Resident Manual of Trauma to the Face, Head and Neck

maxillary first molar occludes in the buccal groove of the permanent mandibular first molar (Figure 5.8). 2. Angle Class II Occlusion Angle Class II occlusion is the posterior relationship of the mandible to the maxilla. The mesiobuccal cusp of the permanent maxillary first molar occludes mesial to the buccal groove of the permanent mandibu- lar first molar. 3. Angle Class III Occlusion Angle Class III occlusion is the anterior relationship of the mandible to the maxilla. The mesiobuccal cusp of the permanent maxillary first molar occludes distal to the buccal groove of the permanent mandibular first molar. 4. Maximum Intercuspation Maximum intercuspation refers to the occlusal position of the mandible in which the cusps of the teeth of both arches fully interpose them- selves with the cusps of the teeth of the opposing arch. This position is the goal in repositioning the teeth in proper occlusion during MMF. 5. Wear Facets A wear facet is a highly polished wear pattern or spot on a tooth produced by an opposing tooth from chewing or grinding. It is useful in repositioning teeth into premorbid occlusion when a pre-existing malocclusion was present (crowding, spacing, midline misalignment).

Figure 5.8 Molar relationship in Class I occlusion, mesiobuccal cusp (MBC) of the upper first molar occludes with the buccal groove (BG) of the lower first molar.

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