Sains Malaysiana 46(1)(2017): 59–65

http://dx.doi.org/10.17576/jsm-2017-4601-08

Reliability of Panoramic-Radiograph to Determine the Position of Third-Molar from Inferior-Alveolar-Canal

(Kebolehpercayaan Radiograf-Panorama untuk Menentukan Posisi Molar Ketiga dari Kanal Inferior Alveolus)

AZIZAH AHMAD FAUZI¹*, MOHAMED EBRAHIM PARKER², E.J. NORVAL²

& PHRABHAKARAN NAMBIAR³

¹Department of Oral Biology (Clinical), Faculty of Dentistry, Universiti Kebangsaan Malaysia

Jalan Raja Muda Abd Aziz, 50300 Kuala Lumpur, Federal Territory, Malaysia

²Department of Oral & Maxillofacial Diagnostic Imaging, University of the Western Cape Robert Sobukwe Road Bellville, 7535 Republic of South Africa

³Department of Diagnostic & Integrated Dental Practice., University of Malaya 50603 Kuala Lumpur, Federal Territory, Malaysia

Received: 26 March 2015/Accepted: 28 April 2016

ABSTRACT

Cone-beam-computed-tomography (CBCT) has been useful in providing insights of relevant anatomy prior to surgical procedures, including the assessment of the proximity of impacted mandibular-third-molar to the inferior-alveolar-canal (IAC). It is important to understand the reliability of conventional panoramic-radiograph in the assessment of this criterion since it is more commonly used as first line radiographic approach due to its availability and lower radiation dose. This study aimed to investigate the reliability of conventional panoramic-radiograph in the evaluation of the proximity of impacted mandibular-third-molar root tip to the IAC by correlating the results with CBCT. A total of 65 root tips of impacted mandibular-third-molars that had both panoramic radiographs and CBCT images were included in this retrospective study. Two trained observers participated in all image evaluations. A prepared standard 1 cm ruler was used to measure the proximity of the third-molar root apices to the IACs. Measurements recorded in this study were categorized into positive (root apex above a roof of IAC), zero (root apex was superimposed on IAC) and negative (root apex below a roof of IAC). Data analysis was carried out using student t-test. In this study, both observers recorded statistically significant differences in the measurement between third-molars root apices and the IAC from panoramic radiographs and CBCT images. The low reliability of panoramic radiograph to assess the vertical proximity between these two anatomical structures suggests the importance of additional assessment with CBCT in cases where panoramic radiograph shows superimposition of the third molar root on the roof of the canal and presence of root below the roof of the IAC.

Keywords: Panoramic radiography; third molar

ABSTRAK

Sinaran-kon-tomografi-berkomputer (CBCT) amat berguna dalam memberikan kefahaman berkenaan anatomi berkaitan sebelum prosedur pembedahan, termasuklah penilaian terhadap kedudukan mandibular-molar-ketiga-terimpak ke kanal inferior alveolus (IAC). Adalah penting untuk memahami kebolehpercayaan radiograf-panorama konvensional dalam penilaian kriteria ini memandangkan ia sering digunakan sebagai pendekatan radiografi baris hadapan kerana lebih mudah diperoleh dan mempunyai dos radiasi yang rendah. Kajian ini bertujuan untuk mengenal pasti kebolehpercayaan radiograf-panorama konvensional dalam penilaian kedudukan mandibular-molar-ketiga-terimpak ke IAC dengan mengaitkan keputusannya dengan CBCT. Sebanyak 65 hujung akar mandibular-molar-ketiga-terimpak yang mempunyai kedua-dua radiograf-panorama dan imej CBCT dipilih dalam kajian retrospektif ini. Dua pemerhati terlatih terlibat dalam penilaian keseluruhan imej. Pembaris berpiawaian 1 cm disediakan bagi mengukur proksimiti akar molar ke IAC. Ukuran yang direkod dalam kajian ini dikategorikan kepada ukuran yang bernilai positif (akar apeks di atas bumbung IAC), sifar (akar apeks bertindih dengan IAC) dan negatif (akar apeks di bawah bumbung IAC). Analisis data dilakukan dengan menggunakan ujian-t pelajar. Dalam kajian ini, kedua-dua pemerhati merekodkan perbezaan statistik yang signifikan dalam ukuran antara apeks akar molar-ketiga dan IAC daripada radiograf-panorama serta imej CBCT. Kebolehpercayaan yang rendah bagi radiograf-panorama untuk menilai proksimiti menegak antara kedua-dua struktur anatomi ini mencadangkan kepentingan penilaian tambahan dengan CBCT dalam kes radiograf-panorama yang menunjukkan pertindihan akar pada bumbung molar-ketiga dan kehadiran akar di bawah bumbung IAC.

Kata kunci: Molar ketiga; radiograf-panorama

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*Corresponding author; email: azizah_fauzi@yahoo.com