Discussion
Implant treatment can have several complications such as
osseointegration failure (loosening), implant fracture,
peri-implantitis, injury to surrounding structures such as nerves and
vessels, and aspiration.1 One of the less common
complications is migration into adjacent structures, most commonly into
the maxillary sinus.1,2 Direct displacement of implant
may occur for various reasons during implant insertion. This might be
due to the dentist’s lack of skill and experience, inappropriate bone
quality, excessive implant tapping, untreated perforation of the sinus
lining (Schneiderian membrane), or application of too much
force.4,6–9 Cases of implant migration into maxillary
sinus are repeatedly reported, but implant displacement into other
anatomical spaces like nasal cavity is scarce.2
We reported a case in which the implant was migrated into the maxillary
sinus due to inappropriate insertion and blunder of the dentist. Then it
accidentally moved into the nasal cavity because of the patient’s
procrastination and attending to the specialist three months after his
dentist’s order.
Up to the present, there are only four reports of implant migration into
the nasal cavity in the literature which indicates how infrequent this
complication is, considering the large number of implant treatments done
in clinical practice (Table 1). Two of these studies have reported that
the implant had migrated into the nasal cavity indirectly from the
maxillary sinus through the ostium, as in our case.3,6While in the other two reports, implants had moved directly from the
oral cavity to the nasal cavity by perforating the nasal
floor.4,5
Although implant treatment itself is more prevalent in females, the
current literature suggests that the prevalence of this complication is
higher in males compared to females. However, this conclusion cannot be
considered robust due to the low number of reported cases. It should be
noted that the mean age of reported patients of implant migration is
approximately one decade lower than the mean age of patients receiving
implant treatment.10 Among the reported patients who
have experienced migration of a dental implant to the nasal cavity, the
youngest and oldest are respectively aged 23 and 65.
Extraction of the migrated implant by surgical operation was the
treatment of choice in all studies, which had good prognosis in every
one of these reports.5,6 However, in two studies it
has been mentioned that the migrated implant is expelled
spontaneously.3,4 In the study of Sanchis & Díaze,
the implant accidentally was thrown off through the
nose.4 But, in van de Loo et al.’s study, the implant
disappeared after being detected in the CBCT.3 Most
probably, the implant entered the gastrointestinal tract subconsciously
and was thus excreted.
Implant migration into paranasal sinuses can cause pain, fungus-related
infections, and sinusitis.6 In all reported cases of
implant migration into the nasal cavity, patients have symptoms like
nasal discomfort, nasal pain, and purulent
discharge;3–6 on the contrary, the patient presented
in this study did not experience any discomfort. The reason for being
asymptomatic is uncertain. However, this could be explained by the short
duration of the presence of the implant in the nasal cavity, the absence
of sinusitis, and the aseptic surgical placement of the implant.
In this case, a possible reason for implant migration from the maxillary
sinus into the nasal cavity can be the ciliary motion of the columnar
epithelium of maxillary sinus membrane, which is toward the primary
ostium, in combination with the patient’s head movements over time that
made the implant move through ostium into the nasal cavity.
Since implant displacement after implant surgery is not
uncommon,4 it is essential to use appropriate
techniques, properly place the implants in a stable and assured
situation, and schedule regular follow sessions. In case of implant
migration, 3D imaging modalities such as CBCT are necessary to determine
the exact place of implant insertion.5 Preoperative 3D
imaging should be conducted prior to removing the migrated implant to
precisely locate the implant. Due to the possibility of additional
migration, the period between imaging and surgery should be kept
minimum.
It is also vital to extract the migrated implant as soon as possible
since it can move into other structures and cause further complications
or cause acute and chronic sinusitis.11,12 Intraoral
surgical and trans-nasal endoscopic procedures have both been documented
for removing implants migrated to nasal and paranasal
cavieties.13–15
Findings of this report could help dentists and surgeons prevent,
diagnose, and manage accidental migration of dental implants into the
nasal cavity.