TOPIC: SELECTION AND ARRANGEMENT OF TEETH
🎯 KEY FACTS
🔹Denture aesthetics is defined as ‘the effect produced by a dental prosthesis that affects the beauty and attractiveness of the person’.
🔹Space of Donders is the space that lies above the dorsum of the tongue and below the hard and soft palates when the mandible and tongue are in the rest position.
🔹 Silverman’s speaking space is the space that occurs between the incisal and/or occlusal surfaces of the maxillary and mandibular teeth during speech.
🔹 For most of the patients, the average speaking space is 1.5–3 mm.
🔹 Patients with class II occlusion have larger speaking space, i.e. 3–6mm.
🔹 Patients with class III occlusion have reduced speaking space, i.e.about 1 mm.
🔹 Palatogram is the graphic record of the area of the palate contacted by the tongue during speech.
🔹No posterior teeth should be placed distal to the retromolar region.
🔹 Size of the artificial teeth is determined by the size of the face ,interarch space, length of lips, skeletal jaw relation, amount of resorption and size of the anterior arch from cuspid-to-cuspid.
🔹Dentogenic Concept is the art, practice and technique of creating an illusion of natural teeth in artificial dentures and is based on the elementary factors suggested by the Sex, Personality, Age (SPA) of the patient.
🔹Modiolus is the meeting place of eight muscles, which forms a distinct conical prominence at the corner of the mouth
🔹J.P. Frush and D.R. Fisher (1956) proposed the dentogenic concept in selecting artificial teeth based on SPA.
💠 According to S. Winkler, aesthetics in complete denture prosthodontics is affected by the following three factors:
(i) Biological
(ii) Mechanical
(iii) Psychological
💠 The three important factors on which the anterior teeth selection is usually based are as follows:
(i) Size of the teeth
(ii) Form of the teeth
(iii) Colour of the teeth
💠 Factors influencing selection of posterior teeth for moderate ridges are:
i ) Size
ii) Form
iii) Colour
iv) Material
💠 The following factors are considered during size selection of the posterior teeth:
(i) Buccolingual width
(ii) Mesiodistal length
(iii) Occlusogingival height
💠 Factors that control the selection of the form of posterior teeth are:
(i) Condylar inclination
(ii) Shape and height of the residual ridge
(iii) Incisal guidance
(iv) Plane of occlusion
(v) Ridge relationship
(vi) Height of occlusal plane
(vii) Compensating curve
💠 Types of posterior teeth form are:
(i) Cusp form:
🔸 Anatomic teeth
🔸 Semi-anatomic teeth
(ii) Cuspless:
🔸 Nonanatomic teeth
♦️ Factors influencing the positions of the artificial teeth are:
🔹 Functions of surrounding tissues
🔹 Quality of the basal seat tissues
🔹 Anatomical limits
🔹 Mechanical factors
♦️ Factors that guide the positioning of the teeth in complete dentures are:
🔹 Horizontal relation with the residual ridges
🔹 Vertical positions of the occlusal surfaces and the incisal edges between the residual ridges
🔹 Aesthetic requirements
🔹 Inclinations for occlusion
🔶 Following are the muscles meeting at the modiolus:
(i) Zygomaticus
(ii) Quadratus labii superioris
(iii) Caninus (levator anguli oris)
(iv) Mentalis
(v) Quadratus labii inferioris
(vi) Triangularis (depressor anguli oris)
(vii) Buccinator
(viii) Risorius