Is it possible to predict neurosensory alterations in impacted lower third molar removal based on preoperative imaging procedures? A prospective cohort study / ¿Es posible predecir alteraciones neurosensoriales en la extracción del tercer molar inferior impactado basándose en procedimientos de imagen preoperatorios? Un estudio de cohorte prospectivo

ABSTRACT

Background: Surgical extraction of the lower third molar (LTM) may trigger neurosensory injury of the inferioralveolar nerve, making extraction a real challenge. This study set out to assess whether is it possible to predictneurosensory alterations from preoperative imaging.Material and Methods: A total of 99 patients underwent 124 impacted lower third molar (ILTM) surgeries. Priorto surgery, panoramic and CBCT images were evaluated in an attempt to predict a neurosensory disturbance.Preoperative data (ILTM position, panoramic radiograph signs, inferior alveolar nerve (IAN) location and its con-tact with the ILTM roots) and intra/postoperative findings (extraction difficulty and sensitivity alterations) wererecorded. Descriptive and bivariate data analysis was performed. Statistical comparison applied the chi-squaretest, Fisher test, and one-way ANOVA test. Statistical significance was established with a confidence interval (CI)of 95%.Results: In 4.03% of cases, patients experienced neurosensory alterations. Of 124 ILTM positions in panoramicradiographs, 76 cases were considered to exhibit a potential neurosensory risk as they presented two or more typesof superimposed relationships between ILTM and mandibular canal. Of these, alterations were reported in onlythree cases (3.95%). Of the 48 remaining ILTM images presenting only one sign, neurosensory alterations wereobserved in two cases (4.17%). No permanent alterations were recorded in any of the five cases observed.Conclusions: Within the limitations of the present study, prediction of neurosensory alterations prior to ILTMextraction by means of preoperative imaging did not show a significant statistical correlation with post-surgicalincidence. Nevertheless, interruption of the canal´s white line (ICWL) or a diversion of the canal (DC) may predictan increased risk of IAN injury.(AU)