A common reason for a referral of a young child to an orthodontist is early signs of developing dental crowding. For example, when there is inadequate space for the eruption of either the upper and/or lower permanent four incisor teeth. The permanent lower incisor teeth typically erupt at age 6-7 years and the permanent upper incisor teeth at age 7-8years.
In cases where there is a severe tooth-size relative to jaw-size discrepancy, eruption guidance may be an excellent treatment procedure. It is frequent that I explain to parents that tooth-size and jaw-size are inherited on two separate genes. Each parent contributes eight pieces of genetic information for each of tooth-size and jaw-size and one of sixteen for each of these factors is randomly assigned to represent their child’s dentition. Sometimes a large tooth-size is inherited with an accompanying small jaw-size and results in varying degrees of dental crowding. It is the orthodontist’s role to determine whether or not an individual’s teeth can be made to fit into their jaws without violating biological health, negatively impacting facial outcome or long-term stability. In order to make a proper diagnosis, a thorough assessment is required. This assessment generally involves diagnostic records that permit an evaluation of space requirements, pre-existing inclinations of teeth, the adequacy of bone and gum tissue support surrounding the teeth, skeletal relationships between the upper and lower jaws, facial patterns and lip balance.
If it is deemed that expansion treatment to gain more space for the crowded teeth is contraindicated, then eruption guidance is appropriate. This is often initiated with the recommendation for removal of the primary (baby) canines. This creates additional space for eruption of the permanent four incisor teeth, and/or some self-correction in the alignment of these teeth. The advantage of this recommendation is that there is an improvement in the appearance of the front teeth without any active orthodontic treatment. Regular follow-up at prescribed intervals however remain important for the orthodontist to follow and continuously assess additional space requirements for the remaining erupting teeth.
In some instances, additional extractions are not necessary. In other instances, serial extractions may be required to manage severe space discrepancies. Serial extraction is the planned extraction of certain primary (baby) teeth and specific permanent teeth (bicuspid teeth) in an orderly sequence and pre-determined pattern to guide the erupting permanent teeth into more favourable positions.
Serial extraction based on the thorough knowledge of the practitioner, a sound diagnosis and when carried out properly on a select group of patients, can most assuredly be a beneficial and valuable treatment procedure.
In suitably selected cases, serial extraction improves the appearance of the dentition before treatment is even initiated. Serial extraction very often reduces the length of active orthodontic treatment that is required and correspondingly the costs of such treatment.
It is common for parents and their dentists to be overwhelmed at the thought of multiple extractions if not be vehemently opposed. Nonetheless, serial extraction is a process that is begun with the removal of primary teeth and once the initial improvement of teeth is seen a greater confidence is developed and understanding of the procedure becomes more clear.
In cases where four bicuspid teeth are ultimately removed, the teeth are aligned, all spaces are closed and the bite is fit ideally with orthodontic treatment. So, unless you’re counting teeth, no one can tell that any were ever removed and the results speak for themselves!