Table 2.
Classification used to assess the morphology of the primary upper and lower molars
Klassifizierung zur Beurteilung der Morphologie der primären oberen und unteren Molaren
| Trait | Features | Grade |
|---|---|---|
| Carabelli’s trait3 (um) | It occurs on the lingual surface of the protocone (mesiolingual cusp). This tuberculum projection is expressed from complete absence, groove or pit to a large cusp | 0. Smooth surface |
| 1. Pit, groove | ||
| 2. Two grooves are roughly parallel | ||
| 3. The area between grooves raised, apex not free | ||
| 4. The expression is similar to type 3 but there is a free apex | ||
| Crown pattern 1st molar2 (um) | The pattern is based on the development of the crown cusps of the upper 1st deciduous molars | 2. Protocone and paracone |
| 3M. Protocone, paracone and metacone | ||
| 3H. Protocone, paracone and hypocone | ||
| 4−. All four cusps but hypocone reduced | ||
| 4. All four cusps but hypocone not reduce | ||
| Crown pattern 2nd molar2 (um) | The pattern is based on the development of the crown cusps of the upper 2nd deciduous molars | 3. Protocone, paracone, metacone, and a small hypocone. The distal marginal ridge can be interrupted by a groove |
| 4−. Protocone, paracone, metacone, and a small hypocone. The distal marginal ridge follows its course without interruption | ||
| 4. Protocone, paracone, metacone, and large hypocone | ||
| Metaconule3 (um) | A 5th cusp on the distal border between the metacone and hypocone. The cusp shows two parallel vertical grooves | 0. Absent |
| P. Present | ||
| Parastyle1 (um) | It is most common expressed on the paracone (mesiobuccal cusp). In some instances, it occurs on the metacone | 0. Smooth buccal surface |
| 1. A small pit near the buccal groove | ||
| 2. Small cusp without free apex | ||
| 3. Medium cusp with free apex | ||
| 4. Large cusp with free apex | ||
| 5. Very large cusp that may extend onto the surfaces of both cusps 2 (paracone) and 3 (metacone) | ||
| 6. Peg-shaped crown attached to root of second or third molar | ||
| Groove pattern1 (lm) | Lower molars can have 5 cusps: cusp 1 (protoconid), cusp 2 (metaconid), cusp 3 (hypoconid), cusp 4 (entoconid) and cusp 5 (hypoconulid). The cusps can make contacts creating patterns | Y. Cusps 2 and 3 are in contact |
| +. Cusps 1–4 are in contact | ||
| X. Cusps 1 and 4 are in contact | ||
| Hypoconulid3 (lm) | Cusp 5 occurs on the distal occlusal surface and is associated with cusp 3 (hypoconid) | 0. Absent |
| P. Present | ||
| Cusp 61 (lm) | This cusp is expressed on the distal portion, but it is associated with the cusp 4 (entoconid). It is important to note that cusp 5 (hypoconulid) has to be present | 0. Absent |
| 1. Much smaller than cusp 5 | ||
| 2. Smaller than cusp 5 | ||
| 3. Equal in size to cusp 5 | ||
| 4. Large than cusp 5 | ||
| 5. Much larger than cusp 5 | ||
| Cusp 72 (lm) | It is a wedge-shaped accessory cusp expressed in the lingual groove between cusps 2 (metaconid) and 4 (entoconid). Cusp 7 is never considered in determining cusp number | 0. Absent |
| 1. Only a very weak short groove extends downward from the lingual ridge of cusp 3 (hypoconid). There is no cusp | ||
| 2. There are two grooves on the lingual surface and a small cusp is present | ||
| 3. The cusp is well developed | ||
| Protostylid1 (lm) | This trait is a cingular derivate on the buccal surface associated with the buccal groove, particularly separating cusp 1(protoconid) and cusp 3 (hypoconid) | 0. Smooth surface |
| 1. Pit present | ||
| 2. Buccal groove curve distal | ||
| 3. Faint groove extending mesial from the buccal groove | ||
| 4. Groove more pronounced | ||
| 5. Groove stronger | ||
| 6. Groove extend across the buccal surface | ||
| 7. Free cusp | ||
| Anterior fovea1 (lm) | This trait is expressed on the mesial occlusal surface. It involves distinct essential ridges on cusp 1 (protoconid) and cusp 2 (metaconid) that meet close to the centre of the trigonid, and a mesial marginal ridge that is expressed to varying degrees | 0. Absent |
| 1. Trace, with a weak ridge connecting the mesial aspects | ||
| 2. Essential ridges on trigonid better developed and resulting groove deeper than in grade 1 | ||
| 3. Essential ridges pronounced and marginal ridge well developed, producing a distinctive fovea on the anterior portion of the trigonid | ||
| 4. The Mesial ridge is robust and the marginal ridge produces a well-defined fovea with a very long groove | ||
| Central ridge of the metaconid2 (lm) | The form of manifestation of the essential medial ridge on cusp 2 (metaconid). This trait is the same as Deflecting Wrinkle on permanent dentition | 1. The essential ridge of the cusp 2 is expressed similar in size and prominence as that of the other cusps |
| 2. The essential ridge is very well developed in its thickness on cusp 2 and also expands its width in the trigonid basin. The ridge sometimes seems to curve distally at its inner end | ||
| Distal trigonid crest2 (lm) | The major mesial cusps of the trigonid (cusps 1 and 2) express distal accessory ridges that are directly connected along the distal portion of the cusps. They can be continuous or discontinuous | 0. Absent |
| 1. Present: distal borders are connected by a ridge |
1ASUDAS methods [9], 2Hanihara methods (1961), 3Sciulli methods (1998), (um)deciduous upper molar, (lm)deciduous lower molar