MyMedR

Genetic study of 12 X-STRs in Malay population living in and around Kuala Lumpur using Investigator Argus X-12 kit

Samejima M, Nakamura Y, Nambiar P, Minaguchi K

Int J Legal Med, 2012 Jul;126(4):677-83.

PMID: 22584910 DOI: 10.1007/s00414-012-0705-7

We investigated 12 X-chromosomal short tandem repeat (STR) polymorphisms in 283 unrelated Malay individuals (160 males and 123 females) living in and around Kuala Lumpur using the Investigator Argus X-12 kit. Heterozygosity among the present 12 X-STRs showed a distribution of from 55.3 to 93.5 %. The diversity values of the haplotypes constructed using four closely linked groups were all higher than 0.9865. A comparison of allelic frequency in each system and haplotype variation indicated that the nature of these X-STRs in the Malay population differed from that in East Asian, European, or African populations. Several microvariant alleles found in the Malay population were characterized and compared with known sequence data. The present data may be helpful in forensic casework such as personal identification and kinship testing in the Malay population in Malaysia.

A case of dengue-related osteonecrosis of the maxillary dentoalveolar bone

Al-Namnam NM, Nambiar P, Shanmuhasuntharam P, Harris M

Aust Dent J, 2017 Jun;62(2):228-232.

PMID: 27743399 DOI: 10.1111/adj.12472

Dengue is a mosquito transmitted flaviviral infection which can give rise to severe haemorrhage (dengue haemorrhagic fever) and with capillary leakage induces hypovolaemic shock (dengue shock syndrome). Although dengue symptoms and complications have been known for many decades, there has only been one documented case of osteonecrosis of the maxilla which was treated by excision of the necrotic bone. In this case of dengue infection, extensive maxillary osteonecrosis and minimal root resorption appeared to follow factitious injury with a toothpick but resolved with non-surgical management.

Fulltext Cosmetic "Gold Thread Therapy": A Nuisance That Decreases the Diagnostic Quality of a Dental Panoramic Image

Ching ME, Joan LZY, Nambiar P

Case Rep Dent, 2021;2021:4077930.

PMID: 34777877 DOI: 10.1155/2021/4077930

During routine imaging of the craniofacial region, it is recognised that some "cosmetic" procedures with metallic insertions can be revealed radiographically. These objects however make it difficult to obtain a good interpretation of anatomical structures for management of diseases. A 58-year-old female patient visited a private dental facility in Kuala Lumpur for prosthodontic replacement of missing teeth. The dental panoramic image revealed generalized bone loss and numerous unusual multiple thread-like radioopacities. These gold threads made radiographic evaluation difficult and complicated the process of treatment planning for dental implant placement advocated for this patient.

Fulltext Population Genetics of Identifiler System in Malaysia

Nakamura Y, Samejima M, Minaguchi K, Nambiar P

Bull. Tokyo Dent. Coll., 2016;57(4):233-239.

PMID: 28049971 DOI: 10.2209/tdcpublication.2016-1400

Short tandem repeat (STR) polymorphisms were investigated in 341 unrelated Malay individuals (218 males and 123 females) living in or around Kuala Lumpur by using a forensic analysts kit. The following STRs were targeted: D8S1179, D21S11, D7S820, CSF1PO, D3S1358, TH01, D13S317, D16S539, D2S1338, D19S433, vWA, TPOX, D18S51, D5S818, and FGA. The purpose of this study was to elucidate population genetics in Malaysia and calculate statistical parameters for forensic and anthropological research. Data on these STRs in the target population were obtained and subjected to statistical analysis. Accordance with the Hardy-Weinberg equilibrium was proven for all the loci targeted. The combined power of discrimination was greater than 0.9999999999, indicating that this multiplex system is an excellent tool for forensic casework. The allele frequency in the data were weighed against that in four other local populations (Chinese, Iranian, Belgian, and African). The average coefficient of correlation was strongest in the order of Africa (0.092522), Belgium (0.264822), Iran (0.404363), and China (0.706661). These results are consistent with what is known about the anthropological history of and prehistoric human migration in the Malay region. We believe that these data offer a valuable anthropological resource, being applicable to the statistical evaluation of DNA evidence in human identification, as well as the determination of ethnicity in healthy populations.

Fulltext Gaining surgical access for repositioning the inferior alveolar neurovascular bundle

Al-Siweedi SY, Nambiar P, Shanmuhasuntharam P, Ngeow WC

ScientificWorldJournal, 2014;2014:719243.

PMID: 24892077 DOI: 10.1155/2014/719243

This study is aimed at determining anatomical landmarks that can be used to gain access to the inferior alveolar neurovascular (IAN) bundle. Scanned CBCT (i-CAT machine) data of sixty patients and reconstructions performed using the SimPlant dental implant software were reviewed. Outcome variables were the linear distances of the mandibular canal to the inferior border and the buccal cortex of the mandible, measured immediately at the mental foramen (D1) and at 10, 20, 30, and 40 mm (D2-D5) distal to it. Predictor variables were age, ethnicity, and gender of subjects. Apicobasal assessment of the canal reveals that it is curving downward towards the inferior mandibular border until 20 mm (D3) distal to the mental foramen where it then curves upwards, making an elliptic-arc curve. The mandibular canal also forms a buccolingually oriented elliptic arc in relation to the buccal cortex. Variations due to age, ethnicity, and gender were evident and this study provides an accurate anatomic zone for gaining surgical access to the IAN bundle. The findings indicate that the buccal cortex-IAN distance was greatest at D3. Therefore, sites between D2 and D5 can be used as favorable landmarks to access the IAN bundle with the least complications to the patient.

Safe zone for bone harvesting from the interforaminal region of the mandible

Al-Ani O, Nambiar P, Ha KO, Ngeow WC

Clin Oral Implants Res, 2013 Aug;24 Suppl A100:115-21.

PMID: 22233422 DOI: 10.1111/j.1600-0501.2011.02393.x

The mandibular incisive nerve can be subjected to iatrogenic injury during bone graft harvesting. Using cone beam computed tomography (CBCT), this study aims to determine a safe zone for bone graft harvesting that avoids injuring this nerve.

Fulltext Effect of ageing towards location and visibility of mental foramen on panoramic radiographs

Ngeow WC, Dionysius DD, Ishak H, Nambiar P

Singapore Dent J, 2010 Jun;31(1):15-9.

PMID: 23739252 DOI: 10.1016/S0377-5291(12)70004-4

Mental foramen is an opening of the mental canal onto the lateral surface of the mandible. In this pilot radiographical study, in Malay population the effects of ageing towards the location and visibility of the mental foramen were determined. Most of the mental foramina were found to be located inferior to the apex of the second premolar. Non-visibility of the foramen was greatly increased in patients aged 50 years and above (Pearson Chi-square; p = 0.00). This finding may provide a guide to dental surgeries in Malay patients of different age groups.

A radiographic study on the visualization of the anterior loop in dentate subjects of different age groups

Ngeow WC, Dionysius DD, Ishak H, Nambiar P

J Oral Sci, 2009 Jun;51(2):231-7.

PMID: 19550091

The anterior loop is defined as where the mental neurovascular bundle crosses anterior to the mental foramen then doubles back to exit the mental foramen. It cannot be seen clinically but can be detected in 11-60% of panoramic radiographs. As this anatomical structure is important in determining the placement position of endosseous implants in the mandibular premolar region, a pilot study was undertaken to determine its visibility on dental panoramic radiographs in dentate subjects of various age groups. One or more anterior loops were visible in 39 (40.2%) radiographs encompassing 66 sites (34.4%). Interestingly, anterior loops were most commonly observed bilaterally, followed by on the right side of the mandible only. An anterior loop on the left side only was observed in just 1 radiograph. Visibility of anterior loops reduced as the age of subjects increased. More than half (58.1%) of subjects aged 20-29 years exhibited at least one anterior loop; this gradually reduced to only 15 percent of subjects aged 50 and older. There was no association between visualization of the anterior loop and subject gender.

Uncommon radiological findings: a case report

Tandjung YR, Hong CP, Nambiar P, Ibrahim N

Int Dent J, 2007 Jun;57(3):173-6.

PMID: 17695738

A 50-year-old friendly and attractive Chinese lady was examined by the Primary Care Unit, Faculty of Dentistry, University of Malaya. Her requests for treatment included implants and crowns. Two periapical radiographs of teeth 16 and 48 were taken to aid diagnosis. Interestingly, pin-like radio-opaque objects were found over the crown of the impacted tooth 15 and also tooth 17. These objects were initially interpreted as silver points or radiographic artifacts but further investigation employing panoramic radiography revealed the distribution of more radio-opaque objects in the orofacial region. Based on a review of the literature and the opinion of experienced radiology and oral surgery lecturers, these foreign radio-opaque objects were diagnosed as susuks or charm needles.

Lim MY, Lim WW, Rajan S, Nambiar P, Ngeow WC

Eur Arch Paediatr Dent, 2015 Oct;16(5):397-407.

PMID: 25894248 DOI: 10.1007/s40368-015-0184-x

To observe age-related changes in the locations of mandibular foramen (MF) and mental foramen (mf) using dental panoramic tomographs (DPTs).

Anatomical considerations for implant placements in first maxillary molar extracted sites in East Asian patients

Ananda GK, Nambiar P, Mutalik S, Shanmuhasuntharam P

Surg Radiol Anat, 2015 Nov;37(9):1099-108.

PMID: 25850735 DOI: 10.1007/s00276-015-1473-0

With the advent of cone-beam computed tomography (CBCT) for maxillofacial imaging, there has been a paradigm shift from two dimensional panoramic radiography to three dimensional imaging. This study investigated the microanatomy of the maxillary permanent first molar socket and its relationship to the floor of the maxillary sinus, especially for immediate or early implant placement.

Copper vapour laser ID labelling on metal dentures and restorations

Ling BC, Nambiar P, Low KS, Lee CK

J Forensic Odontostomatol, 2003 Jun;21(1):17-22.

PMID: 12793127

Denture marking is accepted as a means of identifying dentures and persons in geriatric institutions, or post-mortem during war, crimes, civil unrest, natural and mass disasters. Labelling on the acrylic resin component of the denture can easily be damaged or destroyed by fire but on cobalt-chromium components it would be more resistant. A copper vapour laser (CVL) can be used to label the cobalt-chromium components of dentures and metal restorations easily, and legibly, and miniaturised for the incorporation of more personal particulars necessary for the identification of the deceased person. The CVL beam is focussed by its optics and delivered to the material surface by the two-axis scanner mounted with mirrors. A personal computer controls the movement of the scanner and the firing of the CVL. The high peak power of the pulsed CVL is focussed to very high energy density producing plasma ablation of the alloy surface. Very fine markings of a few microns width can be produced enabling the storage of detailed information of the deceased person on a metal surface for the purpose of rapid identification.

Fulltext Variation in Lingual Nerve Course: A Human Cadaveric Study

Al-Amery SM, Nambiar P, Naidu M, Ngeow WC

PLoS One, 2016 09 23;11(9):e0162773.

PMID: 27662622 DOI: 10.1371/journal.pone.0162773

The lingual nerve is a terminal branch of the mandibular nerve. It is varied in its course and in its relationship to the mandibular alveolar crest, submandibular duct and also the related muscles in the floor of the mouth. This study aims to understand the course of the lingual nerve from the molar area until its insertion into the tongue muscle. This cadaveric research involved the study of 14 hemi-mandibles and consisted of two parts: (i) obtaining morphometrical measurements of the lingual nerve to three landmarks on the alveolar ridge, and (b) understanding non-metrical or morphological appearance of its terminal branches inserting in the ventral surface of the tongue. The mean distance between the fourteen lingual nerves and the alveolar ridge was 12.36 mm, and they were located 12.03 mm from the lower border of the mandible. These distances were varied when near the first molar (M1), second molar (M2) and third molar (M3). The lingual nerve coursed on the floor of the mouth for approximately 25.43 mm before it deviated toward the tongue anywhere between the mesial of M1 and distal of M2. Thirteen lingual nerves were found to loop around the submandibular duct for an average distance of 6.92 mm (95% CI: 5.24 to 8.60 mm). Their looping occurred anywhere between the M2 and M3. In 76.9% of the cases the loop started around the M3 region and the majority (69.2%) of these looping ended at between the first and second molars and at the lingual developmental groove of the second molar. It gave out as many as 4 branches at its terminal end at the ventral surface of the tongue, with the presence of 2 branches being the most common pattern. An awareness of the variations of the lingual nerve is important to prevent any untoward complications or nerve injury and it is hoped that these findings will be useful for planning of surgical procedures related to the alveolar crest, submandibular gland/ duct and surrounding areas.

A pilot study on the effects of direct contact of two different surgical burs on the cadaveric lingual nerve

Al-Amery SM, Ngeow WC, Nambiar P, Naidu M

Int J Oral Maxillofac Surg, 2018 Sep;47(9):1153-1160.

PMID: 29735199 DOI: 10.1016/j.ijom.2018.04.013

The lingual guttering technique for third molar surgery carries the risk of injury to the lingual nerve if the surgical bur comes into direct contact with it. This study investigated the extent of nerve injury caused by two different burs, a tungsten carbide bur and the Dentium implant bur; the latter is designed to be soft tissue friendly. This study also examined whether ultrasound and magnetic resonance imaging are able to detect any injury inflicted. This cadaveric research involved subjecting 12 lingual nerves to the drilling effect of two different burs at two different speeds. The amount of damage caused was measured using different imaging modalities to assess their ability to detect the injury inflicted. At high speed, the Dentium bur caused a deeper and wider laceration than the carbide bur. At low speed, the laceration depths and widths caused by the two burs did not differ significantly. Ultrasound scanning was able to detect the nerve laceration at damaged sites observed using optical coherence tomography. Thus, a carbide bur (at low speed) would be preferable for lingual bone guttering, as it causes less laceration to the lingual nerve. In the event of a suspected injury, ultrasound scanning would provide an objective evaluation of the amount of nerve damage in vivo.

Fulltext Population Genetics in Malaysia and Japanese Populations Using Power Plex Y23 System

Nakamura Y, Samejima M, Minaguchi K, Nambiar P, Hashimoto M

Bull. Tokyo Dent. Coll., 2020 Jul 04;61(2):83-94.

PMID: 32522936 DOI: 10.2209/tdcpublication.2019-0023

Population flow between Southeast Asian countries and Japan continues to gather pace. Accordingly, the number of foreigners involved in incidents in Japan has markedly increased, which means that forensic dentistry is now increasingly being faced with the need to analyze DNA from persons of non-Japanese extraction. The DNA test currently used for personal identification mainly utilizes short tandem repeats (STRs) on autosomal chromosomes and the Y-chromosome. This test was developed for use in personal identification, not for distinguishing among races; nonetheless, the standard method for personal identification is often used because the procedure has been established. To determine the degree to which racial differences can be distinguished by standard DNA analysis, 23 STRs located on the Y chromosome were investigated in 218 Malay and 426 Japanese males. The frequencies of each STR were calculated in the two populations. The difference in the power of discrimination between the Malay and Japanese populations ranged from a minimum of 0.01 to a maximum of 0.27; the difference in polymorphic information content ranged from 0.01 (minimum) to 0.23 (maximum). No major differences were noted in the polymorphisms in these two Mongoloid populations, but the distributions of the 17 STRs differed significantly. Short tandem repeat types demonstrating a likelihood of racial differences were identified in 14 of the STRs. Race-specific STR types were identified in 10 STRs. These results suggest that the likelihood of Malay or Japanese genetic background can be judged based on Y-chromosome STR test results.

Age estimation from developing third molars

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.

Middle mesial canal in mandibular first molar: A narrative review

Penukonda R, Pattar H, Nambiar P, Al-Haddad A

Saudi Dent J, 2023 Jul;35(5):468-475.

PMID: 37520597 DOI: 10.1016/j.sdentj.2023.05.008

PURPOSE: This review aimed to assess the incidence, anatomical characteristics, identification, and clinical management using conventional techniques and advanced tools to manage MMCs successfully.

METHODS: Medline/PubMed and Scopus databases were searched using "Middle mesial canal," "Middle mesial root canal," OR "Accessory mesial canal" keywords from 1 January 1970 and 1 February 2023. The most pertinent articles were chosen for the review from the retrieved articles. In addition, relevant articles were added by manually searching the list of references.

RESULTS: The incidence of MMC is noticeable in younger people, and the confluent canal is the most common type. The majority of MMCs merged with mesiobuccal (MB) canals rather than mesiolingual (ML) canals. Clinical management could be employed using the standard endodontics protocol, and recent radiography technologies, magnification, rotary, and obturation materials can facilitate the procedures.

CONCLUSION: The possibility of the incidence of MMC is not unusual. Detection and thorough debridement followed by obturation of the canal could increase the success rate of clinical outcomes.

The Management of Persistent Pain From a Branch of the Trifid Mandibular Canal due to Implant Impingement

Aljunid S, AlSiweedi S, Nambiar P, Chai WL, Ngeow WC

J Oral Implantol, 2016 Aug;42(4):349-52.

PMID: 27078072 DOI: 10.1563/aaid-joi-D-16-00011

The mandibular canal is a conduit that allows the inferior alveolar neurovascular bundle to transverse the mandible to supply the dentition, jawbone, and soft tissue around the lower lip. It is now acknowledged that the mandibular canal is not a single canal but an anatomical structure with multiple branches and variations. Iatrogenic injury to branches of the mandibular canal that carry a neurovascular bundle has been reported to cause injury to the main canal as severe as if the main canal itself is traumatized. These injuries include bleeding, neurosensory disturbance, or the formation of traumatic neuroma, and so far, they have involved cases with the bifid mandibular canal. This current report presents a case of neurosensory disturbance that resulted from the impingement of a branch of a trifid mandibular canal during implant insertion. Its management included analgesics, reexamination, and reinserting a shorter implant.

Fulltext Cone beam computed tomography assessment of the maxillary incisive canal and foramen: considerations of anatomical variations when placing immediate implants

Al-Amery SM, Nambiar P, Jamaludin M, John J, Ngeow WC

PLoS One, 2015;10(2):e0117251.

PMID: 25679505 DOI: 10.1371/journal.pone.0117251

The maxillary incisive canal connects the roof of the oral cavity with the floor of nasal cavity and has the incisive and nasal foramina respectively at its two opposite ends. Its close proximity with the anterior incisors affects one's ability to place immediate implants in ideal position.

Changes in cell density and morphology of selected cells of the ageing human dental pulp

Daud S, Nambiar P, Hossain MZ, Rahman MR, Bakri MM

Gerodontology, 2016 Sep;33(3):315-21.

PMID: 25266855 DOI: 10.1111/ger.12154

OBJECTIVES: The aim of this study was to determine the changes in cell density and morphology of selected cells of the ageing human dental pulp.

BACKGROUND: Changes in cell density and morphology of dental pulp cells over time may affect their capability to respond to tooth injury.

MATERIALS AND METHODS: One hundred thirty-one extracted teeth were obtained from individuals between the ages of 6 and 80 years. The apical 1/3 of the root region was removed from all teeth prior to routine processing for producing histological slides. The histology slides were used to study the changes in cell density and morphology of selected pulp cells; odontoblasts, subodontoblasts and fibroblasts in the crown and root regions of the dental pulp. Student's t-test and one-way anova were used for statistical analyses.

RESULTS: In all age groups, the cell density for all types of cells was found to be higher in the crown than in the root (p

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