Table 1.

Oral examination criteria of the children’s three-dimensional dental arch relationships

Sagittal	Vertical	Transverse
Incisal relationship- Classified into three categories: Class I, the lower incisor edges occlude with or lie immediately below cingulum plateau of the upper central incisors; Class II, the lower incisor edges lie posterior to the cingulum plateau of the upper incisors; Class III, the lower incisor edges lie anterior to the cingulum plateau of the upper incisors. The overjet is reduced or reversed [44].	Overbite- Coverage of the mandibular incisor by the most protruded fully erupted maxillary incisor and recorded as < 1/2 or ≥ 1/2 [11].	Intermolar width- Distance between mesiobuccal cusp tips of the maxillary second primary molars [40].
Canine relationship- Classified into three categories: Class I, the tip of the maxillary primary canine tooth is in the same vertical plane as the distal surface of the mandibular primary canine; Class II, the tip of the maxillary primary canine tooth is mesial to the distal surface of the mandibular primary canine; Class III, the tip of the maxillary primary canine is distal to the distal surface of the mandibular primary canine [11].	Anterior openbite- When there are no vertical contacts between upper and lower incisal edges [9].	Intercanine width- Distance from cusp tip to cusp tip of the maxillary primary canines [40].
Molar relationship - Classified into three categories: Flush terminal, where the distal surfaces of the upper and lower second primary molars are in the same vertical plane in a centric occlusion; Distal step, where the distal surfaces of the lower primary second molar are in a posterior relationship to the distal surface of the upper second molars in centric occlusion; Mesial step, the distal surfaces of the lower primary second molar are in an anterior relationship to the distal surface of the upper second molars in centric occlusion [11].		Posterior crossbite- Recorded when one or more of the maxillary primary canines or molars occluded lingual to the buccal cusps of the opposing mandibular teeth [11].
Anterior crossbite – It was recorded when one or more of the maxillary incisors occluded lingual to the mandibular incisors [45].
Overjet- Measured from the palatal surface of the mesial corner of the most protruded fully erupted maxillary incisor to the labial surface of the corresponding mandibular incisor [11]. The degree of overjet was recorded in millimeters. In this study, an overjet of greater than 3.5 mm was considered an increased overjet.