Degrees Of Tooth Wear Research Articles

An accurate and efficient method for occlusal tooth wear assessment using 3D digital dental models

Tooth or material wear in a dentition is a common finding that requires timely diagnosis for management and prevention of further loss or associated esthetic or functional impairment. Various qualitative and quantitative methods have been suggested to measure tooth or material wear, but they present with limitations, such as imprecision, subjectivity, or high complexity. Here we developed and assessed an efficient 3D superimposition method to accurately measure occlusal tooth wear on 3D digital dental models. For this purpose, teeth on plaster casts were manually grinded on their occlusal surfaces to simulate various degrees of tooth wear. The casts were scanned using a surface scanner. Grinded tooth crowns (T1) were segmented and compared to the original crowns (T0) using five 3D surface superimposition techniques and a gold standard technique (GS). GS measurements were obtained by using intact adjacent structures as superimposition references. The technique of choice (complete crown with 30% estimated overlap of meshes) showed the best reproducibility (maximum difference < 0.050 mm3) and excellent agreement with the GS technique (median difference: 0.032 mm3). The suggested 3D superimposition method offers a highly efficient and accurate tool for tooth wear assessment, which could be applicable to clinical conditions.

Tooth wear during orthodontic treatment with fixed appliances: a systematic review.

Tooth wear, additional to the physiologic alterations of the dentition, may occur during orthodontic treatment. The objective of the present review was to investigate systematically the literature relevant to its progression in patients having undergone comprehensive orthodontic treatment. Search without restrictions in eight databases since inception and hand searching until October 2017 was performed. Studies evaluating tooth wear immediately before and after the completion of orthodontic treatment with fixed appliance were evaluated independently and in duplicate. Following study retrieval and selection, data on volumetric and surface tooth wear was extracted. Individual study risk of bias assessment was performed using the Risk Of Bias In Non-randomised Studies - of Interventions (ROBINS-I) tool, and the overall quality of the evidence was assessed with the Grades of Recommendation, Assessment, Development and Evaluation approach. All three finally included studies reported wear of teeth during the period of treatment but were at serious risk of bias. Two of them investigated tooth wear by 3D volumetric measurements and one used grading scales. The mean volume reduction was 1.02 mm3 per tooth for the incisor group [95% Confidence Interval (CI): 0.84-1.20], 1.62 mm3 for the canines [95% CI: 0.8-2.38; I2 = 96%; random effects method] and 0.95 mm3 for premolars and molars [95% CI: 0.84-1.07]. The overall quality of evidence limited the confidence in the observed estimates. Varying degrees of tooth wear were reported after comprehensive orthodontic treatment. Further studies are needed in order to elucidate how much is associated with orthodontic treatment and/or physiologic alterations of the dentition.

Oral health-related impact profile in full-mouth restored patients with two different tooth-colored restoration materials.

To analyze the change of oral health impact profile (OHIP) in patients with full-mouth rehabilitations due to moderate/severe tooth wear dependent on different restorative materials (ceramic/experimental CAD/CAM composite). Twenty-nine healthy patients (15 male/14 female, age 44.6 ± 28.4years) requiring full-mouth rehabilitation due to different degrees of tooth wear were instructed to fill the German version OHIP-G49 questionnaire before (baseline) and 30days after prosthetic treatment with ceramic (n = 17) or experimental CAD/CAM composite (n = 12) restorations. Questions were divided into five dimensions: appearance, oral functions, psychosocial impact, linguistic limitations, and orofacial pain; changes between both OHIP-questionnaires for each question and patient were dissected by difference values, separately. Data were analyzed with the Kolmogorov-Smirnov, Wilcoxon's signed-rank, Kruskal-Wallis, Mann-Whitney, and Cronbach's alpha tests (significance level p = 0.01). The appearance dimension showed the highest results (p < 0.001, 100% improvement with all values > 0); the linguistic limitations dimension presented the lowest improvement (p < 0.001). The other three dimensions were not statistically different. No statistical differences between the two materials depending on OHIP questionnaire results occurred. The esthetic appearance of the patients was influenced positively by full-mouth rehabilitation, irrespective of the material used. Improvements were also made in the parameters "toothache" and "problem of food intake." No statements could be made for the parameter "language." With an increasing number of patients with moderate/severe tooth wear, thorough knowledge about the improvement of OHIP is important. This information is advantageous for the consultation and handling of patients when complex treatments are planned.

Impact of tooth wear on masticatory performance

ObjectiveMasticatory performance is influenced by a number of variables such as age, gender, bite force, and occlusal units. Tooth wear may also play a role due to changes in occlusal area and in vertical dimension of occlusion. The aim of this study was to evaluate the effect of tooth wear on masticatory performance, using a communition test. Materials and MethodsPatients with different degrees of tooth wear, referred by their general dental practitioners, and included in the Radboud Tooth Wear Project, were approached for this study and included after informed consent. The amount of post canine wear was scored with the Tooth Wear Index (TWI). The number of occluding posterior units was quantified and the bite force was measured using a transducer. Masticatory performance was measured with a communition test, with the median particle size (X50) after 20 chewing cycles as outcome measure. A multiple regression model was used to assess the relation between TWI, age, gender, bite force, occlusal units and X50. Results52 participants (40 male, 12 female, mean age: 40 ± 8.2y) were included in the study. The post canine TWI-score was between 1.0-3.3. The average number of occlusal units per participant was 11.9 ± 1.4 and the mean bite force 369 ± 172 N. The mean X50 was 4.2 ± 1.1. The results showed no significant relation between post canine TWI-score, age, gender, bite force, and occlusal units upon the X50 (p > 0.13). ConclusionThis study showed that the degree of tooth wear could not be observed to have an effect on masticatory performance. Clinical significanceOn individual level an effect could be present but looking at a larger group of patients, the degree of tooth wear did not have a relation with masticatory performance as measured with a communition test.

Frequency of Obstructive Sleep Apnea Syndrome in Dental Patients with Tooth Wear

To estimate the frequency of obstructive sleep apnea syndrome (OSAS) in dental patients with tooth wear, and to assess the role of dentists in the identification of patients at risk of OSAS. Dental patients with tooth wear and treated with occlusal splint were prospectively recruited to perform sleep study. The severity of tooth wear was established by the treating dentist before patient referral to sleep disorders unit. Sleep questionnaires, anthropometric measurements, and validated respiratory polygraphy were performed. All patients with dental wear were offered a sleepiness analysis. Of 31 recruited patients, 30 (77% males) participated in this study. Patients' mean age was 58.5 ± 10.7 years (range: 35-90 years) and the body mass index was 27.9 ± 3.4 kg/m(2). Tooth wear was mild in 13 patients, moderate in 8 and severe in 9. The mean apnea-hypopnea index (AHI) was 32.4 ± 24.9. AHI < 5 was reported in 2 patients, AHI of 5-29 in 17, and AHI ≥ 30 in 11. A statistically significant association was found between AHI severity and tooth wear severity (Spearman R = 0.505; p = 0.004). Tooth wear could be a tool to identify those patients at risk of having OSAS. This highlights the importance of dental professionals to identify and refer patients with OSAS.

Radiological analysis of the relationship between occlusal tooth wear and mandibular alveolar bone density and height

The aim of this study was to examine the relationship between occlusal tooth wear and mandibular alveolar bone density (ABD) and alveolar bone height (ABH) using computer-assisted densitometric image analysis (CADIA) program. The study was comprised of 134 mandibular first molar teeth in 90 patients with various degrees of occlusal tooth wear. The degree of tooth wear was classified according to the tooth wear index (TWI). Periodontal examinations were performed on all patients and included plaque index, gingival index, probing depth, and clinical attachment loss measurements. ABD and ABH were measured from intraoral digital periapical radiographs and analyzed using CADIA. No increases in ABD were observed between TWI 0 and TWI 1 or between TWI 0 and TWI 2 (P > 0.05). However, increases in ABD were observed between TWI 0 and TWI 3 (P < 0.01), TWI 1 and TWI 3 (P < 0.01), TWI 1 and TWI 2 (P < 0.05) and TWI 2 and TWI 3 (P < 0.05). In addition, ABH was found to increase with increase in wear, with the exception of the interval between TWI 0 and TWI 1. Occlusal tooth wear does not result in any radiologically identifiable changes in the alveolar bone during the initial stages of wear; however, significant increases in both ABD and ABH may be observed as tooth wear progresses.

Dental Abnormalities in Eight Captive Giant Pandas (Ailuropoda melanoleuca) in China

Dental data from eight adult giant pandas (Ailuropoda melanoleuca) (four females and four males) were collected at the Beijing Zoo from February 2009 to July 2010. Examination findings were recorded in dental charts. All the pandas had different degrees of tooth wear. Incisors, canines and second premolars had the most abnormalities. Five animals had caries; molars were the most affected. Chip fractures were found in seven teeth (incisor, canine and premolar) of five pandas; two had complicated fractures of their canines. Premolars and other teeth were missing in three pandas. Different degrees of dental plaque and calculus were found in all animals. Two pandas had mild gingivitis; the depth of periodontal pockets in all pandas was normal (0-2 mm). Five pandas had abnormal tooth mobility. Samples of dental plaque were collected for microbial culture. Two hundred and fifty-three bacterial strains belonging to 48 species of 23 genera were isolated. Streptococcus, Moraxella, Peptostreptococcus and Porphyromonas were the dominant genera. Further research with larger sample sizes of free-ranging and captive giant pandas will be required in order to demonstrate the absence of the premolar tooth, tooth fractures and the relatively low prevalence of periodontal disease in captive giant pandas.

EFFECT OF TOOTH WEAR ON THE RUMINATION-LIKE BEHAVIOR, OR MERYCISM, OF FREE-RANGING KOALAS (PHASCOLARCTOS CINEREUS)

Rumination-like behavior, or merycism, of 5 adult male koalas (Phascolarctos cinereus) with various degrees of tooth wear was investigated using acoustically sensitive radio telemetry. Increased tooth wear was associated with a significant increase in mean rate of merycism mastication, mean number of merycism mastications per bout per 24 h, and mean number of mastications per 24 h. The ratio of mean number of ingestive mastications to mean number of merycism mastications per 24 h remained approximately 17:1 with increasing tooth wear. These results suggest that in contrast to true rumination, alterations in merycism behavior may be important in compensating for reduced molar effectiveness.

The effects of tooth wear on the activity patterns of free-ranging koalas (Phascolarctos cinereus Goldfuss)

The free-ranging activity patterns of five adult males and one sub-adult male koala (Phascolarctos cinereus) with varying degrees of tooth wear were investigated using acoustically sensitive radio-telemetry. Increased tooth wear was found to be associated with a significant decrease in the amount of time spent sleeping and being inactive. Furthermore, compared with individuals with low degrees of tooth wear, individuals with high tooth wear were found to spend considerably less time moving within and between trees, and had home ranges an order of magnitude smaller. Hence, feeding compensations were found to come at the expense of other activities such as sociality and therefore have important consequences for reproductive output. Individuals with high tooth wear also spent longer feeding per bout, and spaced feeding bouts out more evenly throughout a 24-h period, thereby exhibiting reduced degrees of nocturnality. The sub-adult was found to range over a disproportionately large area and spend a relatively large amount of time moving between trees, indicative of a dispersing individual. Moreover, the activity patterns of this individual were found to differ slightly from the adult trends and were perhaps affected by the extra energetic demands associated with dispersal.

The ecology of a late triassic reptile assemblage from gloucestershire, England

Triassic sediments recovered from fissure and cavity systems in Carboniferous Limestone at Cromhall Quarry, Gloucestershire, England have been found to contain abundant reptilian remains. Owing to the lack of spores, the precise ages of the fills are difficult to determined but evidence presented suggests they are Late Norian. Over ten genera of archosaur and lepidosaur have been identified from seven different fissure fills and the different faunal assemblages may represent successional ecosystems. The reptiles are mostly small and the largest, a dinosaur, is no more than one metre long. The lepidosaurs include five or six sphenodontids and the dentitions of four of these are examined in detail. The dietary habits of the sphenodontids are assessed, and by comparison with modern lizards it is concluded that at least one species was herbivorous. Different degrees of tooth wear in some species indicate that there was some intraspecific variation in diet. Interspecific competition partly explains the occurrence of the different proportions of each reptile observed at each of the seven sites.