Why WITS? Why not a way beyond?

INTRODUCTION: WITS appraisal is a common parameter in cephalometrics to assess maxillo-mandibular skeletal relationship as an adjunct to angle ANB. The high variability of the WITS appraisal is attributable to difficulties or inaccuracies in identifying the occlusal plane or variations due to tooth eruption, dental development or treatment changes by vertical movement of incisors, molars, or both. AIM: An extracranial reference line common to both denture bases, instead of the occlusal plane is proposed to assess antero-posterior jaw relationships. MATERIALS AND METHODS: A true vertical obtained by plumb line was recorded, while taking the cephalogram for 40 subjects. A line drawn perpendicular to this true vertical gave a stable and reproducible extracranial true horizontal (HOR) reference line. The linear distance between perpendiculars from points A and B was measured as an adjunct to angle ANB. RESULT: The Pearson's product moment correlation coefficient calculated for the entire sample indicated higher correlation coefficient (r = 0.8712) for the linear measurements on HOR (AH-BH) with respect to the angle ANB when compared with the WITS readings (AO-BO) (r = 0.549). CONCLUSION: The horizontal appraisal method proposed eliminates the demerits of the occlusal plane and has the merits of simplicity and accuracy in comparison to WITS appraisal.