Assessment of Maxillary Molars Interradicular Septum Morphological Characteristics as Criteria for Ideal Immediate Implant Placement—The Advantages of Cone Beam Computed Tomography Analysis

Abstract

The aim of this study was to evaluate the interradicular septum bone morphometric characteristics using cone beam computed tomography (CBCT) images, as well as to establish quantitative shortcuts to allow clinicians to make a faster and more reliable plan for immediate implant placement in the maxillary molars area. This retrospective quantitative study was conducted on CBCT images obtained from 100 patients. The morphometric analysis of the maxillary molars region was based on the parameters obtained on the sagittal and axial slices. The analysis performed on sagittal slices showed that the first maxillary molars had a wider interradicular septum when compared to the second molars, but the septum height in the first molars was significantly below the height in the second maxillary molars. The axial CBCT slices analysis showed that both interradicular septum perimeter and surface area were significantly more pronounced in the first than in the second maxillary molars. The interradicular furcation angle significantly correlated with the surface area (positively) and septum height (negatively) for both molars. The results of this study may recommend CBCT image analysis as a useful tool in predefining the circumstances that can allow for substantially better planning of immediate implant placement procedures in the region of maxillary molars.

Criteria for the Classification of the Interradicular Septum Shape in Maxillary Molars with Clinical Importance for Prosthetic-Driven Immediate Implant Placement

“…The initial insight into the parameters obtained in the area of interest (maxillary molars’ IRS, as previously described by Rajkovic Pavlovic and coworkers [ 20 ]) led us to a certain and repetitive algorithm that we tried to evaluate in general prior to further analyses. Thus, in order to achieve the quantitative criteria that would allow maxillary molars’ IRS shape classification ( Table 1 ) and in order to provide the analysis of individual parameter alterations depending on the IRS shape, we proposed the following numeric determinants for the visually identified shapes (i.e., arrow, boat, drop, and palatal and buccal convergence), as shown in Table 1 .…”

“…Following the described methodology for the maxillary molars’ IRS analysis [ 20 ], the estimation of coronal views for the first maxillary molars revealed the fact that IRS shape significantly affected the dimensions of IRS at all estimated levels (A, B, C, and D; df = 4, F = 27.744, 22.078, 12.740, and 28.041, respectively). As shown in Figure 3 , the diameter determined at level A was significantly lower in the drop when compared to other IRSs.…”

“…The maxillary molars’ interradicular septum morphometric characteristics were evaluated according to the previously described methodology [ 8 , 20 ]. Namely, in the coronal plane, we performed linear measurements (in mm, except for the angle in °) from the CBCT images as follows ( Figure 1 a,b): IRS width at the A level (2 mm from the interradicular furcation); IRS width at the B level (midpoint of IRS height); IRS width at the C level (2 mm from the IRS base); IRS width at the D level (IRS base); IRS height—h (the distance between the interradicular furcation and IRS base); The distance between IRS base and sinus floor—H; Interradicular furcation angle.…”

“…Namely, Amato and coworkers [ 19 ] noticed that over 60% of molars had an IRS height of less than 7 mm. On the other hand, Rajkovic Pavlovic and colleagues [ 20 ] highlighted the importance of the implant length required to achieve primary implant stability. Since the recommended minimal implant length for prime implant fixation is 10 mm [ 21 ], it can be implied that immediate implant engagement in the IRS may often require the elevation of the sinus floor [ 22 ].…”

“…IRS width, another IRS property that can be easily obtained by CBCT analysis, also plays an important role in the prognosis of the implant therapy’s success, as Hayacibara and coworkers [ 24 ] reported an IRS width of 3 mm as the minimum limit that can provide initial implant stability. Since in most cases the IRS width in the region of maxillary molars is less than 3 mm (especially for the second molars [ 20 ]), this structure may usually require additional surgical procedures, such as osseodensification [ 25 ], to provide adequate implant stability.…”