Treatment of class 2 division 1 malocclusion with severe short roots of upper central incisors.

The average amount of resorption per root of examined maxillary incisors or anterior teeth is < 1.5 mm during comprehensive orthodontic treatment. About 5% of adults and 2% of adolescents are likely to have at least one tooth with resorption of more than 5 mm during active treatment. Although resorption stops once the active appliances are removed, fortunately, truly severe resorption that threatens the longevity of the tooth or forces a halt to treatment is rare. The fact is, however that orthodontic tooth movement does directly cause irreversible resorption of the root. As the movers of the teeth, it is incumbent for us to know as much as possible about the causes, effects and prevention of this phenomenon.

This case report describes the importance of maintaining the existing root length during orthodontic treatment for a patient with severe short roots. Patient, a 14-year-old boy, had severe short roots in the upper centrals before treatment. Therefore, the main treatment objectives were to maintain the vitality of the both teeth intact during and after orthodontic treatment. The treatment involved in two phases. The first one was functional jaw orthopedics and the next one was fixed appliance. Facial profile was dramatically improved and a favorable occlusion was obtained. At 1 year 4 months after the Frankel treatment, the facial appearance and occlusion remained favorable. The results suggest that functional appliance was useful in preserving the root length.

Case Report

This male patient, age 14 years and 4 months was brought and referred by his mother because of proclination of upper incisors. His mother gave a history of short roots of the central incisors. The boy had experienced a severe trauma at the age of 4 1/2 and the dental trauma may not be had been noticed.

Diagnosis and Treatment Plan

Clinical and radiographic examination revealed a convex profile with a retrognathic chin, obtuse naso-labial angle, short upper lip relation, horizontal growth pattern and posterior divergent face [Figure 1]. He had bilateral class 2 canine and molar relationship [Figure 1]. His overjet is 12 mm and overbite 50%. Poor oral hygiene visible seen in the mouth [Figure 1]. Lower lip is cushioning the upper anterior teeth palatally. Intraoral periapical shows under developed roots of the centrals [Figure 1]. Orthopantomogram [Figures 1 and 2] shows full complement of teeth. Cepholometric [Figures 1 and 2] analysis showed a class II (ANB angle 6) with a good horizontal growth pattern (SN-GoGn 27) and well-proclined incisors (1-NA = 12 mm, 1-NB = 10 mm, IMPA =109, U1-SN = 122) [Table 1]. The following treatment plan was devised:

Figure 1

Pre-treatment photos

Figure 2

Post-treatment photos

Table 1

Cephalometric analysis

Try a Functional Regulator appliance

Followed by a fixed appliance with class 2 elastics (no bracket fixing on upper centrals)

Bionator retainers

Treatment objectives

The objective was to correct class 2 skeletal jaw relation. And achieve a class 1 molar by a Frankel appliance [Figure 3]. By using a fixed appliance after the functional appliance, coordinate the skeletal and dental midlines; achieve ideal overjet, overbite, an esthetic smile and good change in the profile were desired with mutually protected canine relation.

Figure 3

Mid-treatment photos

Treatment progress

The boy did excellently by wearing it 24 h for 16 months of the functional regulator [Figure 3] (FR 1B). The molar relation was changed into class 1 with an appreciable jaw relation. Now, 022 Roth pre-adjusted edgewise appliance was fixed on both arches. Initially, we did not fix the brackets for upper centrals [Figure 3] until the heavy wires i.e., 19 × 25 SS wires are removed. The alignment was carried out by 014 niti wire placed. Later, we switched to stiffer wires. Once we reached 016 SS wire, we started using class 2 pink elastics (5/16”). It was carried till 19 × 25 SS wire. In the last phase of treatment, both upper centrals were fixed with the brackets [Figure 3]. Then, we used to 017 × 22 multi-strand SS as a finishing wire. The boy did very tremendous job by a good cooperation as well as maintaining good oral hygiene [Figure 2]. The results are very much encouraging as the confidence smile proves it [Figure 2].

We decided not to place a mandibular retainer, to achieve better anterior contact and a proper sagittal molar relationship, instead, a bionator was prescribed to be worn every night for 5 months and then every other night for 3 months. Six months after bracket removal, the bionator was still present. Patient showed good anterior contact, a good sagittal relationship an overjet of 3.5 mm and overbite of 50%.

Discussion

We presumed that the abnormal shape of the maxillary left central incisor root had resulted from patient's severe trauma at age 4 1/2. We believed that the shock had been partially absorbed by the primary incisors, without visible damage. We are sure the under development of the roots of permanent one are due to trauma.[12] Of course, we could not prove a causal relationship of deciduous trauma to permanent root shortening.

About 5% of adults and 2% of adolescents are likely to have at least one tooth with resorption of more than 5 mm during active treatment. The resorption stops once appliance therapy is completed.[3]

Morphological alteration of the incisor can be distinguished from a dilaceration, which is a marked deviation of the long axis of the root produced by atraumatic non-axial displacement of the tooth.[45] Our patient's root not at all developed more than 1/3 cervically. Similar cases have been reported with no history of trauma.[6]

The abnormality may be gender-specific since it is seen six times more often in girls than in boys.[7]

Conclusions

The continuous wearing of the Frankel helped us to correct the jaw relation even at this age.

Bye passing the upper centrals until the final wire in the fixed appliance therapy did not disturb them, though the roots were very short.

It was a satisfactory treatment for the patient (3) as well as for us also.

Vitality [Figure 3] of the teeth being maintained until today.