**4. Alveolar ridge splitting**

Alveolar ridge split is a common technique used in the presence of horizontally deficient alveolar ridges. Surgical procedure for this technique is initiated by one horizontal crestal osteotomy [45]. Piezosurgery, oscillating saws or diamond burs and chisels can be used for the initial osteotomy [2]. Different chisels of increasing width progressively create a gap between the buccal and palatinal/lingual plates afterwards. Interpositional grafting and/or immediate implant placement is oftenly applied to the created gap. This concept is based on the osseous plasticity of trabecular bone. Therefore, a 3- to 5 mm residual crest width is required for the procedure. Fractures may occur in ridges with lower width due to less presence of trabecular bone and less plasticity [46]. To gain greater amounts of new bone, vertical osteotomies may be added to the initial horizontal osteotomy. Another surgical concept of ridge splitting is the displacement of buccal plate by adding a second horizontal osteotomy apically to the initial horizontal osteotomy. In this concept, greenstick outfracture from the basal bone is created on purpose. If full-thickness flap is elevated, the plate should be fixed with screws to the palatinal/lingual plate. Partial-thickness flap is also preferred to keep periosteal vascularization when greenstick fracture is created [47, 48].

This procedure is indicated in cases presenting 3 to 5 mm bone width, with sufficient trabecular bone under the cortical layer. Two-stage ridge split is found to have high success rates up to %97 in terms of implant survival. Studies report 3 to 3.5 mm mean horizontal bone gain with this procedure [48]. Still, there are some drawbacks of this procedure: unpredictable results in severely atrophic crest where

**155**

**Figure 8.**

*Alveolar Ridge Augmentation Techniques in Implant Dentistry*

trabecular bone is not present, high risk of uncontrolled fractures when applied to

Maxillary sinus is one of the paranasal sinuses, located adjacent to posterior maxilla. It's an air-filled anatomical cavity, lined with a membrane called "Schneiderian Membrane". Bone resorption following tooth loss, in conjunction with maxillary sinus pneumatization, causes crestal atrophy in the maxillary posterior region. Maxillary sinus floor elevation provides enough bone height for implant placement in atrophic posterior maxilla. To elevate the Schneiderian Membrane, various techniques are developed. These techniques are classified in two main

This technique consists of preparing a window on buccal bone (also lateral wall of maxillary sinus) and elevating sinus membrane through the window. The superoinferior and anteroposterior borders of lateral window is determined depending on the location of maxillary sinus. Inferior border is usually 2 to 5 mm above the sinus floor to prevent any challenges during the infracturing. Once the lateral window is prepared and Schneiderian Membrane is elevated, various grafting materials can be added to the created space [49]. Barrier membranes are oftenly used to cover the bony window afterwards (**Figure 8**). Use of barrier membranes is reported to be more efficient than no membrane use in terms of implant survival rates [50]. In a clinical trial conducted by Garcia-Denche et al., no significant difference was found in lateral window approach with and without the use of

Lateral window approach is indicated when residual bone height is below 6 mm. Simultaneous implant placement may be applied when residual height is ≥4 mm. In cases presenting less than 4 mm of bone vertically, delayed implant placement is found to be safer [52]. Before proceeding to the surgery, a thorough medical examination is crucial to avoid possible complications. One of the most common complications in lateral window approach is bleeding during the flap elevation or preparation of lateral window. To avoid bleeding, inferior alveolar artery and posterior superior alveolar artery should be well examined, via radiographic images, in terms of location and possible anastomosis. Presence of septa should also be examined for a well-designed window preparation and for avoiding any membrane

*Prepared lateral sinus access window (left) is closed by a resorbable barrier membrane (right) termed as the* 

*"open sinus lifting" or the "lateral window sinus lifting" technique.*

narrow ridges (<3 mm), bone gain only in horizontal dimension [46].

categories: lateral window approach and transalveolar approach.

*DOI: http://dx.doi.org/10.5772/intechopen.94285*

**5. Maxillary sinus augmentation**

**5.1 Lateral window approach**

membranes, though [51].

trabecular bone is not present, high risk of uncontrolled fractures when applied to narrow ridges (<3 mm), bone gain only in horizontal dimension [46].
