FUTURE OFDENTISTRYing, dental development, facial growth, facial esthet-
ics, facial animation, occlusion and mastication, and
psychosocial development. The dental components
to the cleft/craniofacial team represent some of the
most significant contributions to total patient reha-
bilitation, including pediatric dental care, orthodon-
tics, oral and maxillofacial surgery and prosthodon-
tics. In addition, the dental specialists on the
cleft/craniofacial team play key roles at almost every
age and stage of care of the patient with a cleft.
Consequently, they are also uniquely positioned to
document and record treatment outcomes, and par-
ticipate in the clinical research efforts into treatment
efficacy and effectiveness.
Research efforts to determine optimal ways to
deliver health services to these patients have been
hampered by a lack of consensus on minimal stan-
dards for documenting outcomes, as well as agree-
ment on which outcomes are relevant indicators of
successful treatment in the first place. Current out-
comes research has traditionally excluded parent
participation in defining treatment success or fail-
ure, a serious shortcoming emphasized by the
Surgeon General's Conference on Children and Oral
Health (Satcher, 2000). Furthermore, evidence for
something as basic as the cost-effectiveness of team
care is currently lacking, in spite of overwhelming
support among care providers, of its appropriate-
ness. Finally, while the large number of centers pro-
viding treatment for clefts improves patients' geo-
graphical accessibility to care, it simultaneously cre-
ates a fractionation of the cleft population thereby
reducing the probability of developing patient sam-
ples of adequate size to enable valid research. While
several recent research initiatives such as the
Eurocleft project in Europe (Shaw et al, 2001) and
the Craniofacial Outcomes Registry in the United
States (http://www.cfregistry.org/) have begun to
remedy this problem through significant inter-center
collaboration and establishment of common data
bases, the lack of collaboration between these vari-
ous initiatives themselves, continues to limit the
benefits of the globalization of this effort.
MALOCCLUSION AND TOOTH AGENESIS
Malocclusion, or faulty intercuspation of the teeth,
is usually caused by a moderate variation or distortion
of normal growth and development of the teeth or
bones of the mandible and maxilla. Usually it occurs
without any other dental or medical problems, though
occasionally it develops as a symptom of a systemic or
syndromic disease. Malocclusion is a continuum from
slight irregularity of the bite to severe difficulty with
mastication. Abnormal tooth and jaw alignment can
affect speech, and in severe cases an abnormal facial
appearance may affect the psychological well-being of
the individual (Berscheid, 1980).
Although a single specific cause of malocclusion
may sometimes be apparent––e.g., trauma, oral
habit, dental anomalies of tooth shape or number,
or a genetic syndrome––malocclusion is usually the
result of a complex interaction among multiple
hereditary and environmental factors that influence
growth and development. This interaction occurs
in, and has an effect on, the craniofacial skeleton,
dentition, orofacial neuromusculature, and other
soft tissues, including those that border the airway.
Although in the past there has been controversy and
debate about the relative importance of hereditary ver-
sus environmental influences on the etiology of maloc-
clusion, there is evidence of a genetic influence on many
aspects of dental and occlusal variation (Mossey, 1999).IncidenceEstimates of the incidence of malocclusion in the
United States vary with the criteria used. The Index
of Treatment Need (IOTN) (Brook and Shaw, 1989)
relates malocclusion to the need for treatment, using
psychosocial and facial considerations, in addition
to dental health (traits) to assign five grades of treat-
ment need. One study, using only the dental health
(traits) component of the IOTN, estimated the
prevalence of malocclusion and orthodontic treat-
ment need in the United States from data in the third
National Health and Nutrition Examination Survey
(Proffit et al, 1998). This study found that 15% of
the population has dental irregularity severe enough
to affect both social acceptability and function.
Correction of these severe problems may require
major arch expansion or extraction of some teeth.
About 20% of the population has deviations from
ideal bite relationships. One in 50 of these deviations
is severe enough to be disfiguring. Many of these prob-
lems are at the limit of treatment by orthodontics alone
and may require orthognathic surgery. Another study
found sagittal molar asymmetry in 30% of a group of
untreated 8-10 year olds and in 23% in a group of
untreated 14-15 year olds (Sheats et al, 1998). In the
latter group, 12% also showed facial asymmetry and
21% displayed noncoincidence of dental midlines.Dental and Craniofacial Research