I. of swelling on the lower left back


of teeth is a diagnosis made when the tooth has failed to fully erupt into oral
cavity within its expected development time period and can no longer reasonably
be expected to do so. Impaction can lead to various clinical complications like
malocclusion, loss of arch length, migration or loss of neighboring teeth,
periodontal disease, resorption (internal or external) of the teeth, cystic
changes around the impacted teeth like dentigerous cyst and tumors.1
Permanent teeth are more commonly impacted compared to deciduous teeth. The
incidence of impacted permanent teeth has been said to have increasing
frequency in reverse of eruption order. Most commonly impacted teeth are
maxillary and mandibular third molars, followed by maxillary canines,
mandibular premolars, maxillary premolars, and second molars.2
Impaction of first and second molars is reported as very uncommon, with
reported prevalence of less than 0.01% and 0.06 to 0.3% respectively.3
Here we report a case of impacted permanent first molar, which is an extremely
rare and sparingly reported in the literature.



      A 36-year-old otherwise healthy male
patient reported to us with the complaint of swelling on the lower left back
region of the jaw, which started 3 months ago. Swelling was associated with
intermittent dull aching pain radiating to his left TMJ region and was
associated with recurrent pus discharge. His medical, family and habit history was
unremarkable. A thorough intraoral examination revealed, buccal cortical expansion
with respect to 35 to 37 region, which was non tender, hard in consistency with
no evidence of any decayed tooth in that region. Permanent left mandibular
first molar was clinically missing with no space existing between second
premolar and second molar. Patient reported no history of extraction in that
region. Hence a provisional diagnosis of dentigerous cyst associated with
impacted 36 was considered and patient was subjected to radiographic
investigation. Panoramic radiograph showed that 36 was horizontally impacted,
in the body of the mandible apical to the mesial root of 37, the inferior
alveolar nerve canal is pushed inferiorly from its original course, very close
to inferior border of mandible. The crown of impacted tooth appeared to have
carious demineralization involving the enamel and dentin and was associated
with a flame shaped pericoronal radiolucency approximately measuring 5mm x 5mm,
indicating the probability of cystic changes.  Hence correlating the clinical and
radiological 3D imaging – CBCT was advised for the patient followed by surgical
intervention. However, patient denied for both due to financial constraints and
was lost to follow up.



Impaction of teeth can be
caused by systemic or local factors. Systemic factors such as heredity,
post-natal causes such as rickets, anemia, malnutrition, tuberculosis and
congenital syphilis, endocrinal disorders such as hypothyroidism and
hypoparathyroidism and other conditions such as cleidocranial dysostosis have
been implicated in causing teeth impaction. Various local factors such as
obstruction of eruption path by cyst, tumors, or supernumerary teeth,
infection, lack of space, over retained/ankylosis/premature loss/lack of
resorption of or injuries to deciduous teeth, or mucosal barriers like scar
tissue left behind by trauma/surgery have also been associated with the
impaction of teeth.4 It is said that first molar impaction is often due to ectopic
eruption, which is very likely in this case; whereas impaction of second molars
is usually associated with arch-length deficiency.5

An impacted tooth, when
left untreated, may lead to pain due to infection in the affected area. P.
Mercier and D. Precious stated that deliberately retaining an impacted third
molar poses a threat of developing crowding of dentition, resorption of
adjacent tooth, periodontal problem of the teeth, or development of
pathological condition such as infection, cyst or tumor.6 In our
case, the follicular space around the impacted first molar was seen to be
enlarged, which very likely cystic change taking place.

Treatment options
suggested for an impacted molar include observation, extraction of the
obstacle, surgical exposure, luxation and extraction of the tooth.7
Appropriate treatment plan is proposed depending on the cause of impaction.
When an obstacle blocking the path of eruption of the tooth is the cause for
impaction, the barrier can simply be removed to allow spontaneous eruption of
the tooth. Surgical exposure and luxation of the tooth is favorable when enough
space is available for the impacted tooth in the oral cavity, which sometimes
can be achieved with the help of orthodontics.

Important factors which
affect the prognosis and outcome of the treatment include position and
angulation of the impacted tooth, length of treatment time, space availability
and the presence of keratinized gingiva. Other than that, patient’s medical
history, dental status, oral hygiene, functional and occlusal relationship,
attitude towards orthodontic treatment, compliance with treatment and cost of
treatment also affect treatment options.8 In this case, the
patient was advised for surgical removal of the impacted first permanent molar
due to its unfavorable position and angulation of impaction, which is
horizontally impacted apical to the adjacent second molar. It was apparent that
infection had taken place in and around the tooth judging by the radiographic
appearance and the history given by patient. There was no space for the tooth
in the oral cavity, and patient did not have problem in his current

intervention of the impacted tooth is not without any risk. The complication
that patient may undergo may be minor and transient, such as sensory nerve
alteration, alveolitis, trismus and infection, hemorrhage, dentoalveolar
fracture and displacement of tooth. There could also be some permanent changes
such as periodontal injury, injury to adjacent tooth or the temporomandibular
joint. More severe complication may include altered sensation, vital organ
infection, fracture of the mandible and maxillary tuberosity, injury and
litigation.6 Due to the close proximity of the impacted tooth to
inferior alveolar nerve in this case, the patient might suffer injury to the
nerve and experience some neurosensory disturbances.