Molars Flashcards
Buccal View Max 1
- 3 roots, 2 cusps, 1 groove • Lingual root > MB > DB in root size
- Buccal roots are shaped like pliers handles
- MB cusp broader than DB but not as sharp
- Roots are twice as long as crown
- Deep developmental groove on the root trunk that extends from the furcation
- ML>MB>DB>DL cusp size
Root trunk
area between crown and root furcation
Lingual View max 1
- 2 cusps ML > DL
- Sometimes there’s a 5th cusp present on the ML – cusp of Carabelli
- 1 groove: lingual groove
- Lingual surface may be as wide or wider than the Buccal surface
Mesial View Max 1
- Crown convergence toward the occlusal surface
- High, prominent marginal ridge
- The Broad MB root hides the skinnier DB root
- Lingual root is the longest
- Buccal cervical ridge – a ridge running mesiodistally on the cervical third of permanent molars and ALL deciduous teeth
Distal View max 1
- More occlusal surface can be seen than from mesial view
* The small DB root does not mask the larger MB root
Occlusal View max 1
• Rhomboid with 2 acute and 2 obtuse angles
• Oblique ridge – a diagonal ridge formed by the lingual cusp ridge of the DB cusp and the distal cusp ridge of the ML cusp
• 2 major fossae and 2 minor fossae
o Central fossa is triangular in shape and contains a Buccal and central groove
o The distal fossa is linear and has a distolingual oblique groove
Buccal View max 2
- Buccal roots are less curved and more parallel to each other than the first molar
- Crown tapers toward the cervical on the distal side
- MB cusp is clearly larger than the DB cusp
Lingual View max 2
• 2 forms
o 2 lingual cusps (62%) or 1 lingual cusp
• DL much smaller than ML cusp (in the 2 cusp form)
• In general the roots are inclined more distally than first molar
Mesial View max 2
• The roots do not spread as far buccolingually
o They stay within the confines of the buccolingual crown outline
Distal View max 2
- Similar to first molar
* DB cusp is smaller than on the first molar and thus more of the MB cusp can be seen
Occlusal View max 2
• Usually has 4 cusps but may have only 3
• Narrower mesiodistally than the first molar, but the same buccolingually
• 3 cusp type
o Distal fossae and distal oblique(lingual groove) are absent
Maxillary Third Molars
▪ Often appear to be developmental anomalies as they vary widely in size, contour, and shape
▪ Crowns are smaller than the second molar and the roots tend to fuse
▪ All third molars, Mandib. And Max., show more variation in development than any other teeth in the mouth
▪ Occlusal view
• Typically a heart shaped outline with well developed single lingual cusp
• Many supplementary grooves
Maxillary molar summary
▪ Wider faciolingually than mesiodistally
▪ 3 major cusps and they have an oblique ridge (ML > MB > DB)
▪ 3 roots (lingual > MB > DB)
Mandibular Molars
o Functions
▪ Mastication of food
▪ Maintaining the vertical dimension of the face
▪ Maintain continuity within the dental arches
o Perform major portion of the work in the mandible
o Flattened Buccal cusps are typical of mandibular molars
Buccal View man 1
- Crown has largest mesiodistal dimension of any tooth
- 3 cusps, 2 grooves
- 2 roots – this tooth has the highest root to crown ration of any other tooth
- MB, DB, Distal cusps are relatively flat
- Mesial root more curved than the distal root
- Developmental depressions on both roots
- There is a deep developmental depression buccally on the root truck and the roots are broad buccolingually, twisted slightly distally, root depressions all result in enhanced anchorage
- Mesial contact located furthest bucally than any of the contact areas on mandibular posterior teeth
Lingual View man 1
- 2 cusps (ML wider and more pointed than DL)
- More pointed and slightly longer than the Buccal cusps
- Roots measure about 1mm longer lingually than buccally
Mesial View man 1
- 2 cusps and 1 root are seen
- Buccolingual measurement of the crown is wider on mesial than distal
- Both mesial and distal surfaces on the mesial root have developmental depressions
Distal View man 1
- Can see more of the other surfaces of the molar than you can from the mesial view
- Distal root is narrower than the mesial
- So you can see the mesial root behind the distal root from this view
- Usually a developmental depression on the distal surface of the distal root, but NOT on the mesial surface of the distal root
- The distal marginal ridge is made up of the distal cusp ridge of the distal cusp and the distal cusp ridge of the DL cusp
Occlusal View man 1
- Pentagon outline
- 5 cusps, 2 transverse ridges, 3 fossae
- Zig-zag central groove
Buccal View man 2
- 2 cusps, 1 groove, 2 roots
* Crown is shorter cervicoocclusally and narrower mesiodistally than mandibular first molar
Lingual View man 2
- Similar to first molar but less convergence to the lingual so that not much of the mesial or distal surface can be seen
- Narrower mesiodistally at the cervix than the first molar
Mesial View man 2
- Very similar to first molar except that the Buccal cervical ridge is less prominent
- Can see sharp drop on mesial outline – outline is rectangular
Distal View Man 2
• NO distal cusp, major difference from the first molar
o Distinguishing trait
o Can see the semi-circular distal outline
o Can see mesial root
Occlusal View man 2
- Rectangular shape
- 4 cusps, 3 fossae, Central groove, Buccal groove, and lingual groove for a + shape… known as +4 morphological category
- Distal crown outline is semicircular whereas the mesial crown outline is rectangular
- DB cusp ridges lie further Buccal than MB cusp ridges
- Widest buccolingually at the MB cusp due to prominent Buccal cervical ridge
Mandibular Third Molars
▪ Vary considerably and present many anomalies
▪ Many have abnormally large crowns with undersized roots
▪ Most likely to be impacted, due to lack of space accommodation in the jaw
Mandibular Molars Summary
▪ Crowns are oblong – wider mesiodistally than buccolingually
▪ 4 major cusps – and the lingual cusps are nearly equal in size
▪ 2 roots
▪ Crowns tip lingually
Molar Class Traits
o Broader occlusal surfaces than other classes of teeth
o Have at least 3 cusps and at least 2 buccal cusps
o Distal side narrower buccolingually than mesial
o Shorter cervicoocclusally than other classes of teeth
o Slightly longer mesiodistally than buccolingually
o Broad, bifurcated roots result in surperior anchorage
Triangular ridge
any ridge that descends from the cusp tip of a posterior tooth toward the central part of the occlusal surface
Inclined plane
the sloping area found between two cusp ridges
Developmental groove
narrow and linear line between the primary parts of the teeth
Transverse ridge
the union of two triangular ridges crossing transversely across the surface of a posterior tooth
Oblique ridge
diagonal ridge formed by the lingual cusp ridge of the DB cusp and the distal cusp ridge of the ML cusp of max 1
this tooth has the highest root to crown ration of any other tooth
Mandibular First Molar
