How can we tackle Class I in Aligners?

Malocclusion presents as the third most prevalent oral pathology worldwide, only secondary to dental caries and periodontal disease. Unsurprisingly so, the World Health Organization has ranked malocclusion as the third priority for oral health disease. According to a systemic review, malocclusion affected 56% of people worldwide, without any differences or predisposition for gender. Considering this colossal figure, we can speculate that most dental patients that walk into a dental establishment have issues relating to orthodontic malalignments.

Class I malocclusion is the most common alignment issue found amongst the population. This happens when there is a normal relationship between the upper and lower teeth. Here, the mesiobuccal cusp of the maxillary first molar occludes with the mesiobuccal groove of the mandibular first molar. While the jaw bones are often well-positioned, Class I may present with mild obstacles like crowding, rotations, spacing, protrusive or flared teeth, and/or retrusive teeth.

Malocclusion, in general, not only poses great difficulties in basic functions like chewing, swallowing, and speaking but can also impact dentofacial aesthetics and psychosocial self-confidence. Aligners are widely popular in the orthodontic realm with Class I malocclusion being one of the most elective conditions to be treated with aligners.

With only a handful of studies substantiating the efficiency of aligners in the treatment of Class I malocclusion, many are left wondering if clear aligner therapy is a good call for treating it.

Can Class I be treated with aligners?

For most Class I malocclusion, aligners like Invisalign can be a definitive solution and often the first line of treatment provided to the patient, in recent years. A study published in 2020, provided us with more information on this subject.

The authors of this study performed an electronic search of dental databases in an attempt to discover if clear aligners are just as effective as fixed appliances in treating orthodontic malocclusion. Ultimately, they concluded that clear aligners (in this case, Invisalign) were able to provide successful alignment, especially in the treatment of Class I malocclusions in extraction cases.

They did, however, clarify that aligners were not as successful in achieving occlusal contacts, buccolingual inclination, and vertical movement of teeth, therefore, may not be the right choice for treating more complex malocclusion cases like Class II with dentoalveolar discrepancies and Class III. Some studies even pointed out that clear aligner cases were susceptible to relapse, especially ones that were more complicated.

Clear aligners work best for Class I and II malocclusions. Experts affirm that aligners can fix mild to moderate overbites, open bites, and crossbites where re-alignment of the teeth requires slight tooth movement. For more complex movements like rotations, fixed appliances may be a better fit.