ResearchCorrelation of root resorption and infraocclusion in mandibular deciduous second molars without succedaneous permanent teeth
Introduction
The high prevalence of agenesis of mandibular second premolars is very important in orthodontics, because it significantly influences treatment planning and may impose certain mechanical difficulties [1], [2], [3]. Once agenesis of a permanent second premolar is identified, the orthodontist often faces a challenging decision regarding the proper treatment option: extraction of the deciduous tooth, followed by space closure or implant replacement, or maintenance of the deciduous tooth until its exfoliation.
Recent studies have shown that maintenance of mandibular deciduous second molars in patients with second premolar agenesis represents a viable treatment option for solving this tooth disorder [4], [5], [6], [7]. There are many advantages with this treatment alternative, such as prevention of the need for prostheses or implants and avoidance of excessive anterior retraction, which could negatively affect the facial profile. However, concerns regarding maintenance of the deciduous molars would be associated with some regressive changes that can be seen in these teeth, such as the reduction of pulp size, pulp degeneration, pulp stones, abnormal odontoblastic pattern, hypercementosis, shortening of root lengths, and the submergence of deciduous molars in alveolar bone compared with the occlusal level of adjacent teeth [8], [9]. Furthermore, there is an uncertainty about the duration of deciduous mandibular second molar exfoliation [8].
Regarding the exfoliation time, Kurol and Thilander [8] showed that root resorption in deciduous molars that lack permanent succedaneum teeth is often slow compared with that in deciduous molars with permanent successors. Some investigators have pointed out that deciduous teeth without a permanent successor are often retained beyond the time of normal exfoliation [7], [8]. According to Bjerklin and Bennett [10], if deciduous molars are present at 20 years of age, they appear to have good prognoses for longitudinal maintenance.
Likewise, mandibular deciduous second molars with no succedaneous permanent teeth often show infraocclusion [7]. Classic studies have reported that if infraocclusion occurs early, the prognosis for occlusion development is worse [11], [12], and that this disturbance could require extraction of the deciduous molar [8].
Evaluation of the extent of root resorption and infraocclusion is important in establishing a prognosis for deciduous tooth maintenance in the long-term and for treatment planning [6], [7], [13]. According to a longitudinal study in Scandinavian individuals, a positive significant correlation between the extent of root resorption and infraocclusion of mandibular deciduous second molars was found [10].
This study aimed to evaluate the extent of root resorption, the prevalence of infraocclusion, and the correlation between these variables in orthodontic patients with mandibular deciduous second molars lacking succedaneous permanent teeth, from childhood to 30 years of age.
Section snippets
Sample selection
The sample consisted of male and female patients aged 6 to 30 years with agenesis of 1 or both mandibular second premolars whose records included panoramic radiographs and dental casts. This sample was the same as that used by Garib et al. [14] in an earlier study and included all cases of mandibular second premolar agenesis from a Brazilian Dental School and from eight private dental offices. The orthodontic records of 158 patients (99 females, 59 males) were included. The majority of the
Results and discussion
Intraexaminer reliability was very good according to the kappa statistics (Table 1). Group 1 (age 5–<10 years) had a significantly lesser mean extent of root resorption than did the other groups (Table 2). On the other hand, although there was a tendency of the prevalence of infraocclusion to increase with age, significant differences between the age groups were not found (Table 3). Table 4 shows that there was a positive significant correlation between the presence of infraocclusion and the
Conclusions
The extent of root resorption in the mandibular deciduous second molars without succedaneous teeth tended to increase from mild to moderate from childhood to adulthood. Twenty-five percent of the teeth had infraocclusion in the sample studied. Mandibular second molars in infraocclusion showed a greater extent of root resorption.
Acknowledgment
Source of financial support: The authors have no financial relationships to disclose.
References (24)
- et al.
Retained deciduous mandibular molars in adults: a radiographic study of long-term changes
Am J Orthod Dentofacial Orthop
(2003) The problem of the ankylosed tooth
Dent Clin North Am
(1968)- et al.
A meta-analysis of the prevalence of dental agenesis of permanent teeth
Community Dent Oral Epidemiol
(2004) - et al.
Hypodonhia—A retrospective review of prevalence and etiology. Part I
Quintessence Int
(2005) - et al.
Agenesis of permanent teeth in 8138 Danish schoolchildren: prevalence and intra-oral distribution according to gender
Int J Paediatr Dent
(2009) - et al.
A treatment decision-making model for infraoccluded primary molars
Int J Paediatr Dent
(2001) - et al.
Persistence of deciduous molars in subjects with agenesis of the second premolars
Eur J Orthod
(2000) - et al.
Primary teeth in adults–a pilot study
Swed Dent J
(2005) - et al.
Infraocclusion of primary molars with aplasia of the permanent successor. A longitudinal study
Angle Orthod
(1984) Regressive changes of the dental pulp complex in retained primary molars with congenitally missing successor teeth
J Clin Pediatr Dent
(1997)
The long-term survival of lower second primary molars in subjects with agenesis of the premolars
Eur J Orthod
Ankylosis of primary molar teeth. I. Prevalence and characteristics
ASDC J Dent Child
Cited by (8)
Advancements in tooth autotransplantation
2024, Journal of the American Dental AssociationRestorative dentistry clinical decision-making for hypodontia: retained primary molars
2023, British Dental JournalStatus of retained deciduous second molars in subjects with agenesis of second premolars in relation to age
2023, European Journal of Paediatric DentistryMandibular Molar Protraction with the Forsus Appliance as Anchorage Reinforcement
2022, Journal of Clinical OrthodonticsDistribution of congenitally missing teeth and treatment options for the lower second premolars in patients referred to special care
2022, Acta Odontologica Scandinavica