Orthodontic space closure: Midline diastema related to mesiodens

A comprehensive treatment approach to address severe midline diastema associated with mesiodens and malocclusion by Dr Emil Angelo Santos.

A 10-year-old male patient was referred to our private office (Figs. 1a-c). His chief complaint was the presence of a large midline gap accompanied by an unidentified structure in between the upper central incisors. His medical history was uneventful.

Previous dental history revealed that the patient has never visited a dentist before due to poor socio-economic status.

Intraoral examination, in the correlation of his panoramic radiograph, showed that the patient was in the mixed dentition stage with the permanent maxillary central incisors and first molars erupted (Fig. 2). A 6mm midline diastema due to an erupted mesiodens along with anterior crossbite associated with crowding was noted. The molars on the right side were in Class I relationship, whereas on the left side were in Class II (Figs. 3a-c).

The panoramic radiograph also revealed that there is an impacted mesiodens in addition to the one that is clinically visible.

The postero-anterior radiograph was unremarkable (Fig. 4), but the cephalometric radiograph indicated that the patient has an orthognathic maxilla and a retrognathic mandible, leading to a Class II malocclusion (Fig. 5).

Treatment options were outlined including removal of the infected primary teeth, surgery of the mesiodens, and finally the orthodontic treatment to address the spaces and locked lateral incisors. Aesthetic restorative composite treatment was also suggested to close the diastema, but further on decided that orthodontic treatment would be a better choice to address the patient’s malocclusion at the same time.


The first step in interceptive treatment was to inform the patient and his parents of the need for extraction of the infected primary tooth and the surgical removal of the erupted and impacted mesiodens in between the upper central incisors to reestablish the normal dental occlusion and tooth position.

Surgical removal of the mesiodens was then performed and co-managed with the oral surgeon, and after two weeks, orthodontic treatment was introduced to the patient through the use of standard edgewise brackets (Figs. 6a-b).

The first stage of orthodontic treatment was done through an initial 2×2 appliance bracket system in the upper arch and a 2×4 fixed appliance in the lower with both having 0.016 stainless steel wires as the initial wires.

A month after the orthodontic treatment was started, 1mm spontaneous closure on the diastema was noted. Central incisors observed a more levelled position than the initial position.

At this stage, space closure was initiated on the space left by the mesiodens, before starting to align the upper lateral incisors. A 0.016×0.016 square stainless-steel wires were placed on both upper and lower arches, followed by initial space closure of upper diastema (Figs. 7a-c).

Total space closure was almost 2mm during this stage. After three months of treatment, space closure was almost done, therefore allowing space to be regained in the area of the upper lateral incisors (Figs. 8a-c).

Four months of treatment led to complete space closure of the upper incisors, and brackets are now placed on teeth 12 and 22 to initiate their levelling and alignment. At this time, both the upper and lower arches were now in a 2×4 fixed appliance set-up as a part of the first phase of orthodontic treatment (Figs. 9a-d).

Overlay 0.014 nickel-titanium wires were used to align the lateral incisors. Replacement of the 0.014 thermal nickel-titanium wires for the piggyback technique was done after a month with an 0.016 thermal nickel-titanium wire.

An additional two months were spent bringing teeth 12 and 22 into the arch alignment. The final wire that was used was a 0.017×0.025 stainless steel wire where bends were incorporated for detailing the occlusion for the first phase of orthodontic treatment (Figs. 10a-c).

The analysis of the final photographs showed the reestablishment of normal dental development, highlighting the efficiency and effectiveness of the treatment (Figs. 11a-c). Furthermore, due to the aesthetic improvement of the smile, the patient reported a higher level of self-confidence and was generally happier than in the original situation.

A re-evaluation of the case will be done once all the permanent teeth have erupted to determine the need for a complete fixed appliance in the future.

Continue reading here. Published in Dental Asia July/August 2022 issue.

About the author

Dr Emil Angelo Santos graduated with a degree of Doctor of Dental Medicine in 2015 and Masters of Science in Clinical Dentistry major in Orthodontics in 2018 from the University of the East, College and Graduate School of Dentistry, respectively. He is a lecturer at De Ocampo Memorial College, a clinical consultant at the Graduate School of Orthodontics, Manila Central University, and a core trainer at UY Dental Clinic Group. Dr Santos is also the owner and head dentist of the Dayanghirang Dental Clinic Manila branch.