Dens invaginatus is an anomaly of dental development in which calcified tissues, such as enamel and dentin, are invaginated into the pulp cavity. This morphologic alteration is more frequent in maxillary permanent lateral incisors and makes them more susceptible to carious lesions and pulp alterations.
This case report describes a patient with maxillary lateral incisors affected by dens invaginatus . The maxillary right lateral incisor had already undergone endodontic treatment, and the maxillary left one had a periapical lesion. Additionally, the patient had a Class II Division 1 malocclusion, with anterior open bite, posterior crossbite, and an impacted mandibular left second molar.
The orthodontic treatment involved extraction of the maxillary lateral incisors and 2 mandibular premolars, resulting in proper overjet and overbite with good arch coordination and occlusal stability.
Treatment results were stable, as evaluated in a 6-year posttreatment follow-up.
Dens invaginatus can lead to premature caries and pulp infections.
Orthodontic treatment can include extraction of an affected lateral incisor.
Long-term follow-up confirmed the stability of this treatment alternative.
Dens invaginatus , also known as dens in dente , is an odontogenesis alteration in which the development of the enamel is affected. It occurs due to the deepening of the enamel epithelium into the dental papilla, causing a defect on the dental crown.
It is considered an imperfection in dental development, caused by the invagination of coronal tissues before tissue calcification, with prevalence reportedly varying from 0.17% to 12%. Clinically, the depth of the invagination may go from a slightly exaggerated pit of the cingulum to a deep infolding that extends in the direction of the dental apex. Diagnostic radiographic imaging shows the abnormal enamel with a well-defined appearance, giving the impression of a small tooth inside another one. It may affect both the deciduous and permanent dentitions; the most commonly affected teeth are the central and lateral incisors, predominantly in the maxillary arch.
Because dens invaginatus is an anatomic alteration, it causes the affected tooth to be highly susceptible to carious lesions and pulpal alterations soon after eruption. The treatment for dens invaginatus may include various clinical procedures. If the teeth are sound, the application of pit and fissure sealant is recommended for physical protection of the invagination. In case of carious tissue without pulp exposure, restorative treatment can be done. If there is pulpal involvement, a conservative approach using direct pulp capping or pulpotomy may be feasible. Endodontic treatment or dental extraction (with or without autotransplantation) may be another alternative.
This case report describes an orthodontic treatment with extraction of the 2 maxillary lateral incisors with dens invaginatus and 2 mandibular premolars, and the 6-year follow-up.
Diagnosis and etiology
A girl, age 12 years 5 months, had a chief concern of maxillary dental crowding and anterior open bite ( Fig 1 ). Upon examination, it was noted that her speech had also been affected. She had no temporomandibular joint symptoms. She had a history of previous orthodontic care with maxillary expansion and incisor alignment.
The extraoral photographs showed a convex profile, with an obtuse nasolabial angle, an acute mentolabial fold, and passive lip closure. Her facial thirds were well balanced.
The intraoral analysis showed an Angle Class II Division 1 malocclusion, with 2 mm of anterior open bite and 3 mm of overjet ( Fig 2 ). A posterior crossbite on the left side was also present. Crowding was 2.5 mm in the maxillary arch and 1 mm in the mandibular arch. The midlines were coincident. Some gingival recession was noticed in the mandibular anterior segment.
The panoramic x-ray ( Fig 3 ) indicated the presence of all teeth, including the tooth germs of the third molars. The mandibular left second molar was mesio-angulated and impacted. Radiographs showed previous endodontic treatment of the maxillary right lateral incisor (reported to have dens invaginatus ), and the contralateral incisor had a periapical lesion as well as the typical radiographic appearance of dens invaginatus . The roots of the maxillary central incisors showed preexisting external resorption. The cephalometric analysis demonstrated a normal maxillary and mandibular sagittal and vertical relationship. The maxillary and mandibular incisors had excessive labial inclinations.
The following treatment options were considered.
Extraction of the maxillary lateral incisors with dens invaginatus and extraction of the mandibular second premolars.
Extraction of the 4 first premolars and anterior retraction, along with endodontic treatment of the maxillary left lateral incisor.
Use of skeletal anchorage to correct the Class II anterior open bite and impaction of the mandibular second molar.
After consideration, option 1 was chosen with extraction of the maxillary lateral incisors and mandibular second premolars. Contributing to this decision was the high risk of extreme external root resorption of the maxillary lateral incisors during orthodontic movement, since the dentin in these roots was thin due to early pulpal necrosis. Lateralization of the maxillary canines was also planned. To improve the diagnosis protocol and treatment outcome, considering the uniqueness of the extraction pattern, a digital setup was made ( Fig 4 ).
Bands were placed on the first molars with bonding of the remaining teeth. Preangulated Roth prescription brackets were inverted on the maxillary permanent canines to enable proper root positioning of these teeth.
A stainless steel removable transpalatal bar was placed and activated to aid in the correction of the posterior crossbite.
A mandibular lingual holding arch was placed as anchorage for uprighting the left second molar. A tube was bonded on the exposed coronal portion of the impacted molar followed by a segmental passive 0.020-in stainless steel wire connecting the first and second molars, where a nickel-titanium open-coil spring was placed to distalize the impacted molar. In addition, spurs were bonded on the lingual surfaces of the mandibular incisors to control tongue thrusting.
Alignment and leveling were performed using 0.014-in and 0.016-in nickel-titanium archwires followed by 0.016-, 0.018-, and 0.020-in stainless steel archwires. The patient was then referred for extractions, and the maxillary space closure began ( Fig 5 ).
Next, the 4 maxillary anterior teeth were moved together, and the mandibular alignment was completed; 0.019 × 0.025-in archwires were placed in both arches to promote space closure using sliding mechanics with superelastic nickel-titanium springs with 250 to 300 g force magnitude. Then, enameloplasty was done to improve the shape and size of the maxillary canines.
At this point, follow-up periapical radiographs were requested ( Fig 6 ). These showed evidence of increased root resorption, particularly in the maxillary central incisors that had been diagnosed previously with some root shortening. As a result, active tooth movement was suspended for 90 days and later resumed gradually, with orthodontic activation at 2-month intervals.