A 14-year-old female presented with the extraoral inverted eruption of her left mandibular permanent molars 18 and 19 through the inferior border of her mandible. The teeth started erupting 1 year after an extraoral surgical intervention for a discharging sinus 6 years prior. The subsequent extraoral eruption of the permanent molars may have resulted from the previous surgical procedure or abnormal positioning of the teeth. Extraction of the extraorally erupted teeth was performed, leaving clean sockets. Histopathological examination of the surrounding soft tissue found hyperkeratosis and fibrosis.

1. Extraoral inverted teeth eruption: A case report
Jayanta Kumar Dash, MDS,a
Mounabati Mohapatra, MDS,b
and Lily Mishra, MDS,c
Bhubaneswar, India
MKCG MEDICAL COLLEGE
A 14-year-old female presented with extraoral inverted eruption of left mandibular permanent molars 18 and 19
at the lower left inferior border of the mandible. Both the teeth started erupting 1 year after an extraoral surgical
intervention for a discharging sinus 6 years ago. The subsequent eruption to the extraoral position of the permanent
molars at the inferior border of mandible may be the result of the previous surgical procedure or pathology related to the
abnormally positioned teeth. This case presents an infrequent complication affecting the adjacent permanent teeth.
(Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2004;98:37-9)
Tooth development results from a complicated process
of interaction between the oral epithelium and the
underlying mesenchymal tissue. This process starts with
the formation of the maxillary and mandibular dental
laminae in the region of the future alveolar process at the
sixth week in utero. The ectodermal derivative un-
dergoes further proliferation to form 20 tooth germs for
the primary teeth (sixth to eighth week prenatal life) and
32 additional tooth germs, which differentiate to form the
permanent dentition between fifth (incisors) and tenth
months (premolars) of the extrauterine life. The series of
complex tissue interaction results in the formation of
mature teeth, each with a crown and root.1
Any abnormal
tissue interaction during development may result in
ectopic tooth development and eruption.
Ectopic eruption is a broadly applied term that may
indicate an abnormality of direction during tooth
eruption and/or final tooth position. The exact nature
and mechanism of ectopic eruption of teeth varies from
case to case. Those cases involving ectopic eruption of
the maxillary and mandibular canines are attributed to
the long eruption path of these teeth; and the particular
anatomical form of conical crown and root structure
increases its susceptibility to anomalies during eruption.
Other factors responsible for ectopic eruption may
include abnormal displacement of the tooth bud in
embryonic life, crowding, supernumerary teeth, endo-
crine disorders, hereditary factors, and trauma.2-5
Ectopic development and eruption of teeth into regions
other than the oral cavity is rare, although there have been
reports of teeth in the maxillary sinus,6,7
mandibular
condyle,8
coronoid process,9
palate,10
chin,4,11
skin,12
and the nasal cavity.13,14
Teeth have also been found in
various unusual locations including the ovaries, testes,
anterior mediastinum, retroperitoneal area, and the
presacral and coccygeal regions.15
Inverted teeth have been reported in both maxilla and
mandible, and most of them are invertedly impacted
third molars and premolars.16
However very few cases of
extraoral ectopic inverted tooth eruption have been
reported. Shah5
reported a case in which extraoral
eruption of a lower mandibular canine at the inferior
anterior border of mandible was presented after 3 months
following trauma to the chin. Dhooria et al17
reported
a case of extraoral eruption of an upper primary canine
from the lip 6 weeks following trauma.
This report presents an interesting case of extraoral
ectopic inverted eruption of the mandibular left perma-
nent molars 18 and 19 following surgical trauma.
CASE REPORT
A 14-year-old girl was admitted for extraction of teeth at the
Department of Dental Surgery MKCG Medical College,
Fig 1. Close-up extraoral view showing the extraoral inverted
eruption of 18, 19, and scar on the skin of previous surgery.
a
Associate Professor, Department of Dental Surgery, MKCG Medical
College, Brahamapur, Orissa, India.
b
Assistant Professor, Department of Dental Surgery, MKCG Medical
College, Brahamapur, Orissa, India.
c
Lecturer, Department of Dental Surgery, MKCG Medical College,
Brahamapur, Orissa, India.
Received for publication Aug 25, 2003; returned for revision Nov 7,
2003; accepted for publication Feb 10, 2004.
1079-2104/$ - see front matter
Ó 2004 Elsevier Inc. All rights reserved.
doi:10.1016/j.tripleo.2004.02.060
37

2. Berhampur, India. Her presenting complaint was extraoral
eruption of teeth at the inferior border of the left side of the
lower jaw. Her general medical history was not contributory.
Dental history revealed that she had severely carious primary
teeth with a history of external dry heat application leading
to cellulites and formation of an extraoral discharging sinus.
She had undergone surgery in a remote general hospital 6 years
earlier without any dental assistance. After the surgery the pa-
tient was noncomplainant for a period of 1 year; then eruption
of the teeth 18 and 19 started extraorally in an inverted position
at the lower border of the left side of the mandible and continued
for 5 years. On extraoral examination, the crowns of both 18
and 19 projected out at the inferior border of the left side of the
body of the mandible mesially and were firmly attached to the
bone. The skin around the erupted teeth was filled with scar
tissue from the previous surgery and hyperpigmented (Fig 1).
There were no other signs of acute inflammation. On intraoral
examination, teeth 20, 21, and 22 were found missing. The
mandibular midline was shifted to the left while there was
a class 1 molar relationship on the right side. There were no
carious lesions associated with either extraorally erupted tooth
and both responded positively to electric pulp test.
A panoramic radiograph was taken showing a hypoplastic
underdeveloped mandible on the left side with 18 and 19
positioned at the inferior border of the mandible with slight
radiopacities at the apical region. All the permanent third
molars were developing and teeth 20, 21, and 22 were absent. A
higher radiodensity of the bone in relation to body of the
mandible in the same side was also visible (Fig 2).
The patient was presented with the treatment plan, which
included extraction of the extraorally erupted teeth under
general anesthesia. Both the teeth were extracted leaving clean
alveolar sockets at the lower border of the mandible. The
surrounding soft tissue was retracted, curreted, and sutured
closed.
The coronal morphology of both the teeth was normal with
fully formed roots; the mesial root of 19 was narrow and
Fig 2. Panoramic radiograph showing the presence of 18 and 19 at the lower border of mandible and hypoplastic mandible on the
same side.
Fig 3. Extracted teeth no. 18 and 19 with fully formed crown
and roots.
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38 Dash, Mohapatra, and Mishra July 2004
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38 Dash, Mohapatra, and Mishra July 2004

3. dilacerated. In case of 18, the roots were fused in the apical
region (Fig 3). The excised soft tissue around the radicular
portion of the teeth was sent for histopathological examination.
Microscopic examination revealed hyperkeratosis and pseudo-
epitheliomatous hyperplasia. The subepithelium showed marked
fibrosis with chronic inflammatory cell infiltration and vas-
cular congestion. No abnormal pathological condition was ob-
served. Six months after surgery normal healing was seen.
DISCUSSION
The eruption of an inverted tooth extraorally is rare.
Trauma is the most common factor attributed to such
a condition.4,5
Displacement of immature developing
teeth and subsequent eruption extraorally following
trauma and fracture of the jaw is known.5,17
Many cases
with intraoral or extraoral ectopic tooth position, earlier
assessed as developmental anomalies, are frequently
found to have history of trauma.18
The effect of trauma
and jaw fracture on development and eruption of teeth
has been found to be that in teeth in which root formation
has started, erupt normally but their roots remain shorter
compared to the contralateral teeth.16
In the present case
the mesial root of 19 was short and dilacerated.
In this case, there was history of an extraoral
discharging sinus, which was excised 6 years previously.
The cause of the sinus was due to either infected teeth or
osteomylitis. The premature loss of 20, 21, and 22 at the
time of previous surgery led to hypoplasia of the man-
dible in comparison to contralateral side, with shifting
of the midline. There is the evidence that either trauma
or the surgery caused a green stick fracture of the man-
dible, which caused displacement of permanent teeth
at the time of injury but healed quickly without any
fixation in this young patient.
The cause of the present condition may have been due
to the following:
Early loss of 20, 21, and 22 and bone loss in the body
of the mandible, which allowed the erupting 18 and
19 to drift mesially and reach a transverse position in
the bone. Subsequent eruption occurred along the
path of least resistance.
Both the teeth had developed in an abnormal position
since the beginning of the developmental stage and
subsequently erupted in an inverted position as the
path of the eruption was altered by a surgical sinus
excision procedure.
During the surgery there was partial fracture of
alveolar bone along with developing 18, 19, and the
segment was replaced in an inverted position at the
lower border of the mandible. It maintained its
vascularity from the basal bone leading to complete
development of the teeth and eruption in the present
position.
When a tooth erupts, the bone through which it passes
shows normal radiographic appearance. In this case, the
appearance of radiopacity in the body of the mandible
may be seen as a healing phenomena or remodeling
of bone after the passage of the migrating tooth
from normal to inverted positions and its subsequent
eruption.
Whatever the cause may be, this type of extraoral
inverted eruption is rare. Six-month follow-up shows
normal healing with significant psychological improve-
ment of the poor tribal girl. Years of suffering from an
inferiority complex in a superstitious environment and
being taunted as a witch and hiding her face are now
behind her.
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Reprint requests:
Jayanta Kumar Dash, MDS
Associate Professor
Dental Surgery
MKCG Medical College
Brahamapur, Orissa
India 760004
dashjayant@rediffmail.com
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