The State of Edentulism
The Mandibular Two-Implant Overdenture
Joseph R. Carpentieri, DDS • Dennis P. Tarnow, DDS
Edentulism is the state of being without natural teeth. Before exploring
its treatment, a diagnosis of edentulism needs to incorporate a thorough
understanding of the disease process. This includes the consequences of tooth
loss and an understanding of how it affects treatment decisions.
IMPAIRMENT, DISABILITY, HANDICAP
For millions of people worldwide, edentulism is a major health problem.
Although most industrialized countries report a decline in the percentage of
edentulism, the rapid aging of the population is outpacing this change, and the
overall prevalence of edentulism is expected to increase over the next several
decades. According to World Health Organizations (WHO) criteria, edentulism
represents a physical impairment
because important body parts have been lost. When tooth loss limits the ability
to perform the two essential life tasks of speaking and eating, it may become a
disability. For those among whom
significant life-altering changes are required to compensate for tooth loss,
edentulism may truly represent a handicap.1
Social withdrawal and isolation among these patients is common.
This impairment has all the characteristics
of a chronic disease--it is incurable, it is functionally and psychologically
disruptive, and it requires specific management strategies to either overcome
or limit these disruptive effects. It is also important to understand that the
edentulous condition affects patients on an entirely personal level,2
and dentists must carefully reevaluate how they interpret this impairment to
ensure that they consider the psychological, physiological, and social needs of
these patients on an individual basis.
Edentulous people exhibit a wide range of anatomic variations and health
concerns. As a result, classifying all edentulous patients as a single
diagnostic group is insensitive to the diversity of conditions and to the
variety of treatment procedures required to restore function and comfort.
The American College
of Prosthodontists has developed a classification system for complete
edentulism based on diagnostic findings (eg, bone height, ridge morphology,
muscle attachments, maxillofacial relationships).3 These guidelines
may help practitioners determine appropriate treatments for their patients.
Four categories are defined, ranging from Class I to Class IV, with Class I
representing a potentially uncomplicated clinical situation and a Class IV
patient representing the most complex and a situation of potentially higher
risk. The system is designed for use by dental professionals who are involved
in the diagnosis of patients requiring treatment for complete edentulism. The
potential benefits of the system include l) more ideal patient care, 2)
improved professional communication, and 3) better screening in dental schools.
This classification system is a useful diagnostic tool but does not predict the ability of a person to
successfully wear any prosthesis or address a patient’s individual and
EFFECTS OF EDENTULISM
1. Bone Loss
When teeth are lost, bone undergoes a remodeling or wound healing
process over an 8-week to 12-week period. After this time, however, patients
wearing complete dentures generally experience a mean alveolar ridge reduction
in the edentulous mandible of 0.4 mm/year. The reduction of the mandibular
residual ridge is particularly marked as four times greater than in the
maxillary arch (Figures 1 and 2).4 In addition, the rate of resorption is
most rapid during the first year, rendering the temporal component of implant
placement critical. Although the magnitude and pattern of bone loss show great
individual variation, the continued resorptive process results in an impaired
denture-bearing area and may cause extreme difficulties in wearing dentures as
time passes. Thus, while the remodeling
process is considered “normal,” the destructive resorptive process should be
characterized as “pathologic” and should no longer be reviewed as acceptable.
Rather, clinician’s goal should be the preservation of the bone that remains.
Although teeth are not an absolute necessity for digestion, a reduction
in the number of teeth may make mastication difficult, leading to avoidance of
specific food types that require vigorous chewing.5-8 Unhealthy
dietary modifications (eg, higher fat content, lower protein and vegetable
intake, reduction in key nutrients) often result and create a nutritional disadvantage for
edentulous patients when compared to the fully dentate.9-11 The
relationship between nutrition and health is important, and treatment of
edentulism should consider the effects of the chosen prosthesis on both.
Assessing quality of life is multifaceted and complex. For those
patients who are unable to cope and adapt to tooth loss and a denture
prosthesis, edentulism can cause profound and lasting psychological
disturbances to functional and emotional health, life experience, and
self-esteem.12 It may also precipitate bereavement, reduction of
self-confidence, disturbances of self-image, shame, and secrecy. Social labels
and stigmas may further magnify these problems. Together with bone loss and
nutritional deficiency, these effects need not be inevitable consequences of
This discussion of edentulism continues with Treatment Planning for such patients, and the authors encourage further exploration of this important topic.
Health Organization. International Classification of Functioning, Disability
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- Amler M, Johnson P, Salman I. Histological and histochemical investigation of human alveolar socket healing in undisturbed extraction wounds. J Am Dent Assoc 1960;61:32-44.
- Tallgren A. The continuing reduction of the
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