No abstract

A review of the literature is made to evaluate factors that influence probing depth and attachment level on the distal aspect of the lower second molar (L2M) following extraction of a lower third molar (L3M). The PubMed database was searched for studies published between 1997 and March 2009 using the following keywords: mandibular third molar, distal periodontal defect, distal probing depth, distal attachment level, flap design. Randomized prospective studies, with a minimum follow-up of three months for which the full text could be obtained, and that indicated the attachment level and/or probing depth on the distal surface of the L2M in both the preoperative and postoperative periods were included. In the studies obtained, flap design had no influence on distal probing depth or distal attachment level of the L2M following extraction of an L3M. Curettage of the distal radicular surface of the L2M, together with oral hygiene control by the dentist, reduced probing depth values. Various authors recommend bone regeneration techniques in patients with a distal periodontal defect prior to extraction. The placing of membranes (resorbable or nonresorbable) is not justified; however, the use of demineralized bone powder or platelet-rich plasma gel reduces the distal probing depth and attachment level of the L2M.

No abstract

The aim was to carry out a literature review of preoperative radiographic signs in orthopantomography (OPG) and computed tomography (CT) related with the risk of inferior alveolar nerve damage during the surgical extraction of lower third molar (LTM). A search was made on PubMed for literature published between the years 2000 and 2009. In the reviewed literature, radiographic signs in the OPG that indicate a relationship between the LTM and the inferior alveolar canal are considered a risk factor for nerve damage. These signs are darkening and deflection of the root, and diversion and interruption in the white line of the canal. In the majority of these studies, the routine use of CT is not justified, and is only recommended when radiographic signs appear in the OPG that demonstrate a direct anatomical relationship between the LTM and the canal. In the CT, the absence of cortical bone in the canal implies a contact between the root of the LTM and the canal, and is related with the presence of some radiographic signs in the OPG. Some studies demonstrate that despite the absence of cortical bone, the risk of lesion or exposure of the nerve during the extraction of LTM was low.