Anomalies in Number of Teeth in Patients with Lip and/or Palate Clefts
Lucy Dalva LOPES
Beatriz Silva Câmara MATTOS
Depmamento de Cirurgia, Pótese e Traumatologia Maxilo Faciais
Faculdade de Odontologia, Universidade de São Paulo São Paulo,
Braz Dent J (1991) 2(1): 1-84 ISSN 0103-6440
| Introduction | Material
and Methods | Results
and Discussion | Conclusions | References
The authors present a radiographic survey of dental anomalies in 86
patients with cleft lip and /or palate and compare the values observed
with those reported in the literature and with those found in the general
Key Words: anomalies in nunber of teeth, anodontia, supernumerary
Full rehabilitation of patients with lip and palate
malformations requires multidisciplinary teamwork by physicians, dentists,
phonoaudiologists and social assistants. In the specific area of dentistry,
oral rehabilitation is a challenge to the various specialities. In view
of the complexity of the lesion and of the importance of the facial region
involved, the treatment of these patients requires constant follow-up so
that the preventive, interceptive and corrective measures used may be applied
in harmony with oronasal development.
During follow-up, the dentist will frequently note
anomalies involving the shape, number and position of the teeth which may
have a deleterious effect on dentition, leading not only to esthetic problems
but also to impairment of mastication, respiration, deglutition add phonation
(Figures i and 2). Alertness to the appearance of these anomalies is imperative
in the case of patients with cleft lip and/or palate if treatment during
the development of the maxillo-dental complex is to be effective.
The lateral and oronasal maxillary processes are
already markedly developed in 6-week human embryos and will fuse at about
the 7th week, giving origin to the prolabium and primary palate medially
and to the lateral portions of the lip and the upper maxillary bone laterally.
At the same time, two horizontal laminae arise from the lateral maxillary
process, i.e., the palatine processes which develop medially and fuse at
about the 10th week. Fusion occurs by contact and fusion of the epithelial
surfaces of the embryonic processes involved, followed by regression of
this epithelium and penetration of the underlying mesodermal tissue.
At about the 6th week, odontogenesis also starts
through thickening of the oral epithelium, the dental lamina, which extends
along the future occlusal border of the maxilla. At 10 sites in this lamina,
the epithelial cells intensify their proliferation forming 10 epithelial
cell buds which deeply invaginate into the underlying mesodermal tissue,
originating the enamel organs of the dental germs of deciduous teeth. As
these germs reach the stage of ameloblast and odontoblast diflerentiation,
the dental lamina, lingually to the enamel organ, gives origin to the enamel
organ of permanent teeth which will develop much more slowly.
There are many reports of the high incidence of
dental anomalies in patients with cleft lip and palate, especially in the
anterior maxillary region. Bohn (1950) stated that these anomalies mainly
occur at the level of the lateral incisor both in the deciduous and permanent
dentition, pointing out the mesial or distal position that this tooth may
take in relation to the cleft.
Considering that the function of embryonic processes
occurs simultaneously with odontogenesis, it may be understood, as pointed
out by Jordan et al. (1966), how the dental germ will be fully or partially
affected by a cleft, with the occurrence of anomalies involving tooth shape,
number and position.
According to Bhaskar (1976), these anomalies occur
during different phases of dental development, i,e., numerical anomalies
occur during the initial formation of dental germs, shape anomalies during
morphodifferentiation, and position anomalies during tooth eruption.
In view of the above considerations, and to provide
a guide for researchers and clinicians, the objective of the present investigation
was to report on numerical dental anomalies in patients with congenital
lip and/or palate malformations.
Material and Methods
The study was conducted on 432 patients from the
Maxillary Orthopedics Sector of the Hospital for Facial Defects, from the
Maxillary Orthopedics Sector of the "Jorge Psillakis" Foundation, and from
the Department of Surgery, Prostheses and Maxillo-Facial Traumatology of
the Dental School of the Univesity of São Paulo, from January 1980
to December 1982.
Each patient was submitted to radiographic examination,
when periapical, maxillary occlusal and panoramic X-rays were taken using
Kodak Ultra-Speed film.
Upper and lower plaster of Paris casts were obtained
from irreversible hydrocolloid (alginate) molds.
Special cards were elaborated and used to record
general patient data and the data related to numerical anomalies involving
mixed and permanent dentition.
Of the 423 patients exanfined, only 86 satisfied
the requirement of absence of previous tooth extraction and were selected
for the study. The patients ranged in age from 9 to 32 years and were divided
into groups according to type of cleft: cleft lip, lip and alveolar cleft,
cleft lip and cleft palate, and cleft palate.
Results and Discussion
Observation of the casts and- of radiographic data
yielded the data presented in Table 1.
Wide variation in numerical dental anomalies in
patients with cleft lip and/or palate have been reported in the literature.
Damante et al. (1973) established two criteria for the study of numerical
anomalies in the cleft as a function of the mesial or distal position of
the lateral incisor in relation to the cleft, both of them based on the
embryology of the region (Figure 3). It should be emphasized that the values
obtained by these investigators varied widely as a function of the two
In the present study, we employed criterion no.
2 of Damante et al. (1973) on the basis of the arguments presented by these
investigators in its favor. In addition, it is imperative to divide the
sample according to type of cleft, since the cleft may directly affect
the region in which the dental lamina is located during embryonic development.
The present results show that numeric anomalies
are much more prevalent in the types of cleft involving the alveolar ridge.
This fact is quite logical if we consider the disorders occurring within
the embryonic tissue that contains the dental lamina (Figures 4 and 5).
Figure 4 - Unilateral cleft lip and palate. Anodontia of a lateral incisor
in mixed dentition.
Another feature to be considered is the extent of
the cleft in terms of the type of numerical anomaly. In the present study,
supernumerary teeth preferentially occurred in the lip-alveolar clefts,
as also observed by Bohn (1963) and Damante et al. (1973). Embryologically,
it would be justified to assume that a bipartition of the dental lamina
of the lateral incisor may occur in these less serious clefts, giving origin
to the supernumerary tooth.
In more severe cases, i.e., lip-alveolar-palate
clefts, the embryonic structures that give origin to the tissue in this
region are severely impaired as early as during the phase of dental development.
Thus, we may explain not only the lower prevalence of supernumerary teeth,
but also the higher prevalence of anodontia in cases of cleft lip and/or
palate. The higher frequency of anodontia observed here in cleft lip and/or
palate patients agrees with results reported by Polaczek (1978) and Fishman
(1970). On this basis, we agree with Damante et al. (1973) that "the incidence
of supernumerary teeth decreases with increasing cleft complexity, whereas
the incidence of agenesis is directly proportional to cleft complexity"
Isolated clefts of the palate seem to represent
a separate situation since their anatomical location apparently does not
interfere with the development of the dental lamina. Indeed, in the present
study the prevalence of dental anomalies in patients with isolated cleft
palate was extremely low when compared to other cleft types, as also pointed
out by Ranta et al. (1983). Similar results were obtained by Bohn (1963)
who only detected premolar anodontia and no supernumerary teeth and by
Nagai et al. (1965) and Fishman (1970), who also detected only premolar
anodontia in these patients. Olin (1964) observed a considerably high prevalence
of premolar anodontia (13 cases in 22 patients), in contrast to the present
study in which only 2 cases of premolar anodontia were detected in 11 patients.
In view of the wide variation of results reported
in the literature, we believe it is imperative to standardize sample selection
as well as diagnostic criteria so that future studies may clarify this
matter. However, there is no doubt that patients with congenital lip and/or
palate malformations exhibit a much higher prevalence of anomalies in the
number of teeth than the general population (Figure 7).
Acomparison of the prevalence of anomalies in number
between patients with cleft lip and/or palate and normal individuals is
presented in Table2.
It should be pointed out that the frequency of anodontia
is twice the frequency of supernumerary teeth both in the general population
and among subjects with lip and/or palate malformations. Furthermore, numerical
anomalies involving either anodontia or the presence of supernumerary teeth
are approximately seven times more frequent among patients with cleft lip/palate
than among the general population, demonstrating a high correlation between
cleft lip/palate and numerical dental anomalies.
On the basis of the methodology employed and of the
results obtained, we may conclude that:
1. Numerical dental anomalies are seven times more prevalent among
patients with cleft lip/palate than in the general population.
2. Anodontia is twice as frequent as supernumerary teeth both in the
general population and among patients with cleft lip/palate.
3. Numerical dental anomalies are related to cleft type, with supernumerary
teeth being inversely correlated to cleft complexity and anodontia being
directly related to cleft complexity.
Bhaskar SN: Patologia bucal. Artes Médicas, São Paulo,
Bohn A: Anomalies of the lateral incisor in cases of hare lip and cleft
palate. Acta Odont Scand 9: 41-59, 1950
Bohn A: Dental anomalies in hare lip and cleft palate. Acta Odont Scand,
21 (suppl. 38): 3-109, 1963
Damante JH, Freitas JAS, Moraes N: Anomalias dentárias de número
na área da fenda, em portadores de malformações congênitas
lábio palatais. Estomatol Cult 7: 88-97, Jan/Jul, 1973
Ferrão NA Prevalência das alterações ósseo-dentais
em crianças de 6 a12 anos observas em radiografias panorâmicas.
Rev Paul Odont 3: 34-39, Jul/Agost, 1981
Fishman LS: Factors related to tooth number, eruption time and tooth
position in cleft palate individuals. J Dent Child 37: 303-306, Jul/Aug,
Jordan RE, Kraus BS, Neptune CM: Dental abnormalities associated with
cleft lip and/or palate. Cleft Palate J 3: 22-55, Jan, 1966
Nagai I, Fujiki Y, Fuchihata H, Yoshimoto T: Supernumerary tooth and
associated with cleft lip and palate. J
Amer Dent Assoc 70: 642-647, Mar, 1965
Olin WH: Dental anomalies in cleft lip and palate patients. Angle Orthodont
34: 119-123, Apr, 1964
Polaczek T: Incidence of reduced number of teeth in persons with cleft
palate. Czas Stomat 31: 379-386, Apr, 1978
Ranta R, Stergars T, Rintala AE: Correlations of hypodontia in children
with isolated cleft palate. Ceft Palate J, 20: 163-165, Apr, 1983
Silling G: The incidence of supernumerary teeth in cleft palate patients.
NY Dent J 32: 70-72, Febr, 1966
Correspondence: Profa.Dra. Lucy Dalva Lopes, Faculdade de Odontologia,
USP, Caixa Postal 8216, 05508 São Paulo, SP, Brasil.