Proximal Surfaces

Proximal Surfaces teeth, then the area between them is called a diastema instead of an embrasure. A tooth has two proximal surfaces (fig 4-17), one that is oriented toward the midline of the dental arch (mesial) and another that is oriented away from the midline of the arch (distal). Other important surfaces of the proximal area are discussed in the following paragraphs. CONTACT POINT.—The point on the proximal surface where two adjacent teeth actually touch each other is called a contact point. An example of a contact point is when you pass dental floss in between two teeth. You should feel some resistance of the contact point while the floss is being passed through. INTERPROXIMAL SPACE.—The inter- proximal space is the area between the teeth. Part of the interproximal space is occupied by the interdental papilla. The interdental papilla is a triangular fold of gingival tissue. The part of the interproximal space not occupied is called the embrasure. EMBRASURE. —The embrasure occupies an area bordered by interdental papilla, the proximal surfaces of the two adjacent teeth, and the contact point (fig 4-18). If there is no contact point between the Figure 4-17.—Proximal tooth surfaces and spaces. Occlusal The occlusal surface is the broad chewing surface found on posterior teeth (bicuspids and molars). To get a clearer picture of the various tooth surfaces, refer to figure 4-15, which has previously been discussed. The Dental Chart shows each of the teeth “unfolded” so that the facial, occlusal, incisal, or lingual surfaces of the teeth can be shown. For posterior teeth, the facial surfaces are shown adjacent to the roots, followed by the occlusal surfaces, and then by the lingual surfaces (which are located next to the numbers on the chart). For the anterior teeth, the facial surfaces are shown as a line between the facial and lingual surfaces. The lingual surfaces are located next to the numbers on the chart. OCCLUSION.—Occlusion is the relationship between the occlusal surfaces of maxillary and mandibular teeth when they are in contact. Many patterns of tooth contact are possible. Part of the reason for the variety is the mandibular condyle’s substantial range of movement within the temporal mandibular joint. Malocclusion occurs when any abnormality in occlusal relationships exist in the dentition. Centric occlusion, figure 4-19, is the centered contact position of the chewing surfaces of mandibular teeth on the chewing surface (occlusal) of the maxillary teeth. OCCLUSAL PLANE.—Maxillary and mandibular teeth come into centric occlusion and meet along anteroposterior and lateral curves. The anteroposterior curve is called the Curve of Spee Figure 4-18.—Embrasure. Figure 4-19.—Centric occlusion. 4-13