A Simplified Method to Identify Patient Face Type for a Prosthodontic Treatment Plan

Abstract

Biomechanical stress is an important risk factor in prosthetic dentistry. It has been demonstrated to be associated with occlusal wear, dentoalveolar trauma, as well as magnifying the risk of stress- related complications. Biomechanical stress intensity is directly related to force applied.1–3 Many clinical studies have shown a correlation between bite force and facial structure. Facial morphology and jaw muscle size are important factors for the degree of bite force.4–8 Facial type assessment is in many aspects crucial for the planning and prognosis of prosthetic treatment. Subjects with a strong bite force present a well-developed masticatory musculature, smaller anterior facial height (short face), and a smaller value in the gonial angle. They are called brachyfacial. Patients with smaller bite force value exhibit a longer anterior and shorter posterior facial height (long face) and a larger gonial angle. These patients are called dolichofacial.9–11 The terms brachyfacial, dolichofacial, and mesofacial, commonly used by orthodontists, were introduced in orthodontic literature by Ricketts RM.5 With regards to the effects of the occlusal load, scientific literature describes patients more prone to overload as individuals who present parafunctions.12–14 However, patients with parafunctions do not necessarily present load forces intense enough to cause damage to the periodontal tissues and teeth. On the contrary, brachyfacial individuals, even in the absence of parafunctions, develop considerably intense bite forces. These jeopardize the integrity of conservative and prosthetic rehabilitation and provoke a broad range of complications.15 Considering the face form of the patient in prosthodontic treatment planning may lead to a better clinical outcome if a relationship between face form and bite force is established. An individual bite force level can be determined with complex electronic devices.6 These instruments are not of easy use in the clinical practice and it is possible to use clinical alternative methods to recognize brachyfacial patients. The aim of the present study is to provide a diagnostic protocol that easily and safely allows recognizing high occlusal risk brachyfacial patients in order to implement a prosthetic therapy that is able to limit possible biological or mechanical damage caused by excessive bite forces.