Specify the variety of dento-maxillary anomaly with inverted labial step.

Specify the variety of dento-maxillary anomaly with inverted labial step.

• A. vertical inocclusion
• B. positive sagittal inocclusion
• C. negative sagittal inocclusion
• D. laterodeviation

Answer: (C)

The main idea here is how the upper and lower incisors relate in the sagittal (front-to-back) direction. An inverted labial step means the lower incisors sit ahead of the upper incisors when the teeth are in centric occlusion, producing a reverse overjet or anterior crossbite. That pattern reflects a negative sagittal inocclusion, which is the hallmark of a Class III dento-maxillary relationship (mandible relatively forward or maxilla relatively back). The other terms describe different aspects: vertical inocclusion concerns vertical bite relationships, not the front-to-back incisor order; positive sagittal inocclusion would indicate the normal/forward upper-incisor relationship rather than a reverse one; laterodeviation refers to a side-to-side (transverse) shift of the midlines, not the sagittal front-to-back relationship. So the variety characterized by an inverted labial step is negative sagittal inocclusion.

The main idea here is how the upper and lower incisors relate in the sagittal (front-to-back) direction. An inverted labial step means the lower incisors sit ahead of the upper incisors when the teeth are in centric occlusion, producing a reverse overjet or anterior crossbite. That pattern reflects a negative sagittal inocclusion, which is the hallmark of a Class III dento-maxillary relationship (mandible relatively forward or maxilla relatively back).

The other terms describe different aspects: vertical inocclusion concerns vertical bite relationships, not the front-to-back incisor order; positive sagittal inocclusion would indicate the normal/forward upper-incisor relationship rather than a reverse one; laterodeviation refers to a side-to-side (transverse) shift of the midlines, not the sagittal front-to-back relationship.

So the variety characterized by an inverted labial step is negative sagittal inocclusion.