Management of ‘Submerged’/ Ankylosed primary molars

A common finding during routine dental examinations is one or more ‘submerged’ (or Infraoccluded) primary molars in a child. This is a misnomer as these teeth aren’t actually retreating from the occlusal plane, rather, the surrounding dentition and alveolar bone continues to develop vertically. However, the affected tooth/teeth does not. This leads to many localised side effects such as tipping of adjacent molars and space loss, vertical bone defects and supra-eruption of opposing molars to name a few.

For the purposes of this blog, we find the term ‘submerged’ is very descriptive to paint a clinical picture, even if it’s not technically correct. Also, parents are likely to find the term easier to understand when explaining things to them.

Aetiology

The aetiology of this is poorly understood with possible familial association. Of clinical importance, is that ankylosis is reversible, in that the submerged teeth can undergo cycles of ankylosis and release from ankylosis. This reversible nature lends itself well to a conservative, regular monitoring approach. However, it can be hard to know when to act and when to monitor. This article will hopefully give you some tips.

Submerged mandibular deciduous molars are more likely to be mild and exfoliate naturally than maxillary deciduous molars, which are more likely to require early intervention. Regardless, they can present a conundrum for practitioners as there are many considerations to make with regards to their management. Usually a team approach together with an orthodontist is required. Please see the attached table for a broad outline of clinical decision making.

We hope this has helped

This was co-written by Erica and Dr Katie Xu. If any dental colleagues in Melbourne would like a patient seen for an opinion about ankylosed teeth, she is accepting new patients in Glen Waverley and referrals can be submitted online at  www.orthodonticcentre.com.au