I like to think about orthodontic case selection for general dentists as falling in to either green, yellow or red light categories:

1. Green Light:
These criteria apply to all general dentists, regardless of experience level.
• Class 1 molar AND canine.
• No missing or impacted teeth except 3rd molars.
• No history of present or past periodontal disease.
• Mild to Moderate (less than 6mm) Crowding or Spacing.
• Overbite (deep bite) between 10%-70%.
• No open bite.
• No crossbite.

2. Yellow Light
These criteria apply to dentists who may have conducted more than 50 aligner and braces cases and who regard themselves as ready to tackle more complex cases:
• Slight Class 2 cases (molar or canine up to 4mm).
• Edge to Edge cases (anterior crossbite only, not  
  posterior crossbite).
• Deep bite/Overbite cases- any severity.
• Open bite, up to 2mm, if the etiology of the open bite (tongue thrust, habits, airway) has already been diagnosed and treated.
• Mild periodontal disease with attachment loss, that has been treated, and is under control (less than 3mm of attachment loss). A 1-month       evaluation has been completed and charted. All pockets are not less than or equal to 3mm.
• Posterior Crossbite cases in children under 13 years old.
• Mixed Dentition Cases.

3. Red Light
Do not take these cases. Refer out unless you have an orthodontist to help you.
• Impacted canine cases – buccal only.
• Full Step Class 2 Cases.
• Negative overjet up to 2mm.
• Open bite up to 4mm
• Moderate Perio Cases

Anything else outside these criteria, should always be referred out to ortho