**6. Full arch rehabilitation in jaw**

The mandible is an odd bone located in the lower third of the face and is shaped like a horseshoe. It is the largest bone in the face and the only one that moves thanks to the insertion of multiple muscles that participate in chewing. Unlike the maxilla, the mandible has a more corticalized bone, which in most cases allows immediate screw loading. The main anatomical structures of importance include the inferior alveolar nerve, the mental nerve, the insertion of the mylohyoid muscle and the floor of the mouth [38].

*A Review of Current Concepts in Full Arch Rehabilitation with Dental Implants DOI: http://dx.doi.org/10.5772/intechopen.99704*

### **6.1 Treatment of jaw alveolar resorption**

The rehabilitation of posterior regions and edentulous arches with mild atrophy, still allows the placement of implants of at least 8 mm or more in the posterior sector without compromising important anatomical structures such as the inferior alveolar nerve (IAN). In these cases, the biomicanic demands with the placement of 4 to 6 implants in the jaw allow adequate rehabilitation with screws [39].

When alveolar atrophy is moderate or severe, implants cannot be placed without invading the inferior alveolar nerve (IAN). In this situation, therapeutic options include regeneration of the lost alveolar bone, lateralization of the inferior alveolar nerve, placement of short implants < 8 mm and the placement of tilted implants anterior to the mental nerve in the All-on-4® concept [40].

Although the minimum number of implants required for a screw-retained prosthesis is 4, recently it has been described in jaws with severe atrophy the placement of up to 3 bicortical implants in the chin region in a Trefoil ™ concept with good results [41].

In general, the conventional surgical technique includes elevation of a full thickness flap to visualize the bone to the extent where the dental implants will be placed. If the residual bone crest shows irregularities, a bone plasty must be performed until a plateau is achieved and the implantation can be carried out according to the drilling sequence for each commercial company. When planning tilted implants anterior to the mental nerve (30° to 45°), it is essential to preserve the mental nerve and its labial branch to avoid neurosensory alterations of the lower lip. After carrying out the implantation of the desired number of implants, the hermetic closure of the wound is essential to avoid dehiscences and achieve a healing by first intention (**Figure 5**) [42].

#### **Figure 5.**

*Clinical and radiographic photograph of maxillary rehabilitation on 5 submerged implants (2 phases) and mandibular rehabilitation on 4 implants with immediate loading (1 phase).*
