Do clear aligners really work?

Question

My lower jaw is not perfectly aligned, especially the canine teeth(lower jaw) are a bit crumpled. I will turn 21 next month and opting for braces is not a viable choice for me. Someone, suggested me clear aligners (Invisalign). I want to know if they really work.

Answer 1

Invisalign® works for many conditions but not all. E.g., see the 2018 systematic review {1}:

There was substantial consistency among studies that the Invisalign® system is a viable alternative to conventional orthodontic therapy in the correction of mild to moderate malocclusions in non-growing patients that do not require extraction. Moreover, Invisalign® aligners can predictably level, tip, and derotate teeth (except for cuspids and premolars). On the other hand, limited efficacy was identified in arch expansion through bodily tooth movement, extraction space closure, corrections of occlusal contacts, and larger antero-posterior and vertical discrepancies.

The 2007 paper {2} gives a list of clinical limitations of Invisalign:

Joffe {3} suggested that the Invisalign appliance is most successful for treating mildly malaligned malocclusions (1 to 5 mm of crowding or spacing), deep overbite problems (e.g., Class II division 2 malocclusions) when the overbite can be reduced by intrusion or advancement of incisors, nonskeletally constricted arches that can be expanded with limited tipping of the teeth, and mild relapse after fixed-appliance therapy.

Conditions that can be difficult to treat with an Invisalign appliance or are contra-indicated altogether include:

• crowding and spacing over 5 mm
• skeletal anterior-posterior discrepancies of more than 2 mm (as measured by discrepancies in cuspid relationships)
• centric-relation and centric-occlusion discrepancies
• severely rotated teeth (more than 20 degrees)
• open bites (anterior and posterior) that need to be closed
• extrusion of teeth
• severely tipped teeth (more than 45 degrees)
• teeth with short clinical crowns
• arches with multiple missing teeth

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References:

• {1} Papadimitriou, Aikaterini, Sophia Mousoulea, Nikolaos Gkantidis, and Dimitrios Kloukos. "Clinical effectiveness of Invisalign® orthodontic treatment: a systematic review." Progress in orthodontics 19, no. 1 (2018): 1-24.
• {2} Phan, Xiem, and Paul H. Ling. "Clinical limitations of Invisalign." Journal of the Canadian Dental Association 73, no. 3 (2007).
• {3} Joffe L. Invisalign: early experiences. J Orthod 2003; 30(4):348–52.