45. Retrusion (retroclination). Clinical manifestation, diagnosis, prevention, treatment

Question 1

Retrusion and how it is categorized

Answer 1

• Posterior positioning of jaws or teeth behind normal limits=>
• Skeletal Retrusion (Retrognathism)
• Dentoalveolar Retrusion

Question 2

Skeletal Retrusion (Retrognathism)

Answer 2

• Bimaxillary Retrognathism=> Both jaws posterior to normal facial limits
• Maxillary Retrognathism=>maxilla posterior to normal facial limits
• Mandibular Retrognathism=>mandible posterior to normal facial limits

Question 3

Dentoalveolar Retrusion

Answer 3

• Bimaxillary Dentoalveolar Retrusion=> Anterior teeth of both jaws posterior to normal limits of basal bone
• Maxillary Dentoalveolar Retrusion=>Maxillary anterior teeth posterior to normal limits of basal bone
• Mandibular Dentoalveolar Retrusion=> Mandibular anterior teeth posterior to normal limits of basal bone

Question 4

Etiological factors of Maxillary Retrognathia

Answer 4

• Heredity
• After cleft lip and palate surgery=>affect maxillary growth
• Premature loss of primary teeth=> posterior positioning of permanent teeth
• Extraction of teeth=>adjacent teeth shift posteriorly
• Underlying causes=>Crouzon syndrome=>
• Genetic disorder affecting facial structure

Question 5

Etiological factors of Mandibular Retrognathia

Answer 5

• Heredity
• Osteomyelitis in childhood=> Infection affecting bone growth.
• Fracture of the TMJ
• Ankylosis of the TMJ=>Fusion limits growth
• Inflammation of epiphysis=>affect jaw development
  Underlying causes

Question 6

Underlying causes leading to Mandibular retrognathia

Answer 6

• Trisomy 9=> Chromosomal disorder
• Zellweger syndrome=>Genetic disorder affecting multiple organs
• Pierre-Robin syndrome=>Condition w/ small jaw and potential airway obstruction
• De-Grouchy syndrome=> Genetic disorder w/ facial and limb abnormalities

Question 7

Extraoral clinical features of retrusion

Answer 7

• Maxillary Retrognathia=>
• Prominent chin
• Concave facial profile
• Dominant nasolabial folds
• Breathing difficulties
• Mandibular Retrognathia=>
• Fleeing chin
• Dominant upper lip
• Bird-like face

Question 8

Intraoral clinical features of retrusion

Answer 8

• Distoocclusion (class II malocclusion)
• Increased overjet
• Lower anterior teeth may occlude w/ palate

Question 9

How retrusion diagnosed

Answer 9

• Anamnesis=>Detailed patient history
• Clinical Examination=>
• Eschler-Bittner test (Class II test)
• Class III test
• Dental Model Analysis=>
• Lo and Lu assessment
• Tooth malposition and inclination analysis
• Radiographic Examination

Question 10

Radiographic Examination of retrusion

Answer 10

• Cephalometric findings=>
• Bimaxillary retrusion=>Specific angular measurements
• Maxillary retrognathism=>
• Normal SNA and decreased SNB
• Increased SNA and decreased SNB
• Increased SNA and normal SNB
• Mandibular retrognathism=>
• Normal SNA and increased SNB
• Decreased SNA and normal SNB
• Dentoalveolar retrusion
• Decreased values of maxillary and mandibular incisor axes relative to specific planes (SN, FH, SpP, MP)

Question 11

Preventive measures for retrusion

Answer 11

• Early management of genetic and developmental factors
• Monitoring and addressing early signs of dental anomalies
• Regular dental check-ups=>manage primary teeth loss and prevent injuries

Question 12

Treatment options for retrusion

Answer 12

• Maxillary Retrognathia=>
• Extraoral Anchorage=>promote maxillary growth
• Facemask=>forward traction on maxilla
• Chin Cap=>hinder excessive mandible growth
• Surgical Intervention=>LeFort I Osteotomy=>
• Repositions maxilla
• Mandibular Retrognathia=>
• Distraction Osteogenesis=>Surgical method to gradually lengthen mandible