Orthodontic-surgical treatment
1-Introduction
Orthognathic surgery aims to correct maxillary dysmorphias, the origin of which may come from growth disorders of the maxilla and mandible. The therapeutic schedule of a surgical protocol calls for the intervention of different actors and it is on the good coordination of these practitioners that the quality of the final result will depend.
With the improvement of surgical techniques towards total osteotomies, orthodontic preparation has become a necessity; it has emerged as a determining factor in surgical stability.
Orthodontic-surgical treatment
2-Indications:
Assessing the severity of anomalies is often tricky; it is based on:
– The severity of the dysmorphosis and the associated aesthetic damage;
– The hereditary nature of the observed anomaly;
– The usual evolutionary characteristics of this type of dysmorphosis. Thus, skeletal classes III, facial asymmetries, large vertical excesses tend most often to worsen during growth;
– The type of growth of the patient, the estimation of which is somewhat random.
*Indications for surgical-orthodontic protocols:
*Major syndromes: these major craniofacial anomalies, often accompanied by significant aesthetic damage, require complex surgical protocols, often performed earlier, in which bone distractions can sometimes be of major interest.
*Severe skeletal shifts that exceed the possibilities of alveolar compensation ; or whose aesthetic repercussions require surgical restoration of facial balance and harmony;
* Orthodontic treatments with aesthetic risk: in certain cases, malocclusion, in particular increased incisal overjet, provides support to the lips, minimizing the impact of dysmorphosis on facial aesthetics.
* Recurrences or therapeutic failures linked to unfavorable growth or lack of cooperation during the orthopedic phase.
3- The therapeutic strategy :
is based on the clinical examination which allows to evaluate at the facial level the imbalances of the face in the three dimensions of space and the aesthetic damage which results from it, and on the complementary examinations which allow to confirm the location of the different anomalies, to quantify their importance. The dialogue between the surgeon and the orthodontist during this initial phase allows to compare their aesthetic approach and especially to specify the imperatives and the therapeutic limits of each specialty,
This dialogue is most often organized around occlusal and especially cephalometric simulations (pre-surgical set-ups). Thanks to these simulations, the two practitioners can refine the therapeutic strategy and quantify the dental and surgical movements to be carried out.
4- The therapeutic calendar:
4.1-Orthodontic preparation phase:
Orthodontic preparation is most often carried out just before surgery, around the age of 15 or 16. Can last from one year to 2 years.
*Objectives of orthodontic preparation:
– Remove all alveolar compensations and give the surgeon the range of movement necessary for skeletal correction. The removal of alveolar compensations concerns the three dimensions of space, thus worsening the inter-arch relationships is done by:
* The use of reverse maxillary traction: Class II TIM in Class III and Class III TIM in Class II;
* Reverse extraction choices: 15, 25, 34 and 44 in classes II and 14, 24, 35 and 45 in classes III.
-Resolution of crowding and correction of dental dystopias.
– The placement of the included teeth.
-Restoration, if possible, of the symmetry of the arch.
-The most perfect intercuspidation possible at the end of the procedure guarantees good post-surgical stability.
-Provide anchoring for the post-surgical retention device (large rectangular arches with welded or clipped pins, constitute a reliable anchoring that respects the periodontium for intraoperative intermaxillary blocking during osteosynthesis);
-The position of the inter-incisal points must allow their alignment in the median sagittal plane after surgery (In the maxilla, the inter-incisal point is most often aligned during orthodontic preparation with the median sagittal plane and in the mandible, the inter-incisal point must be aligned, in the event of asymmetry, with the chin point);
-Transverse concordance of the arches (maxillary endo-alveolism must be corrected during orthodontic preparation using a quad’helix, expanding arches, maxillary endognathism which results from maxillary disjunction);
Beyond 14 years in girls and 17 years in boys, the suture may be partially synostotic, limiting the possibilities of expansion.
Orthodontic-surgical treatment
4.2 – The surgical phase :
even when the surgical indication is made early, orthognathic surgery only occurs at the end of growth, around 16 or 17 years in girls, 18 years in boys in order to avoid the risks of relapse linked to unfavorable late mandibular growth, especially in class III and asymmetries;
At the end of the orthodontic preparation, a new pre-surgical assessment is carried out based on the models and new X-rays or a CT scan of the patient. If the objectives of the orthodontic preparation have been achieved, the date of the intervention is set jointly by the orthodontist and the surgeon.
-The surgeon must respect the play of the temporomandibular joint, muscular balance, bone continuity and the vascular-nervous bundle.
4.2.1- Osteotomies: In almost all cases, these are total osteotomies of the maxilla and mandible, most often associated,
a- Maxillary osteotomies: These are Lefort I osteotomies, more rarely Lefort II or Lefort III modified in certain syndromic anomalies.
This osteotomy allows, depending on the desired result:
*Maxillary advancement, it corrects a maxillary deficit in the sagittal direction. It induces an advancement of the upper lip and a closure of the nasolabial angle associated with a slight counterclockwise rotation of this angle, it is accompanied by a straightening of the tip of the nose.
*Maxillary impaction: it reduces the vertical dimension and causes mandibular anterotation (mandibular autorotation) which projects the mental symphysis.
*Maxillary expansion: This procedure allows correct occlusion to be reestablished in the lateral sectors.
b- Mandibular osteotomies:
– Allow to advance, move back, raise, lower or derotate the mandibular arch and symphysis. The soft tissues follow the mandibular displacement;
– Mandibular advancement tends to widen the face at the mandibular angles and expose the smile more.
-Osteotomy of the horizontal branches, horizontal branches or mandibular angle.
c- Bimaxillary osteotomy: is often the most suitable surgical protocol, particularly in cases of facial asymmetries, severe sagittal shifts and large vertical excesses;
Orthodontic-surgical treatment
It allows you to:
-Restore facial aesthetic harmony by correcting all dysmorphosis.
-Limit the range of movement at each bone part.
– Better stability of results;
Classically, the osteotomy is first maxillary then mandibular.
4.2.2- Contour surgeries : These complementary surgical procedures complete the harmonization of the face by balancing the protrusions and depressions of the profile or by correcting a residual asymmetry of the nose or chin. They can concern the nose ( septorhinoplasty ) and/or the chin (genioplasty).
*Genioplasty: allows all symphyseal adaptations: advancement, augmentation, diminution, translation, tilting, recentering.
4.2.3-Surgeries of the muscular environment (cheiloplasty, glossoplasty, muscular detachment):
* Glossoplasties: They sometimes complement osteotomies to ensure the stability of the result obtained. The indications for glossoplasties remain limited to severe macroglossia.
4.2.4- Bone distractions : This surgical technique, which allows bone to be lengthened and bone to be created by exerting traction between the two parts of an osteotomized bone using a distractor, is a complementary solution to conventional orthognathic surgeries and an alternative to certain grafts. It is a relatively heavy technique that requires one or more osteotomies, a latency period, a phase of activation of the distractor at a rate of 1 mm lengthening per day, most often followed by a consolidation phase and then bone remodeling.
*Its main indications concern:
– Major malformation syndromes affecting the craniofacial skeleton.
-It can therefore be indicated in the management of severe sleep apnea syndromes.
– Mandibular lengthening [13] when the possibilities of orthognathic surgery are exceeded.
-Mandibular widening by symphyseal distraction in certain cases of dento- maxillary disharmony to avoid extractions.
Orthodontic-surgical treatment
4.3-Post-surgical phase :
This is the main risk phase of these treatments. The radical transformation brought about by surgery can have major psychological repercussions. The patient no longer recognizes himself and must regain his image. Support and listening to the patient during this phase are essential to improve the experience of these treatments and facilitate this transition.
*monitoring and containment of the surgical result
The contention of osteotomies is currently mainly provided by the osteosynthesis device, in particular miniature plates.
– Blocking by intermaxillary tractions (we recommend starting it on the third day after the operation to allow a risk-free awakening and a reduction in postoperative edema and to maintain it for around 25 days), intermaxillary tractions, in addition to their role of containment, relieve the orofacial musculature and secure the patient during this phase of incoordination.
At the end of this phase of contention, careful physiotherapy allows a new neuro-musculoskeletal balance to be established, rehabilitation of parafunctions or dysfunctions that have appeared or persist may be necessary to maintain the stability of the result.
4.4- The orthodontic finishing phase :
Classically, this phase of post-surgical orthodontics is limited (3 to 8 months depending on the authors and the cases), because most of the orthodontic finishing work was carried out before the operation. Its main aim is to:
– Seat the occlusion.
– Correct the parasitic effects of intermaxillary tractions on the anterior and lateral torques and the last imperfections
– Leveling of the speed curve;
-Finalize inter-arcade reports and coordination;
-Harmonization of smile and skin profile;
Once all the occlusal, aesthetic and functional objectives have been established, we move on to retention (see retention course).
Orthodontic-surgical treatment
5- Conclusion:
Proper orthodontic preparation is the key to successful orthognathic surgeries. Understanding the dental compensations that tend to be associated with certain types of malocclusions helps to construct an appropriate treatment plan for each individual that optimizes surgical benefit and stability. The multidisciplinary approach that includes proper planning, ongoing monitoring of treatment progress, and communication between professionals and patients is of paramount importance in this type of approach.
Orthodontic-surgical treatment
Plan :
1-Introduction
2 – The indications
3- The therapeutic strategy
4 – The therapeutic calendar:
4.1 – Orthodontic preparation phase
4.2 – The surgical phase
4.2.1 – Osteotomies
*Maxillary osteotomy.
*Mandibular osteotomy.
*Bimaxillary osteotomy.
4.2.2- Skin contour surgery.
4.2.3-Geniopalasty.
4.2.4- Glossoplasty.
4.2.5- Maxillary distraction.
4.3 -Post-surgical phase
4.4- The orthodontic finishing and retention phase
5- Conclusion
Good oral hygiene Regular scaling at the dentist Dental implant placement Dental x-rays Teeth whitening A visit to the dentist The dentist uses local anesthesia to minimize pain