INTRODUCTION
Treatment of patients with cancer of the upper aerodigestive tract (UADT) is based on a resective surgery, and/or radio/chemotherapy. The consequences of such a management are quite serious: they lead to tissue loss (more or less compensated by fibula or scapula grafts), hyposialia or asialia, increased carious and periodontal risks, limitation in mouth opening, and microstomia (1). The prosthetic rehabilitation of this type of patient may be quite challenging for the clinician, due to a « clinical paradox ». Indeed, while the tissue loss aggravated by bone resorption should lead to an increase of the prosthetic space, limitation of mouth opening and microstomia cause labial inocclusion at rest, and finally end up with a reduced occlusal vertical dimension (OVD). Rehabilitation of the occlusal vertical dimension (OVD) is then achieved with the best possible compromise in terms of esthetics, phonetics and function, and is most often reduced compared to the intial pre-trauma situation.
The treatment options allowing to compensate for this tissue loss include complete removable dental prostheses (RDP) either conventional or stabilized with dental implants. When the appropriate indication is selected, the survival rate of a fibula flap would be around 97%, and the implant survival rate around 78%, according to a retrospective study with 11 years of follow up (2). Several implant-supported prosthetic options may be considered according to the clinical situation : a fixed implant-supported prosthesis, a complete removable-fixed dental prosthesis supported by a bar and a counterbar, and a complete removable dental prosthesis stabilized over implants with ball-attachments or a connecting bar (CB). Several types of bars have been described in the scientific literature. The purpose of this article was to present different types of bars and their indications for patients, illustrated by two clinical cases. The different types of bars are described in Table 1, and their indications are displayed in a decision tree in Figure 1.