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.