Changes in root length during orthodontic treatment: advantages for immature teeth

Abstract

The purpose of the study was to investigate root lengthening during orthodontic treatment in relation to the age of the patient, the developmental stage of the root, and the anticipated growth. Specifically, the potential benefit of treating young teeth was addressed. The sample consisted of 80 patients with Angle Class II division 1 malocclusions, treated with extraction of at least two maxillary first premolars, and edgewise technique with 0.018-inch slot brackets. Additionally, a cross-sectional control group of 66 untreated individuals matched to gender, and pre- and post-treatment age of the experimental group was included. Crown and root lengths of the maxillary incisors were measured on peri-apical radiographs before and after treatment, and corrected for image distortion. The stage of root development before treatment was recorded. Root elongation during treatment was found for 50 out of the 280 examined teeth. Age at treatment start was significantly higher among the patients showing root shortening of the lateral incisors during treatment than among those showing root elongation (P < 0.05). The stage of root development was significantly related to the direction of root length change, i.e. shortening or elongation. Roots elongated during treatment did not differ in length from untreated teeth of similarly aged individuals. There was no significant difference in the extent of root lengthening between the roots elongated during treatment and the normal root lengthening in age-matched untreated individuals. Post-treatment root length was significantly related to pre-treatment age. Roots that were incompletely developed before treatment reached a significantly greater length than those that were fully developed at the start of treatment. The results of this study show a definite advantage for younger teeth with regard to post-treatment root length. This finding may influence treatment planning strategy.

A radiographic study of external apical root resorption in patients treated with single-phase fixed orthodontic therapy

“…However, all reported that the majority of teeth experienced mild to moderate resorption following treatment. [18][19][20] In the present study, more EARR was observed in molar teeth compared to other teeth. Maximum EARR was observed in maxillary molars (53.3-63.3%).…”

“…However, most large-scale studies reported in literature have found no statistically significant gender difference in the rate and extent of RR. 20,24,25 In the present study, the cases in which patients underwent therapeutic extraction had a relatively higher amount of EARR (55.9%) compared to the cases in which patients were treated by non-extraction therapy (37.9%) and this was statistically significant (P < 0.001). It is in agreement with other studies that described more resorption after extraction therapy.…”

“…[18][19][20] Overall RR reported in the present study (46.8%) was less than this range. However, it was greater than 1.7-27.1% reported by De Shields, 18 Hollender et al 19 and Martins et al 21 in their studies.…”

Root Resorption in Orthodontics: An Evidence-Based Approach

“…Possible patient-related risk factors include a previous history of root resorption Hartsfield et al, 2004;Marques et al, 2010), tooth/root morphology, length and roots with developmental abnormalities (Brin et al, 2003;Fox, 2005;;Marques et al, 2010;Sameshima & Sinclair, 2001Smale et al, 2005), genetic influences (AlQawasmi et al, 2003;Bollen, 2002;Hartsfield et al, 2004;Ngan et al, 2004;Sameshima & Sinclair, 2001), systemic factors (Adachi et al, 1994;Igarashi et al, 1996), including drugs (nabumetone) (Villa et al, 2005), hormone deficiency, hypothyroidism, hypopituitarism Poumpros et al, 1994), asthma McNab et al, 1999), proximity of root to cortical bone (Horiuchi et al, 1998;Kaley & Phillips, 1991;Otis et al, 2004), alveolar bone density (Midgett et al, 1981;Otis et al, 2004), previous trauma Brin et al, 2003;Hartsfield et al, 2004;Mandall et al, 2006), endodontic treatment Hamilton et al, 1999), severity and type of malocclusion (Brin et al, 2003;Sameshima & Sinclair, 2001;Segal et al, 2004), patient age (Bishara et al, 1999;Fox, 2005;Harris et al, 1993;Levander & Malmgren, 1998;Mavragani et al, 2002) and gender (Chan & Darendeliler, 2006;Fox, 2005;Harris et...…”

Root Resorption in Mandibular Incisors During Orthodontic Treatment with Invisalign®: A Radiometric Study

“…Lower percentages are reported when diagnostic radiographic techniques are used. The average amount of tissue loss is usually less than 2.5 mm (11)(12)(13)(14) or varies from 6 to 13% for different teeth in radiographic studies (15). RR is usually classified as minor or moderate in most orthodontic patients.…”