Treatment of Dento-Maxillary Disharmony

Treatment of Dento-Maxillary Disharmony

1. Definition :

Dentomaxillary disharmony corresponds to a disproportion between the size of the teeth and the dimension of the jaws, the continuity of the arches no longer being ensured.

We diagnose:

  -DDM by dental default when there is true microdontia or relative microdontia 

  -DDM due to dental excess when one has true macrodontia or relative macrodontia.

II. purposes and principles of processing:

• DDM treatment objectives:

• Find satisfactory proximal contacts.
• Promote normal growth of the jaws
•  Reconstruct a balanced occlusion, taking into account the facial profile and initial periodontal conditions.
• Treatment principles:

• Assessment of the overall space deficit . 
• The result of this analysis is the numerical measurement of a space deficit based on therapeutic possibilities and the muscular and periodontal environment. 
• Based on this assessment, a decision will be made whether to proceed with extraction or non-extraction treatment and whether to proceed early or late.
• A fixed multi-attachment technique is essential in adult teeth.

3. Prevention of DDM:

• Promote a balanced diet rich in fiber from the moment teeth appear;
• Eliminate all harmful habits that contribute to the deformation of the arches;
• Rehabilitation of different functions;
• Elimination of any obstacles hindering dental eruption;
• Early diagnosis and treatment of caries;
• Maintains space after premature loss of primary teeth.

4. DDM interception:
5. DDM due to dental excess:

Interceptive treatment of DDM due to dental excess consists of 

• Increased available space
• Reduction in space required

1. Treatments without extractions:

• Indications  :

    -DDM less than 7 mm

    -Straight or concave profile, thin or long lips, average lip tone

    -Anterior mandibular growth

    -Good quality periodontium

• Means :

1.1.1. Low or transient DDM with bulk up to 4 mm.

a) preservation of mesial drift space (anchoring) 

• The goal is to ensure that no space is lost on the arch. Conservative care must be carried out (filling, reconstruction of a damaged baby molar, etc.).
• Extractions are contraindicated.
• The mesial drift space (approximately 4 mm), can be preserved to resolve the crowding.
•  To preserve it, it is recommended to use space maintainers 
• in the mandible: lingual arch, lipbumper…
• -in the maxilla: Nance arch, transpalatal bar, etc.

b) Guidance of eruption by wearing the proximal faces (stripping) of certain temporary teeth:

 Followed or not by simple orthodontic treatment with the aim of promoting the establishment of permanent teeth

• Sequences:

•    Incisal crowding situation, lower, grind the baby canine mesially To correct incisal crowding
• Grind the mesial edge of the first deciduous molar before the eruption of the canine to allow the distal eruption of the latter;
• Grind the second baby molar mesially to allow distal eruption of the first premolar 
• The eruption of the second premolar occurs by occupying the mesial derivative space of the molar.

c) Correction of mesiopalatal rotation of molars 

• The first molar in rotation occupies, on average, a space of 12 mm whereas when straightened, it only occupies 10 mm of arch length.
• This correction therefore theoretically frees 2mm per side and can be obtained using a transpalatal bar, a quadhelix, a lipbumper, an FEO, etc.

1.1.2. DDM between 4 and 7 mm.

A careful clinical examination with particular attention to the functional matrix, a cephalometric study, an evaluation of the casts, to verify the possibility:

        – to make transverse expansion in order to recover the perimeter of the arcade,

        – to straighten the molar (distalization).

– move the incisors forward

a) Expansion:

•  in the upper arch: a quadhelix (, a quadhelix-crozat, a removable expansion device.;
• on the lower arch: a bihelix, a bihelix-crozat if it is necessary to advance the incisors¨
• by a Frankel. This device moves away, thanks to screens, the centripetal forces of the lips and cheeks and allows the tongue to express all its conforming action with a spontaneous expansion of 4-5 mm on the alveolodental arch;
• by a maxillary expander). This device is capable of achieving up to 11 mm of expansion in the maxilla, 

b ) distalization of molars:

Indicated when there is no posterior DDM, sufficient space between the 6th and the germs of the 2nd ^and 3rd ^molars .

Means:

Cetlin plate,

Lipbumper;

Extra oral force

Pendulum

Minivis

2. Treatment with extractions:

• If, after reviewing all means to recover the space necessary to correct the congestion, it proves impossible to treat the case without extraction, two options can be taken:

• refrain from treating mixed dentition; treat permanent dentition by extracting permanent teeth and above all: avoid trying to create space through expansion at all costs.

• practice, as recommended by some, the method of “programmed” or “serial” extractions.

• Controlled extractions: (programmed, serial, etc.)

A process aimed at adapting dental equipment that does not correspond to its bone support by successively extracting temporary then permanent teeth according to a pre-established sequence.

PRINCIPLES:

• the avulsion of a temporary tooth, the root of which is just beginning to resorb, causes a delay in the eruption of the underlying permanent tooth;
• – the avulsion of a temporary tooth whose root is resorbed by more than half allows an earlier eruption of the underlying tooth;
• – the objective is to develop the first premolars before the canines;
• – after all permanent teeth have erupted, orthodontic treatment will finalize the occlusion.
• The extraction of the baby canines must be done at the same time, in order to avoid a shift in the incisor medians.

Directions:

• Skeletal Class I with significant bulk;
• mixed dentition with ^terminal plane with mesial step which will evolve into Class I;
• little overhang and overlap;
•  mesofacial and dolichofacial typology;
•  age around 8 years old.

Contraindications:

• Skeletal Class II;
• Skeletal Class III;
• brachyfacial typology;
• Low or transient DDM;
•  agenesis;
• biretroalveolia (worsening of profile);
• overbite;

If in doubt, do not extract, as this is an irreversible process.

• HOTZ Method:
  • sequence:

  .Extraction of 53,63,73,83, when the roots are little resorbed, (at 1/3) around 8 years.

  .Extraction of 54,64,74,84 approximately 6 months later

  .Extraction of 14,24,34,44 when 1/3 of the crown is visible 

TWEED METHOD:

• Sequences: 

.IV extraction around 8 years of dental age

.Extraction of PM1 as soon as they appear on the arch and simultaneous extraction of 4 III 4 to 10 months later. 

• Indications:

      .Moderate clutter in class I;

      .Canines present and stable;

      .No incisive denudation;

      .Slight tendency towards overbite;

      .Straight profile. 

• Disadvantages: 

   It has little effect on incisal crowding and canine development and promotes mesial displacement of molars.

5. Late treatment of DDM due to excess dental growth:

Many authors prefer to undertake the treatment of DDM in permanent dentition. The treatment is carried out with multi-attachment appliances.

1. Treatment without extractions:

Anterior sagittal expansion: vestibular incisor repositioning to the extent that aesthetics and the periodontium permit.

Distalization; significant distalization can create posterior crowding, with risk of inclusion of the 2nd and 3rd molars.

Transverse expansion : the disjunction finds its indications limited to adulthood, the quad helix must be associated with a multi-attachment device (torque control).

Stripping: interproximal enamel grinding technique concerns both arches.

It is a treatment procedure in its own right, which according to its author allows to resolve DDMs  of 4 to 8 millimeters without extraction or expansion.

For SHERIDAN 0.8 mm of enamel thickness can be safely removed from posterior teeth and 0.25 mm from anterior teeth.

Followed by polishing and application of a fluoride varnish

• 2. treatment with extractions:

Extraction treatment will allow a significant reduction in the space required (approximately 15 mm in the case of extraction of two lower premolars).

It is therefore aimed at patients with significant DDM.

The choice of teeth to be extracted will be made

Treatment of Dento-Maxillary Dysharmony depending on the value and location of the DDM but also according to aesthetic, occlusal, periodontal and endodontic criteria.

6. Treatment of DDM by relative microdontia:

• Treatment is undertaken late after eruption of all permanent teeth, recommending possible prosthetic restoration to maintain the results.
• Normalization of tongue position may be necessary, 
• Frenulumectomy

Conclusion :

DDM is an anomaly very often presenting aesthetic , occlusal, carious or periodontal damage and a precise diagnosis of this anomaly will be the best asset in the choice of means and date of treatment to achieve the best aesthetic, occlusal and functional balance guaranteeing the stability of the results.

Treatment of Dento-Maxillary Disharmony

Untreated cavities can damage the pulp.
Orthodontics aligns teeth and jaws.
Implants replace missing teeth permanently.
Dental floss removes debris between teeth.
A visit to the dentist every 6 months is recommended.
Fixed bridges replace one or more missing teeth.
 

Treatment of Dento-Maxillary Disharmony