CBCT data relevant in treatment planning for immediate maxillary molar implant placement

Abstract

Background. This study used CBCT images to evaluate the suitability of maxillary first and second molar sites to receive immediate implants. Buccopalatal and mesiodistal widths of maxillary molar inter-radicular septum were evaluated at three different levels (crestal, middle, and apical), in addition to assessments of the root apex and furcation proximities to the sinus floor and comparisons of these measurements between the first and second upper molar sites before extraction.Methods. A total of 427 dental sites from 223 patients were used to measure the buccopalatal and mesiodistal widths of inter-septal/furcal (IRS) bone of maxillary first and second molars and vertical distances from the furcation and from all the root apices to the sinus floor (SF).Results. Mean coronal-most buccopalatal/mesiodistal IRS widths were 7.33/6.52 mm for the first and 6.86/5.85 mm for the second molars (P=0.008). Corresponding mean FSD (furcation-sinus floor) values were 9.69 mm (range: 2.02-24.68 mm) and 8.84 mm (range: 1.48-25.09 mm). Mean distances from all the root apices to SF were <3 mm. The palatal roots of the first molars had higher sinus intrusion rates (28.85%) than their buccal counterparts, while for the second molars, the mesiobuccal roots showed the highest sinus intrusion (37.65%).Conclusion. In the current patient sample, 61.7% of the first and 34% of the second molars had a sufficiently broad IRS to encase a 5-mm-diameter IMI (immediate molar implant) completely. The mean FSD of 9 mm for both molars indicated that some sinus floor elevation would likely be needed unless short implants were used.

Cone-Beam Computed Tomography (CBCT)-Based Assessment of the Alveolar Bone Anatomy of the Maxillary and Mandibular Molars: Implication for Immediate Implant Placement

“…However, in this study, the FMS-P distance was less than 0.5 mm in both the first and second molars, and the palatal intruded into the sinus in 49% and 30% of the first and second molars, respectively. Other studies have reported similar findings, with palatal root intrusion into the sinus ranging between 29% and 73% and 23% and 69% for first and second molars, respectively [13,18].…”

“…Only 37% of the first molars and 35% of the second molars in this study fulfilled these criteria. Similarly, Deporter et al [ 13 ] reported that only 61.7% of maxillary first molars and 34% of second molars are potential candidates for immediate implants.…”

“…The close relationship between molar roots and the sinus floor has been emphasized in several studies [ 9 , 13 , 16 , 17 ]. Some studies have reported that the MB and DB roots of the second molar are those that are most often in contact with the sinus floor [ 10 , 18 ], while others have indicated that the palatal root commonly intrudes into the sinus [ 19 , 20 ].…”

“…Smith and Tarnow [ 7 ] classified molar sites into three types according to the availability of furcal bone surrounding the future implant. Most maxillary first molars are type A (IRB >6 mm), while 60% of second molars are type B (IRB = 3-6 mm) [ 13 ]. While in the mandible, most extractions sockets were type B in the first molar site and type C in the second molars [ 21 ].…”

“…Previous studies have used CBCT to determine the average distance from the root apices to vital structures in the maxilla [ 9 , 10 ] and mandible [ 11 , 12 ] and between molar furcation and vital structures [ 13 ]. However, few studies have addressed other dimensional differences between the first and second molars in the maxilla and mandible.…”