Case report:
A 10 years-old-girl was referred to the department of Pediatric and
Preventive Dentistry, Monastir Dental Faculty, Tunisia, regarding the
enhancing appearance of her teeth.
The young child chief complaint was the unaesthetic appearance due to
the presence of a single large upper front tooth.
The patient general condition was good but she showed a very low
self-esteem because of her poor teeth appearance.
The interrogatory of her parent revealed that they had noted the
condition around 3 years of age when a solitary median deciduous
maxillary incisor had erupted but they did not give focus on that. The
physical examination showed a normal stature.
The extra-oral examination showedspecific facial features such as a long
and narrow face, pinched nostrils and a slight facial asymmetry to her
right side. An indistinct philtrum with an atypical arch-shaped outline
of the upper cupid’s bow associated with labial open bite were evident
(Figure 1a).
The lateral view exhibited a convex profile (Figure 1b).
The intraoral inspection revealed that the patient was in mixed
dentition, with a totally symmetrical, large central incisor positioned
precisely in the maxillary midline with the absence of the upper labial
frenum (Figure 2 a,b, and c).
Bilaterally, the first molars were in full Class II occlusion with a
bilateral crossbite, and a 4 mm overjet which was assessed between the
large unique maxillary incisor and the mandibular incisors associated to
a large open bite(Figure 2d and e).
The patient presented also a swallowing disorder.
The lower midline was mildly deviated to the left side by 1.5 mm.
The panoramic radiograph evidenced a solitary median maxillary central
incisor exactly in the maxillary midline, with deviation of the nasal
septum to the left side and an age-typical development of all other
permanent teeth (Figure 3 a).
The cephalometric analysis revealed a Class II skeletal pattern (SNA :
87°, SNB : 78°, ANB : 9°, AoBo : 5 mm), an increased vestibular
inclination of the maxillary and mandibular incisors (I /F : 125°,
IMPA : 102°, I/i : 106°) and a normal skeletal divergence (FMA : 27°)
(Figure 2 b).
For more investigation, the patient was referred to the pediatric and
neurologic consultations.
The cone-beam computed tomography of the facial bone was indicated.
The examination was performed on a Toshiba-type 128-slice scanner using
volume acquisition without IV injection of PDC with multiplanar
reconstruction.
The CBCT revealed an appearance in favor of a single midline incisor
syndrome and there were not any other health issues (Figure 4).
On overall assessment and as no history of dental trauma with avulsion
of a central incisor was reported, and all typical extraoral and
intraoral traits of the Solitary Median Maxillary Central Incisor
(SMMCI) syndrome phenotype were present, the patient was finally
diagnosed with SMMCI syndrome.
A treatment plan was developed which the main objective was to improve
esthetics and restore masticatory function of the young patient.
First, the patient was advised to brush her teeth with normal fluoride
toothpaste.
Second, a swallowing rehabilitation combined with a palatal expansion to
correct the posterior crossbite was performed
Finally, the young patient was referred to the Orthodontic Department to
correct the skeletal Class IIand to create a pleasing symmetrical smile
either by extraction of the SMMCI with space closure or by space opening
associated to a prosthodontic replacement for the a maxillary central
incisor with either an implant borne crown or a resin bonded bridge.