Department of Pediatric and Preventive Dentistry, Faculty of Dentistry, Jamia Millia Islamia, New Delhi 110025, IndiaIndia
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Fusion is a developmental anomaly of teeth. It is defined as the dentinal union of two embryologically developing teeth. It is more commonly seen in primary dentition and more frequently in incisor region. This paper reports a rare case which had the presence of bilaterally fused primary central incisor and lateral incisor in the mandibular region. KEY WORDS:; ;
Keywords: Fusion; Developmental anomaly; Primary incisors
Fused teeth arise through union of two normally separated tooth germs and they can be found in almost any region of the dental arch, both in primary and permanent dentitions. According to the most accepted theory, some physical force or pressure is responsible for contact between developing teeth and their subsequent fusion.7 Genetic predisposition and racial differences are other predisposing factors. Fusion can be classified into complete and incomplete types. In case of complete fusion the union begins before calcification and crown of the fused tooth incorporates features of both teeth, but in incomplete fusion union of teeth occur at a much later stage and tooth might exhibit separate crown and fusion may be limited to roots with pulp canals fused or sep-
arate.8 Fusion may affect two normal teeth or it may also occur between a normal tooth and a supernumerary tooth which may 7,9 be a mesiodens or a distomolar.7,9 Although, case of bilaterally fused mandibular lateral incisors and canines in the primary dentition have been reported in the literature, but interesting finding of bilaterally fused central and lateral incisors in the mandibular region makes the present case more extraordinary and worthy to report. Most of the fused teeth are associated with occlusal disturbances, space problems and delayed eruption of the permanent successors. The fissure present at the union between fused teeth predisposes it to dental caries and in some cases periodontal disease.9 Fused primary teeth may result in delayed resorption of roots due to its big root mass thereby leading to ectopic resorption of the permanent teeth.10 The presence of fused teeth in primary dentition has been associated with absence of permanent dentition and the prevalence depends on the combination of fused primary teeth.11 Cases of fusion of primary mandibular anterior teeth associated with partial anodontia of both primary and permanent dentition12 or with anodontia of permanent dentition alone have also been reported.13 The presence of fused teeth can also cause aesthetic problems, especially in the anterior region.
The treatment of fused teeth depends on the clinical sit-
uation, patient’s expectations and degree of compliance.14 Proper instructions regarding maintenance of oral hygiene should be given to the patient to avoid caries. Fissure sealants can be used as they reduce the risk of caries. A multidisciplinary approach can also be used to ensure functional occlusion and aesthetics.
In the present case restoration of 85 was done with glass ionomer cement and fused primary teeth were retained as such as they were free from caries (Figure 3). Preventive approach was planned that included application of topical fluoride, oral hygiene instructions and periodic follow-ups.
• A thorough clinical and radiographic evaluation is compulsory as early diagnosis results in enhanced prognosis. • Early detection and intervention of fused teeth is essential part of preventive dentistry as it is one of the rare anomalies of shape of tooth.
• Hypodontia of permanent dentition is a complication associated with fused primary teeth and the prevalence depends on the combination of fused teeth.
• Fusion of primary teeth may be associated with pulp exposure due to presence of deep grooves.
• Careful monitoring is required in most of the cases as regular and long-term follow-up is required to manage fusion.
SOURCES OF SUPPORT: None.
Written informed consent was obtained from the patient for publication of this case report.