Suggestions of dental agenesis and genetics
Chatting with patients beyond the professional relationship, sometimes and by chance, brings surprises that can arouse our curiosity. How many times does it happen that, when asked about medical, personal or family history where allergies or coagulation disorders, jump to the first… the answer is: “nothing, everything is fine”. Insisting is not superfluous, as we will see below.
Dental agenesis, as well as other abnormalities of dental development, are part of the routine of clinical work in dentistry and especially in orthodontics. We know that dental development is under strict genetic control that determines the position, number and shape of the teeth. Articles like the one published by P Ritwik et al “Diagnosis of Tooth Agenesis in Childhood and Risk for Neoplasms in Adulthood” [11] make sense of the paragraph I started with.
Entering the world of genetics is not easy, which is why papers such as the one published by Meredith A. Williams and Ariadne Letra in 2018, in the journal Genes [12] are so important; an article that leaves a mark. It puts order and facilitates the understanding of a complex subject for its clinical integration. Looking back in time, it makes you understand all those treatments where non-syndromic agenesis was accompanied by “something else…” but where we had not quite found the links or the current “clarity”.
Dental agenesis is classified according to its number of involvement (not including wisdom teeth) in: hypodontia (less than or equal to five agenesis), oligodontia (more than 5) or anodontia (total absence of permanent teeth). The most affected teeth are mandibular second premolars, maxillary lateral incisors, and maxillary second premolars.
On the other hand, agenesis can be syndromic or non-syndromic. Although they can appear in more than 150 syndromes, the most common is that they are isolated, sporadic or segregated in families.
The association of dental agenesis with certain syndromes has been known and studied for years. Most of them are syndromes that can be presented in our clinic already diagnosed, since other phenotypes have been evidenced in early stages of life at the medical level. In these cases, other dental anomalies may occur: microdontia, short roots, dental impactions, delayed or altered dental eruption, canine and premolar transposition, taurodontism and enamel hypoplasia.
On the other hand, the presence of non-syndromic dental agenesis may be due to:
- Local factors that altered the development of tooth formation (trauma, exposure to thalidomide, antineoplastic chemotherapy, radioactive therapy, maternal rubella infection,…).
- Associated with genetic mutations.
I have been especially interested in studying this last group in recent years, and it is the one I will focus on in future articles. It will be non-syndromic dental agenesis caused by genetic mutations that are also responsible for associated medical alterations but not previously identified, silent. For this reason, I like to call this group the suggestions of dental agenesis, they warn us of what is to come.