A data set of proximity of mandibular third molar roots with Inferior Alveolar Canal.

OPG’s are inexpensive, low radiation and easily available in smaller dental
units and hospitals also however, a real three-dimensional picture and buccolingual relationship is unknown. Dearth of studies on third molar roots and inferior alveolar canal in Nepalese
population persuaded us to carry out this study to describe the
proximity of mandibular third molar roots to the inferior alveolar canal and nerve. A single centre cross-sectional study was designed with sample
size of 475 patients collected from July 2017 to July 2019, at
the department of Oral and maxillofacial surgery of College of
Medical Sciences and Teaching Hospital (COMS-TH), Bharatpur,
Nepal.
Ethical approval was obtained from institutional review
committee of COMS-TH. All the patients who reported the signs
and symptoms of third molar pain and difficulty were included.
Pregnant patients and those who didn’t provide consent were
excluded. Orthopantomogram (OPG) of patients were retrieved
from imaging software records. Baseline demographic data
was obtained from patient’s entry in OPG imaging software
program (Orthoralix Vixwin software) and signs of proximity
of mandibular third molar roots to inferior alveolar canal as described by Rood and Shebab were ascertained.
The seven
radiographic signs were observed on digitally magnified OPG’s
using Orthoralix Vixwin software (Gendex, USA) and presence
or absence of signs were entered. Presence of simultaneous
multiple signs were entered. Explicit prior criteria have been
used to designate each of the seven panoramic radiographic
signs as “positive” when present or “negative” when absent. All observations and demographic datas were entered
in Microsoft excel and descriptive analysis was performed with
SPSS Version 20. Frequency was used to describe presence
of radiographic signs and means were used to describe
demographic variables. Cross tabulation was done to analyse
the pattern of combination of signs. One or more radiographic signs were observed in 49.6% of mandibular third molars. Interruption of white line followed by narrowing of canal and darkening of roots was observed in
decreasing order of frequency and no statistically significant association between sex, age and side
of impacted third molar with presence of radiographic signs. Absence of any radiographic sign was observed in 245 cases
(51.6%). When only one sign was observed (n=71), the most
common sign was, interruption of white line of canal followed
by deflection of roots. The next most common pattern of combination was 3 signs (n=60) followed by two signs together
(n=55).