Dental age estimation of Malaysian children: a comparison of two-dimensional versus three-dimensional imaging analyses of the developing root apices.

AIM: This study compared the effectiveness of the three-dimensional (3D) cone beam computed tomography (CBCT) method of age estimation developed by Asif et al. with two-dimensional Cameriere's method. SUBJECTS AND METHODS: CBCT images belonging to 129 Malaysian Chinese and Malay ethnic groups aged 7-14 years were investigated and analysed. RESULTS: The results indicated a strong correlation between chronological age and the predictor variables for both Cameriere's (r = 0.984) and Asif's (r = 0.988) methods of age estimation. Fisher Z test analysis indicated no statistically significant difference in the correlation values between the two methods. Mean absolute error (MAE) value of 0.613 was observed for Cameriere's and 0.290 was observed for Asif's method. CONCLUSIONS: The results indicated that the methods of age estimation from both Asif et al. and Cameriere et al. are applicable on Malaysian children. However, Asif et al.'s 3D CBCT method of age estimation resulted in greater accuracy and reliability in estimating chronological age.

Pre-schoolers' tooth brushing behaviour and association with their oral health: a cross sectional study.

BACKGROUND: Toothbrushing is an important yet neglected behaviour that affects the oral health of preschool children. Little is reported on parental supervision, an essential aspect of routine effective toothbrushing in this age group. The aim of this study was to evaluate pre-schoolers' toothbrushing behaviour including parental involvement and its association with their oral health. METHODS: This was a cross-sectional study. A total of 92 preschool children (4-6 years) were invited to participate with their parents/guardians. Nine parameters of toothbrushing behaviour were assessed from parental responses (questionnaire) and observation of child and parents/guardians (video recording). Oral examination included recording plaque, gingival and dental caries indices. BORIS software was used to assess toothbrushing parameters and Smart PLS was used to perform association with a second-generation multivariate analysis to create models with and without confounding factors. RESULTS: Girls were slightly more (53%) than boys (47%). Children aged 4 years were slightly more in number (38%), followed by 6-year-olds and 5-year-olds. Nearly, 90% parents had tertiary education and 46% had more than 2 children. Differences were recorded in the reported and observed behaviour. Thirty-five percent parents/guardians reported using pea-size toothpaste amount but only 28% were observed. Forty percent reported to brush for 30 s-1 min, however 51% were observed to brush for 1-2 min. Half the children were observed to use fluoridated toothpaste (F < 1000 ppm) under parental supervision (11%). The mean (SD) plaque score reduction after toothbrushing was 10.80 (2.46), mean pre-brushing plaque score was 90.3 (10.2), mean gingival index was 0.89 (0.65) and mean dental caries status (ICDAS(1-6)) was 18.87 (12.39). Toothbrushing behaviour in terms of toothbrushing technique, duration, pattern and frequency, toothbrush type and grip type, toothpaste type and amount, post-brushing mouth rinsing and parental involvement contributed significantly to plaque score change (86%), dental caries status (73%), gingival index (66%) and pre-brushing plaque score (31%). The significant confounding variables had a small influence on oral health of preschool children. CONCLUSIONS: Preschool children's toothbrushing behaviour was inadequate while their oral health was poor, with a significant association between the two parameters.

Enhancing the three-dimensional visualization of a foreign object using Mimics software.

A patient was referred to the Oral and Maxillofacial Imaging Division and the attending dental specialist suspected a foreign object at the anterior region of the maxilla. The region was scanned using Kodak 9000 3D cone-beam computed tomography (CBCT) extraoral imaging system (Carestream Health, Inc.) to determine the type and morphometric characteristic of foreign object. The CBCT images failed to determine the identity and nature of the foreign object. CBCT images were then exported to the Materialise Interactive Medical Image Control System (Mimics) software to evaluate whether this software can help in enhancing the visualization of the foreign object in the maxillofacial region. The findings showed that there was an improved visualization of the foreign body and the type of the object could be determined with certainty. The object was identified as an endodontic file and was clearly visible when visualized as a reconstructed 3D model in Mimics software. Although the identification of abnormalities has been dramatically improved using 3D scans, the visualization can be further enhanced using image processing software like Mimics.

Three-dimensional image analysis of developing mandibular third molars apices for age estimation: A study using CBCT data enhanced with Mimics & 3-Matics software.

Three-dimensional imaging has improved the method of analysis in many forensic science investigations. The study aimed to derive regression equation for age estimation by investigating the relationship between chronological age and surface area of the developing mandibular 3rd molars apices. Furthermore, other predictor variables: ethnicity (Malay and Chinese), gender and status of the root development completion (open/closed apices) were also investigated in terms of fit to the age estimation model. One hundred and twenty eight training and 55 validation samples of intact mandibular 3rd molars were selected from 183 CBCT scans. The samples comprised of 93 Malays and 90 Chinese, ranging in age from 13 to 24 years. Three-dimensional image modeling and surface area analysis of the developing mandibular 3rd molars apices were performed using Mimics and 3-Matics software. Multiple linear regression analysis was used to derive age estimation model using chronological age as a dependent variable and surface area of the apices, ethnicity, gender and status of the root development completion (open/closed apices) as predictor variables. A strong inverse correlation (r = 0.95, SD = 1.144) was observed between chronological age and all the predictor variables. The results showed that 89.6% of the variation in age can be explained by the predictor variables. Mean absolute error (MAE) value of 0.8223 was observed when the derived regression equation was tested on the independent validation sample. In conclusion, three-dimensional surface area analysis of the developing mandibular 3rd molars apices can be used as a reliable method for age estimation.

Dental age estimation in Malaysian adults based on volumetric analysis of pulp/tooth ratio using CBCT data.

Forensic odontology plays an important role in human identification and dental age estimation is an integral part of this process. The aim of the study was to investigate the association between chronological age and pulp/tooth volume ratio in a Malaysian population (Malays and Chinese) from cone-beam computed tomography (CBCT) scans, enhanced with Mimics software. Three hundred CBCT scans of 153 males and 147 females, aged between 16 and 65 years were divided into 5 age groups. Volumetric analysis of the pulp/tooth ratio was performed in maxillary left canines, maxillary right canines and maxillary right central incisors. Simple linear regression and Pearson correlation analysis indicated the strongest coefficient of correlation (R) values for maxillary right central incisors (0.83) followed by maxillary right canines (0.74) and maxillary left canines (0.73). Fisher's Z test indicated that dental age estimation is gender independent. The derived regression equations were further validated on an independent group of 126 teeth. The results indicated mean absolute error (MAE) values of 6.48 and 8.58 years for maxillary right central incisors and maxillary canines respectively. It was also noticed that MAE values were higher among the age groups ranging from 46 to 65 years. This study showed that a volumetric change in the pulp cavity with age is a valuable assessment method for dental age estimation among Malaysian population.

Dental age estimation employing CBCT scans enhanced with Mimics software: Comparison of two different approaches using pulp/tooth volumetric analysis.

The methods of dental age estimation and identification of unknown deceased individuals are evolving with the introduction of advanced innovative imaging technologies in forensic investigations. However, assessing small structures like root canal volumes can be challenging in spite of using highly advanced technology. The aim of the study was to investigate which amongst the two methods of volumetric analysis of maxillary central incisors displayed higher strength of correlation between chronological age and pulp/tooth volume ratio for Malaysian adults. Volumetric analysis of pulp cavity/tooth ratio was employed in Method 1 and pulp chamber/crown ratio (up to cemento-enamel junction) was analysed in Method 2. The images were acquired employing CBCT scans and enhanced by manipulating them with the Mimics software. These scans belonged to 56 males and 54 females and their ages ranged from 16 to 65 years. Pearson correlation and regression analysis indicated that both methods used for volumetric measurements had strong correlation between chronological age and pulp/tooth volume ratio. However, Method 2 gave higher coefficient of determination value (R2 = 0.78) when compared to Method 1 (R2 = 0.64). Moreover, manipulation in Method 2 was less time consuming and revealed higher inter-examiner reliability (0.982) as no manual intervention during 'multiple slice editing phase' of the software was required. In conclusion, this study showed that volumetric analysis of pulp cavity/tooth ratio is a valuable gender independent technique and the Method 2 regression equation should be recommended for dental age estimation.