Table 1.
Classification used to assess the morphology of the permanent upper and lower molars
Klassifikation zur Beurteilung der Morphologie der oberen und unteren bleibenden Molaren
| Trait | Features | Grade |
|---|---|---|
| Carabelli’s trait(UM) | It occurs on the lingual surface of the protocone (mesiolingual cusp) and is expressed from complete absence, groove or pit (regarded a negative expression) to a large cusp (positive expression) | 0. Smooth mesiolingual surface |
| 1. Vertical groove present | ||
| 2. Pit present | ||
| 3. Small Y‑shaped depression | ||
| 4. Large Y‑shaped depression | ||
| 5. Small cusp without free apex | ||
| 6. Medium cusp with free apex making contact with the medial lingual groove | ||
| 7. Large free cusp | ||
| Metacone(UM) | The upper molar has 3 major main cusps regarding the metacone cusp. It is named the distobuccal cusp or cusp 3 | 0. Absent |
| 1. There is a ridge but no free apex | ||
| 2. Faint cuspule with a free apex | ||
| 3. Weak cusp | ||
| 3.5. Intermediate-sized cusp that falls between grades 3 and 4 | ||
| 4. Large cusp | ||
| 5. Very large cusp, equal in size to a large hypocone | ||
| Hypocone(UM) | The distolingual cusp is derived from the cingulum and attached to the distolingual surface of the trigon (protocone or cusp 1, paracone or cusp 2 and metacone or cusp 3) | 0. Smooth surface |
| 1. Faint ridge | ||
| 2. Faint cuspule | ||
| 3. Small cusp | ||
| 3.5. Moderate-sized cusp | ||
| 4. Large cusp | ||
| 5. Very large cusp | ||
| Metaconule(UM) | A 5th cusp on the distal border between the metacone (cusp 3) and hypocone (cusp 4). The cusp shows two parallel vertical grooves | 0. Trait is absent |
| 1. Faint cuspule | ||
| 2. Trace cuspule | ||
| 3. Small cuspule | ||
| 4. Small cusp; | ||
| 5. Medium-sized cusp | ||
| Parastyle(UM) | It is most commonly expressed on the paracone (mesiobuccal cusp or cusp 2). In some instances, it occurs on the metacone (cusp 3) | 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 and 3 | ||
| 6. Peg-shaped crown attached to root of second or third molar | ||
| Groove pattern(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 | ||
| Hypoconulid(LM) | The cusp 5 occurs on the distal occlusal surface and it associated with cusp 3 (hypoconid) | 0. Absent. The molar has only 4 cusps |
| 1. Very small | ||
| 2. Small | ||
| 3. Medium-sized | ||
| 4. Large | ||
| 5. Very large | ||
| Cusp 6(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 7(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. Faint cusp, two weak lingual grooves | ||
| 1A. Faint tipless displaced on the lingual surface of cusp 2 | ||
| 2. Small | ||
| 3. Medium-sized | ||
| 4. Large | ||
| Protostylid(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 Fovea(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 | ||
| Deflecting Wrinkle(LM) | The form of manifestation of the essential medial ridge on cusp 2 (metaconid) | 0. Absent |
| 1. The essential ridge is straight and shows a midpoint constriction | ||
| 2. The essential ridge is deflected distally. There is no contact with cusp 4 (entoconid) | ||
| 3. The essential ridge shows strong deflection at the midpoint forming an L‑shaped ridge. There is contact with cusp 4 (entoconid) | ||
| Distal Trigonid Crest(LM) | The major mesial cusps of the trigonid (protoconid or cusps 1, and metaconid or cusp 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 |
ASUDAS method was used [9]
(UM)permanent upper molar, (LM)permanent lower molar