Assessment of Age at the Stages of the Eruption of Third Molar Teeth among the People of North-Eastern India.

METHODS: A cross-sectional descriptive and analytical study was undertaken with 1060 Assamese individuals (642 males and 418 females) aged 14-26 years and was subjected to a clinical, dental, and general physical examination from January 2014 to December 2018. The data were statistically analyzed using Microsoft Excel and the Statistical Package for the Social Sciences (SPSS) version 22. The significant differences among variables were tested using the chi-square test and Student's t-test, considering a p value < 0.05 as significant. RESULTS: The carried-out research showed no eruption (NE) status of M3 with an overall mean (±SD) age at 17.39 (±2.273) years, although a significantly lower age among males with a mean age of 16.92 (±2.138) years (p value < 0.001) was observed. The mean age (overall) for the complete eruption (CE) was observed at 20.33 (±2.566) years, which was seen earlier in males. The mandibular M3 appears earlier compared to the maxillary M3. The third molar eruption (TME) on both left and right quadrants of the jaw was observed substantially earlier in the lower jaw, compared to the upper jaw (p value < 0.025). The earliest CE of M3 was marked at 15 years. The differences in the frequencies of TME in different chronological age groups were found significant (p value < 0.001). A significant association between gender and TME (p value < 0.045) in the current study is worth noting. CONCLUSION: Thus, determined by TME as a valid method, age can be used for various purposes to establish a person's identity. Dental age estimated using third molar eruption status has a weighty association with chronological age. Thus, it should be utilized to determine the likely age of an individual.

Age assessment based on third molar mineralisation : An epidemiological-radiological study on a Central-European population.

PURPOSE: The method published in 1973 by Demirjian et al. to assess age based on the mineralisation stage of permanent teeth is standard practice in forensic and orthodontic diagnostics. From age 14 onwards, however, this method is only applicable to third molars. No current epidemiological data on third molar mineralisation are available for Caucasian Central-Europeans. Thus, a method for assessing age in this population based on third molar mineralisation is presented, taking into account possible topographic and gender-specific differences. METHODS: The study included 486 Caucasian Central-European orthodontic patients (9-24 years) with unaffected dental development. In an anonymized, randomized, and blinded manner, one orthopantomogram of each patient at either start, mid or end of treatment was visually analysed regarding the mineralisation stage of the third molars according to the method by Demirjian et al. Corresponding topographic and gender-specific point scores were determined and added to form a dental maturity score. Prediction equations for age assessment were derived by linear regression analysis with chronological age and checked for reliability within the study population. RESULTS: Mineralisation of the lower third molars was slower than mineralisation of the upper third molars, whereas no jaw-side-specific differences were detected. Gender-specific differences were relatively small, but girls reached mineralisation stage C earlier than boys, whereas boys showed an accelerated mineralisation between the ages of 15 and 16. CONCLUSIONS: The global equation generated by regression analysis (age = -1.103 + 0.268 × dental maturity score 18 + 28 + 38 + 48) is sufficiently accurate and reliable for clinical use. Age assessment only based on either maxilla or mandible also shows good prognostic reliability.

Radiographic assessment of lower third molar eruption in different anteroposterior skeletal patterns and age-related groups.

OBJECTIVE: To analyze radiographic predictors for lower third molar eruption among subjects with different anteroposterior skeletal relations and of different age groups. MATERIALS AND METHODS: In total, 300 lower third molars were recorded on diagnostic digital orthopantomograms (DPTs) and lateral cephalograms (LCs). The radiographs were grouped according to sagittal intermaxillary angle (ANB), subject age, and level of lower third molar eruption. The DPT was used to analyze retromolar space, mesiodistal crown width, space/width ratio, third and second molar angulation (α, γ), third molar inclination (ß), and gonion angle. The LC was used to determine ANB, angles of maxillar and mandibular prognathism (SNA, SNB), mandibular plane angle (SN/MP), and mandibular lengths. A logistic regression model was created using the statistically significant predictors. RESULTS: The logistic regression analysis revealed a statistically significant impact of ß angle and distance between gonion and gnathion (Go-Gn) on the level of lower third molar eruption (P < .001 and P < .015, respectively). The retromolar space was significantly increased in the adult subgroup for all skeletal classes. The lower third molar impaction rate was significantly higher in the adult subgroup with the Class II (62.3%) compared with Class III subjects (31.7%; P < .013). CONCLUSION: The most favorable values of linear and angular predictors of mandibular third molar eruption were measured in Class III subjects. For valid estimation of mandibular third molar eruption, certain linear and angular measures (ß angle, Go-Gn), as well as the size of the retromolar space, need to be considered.

Avaliação da ansiedade ao tratamento odontológico e do estresse relacionado à cirurgia de terceiro molar inferior / Assessment of dental anxiety and stress related to inferior third molar surgery

A ansiedade é descrita como um estado emocional transitório que possui uma relação estreita com a dor, e o estresse, um desequilíbrio do organismo em resposta a influências ambientais gerado por um evento desagradável. O objetivo deste estudo foi avaliar a presença de ansiedade ao tratamento odontológico, por meio da Modified Dental Anxiety Scale (MDAS), em pacientes que necessitam de exodontia de terceiro molar inferior e as possíveis associações com parâmetros objetivos, como cortisol e -amilase salivares, que são cada vez mais utilizadas em pesquisas que estudam a resposta do organismo frente a situações adversas. A amostra foi constituída de 30 pacientes com indicação para extração de terceiros molares inferiores erupcionados, sem preferência por gênero ou classe social. Após uma triagem prévia, foi marcado um dia para a entrevista desde que os pacientes atendessem aos critérios de inclusão. Foram coletadas as amostras de saliva em três momentos (entrevista, cirurgia e pós-operatório), todas no mesmo horário (9h00), com intervalo de uma semana. Para avaliação do cortisol e da -amilase foram utilizados kits especificamente formulados e validados para pesquisa em humanos da Salimetrics®..

Os testes foram executados no laboratório Science Pro Ltda. A amostra foi caracterizada quanto ao gênero, idade, escolaridade, renda familiar, evento traumático prévio, intensidade de dor, e ansiedade ao tratamento odontológico. Apenas 3 pacientes foram classificados como ansiosos e 4 relataram algum evento. Estes pacientes foram reunidos em um grupo. Não houve diferença significativa entre este grupo e os não ansiosos em relação às categorias sócio-demográficas e dor pós-operatória. Os valores de cortisol encontrados foram 0.23 g/dl, 0.18 g/dl e 0.19 g/dl e de -amilase, 134.2 U/ml, 162.9 U/ml, 163.5U/ml para os três momentos, respectivamente. Para o grupo ansiosos/ evento, 0.41 g/dl, 0.19 g/dl e 0.30 g/dl de cortisol; 115.7U/ml, 181.7 U/ml, 193.7 U/ml de -amilase. Para o grupo não ansioso, 0.18 g/dl, 0.18 g/dl e 0.16 g/dl de cortisol; 138.8 U/ml, 158.2 U/ml e 155.9 U/ml de -amilase. Foi verificado se havia diferença entre as concentrações dos dois analitos e os momentos em que as amostras de saliva foram coletadas no grupo como um todo e dividido nos dois grupos. Nenhuma associação se mostrou significativa. Os parâmetros biológicos utilizados mostraram-se promissores para o estudo da ansiedade e estresse relacionados ao tratamento odontológico. Envolver pessoas ansiosas neste tipo de pesquisa é uma barreira que precisa ser ultrapassada apesar de todas as dificuldades que se apresentam.

Anxiety is described as a transient emotional state that has a close relationship with the pain, and stress as an unbalance in the body in response to environmental influences generated by an unpleasant event. The aim of this study was to evaluate the presence of anxiety during dental treatment through the Modified Dental Anxiety Scale (MDAS) in patients requiring extraction of third molar and possible associations with objective parameters, such as salivary cortisol and -amylase, which are increasingly used in research studying the response of the organism to adverse conditions. The sample consisted of 30 patients with indication for extraction of third molars erupted, without preference for gender or social class. After a preliminary screening was scheduled for an interview one day since the patients met the inclusion criteria. We collected saliva samples at three time points (interview, surgery and postoperative), all at the same time (9:00 a.m.), with an interval of one week. For the evaluation of cortisol and -amylase kits were used and validated specifically formulated for research in human Salimetrics®. Tests were performed in the laboratory Science Pro Ltd. The sample was characterized by gender, age, education, family income, prior traumatic event, pain intensity and dental anxiety. Only 3 patients were classified as anxious and four reported an event. These patients were divided into one group. There was no significant difference between this group and not anxious in relation to socio-demographic and postoperative pain. The cortisol values found were 0:23 g / dl, 0.18 mg / dl and 0.19 mg / dl and -amylase, 134.2 U / ml, 162.9 U / ml, 163.5U/ml for three times, respectively. For the anxious group / event, 0:41 g / dl, 0.19 mg / dl and 0.30 mg / dl of cortisol, 115.7 U / ml, 181.7 U / ml, 193.7 U / ml of -amylase. For the group not anxious, 0.18 mg / dl, 0.18 mg / dl and 0.16 mg / dl of cortisol,...

Dental age assessment (DAA): a simple method for children and emerging adults.

INTRODUCTION: Methods of dental age assessment (DAA) give a wide margin of error and, because third molars are usually excluded, prevent estimation around the age of 18 years. This study extends the use of defined tooth development stages (TDSs) to include third molars. SUBJECTS AND METHODS: Re-use of dental panoramic tomographs (DPTs) and other X-rays taken for clinical use comprised the sample of 1,547 subjects. The radiographic images were then captured in digital format. The TDSs were assessed and the estimated mean age and its standard error were calculated for each TDS. The mathematical technique of meta-analysis was used to provide an estimate of the mean age, with 99% confidence interval, of a new 'test' subject. To assess the accuracy of the method, each of these mean values was then compared with the gold standard of chronological age. RESULTS: On average, estimated dental age (DA) over-estimated chronological age (CA) by 0.29 years, approximately 3(1/2) months. The maximum likely difference between the estimated DA and CA was 1.65 years. CONCLUSION: Estimation of dental age using well defined TDSs, extended to include third molars and combined with the statistical technique of meta-analysis, provides investigators with a rapid and accurate estimation of age.

Lower third molar eruption following orthodontic treatment.

This study assessed the effect of extraction and preservation of the 1st premolar on lower 3rd molar eruption. Orthodontic clinic records from 1993 to 1995 were evaluated before and after treatment and 8-9 years after treatment for 3 groups of patients: 32 with extraction of 1st premolars in both jaws, 32 with no extraction but orthodontic treatment and 48 controls with no extraction but orthodontic treatment in the upper jaws only. Successful eruption of 3rd molars was evaluated. There was a significant difference in the rates of successful eruptions in the extraction (42%), non-extraction (12%) and control (20%) groups. The findings indicate that 1st premolar extraction may increase the chance of 3rd molar eruption, leading to a lower incidence of health and economic complications.

Eruption of third permanent molars after the extraction of second permanent molars. Part 1: Assessment of third molar position and size.

The eruptive path of third molars after extraction of second molars was examined in 63 patients. Panoramic radiographs from the start and the end of active treatment and 3 or more years after treatment were assessed. Study models were used to compare the size of the second and third molars and to assess the final position of the third molars. All third molars erupted; none became impacted. During eruption, maxillary third molar crowns uprighted and maintained their angulation as they came into occlusion. Mandibular third molar crowns continued to upright significantly mesiodistally after active treatment, with space closure the result of horizontal translation rather than mesial tipping. Further uprighting occurred once occlusion was established, although few became as upright as the second molars they replaced. However, mandibular third molar roots were frequently curved distally, thus the third molar crown position was invariably better than the overall tooth angulation would suggest, by 16.5 degrees on average. Model analysis (Richardsons' scoring system) showed 96% of mandibular and 99% of maxillary third molars erupted into a good or acceptable position. Limitations of this scoring system are discussed. The mesiodistal size of third molars was suitable to replace second molars; on average, mandibular third molars were 0.55 mm larger and maxillary third molars were 0.7 mm smaller than second molars.

A study of the validity of a simulation of third molar eruption based on Markov modelling.

PURPOSE OF INVESTIGATION: The study was undertaken to examine the extent to which a model based on a Markov modelling process would simulate the eruption of lower third molars. BASIC PROCEDURE: A Markov process model was developed to model eruption of lower third molars using a 1-year time increment based on simulated eruption data relating to 100 lower third molars. This model was tested using a Monte Carlo simulation and compared with eruption patterns of 973 actual lower third molars. Statistical analysis of the differences between the simulated and actual groups was undertaken. MAIN FINDINGS: There were no differences between the simulated and actual data other than for the subgroup aged 30-34 where the simulation overestimated the probability of parteruption and underestimated the probability of uneruption and full eruption. PRINCIPAL CONCLUSIONS: This methodology produced an accurate model that may be of use in service planning.