Treatment of Transverse Malocclusions PDF

Treatment of Transversal Malocclusions Index  1. Concept and classification  2. Epidemiology  3. Etiopathology  3.1. Genetic factors  3.2. Habits  4. Diagnosis  5. Treatment  6. Frontal Rx  1. CONCEPT & CLASSIFICATION How do we determine maxillary deficiency? -...

Treatment of Transversal Malocclusions Index  1. Concept and classification  2. Epidemiology  3. Etiopathology  3.1. Genetic factors  3.2. Habits  4. Diagnosis  5. Treatment  6. Frontal Rx  1. CONCEPT & CLASSIFICATION How do we determine maxillary deficiency? - Alterations in occlusion in the transversal plane. - Independent of the intermaxillary relationship in the sagittal and vertical planes.  CONCEPT & CLASSIFICATION Transversal anomalies: Posterior crossbite Scissor bite Cuspid to Cuspid  CONCEPT & CLASSIFICATION Posterior crossbite - Bilateral posterior crossbite - Unilateral posterior crossbite - Monodental posterior crossbite  CONCEPT & CLASSIFICATION Scissor bite - Bilateral scissor bite / Brodie’s syndrome - Unilateral scissor bite - Monodental scissor bite  1. Skeletal  2. Dento-alveolar  3.Functional  4. Mixed  How to know what type of transverse malocclusion is?: differential diagnosis 1. Patient history and examination 2. Ordinary records - -Extraoral and intraoral photos - -Study models (articulator) - - Panoramic Rx - - Lateral Teleradiography of the Skull - - Frontal Teleradiography of the Skull 3. Complementary explorations Complementary explorations  basecranial radiography Complementary explorations  99Tc scintigraphy, SPECT Complementary explorations  Computed axial tomography 2. EPIDEMIOLOGY POSTERIOR CROSSBITE - Prevalence in general population: 1-23% - Monodental crossbite: 6-7% - Unilateral crossbite: 4-5% - Bilateral crossbite: 1.5-4% - Prevalence in orthodontic population: 48% BILATERAL POSTERIOR CROSSBITE ORIGIN - Frequently due to the lack of growth of the maxilla on the horizontal plane. - Morphology vs Malocclusion - Classification: - Dentoalveolar compression - Maxillary compression - Mandibular dilation 3. ETIOPATHOLOGY 1. GENETIC FACTORS a) Maxillary hypoplasia b) Mandibular hyperplasia c) Combination of both d) Malformation syndromes  3. ETIOPATHOLOGY 2. HABITS a) Oral breathing b) Infantile swallowing, lingual thrust c) Thumb sucking 3.1. GENETIC FACTORS 1. Maxillary Hypoplasia A)Compression & Crowding: 1. Angle Class I dental relationship 2. Crowding in the upper arch / lack of space for the canines 3. In case of associated lack of anteroposterior maxillary growth  Class III of maxillary origin B) Compression & incisor protrusion:  3.1. GENETIC FACTORS 1. Maxillary Hypoplasia B) Compression & incisor protrusion: 1. “Pearl necklace” 2. Mandible trapped in a class II relationship.  3.1. GENETIC FACTORS 2. Mandibular Hyperplasia a) Excess mandibular growth in the transversal and sagittal planes. b) Not frequent associated to class I. c) Real mandibular prognathism / surgical class III. 3.1. GENETIC FACTORS 3. Combination of both a) Present in most skeletal class III b) Hypoplasia of the maxilla in the transversal and sagittal planes. c) Hyperdevelopment of the mandible. 3.2 HABITS 1. Oral Breathing 1. Any obstacles in nasal breathing  oral breathing. 1. Frequently, after the obstacle has been eliminated, oral breathing persists  habit 2. Causes: 1. Allergic rhinitis 2. Adenoid hypertrophy, chronic sinusities HABITS 1. Oral Breathing 3. Conseguences in the development of the maxilla: 1. Opacity and hypodevelopment of the maxillary sinuses , which are the basis of the dental arches 2. Predominance of the elevator muscles of the upper lip, over the paranasal muscles  elevation and retrusion of the anterior nasal spine. HABITS 1. Oral Breathing 3. Conseguences in the development of the maxilla: 3. Global/transversal hypodevelopment of the maxilla: separated lips & low tongue  disruption of the equilibrium of the forces exerted by the tongue and the cheeks  compressión of the lateral sectors. 4. Incisor protrusion due to the lack of lip pressure. HABITS 1. Oral Breathing 4. Conseguences in the development of the mandible (not as constant): 1. Mandibular protrusion due to the low position of the tongue. 2. Clockwise rotation of the mandible with elongation of the alveolar bone 1. Class II tendency 2. Increase in the lower facial height. 3. Functional lateral deviation HABITS 1. Oral Breathing HABITS 2. Infantile swallowing 1. Characteristics of mature swallowing: 1. Tip of the tongue located behind the incisors, in contact with the palate. 2. Teeth are in contact or very close. 3. Mandible in retrusive position 4. Almost inexistent lip contraction. HABITS 2. Infantile swallowing 2. Etiologic factors: 1. Increase in tonsils’ size 2. Oral breathing 3. Psychologic licking habit 3. Characteristics: 1. Interposition of the tongue between the teeth to stabilize the mandible. 2. Lack of tongue pressure + pressure of the buccinators  lack of development of the upper maxilla. HABITS 2. Infantile swallowing 4. Consequences 1. Compression of the maxilla 2. Open bite tendency HABITS 3. Thumb sucking 1. Effects on occlusion depend on: position, time and morphogenetic pattern. 2. Etiology: 1. Low position of the tongue 2. Effect of the buccinators 3. Reduction of the intraoral pressure of air during suction. 3. Malocclusions produced by habits usually produce dentoalveolar compression. DIAGNOSIS 1. Identify the origin of the anomaly 1. Maxilla / Mandible /Combination 2. Skeletal / Dentoalveolar 2. Frontal XR Most frequent clinical presentations of transverse and symmetrical skeletal deficit of the maxilla:  1. Bilateral crossbite without mandibular deviation  2. Unilateral crossbite  2.1. with mandibular deviation  2.2. without mandibular deviation  3. No crossbite and no mandibular deviation  3.1. Increased upper Wilson curve  3.2. Increased lower Wilson curve  3.3. Increased upper and lower Wilson curve 1. Maxillary skeletal  A Bilateral symmetrical crossbite without mandibular deviation, of skeletal origin and with normal implantation of the upper teeth in the bone (normal Wilson curve)  B Treatment: Skeletal expansion of the maxilla: Rapid palatal expansion Bilateral symmetrical crossbite without mandibular desviation Maxyllary skeletal  A Unilateral symmetrical crossbite with mandibular deviation to the right and left unilateral maxillary dentoalveolar compensation  B Treatment: Correct incorrect twisting of the upper left teeth. Note that this generates a left cross bite. Now that the teeth are well implanted in the bone, the real problem of the patient is observed in the occlusion, a narrow and symmetrical maxilla.  C Skeletal expansion of the maxilla: Rapid palatal expansion Unilateral symmestrical crossbite with mandibular deviation to the right and left unilateral maxyllary dentoalveolar compesation Unilateral symmetrical with mandibular deviation Maxyllary skeletal  A No crossbite and no mandibular deviation. Bilateral maxillary dentoalveolar compensation. Increased Wilson's curve  B Treatment: Correct incorrect twisting of the upper teeth. Note that this generates a bilateral crossbite. Now that the teeth are well implanted in the bone, the real problem of the patient is observed in the occlusion, a narrow and symmetrical maxilla.  C Skeletal expansion of the maxilla: rapid palatal expansion No crossbite and no mandibular deviation. Bilateral maxyllary dentoalveolar compensation Without crossbite and no deviation mandibular. Increase C Willson  Remember, the alteration of the curve of Wilson may be masking a basal skeletal problem, even in the absence of a posterior crossbite. Maxyllary skeletal  A No cross bite and no mandibular deviation. Bilateral mandibular dentoalveolar compensation. Increased lower Wilson curve. Inferior dentoalveolar compression.  B Treatment: Correct the incorrect twisting of the lower teeth. Note that this generates a bilateral crossbite. Now that the teeth are well implanted in the bone, the real problem of the patient is observed in the occlusion, a narrow and symmetrical maxilla.  C Skeletal expansion of the maxilla: Rapid palatal expansion No crossbite and no mandibular deviation. Bilateral mandibular dentoalveolar compensation 2. Mandibular skeletal  Very rare. They are usually associated with maxillary hypoplasia and severe Class III  Surgical treatment in the mandible, orthopedic or surgical treatment in the upper jaw  Remember, transverse orthopedic treatment is not possible in the mandible, since the mandibular symphysis closes during the first year of life. Mandibular skeletal Skeletal: scissor bite  Infrequent. A similar classification can be applied to vestibular crossbites, and the same treatment philosophy applied. Bilateral: Brodies’s syndrome 3. Dentoalveolar  Frequent 10-15% of crossbites  Most of superior maxillary origin (82%)  Associated with Habits or Dental Malpositions  Almost always unilateral with/without mandibular deviation  Treatment: ORTHODONTICS, tooth movement Most frequent clinical presentations of dento-alveolar crossbites (without basal skeletal involvement):  1. Unilateral cross bite  1.1. with mandibular deviation  1.2. without mandibular deviation  2. Bilateral crossbite  2.1. with mandibular propulsion (associated with Class III)  2.2. without mandibular deviation Dentoalveolar: symmetric maxyila  A Usual occlusion: With cross bite and mandibular deviation. Bilateral maxillary dentoalveolar compensation. Decrease or inversion of the Wilson curve.  B Centric relation: Now that we have eliminated the functional displacement of the mandible, the real problem of the patient is observed, a narrow and symmetrical maxillary dental arch.  C Treatment: Dentoalveolar expansion of the upper dental arch: Active or passive orthodontic expansion, Tooth movement Dentoalveolar: symmetric maxilla RC Habitual occlusion Dentoalveolar: asymmetric maxilla  A and B. Habitual occlusion and centric relation coincide, with right crossbite and NO mandibular deviation. Unilateral maxillary dentoalveolar compensation.  C. Treatment: Right unilateral dentoalveolar expansion of the upper dental arch: Active or passive orthodontic expansion, Tooth movement. Dentoalveolar asymmetric maxilla Dentoalveolar: unilateral mandibular With crossbite and without deviation mandibular Dentoalveolar: mix unilateral bilateral Dentoalveolar: scissor bite Unilateral mix Bilateral mix TREATMENT 1. Early treatment: avoid dentoalveolar and/or skeletal compensations 1. Reduce relapse 2. Increase arch length 3. Reduce ectopic eruption and tooth retention 2. Therapeutic Objectives: 1. Control of habits 2. Maxillary expansión 3. Elimination of prematurities  Remember, functional deviations of the mandible, over time, can develop into true skeletal asymmetries. Early treatment is essential CONTROL OF HABITS 1. Oral breathing  Nasal breathing 1. Cooperation with other specialists (alergist, ENT) 2. Eliminate obstruction of the upper airways 3. Sometimes the habit of oral respiration persists 4. Exercises of nasal breathing 5. Correction of habit Expansion of the maxilla CONTROL OF HABITS 2. Thumb sucking habit 1. Children > 4-5yr 1. Interview with patient and parents 2. Child must understand consequences of habit 2. When child asks for help to stop habit 1. Devices that stop the introduction of the finger in the mouth e.g. tongue crib 2. Devices should not impede normal muscular function CONTROL OF HABITS 3. Lingual Rehabilitation 1. Exercises 2. Mechanical obstacle TREATMENT: transversal maloclussions  Depending on the level of the problem  Depending on the age of the patient Dependind on the level of the problem  Dentoalveolar malocclusion  Skeletal malocclusion  True asymmetries Depending on the age of the patient  deciduous dentition  mixed dentition  permanent dentition Dentoalveolar  Mechanics  - Deciduous dentition, selective carvings, composite tracks, removable appliances (Plates), etc.  - Mixed Dentition, Selective Carvings, Removable Appliances, QH etc.  - Permanent dentition, fixed appliances.  Movement type: Tilt controlled (or mass) Force Intensity: 25-50gr/mm2 Activation rate: 1mm/month REMOVABLE APPLIANCES DESIGN: 1. Acrylic base 2. Adam clasps 3. Vestibular arch 4. Posterior bite plane (optional) 5. Expansion screw FIXED APPLIANCES PALATAL ARCH / QUAD-HELIX: Work side AFMP Balance side 0º 35º Right chewing is very easy, however left chewing requires great vertical effort functional masticatory angle of planes: AFMP Remember, the patient with unilateral posterior crossbite eats, preferably, on the side of the crossbite. Unilateral chewing is a cause of asymmetric growth of the mandible Early treatment is essential er treatment with dentoalveolar expansion and lective carvings, the crossbite has been corrected an vertical angle of the right and left lateralities has en equalized. Rehabilitation is now possible! Maloclussion dentoalveolar: retention  NO RETENTION (children-youth) If good interfingering is achieved, the axial inclinations of the posterior teeth are correct and unilateral chewing has been rehabilitated  RETENTION 6 MONTHS (children-adolescents) With the expansion device itself or with removable retainer 10-12h/day  RETENTION 15 MONTHS (Adults) Maintain fixed appliance for at least 3 months after correction Removable retainer 10-12h/day (12 months. However, better fix retention and removable forever Maloclussion skeletal  Objective 1: correct the bone deficit  Therapeutic level: Orthopedics or Orthopedic Surgery (Orthognathic): Mechanics  - Deciduous or Mixed Dentition, Rapid palatal expansion  - Permanent Dentition, rapid palatal expansión or Surgery Force  Intensity: 500-1000gr/mm2. We generate hyalinization of the Periodontal Ligament (SO THE TEETH WILL NOT MOVE FOR ABOUT 14-21 DAYS)  Activation rate: 0.5mm/day, 7.0mm in 14 days.  Objective 2: Correct dento-alveolar compensations with fixed appliances. Pure tooth movements. Usually before orthopedic treatment.  Only rapid palatal expansion 1. Fixed appliances to straighten teeth 2. Rapid palatal expansion  45% opening of midpalatal suture 40% dental movement 15% dental inclination 25% dental displacement 15% Remodelling alveolar process  Rapid palatal expansion Notice how the palatal suture opens and how the nasal width even increases Notice how the central incisors are separated and how the nasal width increases. This has happened in 15 days! Disyunción Maxilar Rápida Disyunción Maxilar Rápida Disyunción Maxilar Rápida Disyunción Maxilar Rápida Hybrid disjunction, dental support and bone support on two palatal screws It is used in permanent dentition screw BENEFIT 2.3X7 MM TELERADIOGRAFIA INICIAL Y POST-DY 9 MM DE 15 días de EXPANSION expansión Surgically Assisted Maxillary Disjunction SARPE  Activation rhythm: 1v (0.25mm) / 12h from day 6 post-surgery Overcorrect 3.0mm Leave the circuit breaker cemented until X-rays confirm that the open space has been correctly ossified (approximately 6- 8 months) SARPE with bone-supported expander Skeletal maloclussion: retention  RETENTION 9 MONTHS (children) With the Disjunction device itself 3 months. Removable retainer 10-12h/day 6 months  RETENTION 18 MONTHS (Permanent dentition) Overcorrect expansion 2-3mm Maintain disjunction appliance 3-6 months after correction Removable retainer 10-12h/day (12 months)  RETENTION 24-48 MONTHS (Adults: SARPE) Overcorrect expansion 2-3mm Keep appliance fixed 6 months after correction Removable retainer 10-12h/day (24-48 months) 3. TRUE ASYMMETRIES  Objective = Orthopedics and Orthopedic surgery Mechanics  - Deciduous or Mixed Dentition, Control of asymmetric growth (Activators, Bone distraction, surgery, etc.)  - Permanent Dentition, Distraction, Surgery, etc… CLASSIFICATION OF MANDIBULAR ASYMMETRIES  1. SECONDARY SKELETAL ADAPTATION TO A MANDIBULAR FUNCTIONAL DEVIATION  2. UNILATERAL HYPOGROWTH  3. UNILATERAL HYPERGROWTH  Evolution from 4 years (top) to 5 years (bottom) of age. See how the right crossbite has developed in less than a year! Above is incomplete (we say “unorganized or unstructured”). Below is complete and organized. From this moment on, the patient will eat almost exclusively on the right side 6 years old. Treatment with adenoidectomy and tonsillectomy, rapid maxillary disjunction and rehabilitation. Observe how the crossbite has been corrected and the mandibular midline has been centered. Chewing can now be rehabilitated RICKETTS FRONTAL CEPHALOMETRIC ANALYSIS  ANATOMY Crista Galli Cranial vault Orbit sphenoid wings Upper border of the Nostrils temporal rock Zygomatic arch Condyle Pyramidal process of the maxilla Coronoid process mastoid RICKETTS FRONTAL CEPHALOMETRY  Horizontal plane: Frontozygomatic (ZA-AZ)  Midsagittal plane: perpendicular to ZA-AZ passing through the upper part of the nasal cavity Frontozygomatic plane Frontal facial plane Bicigomatic plane Pl of the zygomatic Maxilar or jugal plane arch Oclusal plane Front tooth plane Antegonial plane RICKETTS FRONTAL CEPHALOMETRY  FIELD I or DENTAL PROBLEM  - Molar ratio: 1.5 mm +- 1.5  - Intermolar width (lower): 55 mm +- 2  - Intercanine width: 23 mm +- 3  - Dental midline: 0 mm +- 1.5  FIELD II or MAXILO-MANDIBULAR RELATIONSHIP  - Width Mx-Md (Facial plane to J): 10 mm +-1.5  - Mean line Mx-Md: 0º+- 2  FIELD III or OSEODENTARY RELATIONSHIP  - Md-Molar ratio: 6.3 mm +-1.7  - Midline ratio Md: 0 mm +- 1.5  - Occlusal Plane Inclination (ZR-ZL to Occlusal Plane): 0mm+- 2  FIELD IV or CRANIOFACIAL PROBLEM –  Postural symmetry (Facial plane - Zygomatic arch plane): 0º+-2 RICKETTS FRONTAL CEPHALOMETRY  FIELD V OR INTERNAL STRUCTURAL PROBLEM  - Nasal width: 25 mm +- 2  - Nasal height: 44 mm +- 3  - Maxillary width (J-J): 62 mm +- 3, increases 0.6mm/year  - Mandibular Width (AG-AG): 76 mm +- 3, increases 1.4mm/year  - Facial Width (ZA-AZ): 117 mm +-3, increases 2.4mm/year MX-  MD DIFFERENCE RATIO: increases 0.8/year 9 years – 14.0 16 years old – 19.6