Assessment of Difficulty in Mandibular Third Molar Surgery by Lambade-Dawane-Mali's Index

Abstract

The evaluation of mandibular third molar (M3) difficulty is extremely important. This study aims to measure the association between preoperative Lambade-Dawane-Mali's (LDM) M3 difficulty index and postoperative assessment of difficulty score. This prospective cohort study included patients with impacted M3 reported to the Department of OMFS, RRK Dental College, Akola, from 2017 to 2022. The preoperative surgical difficulty was estimated using the predictor, LDM index with scores, easy (15-25), moderate (25-30), and difficult (>30). The postoperative surgical difficulty was analyzed with the primary outcome variable, total time intervention measured from the beginning of incision to the final suturing, wherein extraction was classified as easy if time (<15minutes), moderate (15-30minutes), and difficult (>30minutes). The secondary outcome variable, Modified Parant's Scale (MPS), defines four levels of difficulty required for extraction of M3: Easy I (forceps extraction), Easy II (requiring osteotomy), Difficult III (coronal sectioning), and Difficult IV (complex extraction). Data were analyzed using agreement between LDM difficulty with three established criteria (time, MPS, Pederson index) and were assessed with Cohen's Kappa statistics. McNemar's test for paired data was used to assess concordance between two criteria of evaluation with a P-value <.05 was considered statistically significant. The study sample included 1000 patients with a mean age of 26.7±7.6years and 456 (45.6%) females. Those assessed preoperatively with LDM to be difficult and easy outcomes were found upon postoperative assessment with MPS to be 99% and 99% correct, respectively. Inter-criteria agreement and Kappa statistics suggested a positive Kappa value (κ) and statistically significant agreement between the LDM index with perioperative time (κ=0.8930), MPS (κ=0.6488), and Pederson index (κ=0.4920) at P-value 0.0001. Pair-wise comparisons of LDM criteria with perioperative time, MPS, and Pederson scale were assessed by McNemar's test, which evaluated concordance between the two criteria. Postoperative evaluation of surgical difficulty in M3 extraction was strongly correlated with preoperative variables in the LDM difficulty-scoring index. Preoperative evaluation helps in anticipating the difficulty, planning surgical management, and scheduling time more optimally.