The process of a child losing teeth is often straightforward, but the arrival of molars in the back of the mouth creates uncertainty about which teeth are temporary and which are meant to last a lifetime. Many people question whether the teeth that emerge around adolescence are permanent or if they are destined to fall out like the baby teeth before them. Understanding dental development helps clarify the fate of these later-arriving teeth.
The Two Sets of Teeth
Humans develop two sets of teeth over a lifetime. The first set is the deciduous, or primary, dentition, consisting of twenty teeth that typically appear between six months and age three.
The natural process of exfoliation, or the shedding of teeth, applies only to this primary set. As the body matures, the roots of the baby teeth are absorbed by the underlying developing permanent teeth, causing the primary teeth to loosen and fall out. The succeeding set, known as the permanent dentition, is comprised of up to thirty-two teeth and is not designed to be naturally shed.
Identifying the Second Molars
The teeth commonly referred to as the “12-year molars” are correctly identified as the second permanent molars. They are named for the approximate age range in which they erupt, typically appearing between eleven and thirteen. They are the last teeth to arrive before the potential appearance of wisdom teeth.
These molars are positioned behind the first permanent molars, which usually erupt around age six. Unlike many other permanent teeth, the second molars do not replace a baby tooth; they erupt into newly created space as the jawbone grows and lengthens. Because they are part of the permanent dentition, the second molars are intended to remain in the mouth indefinitely.
Non-Natural Reasons for Tooth Loss
Since the second molars are permanent, they are not naturally lost, but external factors can lead to their removal.
Dental Decay and Infection
Severe dental decay and resulting infection are common reasons for the extraction of any permanent tooth. When a cavity progresses deep into the pulp chamber, the infection can destroy the tooth structure beyond repair, necessitating professional removal.
Periodontal Disease
Periodontal disease, a chronic inflammatory condition, is another major cause of permanent tooth loss. Untreated gum disease destroys the ligaments and bone structure that anchor the molars firmly to the jaw. As this supporting structure degrades, the tooth can become loose, eventually requiring extraction.
Trauma
Physical trauma or injury also accounts for permanent tooth loss. A sudden impact can cause a tooth to fracture severely or result in avulsion, where the tooth is fully knocked out of the socket. If the tooth cannot be successfully replanted or repaired, it is permanently lost.
Wisdom Teeth Complications
The third set of molars, known as wisdom teeth, can sometimes indirectly affect the second molars. If wisdom teeth become impacted or erupt at a poor angle, they can press against the second molars, causing misalignment, crowding, or decay. This pressure can occasionally lead to the therapeutic extraction of the second molar to prevent further complications.