limitations and risks in ortho treatment

Question 1

Anatomic limitations of orthodontic treatment

Answer 1

• Size of ridge — moving big tooth into resorbed ridge
• Space constraints — tooth size arch length discrepancy, limitation if want to do non extraction
• Envelope of tooth movement
• Soft tissue limitations
  
  • Risk of fenestration/dehiscence esp when trying to camouflage constricted maxilla
  • Stripping of gingiva
  • Reciprocal force, instability
• Compromise in aesthetics eg class II orthodontic camouflage result in poor upper lip support, increased lower lip protrusion, lower face deficiency

Question 2

Physiologic limitations of orthodontic treatment

Answer 2

• Systemic problems eg diabetes result in rapid alveolar bone loss
• Medications
• Growth eg latency of growth, respond differently to growth modification, growth modification age dependent, growth modification can only achieve 3-4mm sagittal correction

Question 3

What medications are you concerned about in ortho treatment

Answer 3

• Bisphosphonates — Inhibit osteoclast mediated bone resorption. Teeth may not move as expected, be more conservative about extracting teeth
• Prostaglandin inhibitors eg corticosteroids NSAIDs — tooth movement is inflammatory mediated process, limitations in tooth movement
• Agents with agonistic/antagonistic effects on prostaglandins

Question 4

Therapeutic limitations in orthodontic treatment

Answer 4

• AnchorageEg use single molar as anchorage —> reciprocal mesialisation of molarsConsider number of teeth, periodontal support
• Type of appliance
  
  • Partial vs full
  • Removable vs fixed (removable tipping rather than bodily movement)
• Habits can limit tooth movement
• Unrealistic expectations
• Patient compliance eg to wear removable appliance, maintain good OH, diet to prevent repeated appliance breakage
• Smile aesthetics have many components that cannot be influeneced by ortho alone eg tooth proportions, vertical maxillary excess, harmony of gingival margins
• TMD — ortho cannot predictably resolve TMD
• Complete transposition cannot be corrected
• Ankylosis and primary failure of eruption — do not respond to orthodontic forces

Question 5

What are the risks in orthodontic treatment

Answer 5

• Risk of ginigivitis/of periodontitis becoming active again
• Gingival recession/apical migration of periodontal attachment (consider further risk factors)
  
  • KIV pre orthodontic soft tissue graft for high risk patients
• Decalcification/caries
• Devitalisation
  
  • Over enthusiastic apical movement sever apical vessels and nerves (excess ortho forces or tooth moved out of alveolar process)
  • History of trauma
  • Deep caries
  • Idiopathic
• Root resorption
• Soft tissue inflammation eg traumatic ulceration from braces, stomatitis from removable appliance
• Injury by orthodontic appliance
• Relapse