Tooth morphology-Premolars Flashcards
(199 cards)
1
Q
Why is the term “bicuspid” misleading when describing premolars?
A
Why is the term “bicuspid” misleading when describing premolars?
2
Q
How many lobes do the maxillary first premolars develop from?
A
Four lobes (three buccal and one lingual).
3
Q
What feature distinguishes the maxillary first premolars from anterior teeth in terms of development?
A
The well-formed lingual cusp developed from the lingual lobe.
4
Q
What is the primary function of the maxillary first premolar?
A
Assists in tearing like a canine but also helps in grinding like a molar.
5
Q
How does the crown of the maxillary first premolar compare in length to the canine?
A
It is shorter by about 1.5 to 2 mm.
6
Q
How does the cusp of the maxillary first premolar compare to the canine?
A
The buccal cusp is long and sharp but not as prominent as the canine cusp.
7
Q
What is the primary difference between the first and second premolars in terms of function?
A
The second premolars have less sharp cusps and function more in grinding.
8
Q
What is the general shape of the maxillary first premolar when viewed from the buccal aspect?
A
Trapezoidal
9
Q
How does the mesial slope of the buccal cusp compare to the distal slope?
A
The mesial slope is longer and straighter than the distal slope.
10
Q
Where is the crest of curvature of the cervical line located buccally?
A
Near the center of the root.
11
Q
What is the name of the ridge running from the buccal cusp tip to the cervical margin?
A
Buccal ridge.
12
Q
What are the two depressions on the buccal surface that separate the lobes?
A
Mesiobuccal and distobuccal developmental depressions.
13
Q
How do the contact areas compare mesially and distally?
A
They are at about the same level.
14
Q
How does the lingual cusp compare to the buccal cusp in size?
A
It is shorter by about 1 mm.
15
Q
What is the general shape of the lingual aspect of the maxillary first premolar?
A
It is the reverse of the buccal aspect, tapering toward the lingual.
16
Q
What is the angle formed by the mesial and distal slopes of the lingual cusp?
A
About 90 degrees.
17
Q
What is the name of the ridge on the lingual cusp?
A
Lingual ridge.
18
Q
Why can part of the mesial and distal surfaces be seen from the lingual aspect?
A
Because the lingual cusp is narrower mesiodistally than the buccal cusp.
19
Q
What is the general shape of the maxillary first premolar from the mesial view?
A
Trapezoidal
20
Q
How does the curvature of the cervical line compare to anterior teeth?
A
It is less curved than in anterior teeth.
21
Q
Where is the crest of curvature on the buccal outline located?
A
At the junction of the cervical and middle thirds.
22
Q
What distinguishing feature is found on the mesial surface of the maxillary first premolar?
A
Mesial developmental depression.
23
Q
What is the name of the groove found on the mesial marginal ridge maxillary 1st premolar?
A
Mesial marginal developmental groove.
24
Q
How does the root bifurcation appear from the mesial aspect?
A
Mesial Side:
The bifurcation begins more occlusally (closer to the crown) compared to the distal side. Distal Side:
The bifurcation is positioned more apically (closer to the root tip) than on the mesial side.
25
How does the curvature of the cervical line compare to the mesial aspect mx 1st pm?
It is less curved and often appears straight across.
26
Does the distal aspect have a deep developmental groove like the mesial aspect mx 1st pm?
No, if present, the groove is shallow and insignificant.
27
How does the bifurcation of the roots appear on the distal side?
More abrupt and closer to the apical third than on the mesial.
28
What is the general shape of the maxillary first premolar when viewed from the occlusal aspect?
Hexagonal
29
How does the width of the buccal and lingual sides compare?
The buccal side is wider than the lingual side.
30
How does the buccolingual measurement compare to the mesiodistal measurement?mx first premolar
The buccolingual measurement is greater.
31
What is the name of the groove that runs along the center of the occlusal surface?
Central developmental groove.
32
What are the names of the pits located at the junctions of the occlusal grooves mx 1st ?
Mesial and distal developmental pits.
33
What are the two triangular fossae on the occlusal surface mx 1st ?
Mesial triangular fossa and distal triangular fossa.
34
What two ridges contribute to the prominent anatomy of the occlusal surface mx 1st ?
Mesial and distal marginal ridges
35
How does the alignment of the mesiobuccal and distobuccal cusp ridges differ mx 1st ?
They are aligned in a distobuccal direction, with the distobuccal cusp ridge more buccal.
36
How does the depth of the central groove compare to other teeth mx 1st ?
It is well-defined and relatively deep.
37
What is the difference between the mesial and distal marginal ridges in terms of anatomy mx 1st ?
The mesial marginal ridge has a deep developmental groove crossing it, while the distal does not.
38
How does the occlusal surface of the maxillary first premolar compare in texture to the second premolar ?
It is smoother, with fewer supplemental grooves.
39
How many roots does the maxillary first premolar usually have?
Two: one buccal and one lingual.
40
How common is a single-rooted maxillary first premolar?
Less common, but when present, it still typically has two pulp canals.
41
What is a distinguishing feature of the mesial surface of the root mx 1st ?
A deep developmental depression extending from the mesial developmental depression of the crown.
42
What is the approximate length of the root compared to the maxillary canine?
3 to 4 mm shorter than the canine root.
43
How does the lingual root apex compare to the buccal root apex mx 1st ?
The lingual root apex tends to be blunter.
44
What happens to the root trunk before bifurcation mx 1st ?
It makes up about half the total root length.
45
What is the primary function of the maxillary second premolar?
It supplements the maxillary first premolar in function.
46
How does the maxillary second premolar compare to the first premolar in shape?
It is less angular and has a more rounded appearance from all aspects.
47
How does the root structure of the maxillary second premolar differ from the first premolar?
The second premolar typically has a single root, while the first premolar often has two.
48
How does the root length of the maxillary second premolar compare to the first premolar?
It is usually the same length or slightly longer than the first premolar’s root.
49
How does the consistency of form differ between the first and second premolars?
The second premolar exhibits more variations in size and shape than the first premolar.
50
How does the buccal cusp of the second premolar compare to that of the first premolar?
It is shorter and appears less pointed than the first premolar’s buccal cusp.
51
How do the mesial and distal slopes of the buccal cusp ridge compare maxillary second premolar?
The mesial slope is shorter than the distal slope, the opposite of the first premolar.
52
How does the prominence of the buccal ridge compare to that of the mx first premolar?
It is generally less prominent than the first premolar’s buccal ridge.
53
How does the cervical portion of the second premolar's crown and root compare to the first premolar?
It may be thicker at the cervical portion, but this is not always the case.
54
How does the lingual cusp of the maxillary second premolar compare to that of the first premolar?
The lingual cusp is longer, making the crown appear longer on the lingual side.
55
How much variation is observed in the lingual aspect of the mx second premolar?
Very little variation is observed except for the increased length of the lingual cusp.
56
How do the cusps of the second mx premolar compare in length?
They are shorter and more nearly the same length compared to the first premolar.
57
How does the distance between cusp tips affect the occlusal surface mx 2nd?
A greater distance between the cusp tips results in a wider buccolingual occlusal surface.
58
What distinguishing feature of the mesial surface of the mx first premolar is absent on the second premolar?
The mesial developmental depression is absent.
59
How does the mesial crown surface of the mx second premolar appear?
It is convex instead of having a depression like the first premolar.
60
Is there a deep developmental groove crossing the mesial marginal ridge maxillary second premolar?
No, unlike the first premolar, the second premolar lacks a deep developmental groove on the mesial marginal ridge.
61
What feature appears on the root surface of the mx second premolar?
A shallow developmental groove appears on the single tapered root.
62
How does the depth of the distal root depression compare to the mesial root depression in the mx second premolar?
The distal root depression is deeper than the mesial root depression.
63
How does this characteristic compare to the maxillary first premolar?
It is the opposite of the first premolar, which has a deeper depression on the mesial root surface.
64
Why is it important to understand the location of root depressions in the mx second premolar?
It helps in periodontal instrumentation such as scaling and root planing.
65
How does the shape of the maxillary second premolar’s occlusal outline compare to the first premolar?
It is more rounded or oval rather than angular.
66
How does the central developmental groove of the mx second premolar compare to that of the first premolar?
It is shorter and more irregular.
67
What additional grooves are commonly found on the occlusal surface of the mx second premolar?
Multiple supplementary grooves radiating from the central groove.
68
How do these supplementary grooves affect the appearance of the occlusal surface maxillary second premolar?
They create a wrinkled or irregular appearance.
69
Where do the supplementary grooves terminate in mx 1st premolar?
They terminate in shallow depressions in the enamel that may extend to the cusp ridges.
70
Which premolar is more angular in shape mx?
The maxillary first premolar.
71
Which premolar typically has a deeper mesial root depression mx?
The maxillary first premolar.
72
Which premolar has a more symmetrical occlusal surface mx?
The maxillary second premolar.
73
Which premolar has a single root more commonly mx?
The maxillary second premolar.
74
Which premolar has a longer and sharper buccal cusp mx?
The maxillary first premolar.
75
Which premolar has a greater tendency to have a wrinkled occlusal surface mx?
The maxillary second premolar.
76
How does the size of the crown compare between maxillary first and second premolars?
The maxillary first premolar has a larger, more angular crown, while the second premolar's crown is smaller and more rounded.
77
What is unique about the mesial cusp ridge of the maxillary first premolar's buccal cusp?
The mesial cusp ridge is longer than the distal cusp ridge, positioning the buccal cusp tip distal to the midroot axis.
78
How does the prominence of the buccal ridge differ between the two premolars?
The buccal ridge is more prominent on the maxillary first premolar than on the second premolar.
79
Where is the lingual cusp tip positioned relative to the midline in both maxillary premolars?
The lingual cusp tip is positioned mesial to the midline in both the first and second premolars.
80
What unique feature is present on the mesial surface of the maxillary first premolar?
A prominent mesial crown concavity just cervical to the contact area.
81
How does the presence of marginal ridge grooves differ between the two premolars?
The mesial marginal ridge of the first premolar is almost always crossed by a groove, whereas such grooves are less common on the second premolar.
82
How does the central developmental groove length compare between the two premolars?
The maxillary first premolar has a longer central developmental groove than the second premolar.
83
Which maxillary premolar exhibits more supplemental grooves on the occlusal surface?
The maxillary second premolar has more supplemental grooves, giving it a wrinkled appearance.
84
How does the root structure typically differ between the two premolars?
The maxillary first premolar often has two roots (buccal and lingual), while the second premolar usually has a single root.
85
Which premolar has a greater root-to-crown ratio?
The maxillary second premolar has the greatest root-to-crown ratio of any maxillary tooth.
86
Which maxillary premolar has a more prominent buccal ridge?
The maxillary first premolar has a more prominent buccal ridge than the second premolar.
87
How do the cervical portions of the crowns of the two maxillary premolars compare?
The maxillary second premolar may have a thicker cervical portion than the first premolar.
88
How does the crown shape from the buccal aspect differ between the first and second maxillary premolars?
The first premolar appears more angular, while the second premolar is more rounded.
89
How does the lingual cusp height compare between the first and second maxillary premolars?
The lingual cusp of the first premolar is shorter than its buccal cusp, while in the second premolar, the buccal and lingual cusps are almost equal in height.
90
Which premolar has a more developed lingual cusp?
The second premolar has a more developed and longer lingual cusp.
91
How does the width of the lingual surface compare between the first and second premolars?
The second premolar has a broader lingual surface than the first premolar.
92
What is a distinguishing feature on the mesial surface of the maxillary first premolar?
The maxillary first premolar has a prominent mesial developmental depression extending onto the root, which is absent in the second premolar.
93
How does the curvature of the cervical line compare between the two maxillary premolars?
The curvature of the cervical line is more pronounced in the first premolar than in the second premolar.
94
What is a distinguishing feature of the mesial marginal ridge of the first premolar?
It has a mesial marginal developmental groove that crosses the mesial marginal ridge, whereas this feature is less common in the second premolar.
95
How does the mesial crown surface differ between the first and second premolars?
The first premolar has a concave mesial surface due to the mesial developmental depression, while the second premolar has a convex mesial surface.
96
How does the root depression pattern differ between the first and second premolars?
The first premolar has a deeper mesial root depression, whereas the second premolar has a deeper distal root depression.
97
Why is the root depression pattern important for dental procedures?
It helps in periodontal instrumentation such as scaling and root planing.
98
Which premolar has a smoother and more convex distal surface?
The second premolar has a smoother and more convex distal surface compared to the first premolar.
99
What is the general occlusal shape of the maxillary first premolar?
The first premolar has a more angular, hexagonal occlusal outline.
100
How does the occlusal outline of the second premolar differ from the first premolar?
The second premolar has a more rounded or oval occlusal outline.
101
How does the length of the central groove compare between the first and second premolars?
The first premolar has a longer central groove, whereas the second premolar has a shorter and more irregular central groove.
102
Which maxillary premolar has more supplemental grooves?
The second premolar has more supplemental grooves, giving it a wrinkled appearance.
103
How does the prominence of the triangular ridges compare between the two premolars?
The triangular ridges on the first premolar are more pronounced, whereas they are less prominent in the second premolar.
104
Which maxillary premolar is more likely to have a smooth occlusal surface?
The first premolar generally has a smoother occlusal surface, while the second premolar has a more wrinkled appearance due to supplemental grooves.
105
How many roots do the maxillary first and second premolars typically have?
The first premolar usually has two roots (buccal and lingual), while the second premolar typically has a single root.
106
What is the significance of the root trunk length in the first premolar?
The first premolar has a longer root trunk, which contributes to its bifurcated root structure.
107
Which maxillary premolar has a greater root-to-crown ratio?
The second premolar has the greatest root-to-crown ratio among maxillary teeth.
108
Which premolar has a more pronounced root curvature?
The first premolar often has a more distinct root curvature, especially when it has two roots.
109
How do the pulp chambers of the first and second premolars differ?
The first premolar typically has two pulp canals, even in single-rooted variations, while the second premolar usually has only one canal.
110
Which premolar has a sharper buccal cusp?
The first premolar has a sharper buccal cusp.
111
Which premolar has a longer and straighter mesial cusp ridge?
The first premolar has a longer, straighter mesial cusp ridge.
112
Which premolar has a more symmetrical occlusal surface?
The second premolar has a more symmetrical occlusal surface.
113
Which premolar is more efficient in grinding food?
The second premolar is more efficient for grinding due to its rounded occlusal shape and shorter cusps.
114
Which premolar is more likely to have a well-defined mesial marginal groove?
The first premolar is more likely to have a well-defined mesial marginal groove.
115
Which maxillary premolar is more commonly single-rooted?
The second premolar is almost always single-rooted.
116
Why is the mesial developmental depression on the first premolar clinically significant?
It makes scaling and root planing more difficult and can increase the risk of periodontal disease in that area.
117
Why does the occlusal anatomy of the second premolar affect restorative procedures?
The numerous supplemental grooves on the second premolar can complicate cavity preparation and increase plaque retention.
118
Why is the first premolar more prone to fractures?
Its two-rooted structure and deep mesial concavity create areas of weakness that may lead to fractures under excessive occlusal forces.
119
From how many lobes does the mandibular first premolar develop?
Four lobes: three buccal and one lingual.
120
How does the mandibular first premolar function in occlusion?
Its sharp buccal cusp is the only part that occludes with maxillary teeth, making it function similarly to a canine.
121
Why is the term "bicuspid" misleading for the mandibular first premolar?
Because it implies two functioning cusps, whereas the lingual cusp of this tooth is small and often nonfunctional.
122
How does the mandibular first premolar compare in size to the mandibular second premolar?
It is always smaller than the second premolar, which is the opposite of the maxillary premolars.
123
In what ways does the mandibular first premolar resemble a canine?
It has a long, sharp buccal cusp; similar buccolingual measurement; a steeply sloping occlusal surface; and an incisal outline similar to a canine.
124
Which part of the mandibular first premolar functions like the canine?
The long, sharp buccal cusp is the only occluding part, similar to a canine.
125
How does the occlusal slope of the mandibular first premolar compare to the canine?
It slopes sharply lingually toward the cervical line, resembling the incisal slope of a canine.
126
How do the mesiobuccal and distobuccal cusp ridges compare in mnd 1st PM
The mesiobuccal cusp ridge is shorter than the distobuccal cusp ridge, similar to a canine.
127
Which characteristics of the mandibular first premolar resemble the second premolar?
The overall crown and root shape (except for a longer cusp), similar contact areas, and cervical curvature mesially and distally.
128
How does the root length of the mandibular first premolar compare to the second premolar?
It is shorter than the second premolar but closer in length to it than to the mandibular canine.
129
What is the general shape of the mandibular first premolar from the buccal view?
Symmetrical and roughly trapezoidal.
130
Which lobe is most well-developed on the buccal surface of md 1st premolar
The middle buccal lobe.
131
How does the tip of the buccal cusp appear from the buccal aspect in mnd 1st premolar
It is large, pointed, and slightly mesial to the center of the crown.
132
How do the mesial and distal contact areas compare in mnd 1st premolar?
They are broad and at nearly the same level.
133
Where is the crest of curvature of the cervical line on the buccal surface in mnd 1st pm
Near the center of the root.
134
How does the buccal ridge appear on this tooth mnd 1st pm?
It extends from the cusp tip down to the cervical margin, giving the buccal surface a convex appearance.
135
Are developmental depressions visible on the buccal surface mnd 1st pm
Yes, they are seen between the three buccal lobes.
136
How does the root of the mandibular first premolar compare to the mandibular canine root?
It is 3-4 mm shorter but closely resembles it in shape.
137
How does the mandibular first premolar taper from buccal to lingual?
It narrows significantly toward the lingual, making most of the mesial and distal surfaces visible from the lingual aspect.
138
How does the lingual cusp compare to the buccal cusp in mnd 1st pm?
It is small, sometimes resembling a developed cingulum rather than a true cusp.
139
Where is the tip of the lingual cusp positioned in mandibular first pm?
In line with the buccal triangular ridge of the occlusal surface.
140
What is a characteristic groove on the lingual surface in mnd first pm?
The mesiolingual developmental groove, which separates the mesiobuccal lobe from the lingual lobe.
141
How does the root appear from the lingual aspect mnd 1st pm?
It tapers significantly and has a convex ridge running its full length.
142
What is the overall shape of the mandibular first premolar from the mesial view?
Rhomboidal.
143
How does the occlusal surface slope when viewed from the mesial mnd 1st pm?
Sharply lingually, making much of the occlusal surface visible.
144
How does the buccal outline of the crown curve from this view mnd 1st pm?
It is prominently curved with the crest of curvature near the middle third.
145
Where is the mesial contact area located mnd 1st pm?
Centered in line with the tip of the buccal cusp.
146
How does the mesial marginal ridge appear mnd 1st pm?
It slopes steeply lingually in a cervical direction and is crossed by the mesiolingual developmental groove.
147
What is a common feature on the mesial root surface mnd 1st pm?
A shallow developmental groove that may deepen into a bifurcation at the apical third.
148
How does the distal marginal ridge compare to the mesial marginal ridge?
It is higher and more horizontal, without a developmental groove.
149
How does the contact area on the distal surface compare to the mesial mnd 1st pm??
It is broader.
150
How does the root surface on the distal differ from the mesial mnd 1st pm??
It is more convex with a shallow developmental depression.
151
What is the general occlusal outline shape of the mandibular first premolar?
Diamond-shaped, similar to the incisal outline of a canine.
152
Which part of the crown makes up the majority of the occlusal surface mnd 1st pm??
The middle buccal lobe.
153
Which cusp is the most prominent on the occlusal surface mnd 1st pm??
The buccal cusp.
154
What is a distinguishing feature of the occlusal ridges mnd 1st pm??
A prominent buccal triangular ridge and a small lingual triangular ridge.
155
Where are the mesial and distal fossae located mnd 1st pm??
On either side of the triangular ridge.
156
What structure is commonly found in the mesial fossa mnd 1st pm??
The mesiolingual developmental groove, which extends from the fossa over the mesiolingual surface.
157
How does the distal fossa differ from the mesial fossa mnd 1st pm??
It is more circular and may contain a crescent-shaped groove or a developmental pit with accessory grooves.
158
Why is most of the buccal surface visible from the occlusal view? mnd 1st pm?
Because the occlusal table slopes steeply toward the lingual side.
159
How does the mandibular second premolar compare in size to the mandibular first premolar?
It is larger and has better-developed cusps and root.
160
What are the two common forms of the mandibular second premolar?
Three-cusp type and two-cusp type.
161
Which form of the mandibular second premolar is more common?
The three-cusp type.
162
How does the occlusal aspect differ between the two types?
The three-cusp type is more angular, while the two-cusp type is more rounded.
163
How does the root structure of the mandibular second premolar compare to the first premolar?
The second premolar has a larger and longer single root, which is rarely bifurcated.
164
Does the mandibular second premolar typically show developmental grooves on its root?
Some specimens may show a deep developmental groove buccally.
165
How does the buccal cusp of the mandibular second premolar compare to that of the first premolar?
It is shorter and less pronounced.
166
How do the mesial and distal cusp ridges appear in the mandibular second premolar compared to the first premolar?
They have less angulation in the second premolar.
167
How do the contact areas compare between the mandibular first and second premolars?
Both mesial and distal contact areas are broad and appear higher due to the short buccal cusp.
168
How does the root of the mandibular second premolar compare to that of the first premolar?
It is broader mesiodistally and ends in a blunter apex.
169
How do the lingual cusps of the second premolar compare to those of the first premolar?
They are longer and better developed.
170
Why is less of the occlusal surface visible from the lingual aspect in the second premolar compared to the first premolar?
Because the lingual cusps are longer and cover more of the occlusal table.
171
Which lingual cusp is larger in the three-cusp type of the mandibular second premolar?
The mesiolingual cusp is larger and longer than the distolingual cusp.
172
What structure is present between the mesiolingual and distolingual cusps in the three-cusp type?
A lingual groove that extends a short distance on the lingual surface.
173
How does the lingual cusp of the two-cusp type compare to that of the three-cusp type?
The single lingual cusp of the two-cusp type is about the same height as the lingual cusps of the three-cusp type but has no groove.
174
What characteristic feature is present on the lingual cusp of the two-cusp type?
A distolingual developmental depression where the lingual cusp ridge joins the distal marginal ridge.
175
How does the lingual convergence of the mandibular second premolar compare to that of the first premolar?
There is less convergence toward the lingual, making the lingual portion broader.
176
How does the buccolingual width of the mandibular second premolar compare to the first premolar?
It is wider buccolingually.
177
Where is the buccal cusp located in relation to the root in the mnd second premolar?
It is not as centered over the root trunk as in the first premolar.
178
How does the marginal ridge of the mnd second premolar compare to that of the first premolar?
It is more horizontal and at a right angle to the long axis of the tooth.
179
Why is less of the occlusal surface visible from the mesial view in the mnd second premolar?
Because the lingual cusps are more developed and obscure more of the occlusal surface.
180
What groove is absent on the mesial surface of the mandibular second premolar that is present on the first premolar?
The mesiolingual developmental groove.
181
How does the mesial root surface of the mandibular second premolar appear?
It is usually slightly convex but may vary.
182
How does the root apex of the mandibular second premolar compare to the first premolar?
It is usually blunter.
183
How does the visibility of the occlusal surface differ between the mesial and distal views mandibular second premolar ?
More of the occlusal surface can be seen from the distal aspect because the distal marginal ridge is at a lower level than the mesial marginal ridge.
184
Why is more of the occlusal surface visible from the distal view mandibular second premolar ?
Because posterior teeth are tipped distally relative to their long axes.
185
How does the contact area on the distal surface compare to the mesial contact area mandibular second premolar ?
It is broad and similar in position to the mesial contact area.
186
How does the distal root surface differ from the mesial root surface mandibular second premolar ?
It may have a shallow developmental depression but is generally smoother.
187
What is the general shape of the occlusal outline in the three-cusp type mandibular second premolar ?
Square or angular.
188
Which is the largest cusp in the three-cusp type mandibular second premolar ?
The buccal cusp.
189
Which cusp is the second largest in the three-cusp type mandibular second premolar ?
The mesiolingual cusp.
190
How are the triangular ridges arranged in the three-cusp type mandibular second premolar ?
Each cusp has a distinct triangular ridge separated by deep grooves.
191
What shape does the developmental groove pattern form in the three-cusp type mandibular second premolar ?
A "Y" shape.
192
What are the three major developmental grooves in the three-cusp type mandibular second premolar ?
Mesial, distal, and lingual developmental grooves.
193
What is the general shape of the occlusal outline in the two-cusp type mandibular second premolar ?
Rounded
194
How does the lingual cusp in the two-cusp type compare to the three-cusp type mandibular second premolar ?
It is a single, well-developed cusp aligned directly opposite the buccal cusp.
195
How does the central groove in the two-cusp type differ from the three-cusp type mandibular second premolar ?
It is crescent-shaped rather than Y-shaped.
196
Where do the central groove terminals end in the two-cusp type mandibular second premolar ?
In the mesial and distal fossae.
197
What additional feature may be seen in the fossae of the two-cusp type mandibular second premolar ?
A developmental pit with accessory grooves radiating from it.
198
What is a distinguishing feature on the distolingual cusp ridge of some two-cusp type second premolars mandibular second premolar ?
A developmental depression crossing the ridge.
199
