From: Prevalence of and factors affecting malocclusion in primary dentition among children in Xi’an, China
Types | Diagnosis criteria | |
---|---|---|
Sagittal anomalies | Anterior crossbite | Recorded when the lower incisors or canines are in front of the corresponding upper teeth |
Edge-to-edge occlusion | Recorded when the maxillary incisors and the corresponding mandibular incisors are occluded in an edge-to-edge status, without overbite or overjet | |
Increased overjet | Recorded when the distance from the most labial point of the incisal edge of the maxillary incisors to the most labial surface of the corresponding mandibular incisors is more than 3 mm, measured to the nearest 0.5 mm | |
Vertical anomalies | Open bite | Recorded when the upper and lower incisors are vertically separated regardless of the extent, without any overbite |
Deep overbite | Recorded when the vertical overlap of the incisors, when the posterior teeth are in contact is more than two thirds covered or when the overlap is more than 3 mm, measured to the nearest 0.5 mm | |
Transversal anomalies | Posterior crossbite | Recorded when the buccal cusps of the maxillary molars occlude lingually to the buccal cusps of the mandibular antagonists in at least one pair of teeth, uni- or bilaterally. Teeth in an edge-to-edge position were also included |
Midline deviation | Recorded when the position of the mandibular midline had a more than 2-mm discrepancy relative to the maxillary midline, with the posterior teeth in full occlusion |