Displaying all 13 publications

Abstract:
Sort:
  1. Wilson YP, Nambiar P, Yaacob H, Asif MK
    Med Leg J, 2021 Dec;89(4):254-259.
    PMID: 34758645 DOI: 10.1177/00258172211052930
    We investigated the development of third molars among Malaysians (including variations between jaws and genders) using Demirjian's method. Dental panoramic radiographs of 1224 subjects aged 8 to 24 years were examined, and the molars were assigned Demirjian et al.'s development grades (A-H). Results indicated that 18.8% had congenitally missing or extracted third molars. Development of molars begins earlier in females (also in the mandible), but by age 9, male children's molar development speeds up with more advanced grades in their middle teens than females. Grade C indicates the subject is a juvenile, while initiation of root development (Grade E), was observed from 13 years on. Grade H can occur in a child aged 18 years who technically is still a juvenile. We compared the development and growth patterns of the third molar from both the maxilla and the mandible.
  2. Asif MK, Nambiar P, Ibrahim N, Al-Amery SM, Khan IM
    Leg Med (Tokyo), 2019 Jul;39:9-14.
    PMID: 31158731 DOI: 10.1016/j.legalmed.2019.05.003
    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.
  3. Asif MK, Ibrahim N, Sivarajan S, Heng Khiang Teh N, Chek Wey M
    Am J Orthod Dentofacial Orthop, 2020 Oct;158(4):579-586.e1.
    PMID: 32826123 DOI: 10.1016/j.ajodo.2019.09.022
    INTRODUCTION: The study aimed to investigate the effects of micro-osteoperforations (MOPs) on the mandibular bone volume/tissue volume (BV/TV) ratio changes and the rate of orthodontic tooth movement using cone-beam computed tomography images. Another objective was to evaluate the effects of MOP frequency intervals (4 weeks, 8 weeks, and 12 weeks) on the BV/TV ratio and rate of tooth movement.

    METHODS: In 24 participants, 140-200 g of force was applied for mandibular canine retraction. Three MOPs were made according to the scheduled intervals of the 3 different groups: group 1 (MOP 4 weeks), group 2 (MOP 8 weeks), and group 3 (MOP 12 weeks) directly at the mandibular buccal cortical bone of extracted first premolars sites. Cone-beam computed tomography scans were obtained at the 12th week after MOP application. Computed tomography Analyzer software (version 1.11.0.0; Skyscan, Kontich, Belgium) was used to compute the trabecular alveolar BV/TV ratio.

    RESULTS: A significant difference was observed in the rate of canine movement between control and MOP. Paired t test analysis showed a significant difference (P = 0.001) in the mean BV/TV ratio between control and MOP sides in all the frequency intervals groups. However, the difference was significant only in group 1 (P = 0.014). A strong negative correlation (r = -0.86) was observed between the rate of canine tooth movement and the BV/TV ratio at the MOP side for group 1 and all frequency intervals together (r = -0.42).

    CONCLUSIONS: The rate of orthodontic tooth movement can be accelerated by the MOP technique with frequently repeated MOPs throughout the treatment.

  4. Sultan T, Cheah CW, Ibrahim NB, Asif MK, Vaithilingam RD
    J Dent, 2020 Oct;101:103455.
    PMID: 32828845 DOI: 10.1016/j.jdent.2020.103455
    OBJECTIVES: This clinical study assessed and compared the linear and volumetric changes of extraction sockets grafted with a combination of Platelet-Rich Fibrin (PRF) and Calcium Sulfate (CS) (PRF-CS), and extraction sockets grafted with a combination of PRF and xenograft (X) (PRF-X).

    METHODS: Five single maxillary premolar extraction sockets received PRF-CS grafts and five single maxillary premolar sockets received PRF-X grafts. Linear (horizontal and vertical) measurements were accomplished using Cone Beam Computed Tomography (CBCT) images and volumetric changes were assessed using MIMICS software. Soft tissue level changes were measured using Stonecast models. All measurements were recorded at baseline (before extraction) and at 5-months post-extraction.

    RESULTS: Significant reduction in vertical and horizontal dimensions were observed in both groups except for distal bone height (DBH = 0.44 ± 0.45 mm, p = 0.09) and palatal bone height (PBH = 0.39 ± 0.34 mm, p = 0.06) in PRF-X group. PRF-CS group demonstrated mean horizontal shrinkage of 1.27 ± 0.82 mm (p = 0.02), when compared with PRF-X group (1.40 ± 0.85 mm, p = 0.02). Vertical resorption for mesial bone height (MBH = 0.56 ± 0.25 mm, p = 0.008), buccal bone height (BBH = 1.62 ± 0.91 mm, p = 0.01) and palatal bone height (PBH = 1.39 ± 0.87 mm, p = 0.02) in PRF-CS group was more than resorption in PRF-X group (MBH = 0.28 ± 0.14 mm, p = 0.01, BBH = 0.63 ± 0.39 mm, p = 0.02 and PBH = 0.39 ± 0.34 mm, p = 0.06). Volumetric bone resorption was significant within both groups (PRF-CS = 168.33 ± 63.68 mm3, p = 0.004; PRF-X = 102.88 ± 32.93 mm3, p = 0.002), though not significant (p = 0.08) when compared between groups. In PRF-X group, the distal soft tissue level (DSH = 1.00 ± 0.50 mm, p = 0.03) demonstrated almost 2 times more reduction when compared with PRF-CS group (DSH = 1.00 ± 1.00 mm, 0.08). The reduction of the buccal soft tissue level was pronounced in PRF-CS group (BSH = 2.00 ± 2.00 mm, p = 0.06) when compared with PRF-X group (BSH = 1.00 ± 1.50 mm, p = 0.05).

    CONCLUSIONS: PRF-CS grafted sites showed no significant difference with PRF-X grafted sites in linear and volumetric dimensional changes and might show clinical benefits for socket augmentation. The study is officially registered with ClinicalTrials.gov Registration (NCT03851289).

  5. Ibrahim N, Asif MK, Sivarajan S, Teh NHK, Wey MC
    Am J Orthod Dentofacial Orthop, 2021 02;159(2):e83.
    PMID: 33546837 DOI: 10.1016/j.ajodo.2020.11.009
  6. Tai MW, Chong ZF, Asif MK, Rahmat RA, Nambiar P
    Leg Med (Tokyo), 2016 Sep;22:42-8.
    PMID: 27591538 DOI: 10.1016/j.legalmed.2016.07.009
    This study was to compare the suitability and precision of xerographic and computer-assisted methods for bite mark investigations. Eleven subjects were asked to bite on their forearm and the bite marks were photographically recorded. Alginate impressions of the subjects' dentition were taken and their casts were made using dental stone. The overlays generated by xerographic method were obtained by photocopying the subjects' casts and the incisal edge outlines were then transferred on a transparent sheet. The bite mark images were imported into Adobe Photoshop® software and printed to life-size. The bite mark analyses using xerographically generated overlays were done by comparing an overlay to the corresponding printed bite mark images manually. In computer-assisted method, the subjects' casts were scanned into Adobe Photoshop®. The bite mark analyses using computer-assisted overlay generation were done by matching an overlay and the corresponding bite mark images digitally using Adobe Photoshop®. Another comparison method was superimposing the cast images with corresponding bite mark images employing the Adobe Photoshop® CS6 and GIF-Animator©. A score with a range of 0-3 was given during analysis to each precision-determining criterion and the score was increased with better matching. The Kruskal Wallis H test showed significant difference between the three sets of data (H=18.761, p<0.05). In conclusion, bite mark analysis using the computer-assisted animated-superimposition method was the most accurate, followed by the computer-assisted overlay generation and lastly the xerographic method. The superior precision contributed by digital method is discernible despite the human skin being a poor recording medium of bite marks.
  7. Asif MK, Nambiar P, Mani SA, Ibrahim NB, Khan IM, Lokman NB
    Leg Med (Tokyo), 2019 Feb;36:50-58.
    PMID: 30415192 DOI: 10.1016/j.legalmed.2018.10.005
    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.
  8. Muhammad AMA, Ibrahim N, Ahmad R, Asif MK, Radzi Z, Zaini ZM, et al.
    BMC Oral Health, 2020 02 10;20(1):48.
    PMID: 32041589 DOI: 10.1186/s12903-020-1035-7
    BACKGROUND: Cone Beam Computed Tomography (CBCT) is a reliable radiographic modality to assess trabecular bone microarchitecture. The aim of this study was to determine the effect of CBCT image reconstruction parameters, namely, the threshold value and reconstruction voxel size, on trabecular bone microstructure assessment.

    METHODS: Five sectioned maxilla of adult Dorper male sheep were scanned using a CBCT system with a resolution of 76 μm3 (Kodak 9000). The CBCT images were reconstructed using different reconstruction parameters and analysed. The effect of reconstruction voxel size (76, 100 and 200 μm3) and threshold values (±15% from the global threshold value) on trabecular bone microstructure measurement was assessed using image analysis software (CT analyser version 1.15).

    RESULTS: There was no significant difference in trabecular bone microstructure measurement between the reconstruction voxel sizes, but a significant difference (Tb.N = 0.03, Tb.Sp = 0.04, Tb.Th = 0.01, BV/TV = 0.00) was apparent when the global threshold value was decreased by 15%.

    CONCLUSIONS: Trabecular bone microstructure measurements are not compromised by changing the CBCT reconstruction voxel size. However, measurements can be affected when applying a threshold value of less than 15% of the recommended global value.

  9. Asif MK, Nambiar P, Mani SA, Ibrahim NB, Khan IM, Sukumaran P
    J Forensic Leg Med, 2018 Feb;54:53-61.
    PMID: 29324319 DOI: 10.1016/j.jflm.2017.12.010
    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.
  10. Al-Siweedi SYA, Ngeow WC, Nambiar P, Abu-Hassan MI, Ahmad R, Asif MK, et al.
    Folia Morphol (Warsz), 2023;82(2):315-324.
    PMID: 35285511 DOI: 10.5603/FM.a2022.0024
    BACKGROUND: The purpose of this study was to identify and classify the anatomic variation of mandibular canal among Malaysians of three ethnicities.

    MATERIALS AND METHODS: The courses of the mandibular canal in 202 cone-beam computed tomography scanned images of healthy Malaysians were evaluated, and trifid mandibular canal (TMC) when present, were recorded and studied in detail by categorizing them to a new classification (comprising of 12 types). The diameter and length of canals were also measured, and their shape determined.

    RESULTS: Trifid mandibular canals were observed in 12 (5.9%) subjects or 16 (4.0%) hemi-mandibles. There were 10 obvious categories out the 12 types of TMCs listed. All TMCs (except one) were observed in patients older than 30 years. The prevalence according to ethnicity was 6 in Malays, 5 in Chinese and 1 in Indian. Four (33.3%) patients had bilateral TMCs, which was not seen in the Indian subject. More than half (56.3%) of the accessory canals were located above the main mandibular canal. Their mean diameter was 1.32 mm and 1.26 mm for the first and second accessory canal, and the corresponding lengths were 20.42 mm and 21.60 mm, respectively. Most (62.5%) canals had irregularly shaped lumen; there were more irregularly shaped canals in the second accessory canal than the first branch. None of the second accessory canal was oval (in shape).

    CONCLUSIONS: This new classification can be applied for the variations in the branching pattern, length and shape of TMCs for better clinical description.

  11. Gohain M, Asif MK, Nambiar P, Mohd Noor NS, Hidayah Reduwan N, Ibrahim N
    Leg Med (Tokyo), 2024 Feb;66:102391.
    PMID: 38211402 DOI: 10.1016/j.legalmed.2024.102391
    Three-dimensional surface area analyses of developing root apices for age estimation in children and young adults have shown promising results. The current study aimed to apply this three-dimensional method to develop a regression model for estimating age in Malaysian children aged 7 to 14 using developing maxillary second premolars. A training sample of 155 cone-beam computed tomography scans (83 Malays and 72 Chinese) was analysed, and the formula was subsequently validated on an independent sample of 92 cone-beam computed tomography scans (45 Malays and 47 Chinese). The results showed a strong correlation (r = 94 %) between the chronological age as a dependent variable and the predictor variables, including root surface area of the apex, sex, ethnicity, and root development status (open/closed apices). For this model, the predictor variables accounted for 88.4 % of the variation in age except sex and ethnicity. A mean absolute error value of 0.42 indicated that this model can be reliably used for Malaysian children. In conclusion, this study recognises the method of three-dimensional surface area analyses as a valuable tool for age estimation in forensic and clinical practice. Further studies are highly recommended to assess its effectiveness across different demographic groups.
  12. Asif MK, Ibrahim N, Al-Amery SM, Muhammad AMA, Khan AA, Nambiar P
    Leg Med (Tokyo), 2020 Feb 24;44:101690.
    PMID: 32135489 DOI: 10.1016/j.legalmed.2020.101690
    The study aimed to develop a novel and reliable age estimation method using three-dimensional surface area analyses of maxillary canine apices among Malaysian children using CBCT data. A validated regression equation for age estimation was derived and correlation between chronological age and the surface areas of the developing maxillary canine's apices were investigated. Variations based on ethnicities, gender and status of root development were also investigated in terms of fit to the age estimation model. CBCT images of the patients ranging in age from 7 to 14 years were included in the study. Training sample of 191 intact permanent maxillary canines was selected from 191 CBCT images belonging to 100 Malays and 91 Chinese. Moreover, an independent validation sample of 96 permanent maxillary canines was selected from 96 CBCT images belonging to 48 Malays and 48 Chinese. Three-dimensional image modeling and surface area analyses of the developing canine's apices were performed using Mimics and 3-Matics software. A strong correlation (r = 0.978) was observed between chronological age and surface area of the developing maxillary canine's apices. 95.6% of the variation in age can be explained by surface area of canine's apices, gender and status of the root development (open/closed apices). However, ethnicity did not contributed to the fit of age estimation model. Female showed advanced development as compared to male. Mean absolute error values indicated that this newly developed 3D surface area analyses of canine apex can be used as a reliable method for age estimation among Malaysian children.
  13. Asif MK, Nambiar P, Khan IM, Aziz ZABCA, Noor NSBM, Shanmuhasuntharam P, et al.
    Radiol Case Rep, 2019 Dec;14(12):1545-1549.
    PMID: 31719943 DOI: 10.1016/j.radcr.2019.10.001
    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.
Filters
Contact Us

Please provide feedback to Administrator (afdal@afpm.org.my)

External Links