Age assessment in the living using modified Gustafson's criteria in a northern Chinese population.

Regressive dental changes appear to be suitable for age assessment in living adults. In 2012, Olze et al. showed that several criteria presented by Gustafson for extracted teeth can also be applied to orthopantomograms. The objective of this study was to test the applicability and reliability of this method in a Chinese population. For this purpose, 1300 orthopantomograms of 650 female and 650 male Chinese aged between 15 and 40 years were evaluated. The characteristics of secondary dentin formation, periodontal recession, attrition, and cementum apposition were reviewed in all the mandibular premolars. The sample was split into a training and test dataset. Based on the training set, the correlation of the individual characteristics with chronological age was studied with a stepwise multiple regression analysis, in which individual characteristics formed the independent variable. According to the results, the R values amounted to 0.80 to 0.83; the standard error of estimate was 4.29 to 4.75 years. By analyzing the test dataset, the accuracy of the present study, Olze's and Timme's formulas were determined by the difference between the estimated dental age (DA) and chronological age (CA). Taking both mean differences and mean absolute differences into account, the Chinese age estimation formula did not always perform better compared with Olze's and Timme's formulas for both males and females. It was concluded that this method can be used in Chinese individuals for age assessment. However, the applicability of the method is limited by the quality of the X-ray images, and the method should only be applied by experienced forensic odontologists.

Evaluation of tooth wear by estimating enamel thickness with quantitative light-induced fluorescence technology.

BACKGROUND: Various techniques have been suggested to quantitatively assess tooth wear; most have limited clinical application. The first aim of this in vitro study was to estimate the residual enamel thickness of teeth with various degrees of occlusal wear using quantitative light-induced fluorescence (QLF). The second aim was to identify relationships between the fluorescence parameters of QLF and the conventional tooth wear index (TWI) system. METHODS: Sixty-nine extracted permanent premolars and molars with initial stages of tooth wear (TWI score 1a-2: enamel wear to dentin exposure) were used. Two blinded and trained examiners participated in evaluation procedures. Occlusal QLF-digital (QLF-D) images were acquired for selecting area of interest (AOI) and calculating fluorescence for occlusal tooth wear (ΔFwear) of the AOI by the first examiner. Each specimen was cross-sectioned in the buccal-lingual direction. Enamel thickness from images obtained by stereomicroscopy and TWI of each sample was determined by the second examiner. Spearman correlation was used to determine the relationship of ΔFwear with enamel thickness and TWI. ΔFwear values were compared between histological scores with the Mann-Whitney U test. RESULTS: Seventy-six AOIs were analyzed. As enamel thickness decreased, ΔFwear values significantly increased and strongly correlated with enamel thickness (Spearman rho = -0.825, P < 0.001). There were significant differences in ΔFwear values among TWI scores (P < 0.001); ΔFwear strongly correlated with TWI (Spearman rho = 0.753, P < 0.001). CONCLUSIONS: ΔFwear values, which denote fluorescence difference by using QLF, showed a strong correlation with residual enamel thickness and tooth wear severity.

Age estimation using Olze's method in an adult Brazilian population.

OBJECTIVES: Age estimation is important to set an anthropological profile in human remains, as well as in legal issues where the suspect or victim doesn't have documents that prove the real age. The age estimation, in adults, is a challenge, and it can be analyzed through some dental stages. This study aimed to test Olze's method in a Brazilian sample composed by adults, aged between 20 and 70 years old, both sex. METHODS: For experiments, 306 orthopantomography from Brazilian individuals between 20 and 70 years were selected. The dental involution through four different dental parameters were classified and the correlation between chronological age and the estimated age was examined by means of a multiple regression analysis. RESULTS: The results showed that up to 41 years old, the correlation between real age and the interval obtained was considered strongly positive (R = 0.8-1), and the percentage of matching was 78.78% for men and 71.21% for women. From 42 years old up, the correlation between real age and the estimation was considered null (R = 0) for both sex, and the percentage of matching was 17.24% for men and 6.89% for women. CONCLUSION: It could be concluded that the method is effective for age estimation up to 41 years old, but has limitations to be used over this age in Brazilian people.

Dental age estimation in the living after completion of third molar mineralization: new data for Gustafson's criteria.

There is a need for dental age estimation methods after completion of the third molar mineralization. Degenerative dental characteristics appear to be suitable for forensic age diagnostics beyond the 18th year of life. In 2012, Olze et al. investigated the criteria studied by Gustafson using orthopantomograms. The objective of this study was to prove the applicability and reliability of this method with a large cohort and a wide age range, including older individuals. For this purpose, 2346 orthopantomograms of 1167 female and 1179 male Germans aged 15 to 70 years were reviewed. The characteristics of secondary dentin formation, cementum apposition, periodontal recession and attrition were evaluated in all the mandibular premolars. The correlation of the individual characteristics with the chronological age was examined by means of a stepwise multiple regression analysis, in which the chronological age formed the dependent variable. Following those results, R 2 values amounted to 0.73 to 0.8; the standard error of estimate was 6.8 to 8.2 years. Fundamentally, the recommendation for conducting age estimations in the living by these methods can be shared. The values for the quality of the regression are, however, not precise enough for a reliable age estimation around regular retirement date ages. More precise regression formulae for the age group of 15 to 40 years of life are separately presented in this study. Further research should investigate the influence of ethnicity, dietary habits and modern health care on the degenerative characteristics in question.

Full-mouth composite rehabilitation of a mixed erosion and attrition patient: a case report with v-shaped veneers and ultra-thin CAD/CAM composite overlays.

Loss of tooth substance has become a common pathology in modern society. It is of multifactorial origin, may be induced by a chemical process or by excessive attrition, and frequently has a combined etiology. Particular care should be taken when diagnosing the cause of dental tissue loss, in order to minimize its impact. Several publications have proposed the use of minimally invasive procedures to treat such patients in preference to traditional full-crown rehabilitation. The use of composite resins, in combination with improvements in dental adhesion, allows a more conservative approach. In this paper, we describe the step-by-step procedure of full-mouth composite rehabilitation with v-shaped veneers and ultra-thin computer-aided design/computer-assisted manufacture (CAD/CAM)- generated composite overlays in a young patient with a combination of erosion and attrition disorder.

Radiographic evaluation of Gustafson's criteria for the purpose of forensic age diagnostics.

The main criteria used in dental age estimation in living young individuals are mineralisation and eruption of the third molars. In order to further diversify the spectrum of characteristics after completion of third molar development, tests were undertaken to determine whether the characteristics studied by Gustafson can be ascertained with the required forensic certainty with the aid of the orthopantomogram and whether the evaluation of these could render forensic odontological age diagnoses possible beyond the 18th year of life. For this purpose, 1,299 conventionally produced orthopantomograms of 650 female and 649 male Germans aged from 15 to 40 years were studied. The characteristics of secondary dentin formation, cementum apposition, periodontal recession and attrition were evaluated in all the mandibular premolars. The correlation of the individual characteristics with chronological age was studied with the aid of a multiple regression analysis in which chronological age formed the dependent variable. Depending on the tooth studied, the R values amounted to 0.65 to 0.73; the standard error of estimate was 5.3 to 5.7 years. Basically, the regression equations calculated can be recommended for age estimation in living individuals, although it should be borne in mind that the applicability of the new method presented is limited by the quality of the X-ray images.

Occlusal wear following orthodontic treatment assessed by 3D CT scanning.

AIM: To evaluate occlusal wear after comprehensive orthodontic treatment. METHODS: Consecutive pre- and posttreatment dental casts of 30 patients who had received orthodontic treatment with stainless steel fixed appliances in both dental arches at the postgraduate clinic of Aristotle University of Thessaloniki were digitized by means of a three-dimensional CT scanner. The final sample consisted of 1,256 individual teeth (628 reference-free 3D superimpositions). The data were statistically assessed. Five randomly selected pairs of pre- and posttreatment casts were measured twice; the results were compared by paired t test. The magnitude of the method's error was 0.188 mm(3) (P =.229). RESULTS: After orthodontic treatment, almost all examined teeth had decreased in volume. The mean decrease was 1.03 mm(3) per tooth (P < .001). Treatment duration greater than 30 months was associated with a significant increase in occlusal wear (P < .001). No significant differences were found between extraction and nonextraction treatments, males and females, or different groups of teeth or malocclusions. CONCLUSION: There seems to be a relationship between orthodontic treatment and occlusal wear, which deserves serious attention and further investigation.

[Adoption of the condyle position of patients with extensive tooth wear during occlusal rehabilitation].

OBJECTIVE: To evaluate the adoption of the condyle position of patients with extensive tooth wear during occlusal rehabilitation, and the correlation between increased vertical dimensions and the changes of joint spaces. METHODS: Twenty-seven patients (five from Beifang hospital, others from Peking University School and Hospital of Stomatology) with extensive tooth wear were selected and received occlusal rehabilitation treatment. The radiographs of standard Schüllers position were taken before treatment (stage 1), 1 month following delivery of temporary restoration (stage 2), and 1 month following delivery of permanent restoration (stage 3). RESULTS: The superior, anterior and posterior joint spaces were (3.24 ± 0.16), (2.06 ± 0.11), (1.89 ± 0.13) mm at stage 1; (3.61 ± 0.15), (1.94 ± 0.10), (2.52 ± 0.11) mm at stage 2; (3.49 ± 0.19), (1.93 ± 0.10), (2.40 ± 0.13) mm at stage 3. The posterior joint spaces at stage 2 and stage 3 were significantly larger than that at stage 1(P < 0.01). The superior spaces at stage 2 were significantly larger than that at stage 1 (P < 0.05). No correlations between the increased vertical dimensions and the changes of joint spaces were found in the three stages (P > 0.05). CONCLUSIONS: The condyle positions in the patients with extensive tooth wear changed after occlusal rehabilitation.

Dental status of three Egyptian mummies: radiological investigation by multislice computerized tomography.

OBJECTIVE: The aim of the study was to provide a paleopathologic and radiologic overview of the jaws and teeth of 3 Egyptian mummies preserved in the Civic Museum of History and Art in Trieste. Computerized tomography (CT) imaging and postprocessing techniques were used to examine the oral structures. STUDY DESIGN: A 16-slice CT scanner was used (Aquilion 16; Toshiba Medical Systems Europe, Zoetermeer, The Netherlands). Scans were obtained at high resolution. Orthogonal-plane and 3-dimensional (3D) reconstructions were created along with curved reconstructions of the lower and upper jaws. Determination of decayed/missing teeth (DMT) and decayed/missing/tooth surfaces (DMTs) were made with 3D images. RESULTS: Analyses revealed differences in the embalming techniques and state of preservation of the bodies. Marked wear of the occlusal surfaces was a characteristic finding in all of the mummies. The DMT and DMTs were low compared with values for contemporary populations. Two mummies had fully erupted third molars. All mummies exhibited bone changes consistent with periodontitis. CONCLUSION: The CT evaluations of the oral structures of the mummies provided insight into the dental status and oral diseases of these ancient Egyptians. The low DMT and DMTs values and indications of periodontitis may be associated with the lifestyle of these Egyptians. The fully erupted and well aligned third molars may represent a morphologic adaptation of the arches to the muscular activity associated with grinding tough foods.

Oral rehabilitation of a patient with hypoplastic amelogenesis imperfecta: a case report.

To report a case of oral rehabilitation of a patient diagnosed with hypoplastic amelogenesis imperfecta. A 18-year-old female with hypoplastic amelogenesis imperfecta presented for prosthodontic treatment to eliminate tooth sensitivity while enhancing esthetics and restoring masticatory function. Treatment included, lengthening of the maxillary and mandibular clinical crowns, and placement of metal-ceramic fixed partial dentures. The 1-year recall examination revealed no pathology associated with the rehabilitation, and the patient's esthetic and functional expectations were satisfied. For successful prosthodontic therapy, the clinician should be aware of all condition of patient.

Treatment of a patient with severely worn dentition: a clinical report.

This clinical report documents the prosthodontic treatment of a Prosthodontic Diagnostic Index Class IV 63-year-old white male, referred to the prosthodontic clinic by his general dentist for evaluation and treatment. The patient was concerned about the severe wear on his teeth and understood the need for comprehensive (full-mouth) rehabilitation to restore his dental condition. The clinical findings, diagnosis, treatment plan, and sequence of treatment are presented.

Craniofacial identification by computer-mediated superimposition.

Mass disasters are associated with a large number of fatalities, with victims being visually unidentifiable in most cases. Dental identification, although being an important and valuable identification method, is subject to the availability and quality of antemortem and postmortem dental records. This paper presents a simple-to-use method of human identification using an antemortem photograph showing anterior teeth with superimposition onto a postmortem image using specific features of Adobe Photoshop. We present cases and discuss the benefits and difficulties of this method.

Thickness measurement of worn molar cusps by ultrasound.

This study aimed to evaluate the effectiveness of an ultrasonic system for in vitro measurement of cusp tips of human teeth. Each worn cusp of 12 molar teeth was measured with an industrial ultrasonic system. The teeth were sectioned and measured by polarized light microscopy. The ultrasonic measurements and histological readings were moderately correlated (r = 0.601, p < 0.01). The ultrasonic system used in this study seemed a promising method for measuring thickness of worn cusp tips of extracted human molar teeth.

A comparison of the erosive susceptibility of cuspal and cervical enamel using an ultrasonic technique.

The aim of this study was to compare the erosive susceptibility of cuspal and cervical enamel from human premolar and molar teeth. Small blocks of cervical and cuspal enamel were immersed in either orange juice or Coca-Cola at 37 degrees C and the surface enamel loss was measured by surfometry at 1, 2, 3 and 4 h. Additionally, once-hourly enamel loss was measured, specimens were placed in an ultrasonic bath containing water and ultrasonicated for 5 s to determine the degree of surface demineralization. A further set of enamel specimens were prepared that had 100 microm of the enamel surface removed. This was done to remove the hypermineralized surface enamel layer. Surface enamel loss in orange juice at 4 h, following ultrasonication, ranged from 13.2 to 16.9 microm. The surface enamel loss in Coca-Cola at 4 h, following ultrasonication, ranged from 21.7 to 27.5 microm. Subsurface enamel loss in orange juice at 4 h, following ultrasonication, ranged from 10.7 to 16.1 microm. The subsurface enamel loss in Coca-Cola for 4 h, following ultrasonication, ranged from 36.8 to 37.2 microm. Overall, little difference was found in the erosive susceptibility of cervical and cuspal enamel to the effects of orange juice or Coca-Cola.

Factors affecting the lifespan of the human dentition in Britain prior to the seventeenth century.

OBJECTIVE: To confirm that compensatory eruption (supereruption) of teeth past a stable periodontium occurs in response to severe occlusal attrition. DESIGN: Regression analysis study from radiographs and direct measurements. SETTING: Archaeological material at the University of Aberdeen. SUBJECTS: 47 individuals > 21 years old and dating from Late Mediaeval times (1300-1600 AD). MAIN OUTCOME MEASURES: Occlusal attrition was recorded on the first permanent mandibular molars. Measurements on radiographs of the teeth from the fixed point of the inferior dental canal were taken to the occlusal surface, the alveolar crest and the tooth apex. Regression analysis was undertaken between these variables and related to attrition (age). RESULTS: Continuous eruption of the permanent human dentition past a stable periodontium does occur in response to tooth height lost by wear, despite the fact that supereruption may lead to the eventual self destruction of the dentition. This mechanism was primarily responsible for the early loss (at 40-45 years of age) of dentitions in Mediaeval times. CONCLUSIONS: Stability of occlusal height appears to be an important function of the dentition and if triggered by severe wear will lead to increasing root exposure and eventual exfoliation of the teeth. It is important not to confuse bone loss due to periodontitis with root exposure due to supereruption of the teeth.