Evaluation of nasolacrimal canal morphology in different facial skeletal relationships

Abstract

BackgroundAbnormal morphological variations of nasolacrimal canal (NLC) and its lack of understanding contributes to acquired injuries during craniomaxillofacial surgical procedures which leads untoward postoperative complications like nasolacrimal obstruction (NLO) and epiphora. PurposeThe purpose of this study was to determine dimensional and volumetric morphological variations of nasolacrimal canal in various facial skeletal relationships which aid in performing a precise and safe surgery. Materials and methodsThis retrospective cohort study involved dimensional and volumetric analysis of nasolacrimal canal procured from computed tomography scans of 47 individuals grouped as ClassI, Class II and Class III, and unilateral cleft lip and palate (UCLP) groups. The outcome variables included length of NLC, volume of NLC, distance between the inferior orifice of the NLC to nasal floor, distance between inferior orifice of NLC to canine apex and distance between inferior orifice of NLC to central incisor apex. The objectives were to analyse morphological variation of NLC in different facial skeletal relationships and to evaluate the variation with change in facial sides and its relationship with surrounding structures. ResultsVolume of the NLC was found significant in Class I and UCLP population (p < 0.05) with the greatest volume in the UCLP group. The mean linear and volumetric measurements between the right and left sides were found insignificant among all groups. Inferior orifice of NLC from canine apex were farthest in Class III and nearest in the UCLP group (p < 0.05). There was no significant association between outcome variables and skeletal base configuration. ConclusionNLC demonstrates dimensional and anthropometric variations between different skeletal relationships and this study is inevitable in understanding the probability of NLC injury during maxillofacial surgeries.