Risks of angled implant placement on posterior mandible buccal/lingual plated perforation: A virtual immediate implant placement study using CBCT

Abstract

Background/purpose: Immediate implant placement has been considered to be a successful treatment procedure. The bone plate perforation (BPP) may be one of severe complication and potentially life-threatening situation. The aim of this virtual study is to evaluate the influences of angled implant insertion on BPP during immediate implant installation in the posterior mandible.

Materials and methods: Cone beam computed tomography images of 488 posterior teeth from 61 patients were selected. Virtual immediate implant placement (VIIP) was performed at each posterior tooth following the appropriate axis with the prosthetic-driven planning and different deviation angles of 3-, 6-, or 9-degree. BPP was then examined from cross-sectional images obtained. Furthermore, the relation of lingual bony morphology and BPP were also determined.

Results: The incidence of buccal and lingual BPP increased as the deviation angle increased in posterior mandible area. Incidence of lingual BPP was significantly influenced by angular deviation and type of lingual bony morphology after adjusting for age, gender, tooth type, and right/left side. An increase in incidence odds of over 6-fold (OR = 6.583) was noted for placements angled by 9° compared with placements made without angulation, and an increase in incidence odds of over 3-fold (OR = 3.622) was noted for teeth with the undercut-type lingual morphology compared with the other types.

Conclusion: The present Results indicate that accurate selection of the implant insertion angle and full awareness of the bony anatomy at the implant recipient site are essential to prevent BPP in the posterior mandible.

Keywords: Anatomy; Complication; Cone beam computed tomography; Dental implant; Mandible.

Figure 1

CBCT images of virtual immediate implant placement (VIIP) at the ideal implant position or lingual angulations of 3, 6, or 9 degrees. Lingual bone plate perforation was noted in VIIP at a 9-degree deviation. The bone plate perforation (BPP) was assessed and identified when the virtual implant apical outline was cross over the border of alveolar bone (the white arrow head).

Figure 2

Incidences of lingual BPP after VIIP with and without lingual deviation at each posterior mandibular tooth The parenthesis indicates the incidence of perforation: p = 0.02, 0.004, 0.031, and 0.001 at PM1, PM2, M1, and M2, respectively, as determined by the Cochran-Armitage Trend test. PM1 = first premolar, PM2 = second premolar, M1 = first molar, and M2 = second molar.

Figure 3

Distribution of the incidence of lingual BPP after VIIP without lingual deviation according lingual morphology type in 122 CBCT hemi-mandible images PM1 = first premolar, PM2 = second premolar, M1 = first molar, and M2 = second molar; C type = convergent type, P type = parallel type, U type = undercut type.

Figure 4

Incidences of buccal BPP after VIIP with and without buccal deviation at each posterior mandibular tooth; the parenthesis indicates the incidence of perforation: p < 0.0001 at PM1, PM2, and M1, respectively, and p = 0.0275 at M2, as determined by the Cochran-Armitage Trend test. PM1 = first premolar, PM2 = second premolar, M1 = first molar, and M2 = second molar.