End of treatment criteria
1. Introduction
The end of treatment criteria correspond to the different aesthetic, occlusal and functional objectives of an orthodontic treatment, objectives that each practitioner must set when establishing their therapeutic planning. These criteria, once obtained, must allow for the sustainability of results in the short, medium and long term.
The search for criteria should not be part of a dogmatic approach but rather a reasoned and individualized attitude to each patient, whatever the technique used.
2. Aesthetic criteria
Aesthetics is, along with function, the essential reason for consultation in ODF.
Aesthetic judgment is, by definition, something strictly personal and therefore purely subjective.
The human face is animated and its facial expressions are an important element of its beauty.
The aesthetic assessment must therefore focus on the static face but also on
movement and smiling. The practitioner must study which are the balanced faces and the field
acceptable compromise between the various elements of the face. It nevertheless remains at the service of the
patient, and must therefore take into account the latter’s aesthetic aspirations and grievances.
2.1Facial and skeletal balance
Sagittal direction
● General appearance of the profile
The profile of the face and the face must be assessed as a whole (straight, concave, convex).
This analysis is carried out clinically, but also on photographs and by
methods of cephalometric analysis at the beginning, during and at the end of treatment. It allows
to highlight the balance of projections and depressions, the junction zones
nasolabial and labiomental.
The sagittal aesthetic finishing criteria correspond to a good harmony of the
labial intercourse in the resting and occluded dental position, without contraction of the muscles of
chin tuft at lip closure
This aesthetic assessment is confirmed by a cephalometric study (ANB = 2 ◦ ).
● Nasolabial angle
The value of this angle must be assessed according to the sex and the anatomy of the lip and
of the nose. It also reflects the position of the upper incisor and must correspond
to the objectives initially set by the treatment plan.
● Lip position
Lip relationship analysis is part of many analyses. In the method implemented
as developed by Ricketts, the lips should ideally be located between the so-called “E” line
aesthetic .
End of treatment criteria
● Chin position
According to Tulasne, the submental length, the distance from the chin to the neck, must be in harmony with the depth of the face (from the ear to the base of the nose). It is also important that the practitioner takes into account and anticipates the evolution of the profile with aging: growth and age tend spontaneously to increase the concavity of the profile or to decrease
its convexity. This phenomenon is mainly due to the evolution of the nose, lips and chin.
The preferred male profile is straighter with a prominent chin while the adopted female profile is slightly convex.
Communication with the patient and their psychological assessment are therefore essential in
start of treatment for acceptance of the results obtained at the end of treatment.
Vertical direction
The practitioner must continually keep in mind the objective of not aggravating the vertical sense.
This control must go through the mastery of the occlusal plane, the mastery of the movements
egression or ingression or versions of posterior teeth, desired or induced by the
therapeutic. The finishing criteria then correspond, from an aesthetic point of view, to
the harmony of the height of the different floors of the face, and more particularly at the height
from the lower floor.
The lips should be joined without any strain on the muscles of the chin tuft.
and the labiomental groove must be present. The stomion is ideally located 2 mm from the
incisal edge taking into account the age of the patient, since this ratio tends to decrease with the
time.
Transverse direction
The interpretation of an aesthetically pleasing face is based on the appreciation
of its symmetry. This notion must be relativized given that absolute symmetry cannot
be an achievable goal. The face should be symmetrical about the midsagittal plane
rectilinear. The horizontal planes join the pupils, the wings of the nose and the corners of the
the mouth. They are perpendicular to the median sagittal plane and therefore parallel to each other. Sides
right and left must be equivalent in their transverse and vertical development.
The practitioner must take into account the aspirations of his patients when establishing his plan.
treatment, while referring to aesthetic rules to guide the action of its
therapeutic.
End of treatment criteria
2.2. Alveolodental balance
The quality of the smile confronts two different aesthetic elements: one dynamic, the
lips, the other static, the teeth.
For Janzen, the length and thickness of the upper lip are important
predominant in the smile: the quality of the smile also depends on the shape of the arch, the
buccal width, neuromuscular factors (tone, bilateral innervation of the commissures
and all the muscles of expression).
The criteria of the modern smile:
1. The modern smile is toothed, as opposed to closed-lip smiles.
2. The upper teeth should be aligned in a downward curve.
3. The “smile line” parallel to the free edge of the lower lip during the smile: “Cupid’s bow”
4. The smile should display all of the upper teeth.
5. The neck of the upper teeth should be flush with the lower edge of the upper lip.
6. The free edge of the upper teeth must be in contact with the lower lip.
7. The upper and lower incisal midpoints should match.
8. The axes of the upper canines and premolars must be vertical.
9. During speech/smiling, the “negative space” of the dental embrasures does not exceed 2–3 mm.
10. The persistence of a median diastema is the most rejected criterion.
Concept of dental aesthetics
Size
It can give rise to malpositions or diastemas in the event of disharmony.
dentomaxillary dysharmony (DMD) or dento-dental disharmony (DDD).
If diastemas persist at the end of treatment in relation to a size problem, a
correction by addition or prosthetic therapy should be considered.
Tint
Isolated or generalized color anomalies or dysplasias should be investigated.
support to harmonize the aesthetics of the smile.
Number
The therapeutic decision regarding the management of patients with agenesis,
lateral incisors in particular, influence the aesthetic appearance of the smile, at short, medium and long
long term. The decision to close the spaces induces the need for remodeling of the canines and
premolars for aesthetic but also functional purposes.
Position
The difference in height between the central and lateral incisors depends on their shape and occlusal requirements (canine guidance). The position of the canine is very important in the concept of the smile line.
3. Occlusal criteria
3.1-Static occlusion
3.1.1. Occlusal concepts:
The concept of normocclusion has since its appearance at the beginning of the 20th century aroused a strong
interest within the orthodontic discipline.
The advantage of a standardized occlusion, for these authors, seems to be to codify the work of
the orthodontist, to create rules and protocols as for the other disciplines of the
dentistry:
– Angle normocclusion: the angle classification described in 1899, allows to
determine the pre-treatment and post-treatment orthodontic occlusion. It
concerns dental relationships in sagittal and buccal views. The key to standardized occlusion
d’Angle concerns the interdental relationships of the first molar or 6-year-old tooth. The
Angle class I is the therapeutic occlusion that the author recommends to obtain at the end of
treatment.
End of treatment criteria
In Class I molar, the point of the mesiobuccal cusp of the maxillary molar
is located at the level of the vestibular groove of the mandibular molar.
– Andrews’ normocclusion 1972 : it presents 6 keys to look for at the end of treatment
orthodontic to achieve an ideal, stable occlusion. These criteria were found
on 120 patients without orthodontic history. Modified slightly by the author in
later publications.
Key n°1: concerns the molar ratio: on the one hand, contact is sought between the pan
distal of the disto-vestibular cusp of the maxillary first molar and the mesial pan
of the mesio-vestibular cusp of the second mandibular molar. On the other hand, the
cusp apex of the mesiovestibular cusp of the maxillary first molar is
in occlusion with the vestibular mandibular sulcus.
Key #2 concerns the coronal tip (mesio-distal angulation of the crown), the degree
Coronary tip corresponds to the angle formed between the longitudinal axis of the crown and a
perpendicular to the occlusal plane? the author is looking for a positive coronal tip for
all teeth, this means that the gingival part of the crowns must be redistalted by
relation to the occlusal portion.
Key n°3 coronary torque (vestibulo-lingual angulation): expressed in degrees, it can be
positive or negative, the positive value when the gingival part of the crown is
lingual in relation to the incisal edge, for the author at the maxillary level: there is a
difference in angulation between the lateral and anterior sectors, in addition the angulation
incisor is positive while it is negative for the maxillary lateral sectors, at the
difference of the mandible or all dental organs present an angulation
negative
Key No. 4: the absence of rotation for the author the presence of a rotating tooth induces
bad arrangement intra and inter arches
Key #5: the absence of interdental spaces, tight contact points: according to the author
observation of interdental spaces at the end of treatment means a result
inadequate orthodontics. However, according to Château, if there is a disharmony
dento-dental we should not seek to close the diastemas at the expense of good
occlusion.
Key #6: Leveling the SPEE curve: in order to guarantee obtaining the different
criteria mentioned above, the SPEE curve must be relatively flat.
3.1.2. Recommendations for intra-arcade layout
Intra-arch occlusal criteria must respect the three orders of deformation
that ideal arcs include
First order deformations
The 1st order deformations define the finishing criteria in the VL.
The maxillary arch must have a lateral inset , a canine boss, and a molar offset . The mandibular arch must have a canine boss, a premolar offset , and a molar offset . These deformations compensate for the differences in the vestibulolingual diameter of the teeth in each arch.
2nd order deformations
The 2nd order deformations define the finishing criteria in the vertical plane.
All marginal ridges must be located at the same level
In the maxilla, the withdrawal of the free edge of the lateral incisor by 0.5 mm relative to the central incisor should facilitate the sliding of the canine during lateral movements. In the mandible, the canine protrudes by 0.5 mm, relative to the incisors, in a manner substantially identical to the distobestibular cusp of the second molar.
3rd order deformations
These criteria determine the vestibulolingual inclination of the teeth
In the maxillary arch, the torque values sought are 22̊ for the central incisor and 14̊ for the lateral incisor in the radiculopalatine direction, the value of the canine torque varies according to the authors and the techniques from 0 to 7̊, while the radiculovestibular torque is progressive in the lateral sectors. In the incisal sector, the vestibulolingual inclination directly influences the degree of overjet and coverage as well as the alignment of the dental crowns in the vertical direction. In the mandibular arch, the anterior torque is individualized according to the technique and the case while the radiculovestibular torque is progressive from the canine to the second molar.
End of treatment criteria
3.1.3 Inter-arcade layout recommendations
3.1.3.1 Interincisal media, Incisal overjet and overlap:
– the recommendations concerning the Inter-incisal Middles and the values of the overbite (or overlap) and the overjet (or overjet) are as follows:
Coincidence of Interincisal Midpoints
The value of the overbite or overlap must not exceed 1/3 of the coronal height.
In addition, the maxillary incisors should overlap their antagonists by a maximum of 3 mm.
The value of the overjet or overhang must be between 1 and 3 mm
In fact, we note that these values associated with the incisive overlap and overjet are
approximations with anatomical reference.
However, the notion of the area of the functional field or triangle should be taken into account.
Slavicek’s which is established between the maxillary and mandibular incisor relationships
This constant, specific to the patient, makes it possible to visualize, on the one hand, the recovery, the
overhang, the guide slope.
– In other words: the balance of overhang and overlap conditions the freedom of the
movement while the incisive slope determines its shape as well as its speed at the level
previous”.
– We therefore understand that an open interincisal angle is not sought at the end of treatment because it would be considered incompatible with the functionality of the occlusion of the patient being treated.
3.1.3.2. Recommendations on lateral sectors
Let us quote the recommendations of E. LEJOYEUX on the inter-arcade layout:
– According to the author (1999), the stability of a patient’s occlusion depends on the distribution and importance of interdental contacts.
At the molar level, it is necessary to obtain a double cusp-fossa relationship. In addition, the maxillary palatal cusps occupy the mandibular central fossae and the centro-vestibular cusps the maxillary central fossae. In addition, the author recommends obtaining Andrews’ key 1: the disto-lingual rotation of the maxillary first molar induces occlusal stability.
3.2. Kinetic occlusion:
“Unlike static occlusion, the criteria for end-of-life functional occlusion
successful treatment are not clearly defined, there is to date an absence of
consensus » Alnamiri 2010
Over the years, several authors have tried to establish their own charter in order to obtain a “perfect” dynamic occlusion:
In 1995, Ramfjord pointed out that the functional parameter of occlusion is defined by
the absence of interference at the end or beginning of mandibular movements, initiated in RC
and by the quality of occlusal stability.
The same year Valchos defined 6 objectives of a kinetic occlusion at the end of
treatment:
– light contacts during the various mandibular excursions
– Occlusal stability and distribution of axial forces along the dental axes
– Posterior disocclusion during protrusion movements
– Working lateral contacts: group function and/or canine function
– In left and right laterality, an absence of non-working contacts
– A “RC – OIM” coincidence (tolerance of 1mm)
The criteria for optimal kinetic occlusion:
The coincidence between RC-OIM:
According to DJ RINCHUSE and SASSOUNI 1982: there is an endless debate concerning the mandibular posture obtained at the end of treatment, the practitioner who plans his treatment according to the CR implies obtaining a correspondence between the positions
of RC and OIM.
Recommendations during propulsion : In the mandibular protrusion movement, the free edge of the mandibular incisors slides on the lingual surface of the maxillary incisors and induces the immediate loss of contact of the posterior dental units. This is an anterior group protection or a
previous group function.
Recommendations during laterality:
There are 2 occlusal diagrams to distinguish:
– canine function: due to its strong root implantation in the alveolar bone (canine bump) which allows a strong application of pressure, due to its significant coronal height, but also due to its high level proprioceptive capacities, the canine appears to be the main agent of the terminal mandibular movement of intercuspidation. In fact, it is on the lingual surface of the maxillary canine that the first dento-dental contact occurs.
It is the desmodontal proprioceptors that send the first information to the central nervous system, which ensures the control of muscular activity to complete the mandibular movement towards occlusion,
– group function:
If in the terminal phase of the closing movement, posterior teeth on the same side as the canine accompany it by means of sliding contacts, the functional relationship will then be called “posterior group protection” or “posterior group function”
Sliding contact relationships involve the mandibular vestibular cusps and the central slopes of the maxillary vestibular cusps
In all these kinematic situations, the non-working side must not in any case participate by sliding contacts.
End of treatment criteria
4. Periodontal criteria:
The prerequisite for any orthodontic treatment is the need to be in the presence of a state of periodontal health. This periodontal health must be controlled and maintained throughout the treatment. Concerning patients free of periodontal disease, one of the orthodontic objectives may be the improvement of the gingival architecture and in particular the increase in the quantity of attached gingiva, by controlled movements.
egression for example, the repositioning of teeth in a more favorable bone context, the correction of root proximities, the improvement of contact points promoting oral hygiene. At the end of treatment, there must be no periodontal defects or iatrogenic frenulum or bridle remaining. Collaboration with periodontologists is valuable in order to intervene at the right time to work
throughout treatment with a favorable periodontal environment.
For patients with periodontal diseases, orthodontic treatment must be part of supportive periodontal therapy, in close collaboration with the periodontologist. The finishing criteria are identical and the primary objective remains the correct distribution of occlusal forces and the elimination of occlusal trauma, aggravating factors in periodontal diseases. The choice of retention means is imperative from the beginning of treatment. This retention must
have a definitive character.
5. Neuro-muscular criteria:
Any disturbance of this balance can be the cause of dysmorphia of the dental arches; the stability of the result is linked to orofacial, lingual and postural neuromuscular activities. Careful observation, at the beginning, during and at the end of treatment, of ventilation, swallowing, chewing and phonation
helps reduce the causes of recurrence to the extent that functions are re-educated.
Thus, during the clinical examination, the orthodontist must differentiate between irreducible disturbances (physiological adaptation to a defective central nervous system or to an anatomical disorder) and disturbances presenting possibilities of spontaneous evolution or after rehabilitation (physiological adaptation to a psychological maturation disorder which leads to the persistence of infantile habits). Recovery
neuromuscular is therefore included in the finishing criteria. Relapse may be due to the persistence of abnormal oral and/or perioral muscle pressures, in function or at rest. There is little chance of success if we fail to eliminate functional disorders. The orthodontist, one of whose objectives is to restore the balance of the bony bases, will influence and modify the neuromuscular balance and therefore the function. The goal of functional rehabilitation is to obtain the automation of
the position of the tongue, mature swallowing, nasal breathing when it was oral . This rehabilitation, entrusted to specialized physiotherapists, requires daily work for several months.
6. Radiological criteria:
The most reliable criterion for healing a skeletal shift is the radiological criterion. It alone allows us to assess the results of the treatment and can testify to the return to architectural balance. It seems desirable to us to perform teleradiographies before treatment, after clinical improvement and especially at the end of treatment. It is also desirable to superimpose the tracings in order to control the effectiveness of the treatment, the location and the importance of the improvements obtained.
Likewise, the panoramic radiograph at the end of treatment is important in order to visualize the dental axes at the end of treatment (look for parallelism of the axes
roots), visualize iatrogenic apical bends, root resorptions, etc.
In cases of DDM treated in adolescent dentition, radiological evaluation of the space available for the eruption of the DDS is imperative in order to avoid recurrence.
7. Conclusion
If historically many concepts have followed one another concerning the finishing criteria and their importance in avoiding recurrence phenomena, it now seems essential to take into account all of these factors concomitantly.
The search for an ideal occlusion cannot be a systematized concept but must correspond to a clinical reality adapted to the skeletal pattern, age, intrinsic dental factors and neuromuscular context of each patient.
Compliance with these finishing criteria must remain a therapeutic guide for the practitioner, allowing him to practice orthodontics as objectively as possible. Indeed, the indisputable relationship that exists between the occlusal, functional criteria, which are easier to quantify, and the aesthetic criteria, the assessment of which is more delicate, must avoid a subjective approach that could prove detrimental.
Finally, with regard to the treatment of adults, if the notion of compromise can be considered from an occlusal, aesthetic point of view or in reasoned compensations for skeletal dysmorphias, it remains impossible and could prove to be harmful with regard to periodontal requirements.