Horizontal augmentation techniques in the mandible: a systematic review

Abstract

Purpose: Placement of dental implants has evolved to be an advantageous treatment option for rehabilitation of the fully or partially edentulous mandible. In case of extensive horizontal bone resorption, the bone volume needs to be augmented prior to or during implant placement in order to obtain dental rehabilitation and maximize implant survival and success.

Methods: Our aim was to systematically review the available data on lateral augmentation techniques in the horizontally compromised mandible considering all grafting protocols using xenogeneic, synthetic, or allogeneic material. A computerized and manual literature search was performed for clinical studies (published January 1995 to March 2021).

Results: Eight studies ultimately met the inclusion criteria comprising a total of 276 procedures of xenogeneic, allogeneic, or autogenous bone graft applications in horizontal ridge defects. Particulate materials as well as bone blocks were used as grafts with a mean follow-up of 26.0 months across all included studies. Outcome measures, approaches and materials varied from study to study. A gain of horizontal bone width of the mandible with a mean of 4.8 mm was observed in seven of eight studies. All but one study, reported low bone graft failure rates of 4.4% in average.

Conclusions: Only limited data are available on the impact of different horizontal augmentation strategies in the mandible. The results show outcomes for xenogeneic as well as autologous bone materials for horizontal ridge augmentation of the lower jaw. The use of allogeneic bone-block grafts in combination with resorbable barrier membranes must be re-evaluated. Randomized controlled clinical trials are largely missing.

Keywords: Augmentation; Horizontal; Lateral; Lower jaw; Mandible.

Fig. 1

Tree diagram of exclusion/inclusion of studies for this systematic review

Fig. 2

Schematic of horizontal bone loss in the lower jaw after crestal gingival exposure (A). Principle of bone-block grafting and fixation with screws (B). Depiction of lateral augmentation using particulate bone and membrane placement for coverage (C). Gaining of horizontal bone width by surgical splitting of the alveolar ridge (D)

Fig. 3

Clinical example of a 41-year-old female patient presenting with missing tooth 31 and consecutive horizontal bone loss (A). For dental, functional and esthetic rehabilitation, simultaneous implant placement and lateral augmentation was performed. Implantation of Conelog Progressive Line, harvesting of a retromolar bone block from the mandibular angle with a trephine drill, augmentation and microscrew fixation (1.0-mm steel screws) after rounding of the edges with a burr (B). Relining and fitting with particulate bone placement (C). After 5 months of healing time, implant exposure and fixation screw removal, sequential abutment fitting and placement of dental crown were performed (D)