Back

Volume 43 , Issue 3
May/June 2023
Pages e141–e147

Comparative Study of Two Ways to Measure Root Trunk Length to Assess the Possibility of Crown Lengthening in Molars: Measuring Parallel to the Root Surface vs Parallel to the Tooth Axis

Vittawin Dechosilpa, DDS/Thanaporn Chosivasakul/Thanatcha Munkongdee/Manita Phoamporn/Apinporn Pongpornprot/Chutiya Sriworakul/Anek Chayasadom, PhD

DOI: 10.11607/prd.5801

This study compared root trunk measurement methods—measuring parallel to the tooth axis (TA) vs parallel to the root surface (RS)—to assess the implications for decision-making regarding crown lengthening surgery. A total of 672 root trunks were measured by CBCT in both TA and RS planes. The possibility of performing crown lengthening in each clinical situation, based on the distance from the cementoenamel junction (CEJ) to the crestal bone (CB) after ostectomy (CEJ−CB), was judged and compared between groups. The proportions of cases with CEJ−CB values of 4, 5, and 6 mm in which crown lengthening was judged possible were 83.63%, 59.08%, and 39.18%, respectively, when RS was used as a reference point. When TA was used as a reference point, those proportions decreased 3.87% to 7.29%. The lingual root trunk of the mandibular first molar (LFL) with a CEJ−CB of 4 to 5 mm emerged as the most problematic area where the decision (based on each plane) shows a high rate of inconsistency, with differences between TA and RS measurements occurring in every 1 out of 5 to 6 teeth (16.67% to 18.75%). Within the limits of this study, utilizing TA for treatment-planning of surgical crown lengthening may not be ideal, as it may lead to extraction of many teeth that could otherwise be saved.

Full Text PDF File | Order Article

 

 

Adobe Acrobat Reader is required to view PDF files. This is a free program available from the Adobe web site.
Follow the download directions on the Adobe web site to get your copy of Adobe Acrobat Reader.