Horizontal deficiency of alveolar ridge consists of a major problem that sometimes does not allow the insertion of osseointegrated implants in the edentulous regions. Various treatment strategies and techniques have been proposed for alveolar bone augmentation; most common are guided bone regeneration, split crest, horizontal distraction osteogenesis and autologous bone grafting. Each method have its own limitations which led to the investigation of other bone augmentation techniques. Recently split crest technique and horizontal distraction osteogenesis resulted to be one of the most reliable bone augmentation techniques for the insertion of implants in edentulous and atrophic ridges. 
The aim of this article is the review of the literature, the presentation of the current methods of this technique along with the indications and contraindications of its application
After reviewing with a detailed approach the titles and abstracts of articles eliminating duplicates, 40 relevant articles were considered. Randomized studies, review articles, case reports and abstracts were included while conference papers and posters were excluded.
The techniques that will be presented in this presentation are (1) ridge split either with a chisel or with the use of piezoelectric surgery and immediate implant placement, (2) ridge split with delayed implant placement, (3) horizontal distraction osteogenesis of alveolar ridge with delayed implant placement, and (4) horizontal distraction osteogenesis of alveolar ridge with late implant placement. There are some anatomical requirements that are necessary to be present in order to use the ridge split technique and horizontal distraction osteogenesis.
The technique of ridge split and horizontal distraction osteogenesis seems to have high survival rates and as a result is an alternative treatment for the placement of osseointegrated implants in the narrow alveolar processes. Indeed, the rates of successfully inserted implants with these techniques are comparable to the implants that were placed with the classic technique. Finally, all these techniques are evaluated and compared concerning to our personal experience.

The placement of dental implants in the atrophic jaws with ridge split technique and horizontal distraction osteogenesis. Literature review