Basal anomalies of the anteroposterior sense
(class II and class III)
IA Class 2 division 1 malocclusion:
This is an anomaly characterized by vestibular-version of the incisors, by an exaggerated overjet and class 2 molar relationships.
It is necessary to specify the seat of the anomaly, is it the maxilla that is forward? The mandible that is backward, or both at the same time? because the therapeutic decision depends on it.
Depending on the facial typology or mandibular growth, we distinguish 3 subclasses:
• Class 2 division 1, short face: whose mandibular growth is generally of anterior rotation tendency.
• Class 2, division 1 medium face: whose type of mandibular growth is of an average anterior rotation tendency.
• Class 2, division 1: long face:, whose type of growth is generally posterior rotation.
IAa Class 2 division 1 long face:
1 Clinical signs:
– The face is narrow.
– The lower floor is diminished.
– Convex profile.
– Hypotonicity and open lip at rest revealing the teeth.
– The chin is small and receding (retrogenia)
– The goniac angle is open.
2 Occlusal signs:
– V-shaped upper arch with ogival palatal vault, especially if thumb sucking is present.
– Projection of the upper incisors forward and exaggerated curve of Spee in mixed dentition
– The lower arch is often of normal shape, normal or exaggerated curve of Spee, there may be lower overlaps.
On the occlusal plane:
• Sagittal direction: Class 2 molar, Class 2 canine, increased overjet
• Vertical direction: anterior open bite, especially if a parafunction is the cause.
• Transverse direction: an interlocking occlusion or sometimes a uni- or bilateral reverse occlusion.
3 Neuromuscular functional signs :
– The existing gap between the bony bases often leads to the appearance of mandibular prolapse.
– Mouth breathing is found in relation to high (nasal cavities) or medium (adenoids, tonsils) obstruction of the upper airways.
– Significant insalivation due to the dry mouth caused by mouth breathing.
– A contraction of the chin tuft helping to force the mouth to close.
– Finger sucking is often associated.
4 Radiological signs :
The profile view shows:
• An increased goniac angle, increased FMA.
• An increased convexity angle, A decreased facial angle.
• Increased anterior facial height
– If the anomaly is of maxillary responsibility only: increased SNA, normal SNB, increased ANB
– If the anomaly is of mandibular responsibility only: normal SNA, decreased SNB, increased ANB
– If the anomaly is of mixed responsibility: increased SNA, decreased SNB and increased ANB
In all three cases, we have:
• Increased I/F, i/m=90° or increased OB generally decreased and increased OJ.
Basal anomalies of the anteroposterior sense
IAb Class 2 Division 1 Short Face
1 Clinical signs:
– The face is short and square.
– The lower floor is diminished
– Labial inocclusion at rest in relation to the position of the teeth (upper protuberance)
– Eversion of the lower lip
– Marked labiomental groove
– Convex profile: large chin, closed goniac angle
2 Occlusal signs :
– Anterior accentuated supraclusion
– Vestibular version of the incisors
On the occlusal plane:
• Sagittal direction: Class 2 molar, Class 2 canine, Increased overjet.
• Vertical direction: Increased incisal supraclusion and Over Bite
• Transverse direction: normal
3 Teleradiographic signs:
• Closed gonial angle, decreased FMA, increased convexity angle.
• Increased ANB.
• Normal or increased i/m, increased I/F.
• Increased Over Bite, increased Over Jet.
IAc Class 2 division, 1 medium face
It presents the clinical, occlusal and teleradiographic signs of class 2 division 1 malocclusion, short face but of low amplitude.
IB Class 2 division 2 malocclusion
Considered a true clinical entity because of its particular clinical appearance, characterized by a palatal version of the upper incisors and a vestibular version of the lateral incisors, it presents three clinical forms:
• A palato-version of the two central incisors and a vestibular version of the two lateral ones.
• Palato-version of the 3 or 4 upper incisors and vestibular version of the two canines.
• Box-lid occlusion with a palato-version of the incisor-canine block, overbite of the canines and vestibular inocclusion of the premolars.
Basal anomalies of the anteroposterior sense
IBa Clinical signs:
– The face is of the short face type.
– The lower floor is diminished, the face is square in shape
. – The lips are rather thin and hypertonic.
– The profile is often concave, the nose is large.
– The chin is large, the goniac angle is closed.
IBb Occlusal signs:
– The free edge of the upper incisors is lower than the occlusal plane.
– The lower arch may have dental overlaps
On the occlusal plane:
• Sagittal direction: Class 2 molar, Class 2 canine, Decreased overjet.
• Vertical direction: Excessive overbite.
• Transverse direction: Normoclusion
IBc Teleradiographic signs :
• FMA decreased
• ANB normal or slightly increased
• I/F decreased
• i/m normal or decreased, I/i increased
IC Class 3 Malocclusion
It is a malocclusion characterized by a malocclusion of the first permanent lower molars, a concave profile, anterior reverse occlusion, to which is added the skeletal shift of class 3, it presents to describe four clinical forms:
• Class 3 by upper brachygnathia
• Class 3 by lower prognathia, Class 3 by the association of the two
• Class 3 by mandibular prolapse
I.Ca Class 3 by upper bradygnathia:
1 Clinical signs:
– Upper retrochellia
– Thin upper lip and appears swallowed up in the face.
– The middle floor may be set back in profile.
2 Occlusal signs:
– Inversion of the upper bite
– Upper retroalveolus and dental crowding
– Class III molar in maximum intercuspidation, a sliding is often associated.
3 Teleradiographic signs:
• FMA normal or decreased
• SNA decreased, SNB normal, ANB decreased
• I/F decreased, Over Jet decreased, i/m normal or increased
ICb Class 3 by mandibular prognathism
1-Clinical signs:
-Lower procheillie
– Progeny, concave profile
– The mandible appears long, the goniac angle is obtuse.
2 – Occlusal signs:
– Class 3 molar relationships
– Class 3 canine relationships – Anterior occlusion
inversion , Decreased overjet
3- Teleradiographic signs:
• SNA normal, SNB increased, ANB decreased.
• FMA increased
ICc Class 3 by mandibular prolapse
Mandibular prolapse is most often the starting point of prognathism, often associated with lower proalveolism or upper retroalveolism.
• Clinical signs
– Class 1 molar in centric relation, incisal end-to-end in centric relation
– Closure path deviated forward, class 3 molar in ICM,
– positive DENEVREZE maneuver.
Basal anomalies of the anteroposterior sense
Untreated cavities can reach the nerve of the tooth.
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Preventative dental care avoids costly treatments.
Baby teeth serve as a guide for permanent teeth.
Fluoride mouthwash strengthens tooth enamel.
An annual checkup helps monitor oral health.