Unusual case of rootless premolar.
Article: Premature eruption of the premolars.[show abstract] [hide abstract]
ABSTRACT: This paper presents a variety of cases in which very early loss of abscessed primary molars caused early eruption of the permanent successors. Clinical sequelae including ectopic eruption, alteration of eruption sequence, arch-length inadequacy and tooth impaction are illustrated by five case reports.ASDC journal of dentistry for children. 57(2):128-33.
- British dental journal 08/1975; 139(1):9-11. · 0.81 Impact Factor
- Multipleidiopathicrootresorptionin monozygotic twins: case report. 1989. Pediatr Dent 11 76-78..
Unusual case of rootless premolar
Montserrat Catala, MD, DDS Ana Zaragoza, MD, DDS
Filomena Estrela, MD, DDS Carlota Valdemoro, MD, DDS
tion therapy of the head and neck.1 Possible causes of
root absence are hereditary anomalies such as dentinal
dysplasia, morphological anomalies known as dystro-
phies, and idiopathic root resorption.2
A tooth in a very early stage of root development
can erupt prematurely when a periapical infection of
the overlying primary tooth causes extensive bone de-
struction.3 Failure of the tooth germ to develop as a
sequelae to periapical or inter-radicular infection of the
primary tooth is uncommon but has been reported.4
We present a case of premolar eruption with a mor-
phologically anomalous root.
The patient, a 10-year-old girl, had an unremarkable
health history with no dental complaints. Intraoral ex-
amination revealed late mixed dentition with eruption
of all permanent incisors and the mandibular right first
premolar and canine. Angle Class I occlusion with ex-
treme crowding of anterior teeth and fissure dental
caries in the first permanent molars were noted. Good
oral hygiene and healthy soft tissues were observed.
The initial radiographic examination revealed a root-
less second left premolar in the mandibular arch under
a sound primary molar, with no signs of either infec-
tion or decay (Fig 1). The homologous premolar showed
more than two-thirds of root developed. Normal root
ooth eruption with little or no root development
is rare and is usually associated with neonatal
teeth or defects in root formation due to irradia-
resorption was evident in all of the remaining primary
teeth. The second mandibular left primary molar was
also in a stage of advanced root resorption, with no
signs of pathology to explain the abnormal condition
of the unerupted second left mandibular premolar. No
family history of dental anomalies was reported. The
second mandibular left primary molar was maintained
for as long as possible, and orthodontic treatment was
postponed to see if further changes or even improve-
ments might occur at the root of the premolar. When
the girl was 11 years old, the primary molar exfoliated
and the premolar erupted at a normal rate, exhibiting
normal crown morphology (Fig 2). In a few months the
tooth reached the occlusal plane, with mobility no
greater than normal. Intraoral radiographs showed no
evidence of further root development. Occlusal films
dismissed root dilaceration. A decision was made to
extract the maxillary first premolars and the mandibu-
lar second premolars.
The premolar (tooth #20) was examined macroscopi-
cally and crown enamel was normal with no alterations.
The root region was cylindrical and 2 mm long with a
moderate presence of adhered soft tissues (Fig 3).
Through a decalcification process, the enamel was
eliminated, and the crown was left with dentin and
Fig 1. Periapical radiograph demonstrating no evidence of
decay in the crown of second primary molar and the
extremely short root of the unerupted premolar.
Fig 2. Quadrant view; note normal morphology of the
Pediatric Dentistry - 17:2, 3995
American Academy of Pediatric Dentistry 127
Fig 3. Macroscopic view of extracted tooth.
perfect preservation of the mantle and circumpulpal
levels. No reactive dentin was noted. The pulp, within
a large chamber, was perfectly organized both at cen-
tral and marginal levels, where odontoblasts were ar-
ranged in a stratified epithelioid cylindrical form asso-
ciated with a thick predentin layer.
The short root section had a narrowing of the pulp
chamber, with a superficial cementum layer associated
with remnants of the periodontal ligament. The struc-
ture was, in general, similar to that of the crown, the
perpendicular longitudinal arrangement of the dentin
tubules at the dentino-pulpal limit being particularly
evident in the histological sections. The superficial
cementum formed a fine acellular layer with continu-
ity between the cementum and the collagen bundles
that extended to the limits of the piece. This surface
cementum appeared normal and corresponded to the
lateral surface; the apical margin consisted of a thick
cellular cementum layer with wavy, festooned limits
(Fig 4). A number of sections revealed complex combi-
nations of both structures at the cementum-dentin in-
terphase. No signs of resorption or dysplasia of the
cementum or dentin were observed.
The lesion may be considered a case of malforma-
tion, resulting from root development arrested shortly
after its initiation.
An initial diagnosis of odontodysplasia and shell
teeth was discarded due to normal deposition of enamel
and dentin surrounding a normal pulp chamber. Addi-
tional considerations in establishing the diagnosis were
arrested tooth development or delayed root formation.
Arrested permanent tooth development has been re-
ported5 as a consequence of pulpal infection of carious
primary teeth. Present or past clinical features relating
to the infection of the overlying primary molar could
not be established in our case, however. Delayed root
Fig 4. Histological section corresponding to the lateral
surface of the root, close to the apical margin; normal
appearance is observed with no signs of resorption or
dysplasia. PDL: Periodontal Ligament, D: Dentin, T:
Transition, C: Cementum.
formation and abnormal tooth eruption also have been
reported6 in a girl suffering from congenital kidney
disease. Her general radiographic signs of radiolucent
areas in the sockets of permanent teeth, other oral mani-
festations, and the documented kidney pathology sug-
gested the diagnosis, and the teeth developed roots
after eruption. None of these features corresponded to
our observations in this case. Careful examination of
tooth periapical morphology contributed to the possi-
bility of external root resorption of unknown etiology.
This may have been the final diagnosis, if extraction
and subsequent histopathological examination had not
been performed. Atrophied premolar roots are rare,
with no previous cases reported in the literature. In the
case presented, the condition did not prevent tooth
eruption, though its etiology remains uncertain.
Dr. Catala is professor and chairman, pediatric dentistry; Dr.
Zaragoza is assistant professor, pediatric dentistry; Dr. Estrela is
assistant professor, pediatric dentistry; and Dr. Valdemoro is
assistant professor, operative dentistry, all at the University of
The authors thank Dr. A. Peydro, professor and chairman of
histology at the University of Valencia for his assistance.
1. Gowgiel JM: Eruption of irradiation-produced rootless teeth
in monkeys. J Dent Res 40:538-47,1961.
monozygotic twins: case report. Pediatr Dent 11:76—78,1989.
3. Camm JH, Schuler JL: Premature eruption of the premolars.
ASDC J Dent Child 57:128-33, 1990.
4. Nik-Hussein NN, Majid ZA: Arrested development of a
permanent tooth. J Clin Pediatr Dent 17:167-69, 1993.
5. Brook AH, Winter GB: Developmental arrest of permanent
tooth germs following pulpal infection of deciduous teeth.
Br Dent J 139:9-11,1975.
6. Brin 1, Zilberman Y, Galili D, Fuks A: Eruption of rootless
teeth in congenital renal disease. Oral Surg Oral Med Oral
Pathol 60:61-64, 1985.
128 American Academy of Pediatric DentistryPediatric Dentistry -17:2,1995