Permanent Molars Flashcards
Describe the root trifurcation on maxillary permanent molars
Try furcation forms apical to the root trunk
2 buccal
1 palatal
Which teeth are referred to as the cornerstones of the dental arches?
Maxillary and mandibular first molars
Which maxillary teeth are the largest and strongest?
Maxillary first molars
How many developmental lives to the maxillary first molars have?
4 lobes
Where is the height of contour on the buckle and lingual aspects of the maxillary first molars?
Buccal cervical ridge end cervical third close to the CEJ
And on the lingual cervical third close to the junction of the cervical and middle third
What is the cusp of Carabelli?
Supplemental fifth cusp on the maxillary first molars. Occasionally absent and varies in size and shape
Located on the mesial aspect on the ML cusp in the Occlusal third
How much bigger or maxillary first molars than the maxillary pre-molars?
2 mm larger in all dimensions. Maxillary molars are wider buccolingually than mesiodistally
What is the shape of a maxillary first molar?
Rhomboid
Mesial/distal surfaces are somewhat parallel but not at right angles
What are the four Fosse of the maxillary first molars?
Central Fossa
Distal Fossa
Mesial triangular Fossa
Distal triangular fossa
Where does the oblique ridge run from?
Runs obliquely from the triangular cusp ridge of the DB cusp to the distal cusp ridge of the mesial lingual cusp
Where does the transverse Ridge run from?
Prominent ridge that course transversely from the triangular cusp ridge of the mesial buccal cusp to the triangular cusp ridge of the mesial lingual cusp
How many ridges does each cusp have?
4 per cusp
Mesial, distal, buccal or lingual & occlusal/triangular cusp ridge
What are the 3 pits on the maxillary 1st molars?
Central- very prominent
Distal- prominent
Mesial- not prominent
Why is the route of the buccal groove?
From central pit over the buccal cusp ridge, nearly centered, onto the buccal surface and stops just above the buccal cervical ridge
What is the route of the central groove of the maxillary 1st molar?
Courses across the central fossa in a mesial direction, ends in the mesial triangular fossa
What is the route of the mesial marginal ridge groove in the maxillary 1st molar?
If present, extends from the mesial triangular fossa and crosses the mesial marginal ridge
What is the route of the lingual groove on the maxillary 1st molars?
Extends from DOG to cross the LCR and travels down the lingual surface ending near the cervical line and may extend onto and down the palatal root
What does the 5th cusp groove demarcate?
Cusp of Carabelli/5th cusp
On which aspect may you find a depression on the mesial buccal root of the maxillary right first molar?
On the distal aspect
Which is the smallest of root of the maxillary right first molar?
Distal buccal root
Which is the largest and longest of all three roots of the maxillary right first molar?
Palatal root
Describe the root trunk of the maxillary right first molar?
Short, try furcation occurs in the cervical third of the root
How many pulp horns and canals are present in the maxillary right first molar?
4 pulp horns
3 to 4 pulp canals- usually 3 but if a 4th is present it will be in the MB root that may bifurcate
What may occur if the apices of the maxillary first molars penetrate the floor of the maxillary sinus?
“Sinus infection” Made manifest as a toothache causing dental pain without the presence of dental disease
What are enamel pearls?
Droplets of ectopic enamel occasionally found on the roots of teeth
Uncommon, minor abnormalities which are formed on normal teeth
What is root fusion?
When two tooth buds fuse to make a large tooth
What is germination?
Caused by a single tooth germ that attempted to divide during its development, resulting in a bifid crown
What is the difference in Crown size between the three molars?
Second and third molars are progressively smaller than first molars. B/L width is about the same, M/D width about 1mm smaller
Crown is shorter. Buccal cusps about same size, lingual cusps are smaller
Describe the shape of the occlusal aspect of the maxillary right second molar
Rhomboid or heart shaped
Describe the occlusal anatomy of the maxillary second molars
The same but not as distinct or prominent as the first molars
Describe the buccal groove of the maxillary second molars
Does not cross the buccal height of contour
Describe the lingual groove of the maxillary second molars
Does not extend past the lingual height of contour
Describe the roots of the maxillary second molar in comparison to the maxillary first molar
All three roots are contained within the crown outline. Not as divergent and are the same length
Where does the trifurcation occur on the root trunk of the maxillary second molar?
The middle third of the root trunk
Describe the crowns of the maxillary third molars
Smallest of the maxillary molars. Distal lingual cusp is very small and may not be present
Describe the shape and anatomy of the occlusal all aspect of the maxillary third molar
Usually heart shaped due to reduction or loss of the distal lingual cusp
Very irregular with less prominent grooves and pits
Describe the roots of the maxillary third molars
Shortest roots of all three maxillary molars. Vary greatly and often all are fused together. If fused then grooves will be present to demarcate the roots. Can also be spreader wide apart
Describe the size of the crowns on the mandibular molars
Wider mesial/distal than buccal/lingual
Opposite of the maxillary molars
Describe the roots of the mandibular Molars
Bifurcated: one mesial and one distal. Third molars and some second molars have fusion of these roots
Difference between the roots of the mandibular molars to other mandibular teeth
Molar roots may be a little shorter but multiple roots and broad trunks give them superior anchorage
What is the largest mandibular to end the corner stone of the dental arches?
Mandibular ( and maxillary) first molars
How many lobes form the mandibular first molar?
Five developmental lobes
How many cups on the mandibular first molars?
5 cusps
Two buccal (MB, DB), one distal, two lingual (ML, DL)
Some may only have four cusps, lacking a distal cusp or the distobuccal and distal cusps are fused
Describe the cusp tips and cusp bridges of the mandibular first molars
Cusp tips are somewhat flat
Cusp ridges are less convex each cusp has four
Describe the MB groove of the Mandibular first molar
Longer, in middle third, just mesial to buy furcation
May terminate in a pit
Describe the DV groove of the mandibular first molar
Shorter, found just mesial to the DB line angle
Often no pit present
Do the mandibular first molars have a lingual depression?
There will be a lingual depression if a lingual groove is absent
Lingual groove separates the lingual cusps and extends onto the lingual surface
Which root is wider and longer on the mandibular first molars
Mesial root
What is the shape of the occlusal table on the mandibular first molars?
Y or + shaped
Form and position of the roots on the mandibular first molars
Roots brace the crown against the occlusal forces and prevents the tooth from rotating
How many pulp horns and pulp canals in the mandibular first molars?
Five pulp horns
Three pulp canals or two if the mesial root has only one canal
Distal root only has one canal
What happens when the mandibular first molars are missing?
Teeth become inclined and there is a mesial drift of the mandibular second molar and possibly third molar. Super eruption of the maxillary first molar into the opposing open space
What is a fault pit?
Mandibular buccal pit. Created due to the tiny localized imperfect fusion or defective formation of enamel, found at the buccal and lingual terminations of developmental groups
How do the mandibular second molars compare in size to the first molars?
Mandibular second molars are smaller than mandibular first
How many cups do mandibular second molars have?
For costs. Usually no distal cusp or fifth cusp
How do the roots of the mandibular second molars compare to the roots of the mandibular first molars?
Root trunk is longer and they tend to tilt distally. Mesial route is not as broad and roots are not divergent. May be fused partially or completely
How do the mandibular third molars compare to the mandibular first and second molars?
Very considerably and have many anomalies in form and position
Tends to be more like a second molar than a first molar.
Enamel is usually thicker and crown is often oversized with short, poorly formed roots
Contributes to periodontal defects on distal of mandibular second
Often congenitally missing, usually bilaterally
