Ackerman Proffit classification - outer envelope represent:

ACKERMAN-PROFITT SYSTEM OF CLASSIFICATION CHARACTERISTIC 1 - ALIGNMENT Intra-arch alignment and symmetry are assessed as when seen in the occlusal view. A dental arch is classified as ideal/crowded/spaced. CHARACTERISTIC 2 - PROFILE The profile can be convex/straight/concave. This also includes the assessment of facial divergence, i.e., anterior or posterior divergence. CHARACTERISTIC 3 - TRANSVERSE RELATIONSHIPS This include the transverse skeletal and dental relationships. Buccal and palatal crossbites are noted. These are further subclassified as unilateral or bilateral. Distinction is made between skeletal and dental crossbites. CHARACTERISTIC 4 - CLASS Here the sagittal relationship of the teeth is assessed using the Angle classification as Class I/Class II/Class III. A distinction is made between skeletal and dental malocclusions. CHARACTERISTIC 5-OVERBITE Malocclusions are assessed in the vertical plane. They are described as anterior open bite/posterior open bite/anterior deep bite/posterior collapsed bite. Here, again a distinction is made as to whether the malocclusion is skeletal or dental.