Significance of Periodontal Risk Assessment in the recurrence of periodontitis and tooth loss

Aim: To investigate the association of the Periodontal Risk Assessment (PRA) model categories with periodontitis recurrence and tooth loss during supportive periodontal therapy (SPT) and to explore the role of patient compliance. Material and Methods: In a retrospective cohort, PRA was performed for 160 patients after active periodontal therapy (APT) and after 9.5 ± 4.5 years of SPT. The recurrence of periodontitis and tooth loss were analysed according to the patient's risk profile (low, moderate or high) after APT and compliance with SPT. The association of risk factors with tooth loss and recurrence of periodontitis was investigated using logistic regression analysis. Results: In 18.2% of patients with a low-risk profile, in 42.2% of patients with a moderate-risk profile and in 49.2% of patients with a high-risk profile after APT, periodontitis recurred. During SPT, 1.61 ± 2.8 teeth/patient were lost. High-risk profile patients lost significantly more teeth (2.59 ± 3.9) than patients with moderate- (1.02 ± 1.8) or low-risk profiles (1.18 ± 1.9) (Kruskal–Wallis test, p=0.0229). Patients with erratic compliance lost significantly (Kruskal–Wallis test, p=0.0067) more teeth (3.11 ± 4.5) than patients compliant with SPT (1.07 ± 1.6). Conclusions: In multivariate logistic regression analysis, a high-risk patient profile according to the PRA model at the end of APT was associated with recurrence of periodontitis. Another significant factor for recurrence of periodontitis was an SPT duration of more than 10 years.

Demonstration of pelvic anatomy by modified midline transection that maintains intact internal pelvic organs

Gross dissection for demonstrating anatomy of the human pelvis has traditionally involved one of two approaches, each with advantages and disadvantages. Classic hemisection in the median plane through the pelvic ring transects the visceral organs but maintains two symmetric pelvic halves. An alternative paramedial transection compromises one side of the bony pelvis but leaves the internal organs intact. The authors propose a modified technique that combines advantages of both classical dissections. This novel approach involves dividing the pubic symphysis and sacrum in the median plane after shifting all internal organs to one side. The hemipelvis without internal organs is immediately available for further dissection of the lower limb. The hemipelvis with intact internal organs is ideal for showing the complex spatial relationships of the pelvic organs and vessels relative to the intact pelvic floor.

Immunohistochemical localization of osteoclastogenic cell mediators in feline tooth resorption and healthy teeth

Tooth resorption is among the most common and most challenging problems in feline dentistry It is a progressive disease eventually leading to tooth loss and often root replacement. The etiology of moth resorption remains obscure and to date no effective therapeutic approach is known. The present study is aimed at assessing the reliability of radiographic imaging and addressing the possible involvement of receptor activator of NF kappa B (RANK), its ligand (RANKL), and osteoprotegerin (OPG) in the process of tooth resorption. Teeth from 8 cats were investigated by means of radiographs and paraffin sections followed by immunolabeling. Six cats were diagnosed with tooth resorption based on histopathologic and radiographic findings. Samples were classified according to a four-stage diagnostic system. Radiologic assessment of tooth resorption correlated very strongly with histopathologic findings. Tooth resorption was accompanied by a strong staining with all three antibodies used, especially with anti-RANK and anti-RANKL antibodies. The presence of OPG and RANKL at the resorption site is indicative of repair attempts by fibroblasts and stromal cells. These findings should be extended by further investigations in order to elucidate the pathophysiologic processes underlying tooth resorption that might lead to prophylactic and/or therapeutic measures. J Vet Dent 27(2); 75 - 83, 2010

Tooth wear and erosion: methodological issues in epidemiological and public health research and the future research agenda

This paper addresses methodological issues in the field of tooth wear and erosion research including the epidemiological indices, and identifies future work that is needed to improve knowledge about tooth wear and erosion.

Prosthetic rehabilitation and treatment outcome of partially edentulous patients with severe tooth wear: 3-years results

The purpose of this study was to report on the management and treatment outcomes of partially edentulous elderly patients with severe tooth wear.

[Multiple tooth resorption in an Italian greyhound]

An Italian greyhound was presented three times during a two-year period for dental prophylaxis due to periodontal disease. Clinical examination revealed lesions on several teeth. Radiographs revealed extensive resorptive root lesions. On histological examination, the presence of odontoclasts and signs of boney remodeling of the roots confirmed the resorptive nature of the lesions. Given the extent of the lesions, and poor prognosis with conservative treatment alone, teeth affected by the most severe resorption were extracted at each visit using a flap technique combined with alveolar vestibular osteotomy. Dental resorptive lesions are rarely detected in the dog but may be more frequent than previously thought. The routine use of dental radiographs can be used to reveal these lesions in the dog.

A history of frequent dental care reduces the risk of tooth loss but not periodontitis in older subjects

OBJECTIVES: Information on the significance of dental care in older adults is limited. We hypothesized that regular dental visits has an effect on the number of remaining teeth and periodontal conditions in older subjects. MATERIALS AND METHODS: 1020 randomly selected individuals age 60 - 96 from the Swedish National Study on Aging and Care Blekinge received a comprehensive oral health examination. RESULTS: Dentate women and men had, on average 18.4 teeth (SD +7.6,) and 18.9 teeth (SD + 7.5) respectively (NS). In the youngest group (60 and 66 years old) with less than one dental visit per year, 37% had >20 teeth, compared with 73% among those with at least annual visits. Among the old-old, comparable figures were 1.8 % and 37% respectively. Across age groups, bleeding on probing was 23 %.When adjusting for age, and number of teeth GLM univariate analysis failed to demonstrate an effect of dental visit frequency on alveolar bone loss (p = 0.18), the number of periapical lesions (p = 0.65), or the number of endodontically treated teeth ( p = 0.41). Frequent dental visitors had more teeth than infrequent visitors (p = 0.001). CONCLUSIONS: Tooth loss and alveolar bone loss severity increase with age. Individuals with regular dental visits retained more teeth but the frequency of dental visits had no impact on plaque deposits, gingival inflammation, or alveolar bone levels.

Monte Carlo Dose Calculation on Deforming Anatomy

This article presents the implementation and validation of a dose calculation approach for deforming anatomical objects. Deformation is represented by deformation vector fields leading to deformed voxel grids representing the different deformation scenarios. Particle transport in the resulting deformed voxels is handled through the approximation of voxel surfaces by triangles in the geometry implementation of the Swiss Monte Carlo Plan framework. The focus lies on the validation methodology which uses computational phantoms representing the same physical object through regular and irregular voxel grids. These phantoms are chosen such that the new implementation for a deformed voxel grid can be compared directly with an established dose calculation algorithm for regular grids. Furthermore, separate validation of the aspects voxel geometry and the density changes resulting from deformation is achieved through suitable design of the validation phantom. We show that equivalent results are obtained with the proposed method and that no statistically significant errors are introduced through the implementation for irregular voxel geometries. This enables the use of the presented and validated implementation for further investigations of dose calculation on deforming anatomy.

Teat anatomy affects requirements for udder preparation in Mediterranean buffaloes

The present study was conducted to assess the interrelation between teat anatomy and machine milking in dairy buffaloes raised in Switzerland. A 3-min pre-stimulation induced milk ejection before cluster attachment in most cases and caused an optimal milk removal during machine milking. In an additional experiment, longitudinal cross-section ultrasound was obtained before and after a 3-min pre-stimulation. Teat wall thickness, teat diameter, cisternal diameter and teat canal length were evaluated. It was observed that 3-min pre-stimulation dramatically reduced teat canal length whereas all the other anatomical parameters remained unchanged. The vacuum needed to open the teat canal was also measured before and after a 3-min pre-stimulation by using a special teat cup with only the mouthpiece of the liner remaining on the top of the teat cup (no liner, no pulsation). Without pre-stimulation but after wetting the teat canal by stripping one squirt of milk out of the teat, no milk could be withdrawn with a vacuum up to 39 kPa. However, after pre-stimulation, milk flow occurred in all buffaloes at a vacuum between 16 and 38 kPa. In the last experiment, the teat tissue was examined in slaughtered buffaloes and compared with teat tissue of cows. No difference was noted in histological sections and teat canal length was similar in cows and buffaloes. Proximal to the teat canal, the teat did not pass into an open cistern but the lumen was collapsed. In conclusion, buffaloes need to be well pre-stimulated because the tissue above the teat canal provides additional teat closure before milk ejection. Therefore, milk can only be obtained after pre-stimulation.

Ultrasound anatomy of the nerves supplying the cervical zygapophyseal joints: an exploratory study

Nerve blocks and radiofrequency neurotomy of the nerves supplying the cervical zygapophyseal joints are validated tools for diagnosis and treatment of chronic neck pain, respectively. Unlike fluoroscopy, ultrasound may allow visualization of the target nerves, thereby potentially improving diagnostic accuracy and therapeutic efficacy of the procedures. The aims of this exploratory study were to determine the ultrasound visibility of the target nerves in chronic neck pain patients and to describe the variability of their course in relation to the fluoroscopically used bony landmarks.

Giulio Cesare Aranzio (Arantius) (1530-89) in the pageant of anatomy and surgery

Giulio Cesare Aranzio in Italian (Julius Caesar Arantius in Latin) has not received full acclaim for his achievements in the field of anatomy and surgery that remain unknown to most physicians. His anatomical books Observationes Anatomicas, and De Humano Foetu Opusculum and surgical books De Tumoribus Secundum Locos Affectos and Hippocratis librum de vulneribus capitis commentarius brevis printed in Latin and additional existing literature on Aranzio from medical history books and journals were analysed extensively. Aranzio became Professor of Anatomy and Surgery at the University of Bologna in 1556. He established anatomy as a distinguished branch of medicine for the first time in medical history. Aranzio combined anatomy with a description of pathological processes. He discovered the 'Nodules of Aranzio' in the semilunar valves of the heart. He gave the first description of the superior levator palpebral and the coracobrachialis muscles. Aranzio wrote on surgical techniques for a wide spectrum of conditions that range from hydrocephalus, nasal polyp, goitre and tumours to phimosis, ascites, haemorrhoids, anal abscess and fistulae, and much more. Aranzio had an extensive knowledge in surgery and anatomy based in part on the ancient Greek and his contemporaries in the 16th century but essentially on his personal experience and practice.

Clinical Study Monitoring the pH on Tooth Surfaces in Patients with and without Erosion

The aim of this study was to compare tooth surface pH after drinking orange juice or water in 39 patients with dental erosion and in 17 controls. The following investigations were carried out: measurement of pH values on selected tooth surfaces after ingestion of orange juice followed by ingestion of water (acid clearance), measurement of salivary flow rate and buffering capacity. Compared with the controls, patients with erosion showed significantly greater decreases in pH after drinking orange juice, and the pH stayed lower for a longer period of time (p < 0.05). Saliva parameters showed no significant differences between the two patient groups except for a lower buffering capacity at pH 5.5 in the erosion group.