Abstract
OBJECTIVES: To assess the visibility of the mandibular canal (MC) morphology in different jaw dental segments (JDSs) in relation to morphometric and densitometric parameters on digital panoramic radiographs (DPRs). METHODS: 32 DPRs (155 JDSs) were selected randomly after retrieval. MC visibility in conjunction with superior and inferior border visibility was scored on a 5-point scale in four places on the JDS-that is, for the medial, distal, superior and inferior MC parts. Morphometric and densitometric analyses were made horizontally and vertically in the JDS region. Descriptive statistics, Fisher's exact test, Mann-Whitney U test and additional tests were performed. RESULTS: There was no significant difference in MC visibility for the superior, inferior, medial and distal parts of the JDSs. Statistically significant (p < 0.05) differences were identified between particular visibility scores of the superior and inferior MC borders. In 22.0-24.7% of JDSs, the superior MC border was not visible, more than twice as often as the inferior MC border was not visible (9.1-10.2%). The visibility of superior and inferior MC borders in JDSs was not related to the morphometric or densitometric assessment parameters, or to age, gender, JDS location, condition or the visibility of neighbouring MC parts or contralateral JDSs. CONCLUSIONS: DPRs failed to provide MC visibility based on a single factor. Particular differences were identified between the levels of visibility of the superior and inferior MC borders. More advanced radiological investigation methods could be required for the evaluation of about 25% of JDSs when superior MC border identification is obligatory.