Primary Fused Teeth and Findings in Permanent Dentition

Abstract

Objective: The aim of this study was to investigate the characteristics of primary fused teeth (PFT) and their effect on permanent dentition in a group of Turkish children. Subjects and Methods: Dental records of 13,450 pediatric patients who attended the Pediatric Dental Clinic in northern Turkey between 2015 and 2017 were reviewed. Forty patients had been diagnosed with PFT and were included in the study. Clinical and radiographic examinations were conducted, and the distribution of PFT was calculated by type, sex, affected jaw, associated dental anomalies, and clinical complications. Data analysis involved descriptive statistics. Results: A total of 50 PFT were detected in the 40 patients. The mean age of patients was 6.7 ± 0.3 years (range 3–10 years). The most common PFT were the mandibular lateral incisors and canines (34, 68%). The most prevalent type of PFT was type III (20, 40%). Of the 40 patients with PFT, 34 (85%) also ex­hibited other dental anomalies such as tooth aplasia, peg-shaped incisors, talon cusps, ectopic eruption, and delayed eruption in both related and unrelated areas. The most common complications of PFT were fusion-related tooth aplasia (n = 26 [76%]) and caries formation in the affected teeth (24 [48%]). Conclusion: In this study, PFT were frequently observed in the mandibular anterior region. Caries formation and dental anomalies, especially permanent tooth aplasia, were often encountered in areas where PFT were seen. Hence, parents should be informed about possible dental problems associated with PFT and be encouraged to schedule regular follow-up appointments.

Developmental Dental Anomalies of Primary and Permanent Dentition

“…Radiographically, these teeth would present with two separate pulp chambers and root canals and the fusion will be limited to the roots of these teeth [89]. Fusion more commonly occurs unilaterally in the primary rather than in permanent dentition, and most often in the anterior region with involvement of the mandibular lateral incisors and canines ( Figure 13) [90].…”

“…Such anomalies can occur in regions that are unrelated to the site of the fused teeth or at the site of fusion. Anomalies of the permanent dentition reported at the site of primary fused teeth include peg-shaped incisors, occurrence of fusion of the successors, and supernumerary or congenitally missing successors [90,91]. Unrelated tooth anomalies that have been reported include hypodontia, talon cusps, delayed eruption, and ectopic eruption [90].…”

“…Anomalies of the permanent dentition reported at the site of primary fused teeth include peg-shaped incisors, occurrence of fusion of the successors, and supernumerary or congenitally missing successors [90,91]. Unrelated tooth anomalies that have been reported include hypodontia, talon cusps, delayed eruption, and ectopic eruption [90]. Fused primary or permanent teeth can be at increased risk for caries formation due to the presence of deep buccal and lingual grooves that occur at the site of fusion.…”

Management of Bilateral Mandibular Fused Teeth

“…Tooth fusion is defined as the union between two or more separate developing teeth. Such anomaly may be complete or incomplete depending on the developmental stage of the associated tooth buds [1]. If contact between two tooth buds occurs before calcification, complete fusion ensues.…”

“…If contact between two tooth buds occurs before calcification, complete fusion ensues. This may be seen clinically as an abnormally wide crown usually with a groove that separates the mesial and distal moiety [1]. If contact occurs after crown formation, incomplete fusion occurs at the root level.…”