Reliability of Pederson Scale in Surgical Extraction of Impacted Lower Third Molars: Proposal of New Scale

The aim of this study was to evaluate the clinical reliability of the Pederson index in preoperative assessment of the difficulty of surgical removal of impacted mandibular third molars. Pederson index was found to be unreliable predictor of true difficulty with low sensitivity and specificity. A new index (Kharma scale), which takes into consideration the anatomical form of tooth roots, is proposed and evaluated both pre- and postoperatively. The results of the evaluation indicate that the new estimating index is more reliable and accurate measure than Pederson scale.

[1]  N. Komerik,et al.  Difficulty of impacted mandibular third molar tooth removal: predictive ability of senior surgeons and residents. , 2014, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[2]  J. Hupp.  Principles of Management of Impacted Teeth , 2014 .

[3]  A. Bali,et al.  Is Pederson Index a True Predictive Difficulty Index for Impacted Mandibular Third Molar Surgery? A Meta-analysis , 2013, Journal of Maxillofacial and Oral Surgery.

[4]  B. C. do Egito Vasconcelos,et al.  Assessment of factors associated with surgical difficulty during removal of impacted lower third molars. , 2011, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[5]  A. García-García,et al.  Evaluation of the surgical difficulty in lower third molar extraction. , 2010, Medicina oral, patologia oral y cirugia bucal.

[6]  A. Ladeinde,et al.  Assessment of factors associated with surgical difficulty in impacted mandibular third molar extraction. , 2007, Journal of oral and maxillofacial surgery : official journal of the American Association of Oral and Maxillofacial Surgeons.

[7]  A. García-García,et al.  Pederson scale fails to predict how difficult it will be to extract lower third molars. , 2007, The British journal of oral & maxillofacial surgery.

[8]  H. Yuasa,et al.  Classification of surgical difficulty in extracting impacted third molars. , 2002, The British journal of oral & maxillofacial surgery.

[9]  F. G. Sampedro,et al.  Pell-Gregory classification is unreliable as a predictor of difficulty in extracting impacted lower third molars. , 2000, The British journal of oral & maxillofacial surgery.

[10]  A. García,et al.  Trismus and pain after removal of impacted lower third molars , 1997 .

[11]  A. Macgregor.  The Impacted Lower Wisdom Tooth , 1985 .