OBJECTIVES: This study aimed to investigate the clinical characteristics of deciduous fused teeth and their inherited permanent-tooth performance type by using panoramic radiographs. METHODS: A total of 14 404 panoramic radiographs of 3- to 6-year-old children with deciduous dentition were collected from January 2023 to July 2024. The incidence of deciduous fused teeth was observed, and the abnormality of permanent teeth was recorded. SPSS 24.0 software was used for statistical analysis. RESULTS: The incidence of deciduous fused teeth was 3.06% (441/14 404). The order of dental position was as follows: mandibular deciduous incisors and cusp teeth fused (58.18%) > mandibular deciduous central and lateral incisors fused (30.91%) > maxillary deciduous central and lateral incisors fused (8.89%) > deciduous incisors and supernumerary teeth fused (2.02%). Deciduous fused teeth were found in 226 boys and 215 girls, with no significant difference between the sexes (P>0.05). We observed one pair (87.76%, 387/441) and two pairs (12.24%, 54/441) of fused teeth (54/441), respectively. A total of 287 pairs of fusion teeth on the right side more than 208 pairs on the left side, and the difference between them was statistically significant (P<0.01). More fusion teeth existed in mandibular deciduous teeth (443 pairs) than in maxillary ones (54 pairs), and the difference between them was statistically significant (P<0.01). More unilateral deciduous teeth (387 subjects) were found than bilateral ones (54 subjects), and the difference between them was statistically significant (P<0.01). Three types of deciduous fused teeth with inherited permanent teeth were observed as follows: 1) 49.49% (245/495) of inherited permanent teeth was absent, 2) 46.67% (231/495) of inherited permanent teeth was not absent, and 3) the number of fused permanent teeth accounted for 3.84% (19/495). CONCLUSIONS The incidence of deciduous fused teeth was 3.06%, mostly occurring in the lower anterior teeth region, with no gender difference. One pair of fused teeth is commonly observed, more often on the right than the left. These fusions occur more frequently in the mandible than the maxillary, and unilateral cases are more common than bilateral ones. Deciduous fused teeth had a certain impact on inherited permanent teeth. Pediatric dentists should pay attention to and closely observe whether any abnormality exists in the permanent dentition for early detection to prevent the harm caused by deciduous fused teeth.
Humans ; Tooth, Deciduous/abnormalities* ; Male ; Child ; Female ; Child, Preschool ; Dentition, Permanent ; Radiography, Panoramic ; Fused Teeth/diagnostic imaging* ; Incisor/diagnostic imaging* ; Tooth, Supernumerary/diagnostic imaging* ; Incidence ; Mandible

Fused teeth are usually formed by the partial or complete fusion of two normal tooth germs during the development process and belong to dental developmental abnormalities. Fused teeth are relatively rare clinically, and those occurring in the posterior tooth area are even rarer. This article reports a case of fused teeth between the first permanent molar and the second permanent molar in the right mandible. This fused tooth had a complex root canal anatomical structure (seven root canals). The number and location of the root canals were analyzed by cone beam computed tomography, and root canal treatment was successfully completed with the assistance of microscope.
Humans ; Molar/diagnostic imaging* ; Mandible ; Dental Pulp Cavity/abnormalities* ; Cone-Beam Computed Tomography ; Root Canal Therapy/methods* ; Fused Teeth/surgery*

OBJECTIVEThis study aims to investigate the prevalence and distribution of teeth number and morphology abnormalities in Chinese pediatric patients' permanent teeth at the mixed dentition stage by performing panoramic radiographs analysis.

METHODSA total of 4 347 panoramic radiographs of pediatric patients aged 5 years to 15 years who were admitted to the hospitals from September 2011 to September 2013 were reviewed. The presence of teeth number and morphology abnormalities were recorded as follows: congenitally absent teeth, supernumerary teeth, odontoma, microdontia, fused teeth, dilaceations, and cusp deformity. SPSS 16.0 software was used for statistical analysis.

RESULTSThe prevalence of teeth number and morphology abnormalities in pediatric patients' permanent teeth was 31.79% (1,382/4,347). The prevalence was higher in males. Significant difference between the genders was observed (P < 0.05). Tooth agenesis, the most frequent dental anomaly (15.00%, 652/4,347), was considerably common in females; supernumerary teeth (12.61%, 548/4,347) followed, which was significantly common in males. Both differences were statistically significant (P < 0.05). The levels of prevalence of both microdontia and dilacerations were 4.00% (174/4,347) and 2.16% (94/4,347). The prevalence of cusp deformity, odontoma, and fused teeth were relatively low at 0.74% (32/4,347), 0.51% (22/4,347), and 0.39% (17/4,347), respectively.

CONCLUSIONThe prevalence of teeth number and morphology abnormalities in children's permanent teeth at the mixed dentition stage is apparently high. Tooth agenesis and supernumerary teeth are the most frequent. Panoramic radiograph is an efficient method for the early diagnosis of teeth number and morphology abnormalities. This method can assist pediatric dentists to formulate treatment plans for children at the appropriate time.

Adolescent ; Child ; Child, Preschool ; China ; epidemiology ; Dentists ; Dentition, Mixed ; Dentition, Permanent ; Female ; Fused Teeth ; epidemiology ; Humans ; Male ; Odontoma ; epidemiology ; Patient Care Planning ; Prevalence ; Radiography, Panoramic ; Sex Factors ; Tooth Abnormalities ; diagnostic imaging ; epidemiology ; Tooth, Supernumerary ; diagnostic imaging ; epidemiology

This case report describes the diagnosis and endodontic therapy of maxillary fused second and third molars, using cone-beam computed tomography (CBCT). A 31-year-old Chinese male, with no contributory medical or family/social history, presented with throbbing pain in the maxillary right molar area following an unsuccessful attempted tooth extraction. Clinical examination revealed what appeared initially to be a damaged large extra cusp on the buccal aspect of the distobuccal cusp of the second molar. However, CBCT revealed that a third molar was fused to the second molar. Unexpectedly, the maxillary left third molar also was fused to the second molar, and the crown of an unerupted supernumerary fourth molar was possibly also fused to the apical root region of the second molar. Operative procedures should not be attempted without adequate radiographic investigation. CBCT allowed the precise location of the root canals of the right maxillary fused molar teeth to permit successful endodontic therapy, confirmed after 6 months.
Adult ; Cone-Beam Computed Tomography ; methods ; Follow-Up Studies ; Fused Teeth ; diagnostic imaging ; Humans ; Image Processing, Computer-Assisted ; methods ; Imaging, Three-Dimensional ; methods ; Male ; Maxilla ; Molar ; abnormalities ; Molar, Third ; abnormalities ; Pulpitis ; diagnostic imaging ; Root Canal Therapy ; Tooth Root ; abnormalities ; Tooth, Supernumerary ; diagnostic imaging ; Tooth, Unerupted ; diagnostic imaging

This paper reported a case of fusion between an impacted third molar and a supernumerary tooth, in which a surgical intervention was carried out, with the objective of removing the dental elements. The panoramic radiography was complemented by the Donovan's radiographic technique; but because of the proximity of the dental element to the mandibular ramus, it was not possible to have a final fusion diagnosis. Hence, the Cone-Beam Computed Tomography-which provides precise three-dimensional information-was used to determinate the fusion diagnosis and also to help in the surgical planning. In this case report we observed that the periapical, occlusal and panoramic were not able to show details which could only be examined through the cone-beam computed tomography.
Adult ; Cone-Beam Computed Tomography ; methods ; Diagnosis, Differential ; Female ; Follow-Up Studies ; Fused Teeth ; diagnostic imaging ; Humans ; Imaging, Three-Dimensional ; methods ; Molar, Third ; abnormalities ; diagnostic imaging ; Patient Care Planning ; Radiography, Bitewing ; Radiography, Panoramic ; Tooth Root ; abnormalities ; diagnostic imaging ; Tooth, Impacted ; diagnostic imaging ; Tooth, Supernumerary ; diagnostic imaging