients with at least one pretreatment anterior diastema of 0.77 mm or greater after eruption of maxillary permanent canines. Data were obtained from panoramic radiographs at pretreatment, posttreatment and at least 2 years post-retention. RESULTS: Incisors presented a mesial tipping tendency after treatment, but only lateral incisors showed significant changes between pre and posttreatment stages. CONCLUSION: Regarding post-retention period, no changes were found. Finally, no relation was found between diastema relapse and maxillary incisor axial angulation.

Altinópolis, una utopia brasiliana. Analisi di una esperienza di educazione alla pace e non violenza come pratica alternativa dell'educazione popolare

The present thesis has as its object of study a project called “Education towards Peace and No Violence”, developed in the town of Altinópolis, in the inner part of the state of São Paulo, Brazil. Based on the analysis and the studies that were carried out, it was possible to identify the difficulties in the implementation of the project, as well as the positive results evidenced by the reduction of the reports of violence in the town. Through a careful research of the historical facts, it shall be demonstrated the progress of education, particularly in Brazil, throughout the years. In addition, a panoramic view of the studies and programs for peace developed in North America and Occidental Europe will be presented. The education for peace based in the holistic concept of human development appeared as a new educational paradigm that works as a crucial instrument in the construction process towards a peaceful and more human society based in social justice.

Reconstruction from image correspondences

A single picture provides a largely incomplete representation of the scene one is looking at. Usually it reproduces only a limited spatial portion of the scene according to the standpoint and the viewing angle, besides it contains only instantaneous information. Thus very little can be understood on the geometrical structure of the scene, the position and orientation of the observer with respect to it remaining also hard to guess. When multiple views, taken from different positions in space and time, observe the same scene, then a much deeper knowledge is potentially achievable. Understanding inter-views relations enables construction of a collective representation by fusing the information contained in every single image. Visual reconstruction methods confront with the formidable, and still unanswered, challenge of delivering a comprehensive representation of structure, motion and appearance of a scene from visual information. Multi-view visual reconstruction deals with the inference of relations among multiple views and the exploitation of revealed connections to attain the best possible representation. This thesis investigates novel methods and applications in the field of visual reconstruction from multiple views. Three main threads of research have been pursued: dense geometric reconstruction, camera pose reconstruction, sparse geometric reconstruction of deformable surfaces. Dense geometric reconstruction aims at delivering the appearance of a scene at every single point. The construction of a large panoramic image from a set of traditional pictures has been extensively studied in the context of image mosaicing techniques. An original algorithm for sequential registration suitable for real-time applications has been conceived. The integration of the algorithm into a visual surveillance system has lead to robust and efficient motion detection with Pan-Tilt-Zoom cameras. Moreover, an evaluation methodology for quantitatively assessing and comparing image mosaicing algorithms has been devised and made available to the community. Camera pose reconstruction deals with the recovery of the camera trajectory across an image sequence. A novel mosaic-based pose reconstruction algorithm has been conceived that exploit image-mosaics and traditional pose estimation algorithms to deliver more accurate estimates. An innovative markerless vision-based human-machine interface has also been proposed, so as to allow a user to interact with a gaming applications by moving a hand held consumer grade camera in unstructured environments. Finally, sparse geometric reconstruction refers to the computation of the coarse geometry of an object at few preset points. In this thesis, an innovative shape reconstruction algorithm for deformable objects has been designed. A cooperation with the Solar Impulse project allowed to deploy the algorithm in a very challenging real-world scenario, i.e. the accurate measurements of airplane wings deformations.

Valutazione dello spostamento tridimensionale degli impianti in giovani pazienti affetti da EDs riabilitati con overdenture implanto-supportati

Ectodermal Dysplasias syndrome (EDs) are a heterogeneous group of inherited disorders characterized by dysplasia of tissues of ectodermal origin. Complete or partial anodontia are the most frequent dental findings. Prosthetic rehabilitation is recommended from functional, esthetic, and psychological points of view. Because of the anatomical abnormalities of existing teeth and alveolar ridges, conventional prosthetic rehabilitation in young patient is often difficult. Five growing patients (age 9 to 11 years) with oligo- or anodontia were prosthetically rehabilitated. Panoramic film and Cone Bean Computerized Tomography were performed and a resin model of mandibular bone was made. Despite a remarkable multi-dimensional atrophy of the alveolar bone, the insertion of two tapered implants was possible. After a submerged healing period of 2 month, the implants were exposed and abutment connection was performed. Implants were connected with an expansion bar that permits mandibular growth and prosthetic retention. A removable prosthesis was constructed with ball attachments. Mandibular growth was followed and evaluated using the expansion guide and cephalometric radiographs. Mandibular growth in sagittal and transverse direction had no adverse effects on implant position. The expansion bar permitted the undisturbed growth of the mandible. After 4.5 years of follow-up, this study showed that Implant-supported overdenture may improve oral function, phonesis and esthetics. The mandibular rotation accompanying growth had not caused a significant problem relative to the angulation and migration of the implants. Implants can be successfully placed, restored and loaded in growing EDs patients. The cephalometric analysis supported that EDs patients show midface hypoplasia with a class III tendency, which can be avoided by early rehabilitation. Thanks to the good stability and retention of the implant-supported overdenture, patients considered the prostheses as comparable to natural teeth.

Feasibility and diagnostic effectiveness of new capsule endoscopy techniques

Since its approval by FDA in 2001, capsule endoscopy revolutionized the study of small bowel. One of the main limitations of its diffusion has been the high cost. More recently, a new videocapsule system (OMOM CE) has been developed in China and obtained the CE mark. Its cost is approximately half that of other capsule systems. However, there are few studies regarding the clinical experience with this new videocapsule system and none of them has been performed in the western world. Among the limitations of capsule endoscopy, there is also one linked to the diagnostic yield. The rapid transit of the device in the proximal segments implies a high risk of false negatives; an indirect confirmation of this limit is offered by the poor ability to identify the papilla of Vater. In addition, recent studies show that in patients with obscure gastrointestinal bleeding, the negative outcome of capsule endoscopy is correlated to a significant risk of recurrence of anemia in the short term, as well as the presence of small bowel lesions documented by a second capsule endoscopy. It was recently approved the use of a new device called "CapsoCam" (CapsoVision, Inc. Saratoga) characterized by four side cameras that offer a panoramic view of 360 degrees, instead of the front to 160°. Two recent pilot studies showed comparable safety profiles and diagnostic yield with the more standardized capsule. Namely, side vision has made possible a clear visualization of the papilla in 70% of cases. The aim of our study is to evaluate the feasibility and diagnostic yield of these two new devices, which first may allow a reduction in costs. Moreover, their complementary use could lead to a recovery diagnostic in patients with false negative results in an initial investigation.

Der Retromolarkanal bzw. das Foramen retromolare. Übersicht und Fallbericht

A 19-year old female patient was referred for removal of her wisdom teeth. The panoramic radiograph showed bilateral retromolar canals in the mandible. Since the retromolar canal is neglected in anatomical textbooks and is rarely documented in scientific publications, the case prompted us to perform further diagnostic examinations with informed consent by the patient. A limited cone beam computed tomography was made and, during the surgical removal of the patient's lower right wisdom tooth, a biopsy of the soft tissue bundle emerging from the retromolar foramen was taken. In accordance with the literature, the histology revealed myelinated nerve fibers, small arteries and venules. The limited data available in the literature about the retromolar canal report that this bony canal may convey an aberrant buccal nerve. In addition, sensory nerve fibers entering the retromolar canal from above and branching to the mandibular molars may evade a block anesthesia at the mandibular foramen. These rare anatomic features may explain why the elements of the retromolar canal account for failures of mandibular block anesthesia or postsurgical sensitivity changes in the supply area of the buccal nerve.

Osteoporosis and periodontitis in older subjects participating in the Swedish National Survey on Aging and Care (SNAC-Blekinge)

Abstract Objective. We assessed the relationships between (I) ultrasonography calcaneus T-scores (PIXI) and mandibular cortex characteristics on oral panoramic radiographs in older subjects; and (II) osteoporosis and periodontitis. Material and methods. We examined 778 subjects (53% women) aged 59-96 years. Periodontitis was defined by alveolar bone loss assessed from panoramic radiographs. Results. PIXI calcaneus T-values ?-2.5 (osteoporosis) were found in 16.3% of women and in 8.1% of men. PIXI calcaneus T-values <-1.6 (osteoporosis, adjusted) were found in 34.2% of women and in 21.4% of men. The age of the subjects and PIXI T-values were significantly correlated in women (Pearson's r = 0.37, P < 0.001) and men (Pearson's r = 0.19, P < 0.001). Periodontitis was found in 18.7% of subjects defined by alveolar bone level ?5 mm. Subjects with osteoporosis defined by adjusted PIXI T-values had fewer remaining teeth [mean difference 4.1, 95% confidence interval (CI) -1.1 to -6.5, P < 0.001]. The crude odds ratio (OR) of an association between the panoramic assessment of mandibular cortex erosions as a sign of osteoporosis and the adjusted T-value (T-value cut-off <-1.6) was 4.8 (95% CI 3.1-7.2, P < 0.001; Pearson ?(2) = 60.1, P < 0.001). A significant OR between osteoporosis and periodontitis was only found in women for the T-value cut-off ?-2.5 (crude OR 1.8, 95% CI 1.1-3.3, P < 0.03). Conclusions. An association between osteoporosis and periodontitis was only confirmed in women. The likelihood that the mandibular cortex index agrees with adjusted PIXI T-values is significant.

Reconstruction of the severely atrophic mandible using calvarial split bone grafts for implant-supported oral rehabilitation

OBJECTIVES: This article describes reconstruction of the severely atrophic mandible using calvarial bone grafts for implant-supported prosthetic oral rehabilitation. The study aim was to evaluate the efficacy of the treatment by determining implant survival and complication rates, and the extent of the postoperative graft resorption. STUDY DESIGN: Ten patients who underwent the treatment were followed clinically and radiologically using panoramic radiographs and CT scans during a mean postoperative period of 30 months. RESULTS: Good bone healing was observable 6 months postoperatively. The height reduction measured on panoramic radiographs was insignificant (mean 0.68 mm). Only minor complications occurred. Implant survival was 95%. Prosthodontic treatment was successfully performed in all cases, resulting in an improvement of oral function. Histological analysis of 1 bone biopsy showed minimal resorptive changes in otherwise very dense bone. CONCLUSION: Augmentation using calvarial grafts is a promising treatment alternative for the severely atrophic mandible.

Dental CT imaging as a screening tool for dental profiling: advantages and limitations

The use of dental processing software for computed tomography (CT) data (Dentascan) is described on postmortem (pm) CT data for the purpose of pm identification. The software allows reconstructing reformatted images comparable to conventional panoramic dental radiographs by defining a curved reconstruction line along the teeth on oblique images. Three corpses that have been scanned within the virtopsy project were used to test the software for the purpose of dental identification. In every case, dental panoramic images could be reconstructed and compared to antemortem radiographs. The images showed the basic component of teeth (enamel, dentin, and pulp), the anatomic structure of the alveolar bone, missing or unerupted teeth as well as restorations of the teeth that could be used for identification. When streak artifacts due to metal-containing dental work reduced image quality, it was still necessary to perform pm conventional radiographs for comparison of the detailed shape of the restoration. Dental identification or a dental profiling seems to become possible in a noninvasive manner using the Dentascan software.

[The nasopalatine duct cyst--epidemiology, diagnosis and therapy]

The nasopalatine duct cyst is the most frequent nonodontogenic cyst of the jaws. The cyst originates from epithelial remanents from the nasopalatine duct. The cells may be activated spontaneously during life, or are eventually stimulated by the irritating action of various agents (infection, etc.). Generally, patients present without clinical signs and symptoms. Therefore, the tentative diagnosis "nasopalatine duct cyst" is often based on a coincidental radiological finding on a routine panoramic view or occlusal radiograph. The definite diagnosis should be based on clinical, radiological and histopathologic findings. The therapy of nasopalatine duct cysts consists of an enucleation of the cystic tissue, only in rare cases a marsupialization needs to be performed. The present review of the literature presents and discusses the epidemiology, etiology, diagnostic work-up, differential diagnostic aspects, histopatholgy, and therapeutic strategies for nasopalatine duct cysts.

The radiographic assessment of implant patients: decision-making criteria

Indications for the most frequently used imaging modalities in implant dentistry are proposed based on clinical need and biologic risk for the patient. To calculate the biologic risk, the authors carried out dose measurements. They demonstrated that the risk from a periapical radiograph is 20% of that from a panoramic radiograph. A panoramic radiograph and a series of 4 conventional tomographs of a single-tooth gap in the molar region carry 5% and 13% of the risk from computed tomography of the maxilla, respectively. Panoramic radiography is considered the standard radiographic examination for treatment planning of implant patients, because it imparts a low dose while giving the best radiographic survey. Periapical radiographs are used to elucidate details or to complete the findings obtained from the panoramic radiograph. Other radiographic methods, such as conventional film tomography or computed tomography, are applied only in special circumstances, film tomography being preferred for smaller regions of interest and computed tomography being justified for the complete maxilla or mandible when methods for dose reduction are followed. During follow-up, intraoral radiography is considered the standard radiographic examination, particularly for implants in the anterior region of the maxilla or for scientific studies. In patients requiring more than 5 periapical images, panoramic radiography is preferred.

[Interradicular course of the inferior alveolar nerve at the mandibular right third molar and monostotic fibrous dysplasia affecting the mandibular left third molar in the same patient. A case report]

To minimize the risk of intraoperative complications, a comprehensive radiological diagnostic work-up should be a routine procedure in oral surgery. This is especially true concerning possible damage to the inferior alveolar nerve during surgical removal of the third molars. The course and location of the nerve are best assessed when evaluating panoramic view images or cone beam CTs. The following case report demonstrates and discusses the importance of a thorough radiological evaluation before surgery, the problems raised by an interradicular course of the inferior alveolar nerve, and the finding of a monostotic fibrous dyplasia in the same patient.

Maxillary canine impaction in orthodontic patients with and without agenesis: A cross-sectional radiographic study

ABSTRACT Objective: To assess potential associations between maxillary canine impaction (MCI) and agenesis status as well as between MCI and gender. Materials and Methods: The records of 182 orthodontic patients with agenesis (excluding the third molars) and 630 orthodontic patients without agenesis were examined. Diagnosis of MCI was based on pretreatment panoramic radiographs. Maxillary canines that had not erupted as a result of physical barrier or deflection in the eruption path at the dental age of at least 12 years were considered impacted. Logistic regression analysis was used to test for the associations of interest. Results: MCI was detected in 5.6% (n  =  35) of the nonagenesis group (28 female and 7 male participants) and in 18.1% (n  =  33) of the agenesis group (20 female and 13 male participants). Bilateral impaction was detected in 12 patients (34.3%) of the nonagenesis group and in 11 patients (33.3%) of the agenesis group. There was evidence that maxillary lateral incisor agenesis (odds ratio  =  5.1, 95% confidence interval [CI] 2.5-10.5, P < .001) and second premolar agenesis (odds ratio  =  2.6, 95% CI 1.0-6.6, P  =  .042) were significant MCI predictors after adjusting for gender. The odds of MCI were 69% higher in female versus male subjects after adjusting for agenesis status (95% CI 0.97-2.92, P  =  .063). Conclusions: This study indicates that there is evidence that agenesis status is a strong predictor of MCI, whereas gender is a weak predictor of MCI. Caution should be exercised in interpreting the results because of the observational nature of the present study.

[The mental foramen or "the crossroads of the mandible." An anatomic and clinical observation]

This paper presents a clinical and anatomical review of the mental foramen (MF) based on recent publications (since 1990). Usually, the MF is located below the 2nd premolar or between the two premolars, but it may also be positioned below the 1st premolar or below the mesial root of the 1st molar. At the level of the MF, lingual canals may join the mandibular canal (hence the term "crossroads"). Accessory MF are frequently described in the literature with large ethnic variations in incidence. The emergence pattern of the mental canal usually has an upward and posterior direction. The presence and extent of an "anterior loop" of the mental canal may be overestimated with panoramic radiography. Limited cone-beam computed tomography currently appears to be the most precise radiographic technique for assessment of the "anterior loop". The mental nerve exiting the MF usually has three to four branches for innervation of the soft tissues of the chin, lower lip, facial gingiva and mucosa in the anterior mandible. The clinician is advised to observe a safety distance when performing incisions and osteotomies in the vicinity of the MF.

Lateral incisor agenesis, canine impaction and characteristics of supernumerary teeth in a South European male population

Objective: To assess the prevalence of lateral incisor agenesis impacted canines and supernumerary teeth in a young adult male population. Materials and Methods: The panoramic radiographs of 1745 military students (mean age: 18.6 ± 0.52 years) who attended the Center of Aviation Medicine of the Armed Forces of Greece during the period 1997-2011 were initially analyzed for lateral incisor agenesis by two observers. After exclusion of the known orthodontic cases, a subgroup of 1636 examinees (mean age: 18.6 ± 0.44 years) was evaluated for canine impaction and supernumerary teeth. Results: Twenty-eight missing lateral incisors were observed in 22 military students, indicating an incidence of 1.3% in the investigated population. No lateral incisor agenesis was detected in the mandibular arch. A prevalence rate of 0.8% was determined for canine impaction in the sample of young adults. The majority of impacted teeth (86.7%) were diagnosed in the maxillary arch. Thirty-five supernumerary teeth were observed in 24 examinees (prevalence rate: 1.5%). The ratio of supernumerary teeth located in the maxilla versus the mandible was 2.2:1. The most common type of supernumerary tooth was the upper distomolar. Conclusion: The prevalence of lateral incisor agenesis, canine impaction, and supernumerary teeth ranged from 0.8 to 1.5% in the sample of male Greek military students.