Diagnosis and Endodontic Management of Fused Mandibular Second Molar and Paramolar with Concrescent Supernumerary Tooth Using Cone-beam CT and 3-D Printing Technology: A Case Report

Abstract

Supernumerary teeth in the molar area are classified as paramolars or distomolars based on location. They occur frequently in the maxilla, but only rarely in the mandible. These teeth are frequently fused with adjacent teeth. When this occurs, the pulp cavities may also be connected. This makes diagnosis and planning of endodontic treatment extremely difficult. Here we report a case of a mandibular second molar fused with a paramolar, necessitating dental pulp treatment. Intraoral and panoramic radiographs were obtained for an evaluation and diagnosis. Although the images revealed a supernumerary tooth-like structure between the posterior area of the mandibular second molar and mandibular third molar, it was difficult to confirm the morphology of the tooth root apical area. Subsequent cone-beam computed tomography (CBCT) revealed that the supernumerary tooth-like structure was concrescent with the root apical area of the mandibular second molar. Based on these findings, the diagnosis was a fused mandibular second molar and paramolar with a concrescent supernumerary tooth. A 3-dimensional (3-D) printer was used to produce models based on the CBCT data to aid in treatment planning and explanation of the proposed procedures to the patient. These models allowed the complicated morphology involved to be clearly viewed, which facilitated a more precise diagnosis and better treatment planning than would otherwise have been possible. These technologies were useful in obtaining informed consent from the patient, promoting 3-D morphological understanding, and facilitating simulation of endodontic treatment.

Utilizing a low-cost desktop 3D printer to develop a “one-stop 3D printing lab” for oral and maxillofacial surgery and dentistry fields

“…Surgical simulations using a 3D model have been performed [15–18]. Mavili et al posited that the limitations of this technology are manufacturing time and cost [16], but the desktop FDM 3D printer can solve these problems [18].…”

“…Mavili et al posited that the limitations of this technology are manufacturing time and cost [16], but the desktop FDM 3D printer can solve these problems [18]. In addition to major surgery, such as bone dissection and orthognathic surgery, 3D models are also useful for treatment planning and simulation of minor surgery such as surgical endodontic treatment [19].…”

“…In addition to major surgery, such as bone dissection and orthognathic surgery, 3D models are also useful for treatment planning and simulation of minor surgery such as surgical endodontic treatment [19]. It has been reported that utilization of a low-end 3D printer advances the field of dental treatment, and endodontic management in particular [18–21]. Dramatic evolution of 3D printing technology is expected to further aid the dentistry field.…”

Endodontic applications of 3D printing

“…Tooth prototypes have been used for simulation exercises with advantages over extracted teeth (Kfir et al . , Bahcall , Kato & Kamio , Marending et al . , Robberecht et al .…”

“…Commercially available resin teeth provide a predictable and simple alternative to the natural dentition but can be expensive. Tooth prototypes have been used for simulation exercises with advantages over extracted teeth (Kfir et al 2013, Bahcall 2014, Kato & Kamio 2015, Marending et al 2016, Robberecht et al 2017. Some of the earliest demonstrations utilized CT slices and starch to reconstruct challenging clinical cases such as extracanal invasive resorption (Kim et al 2003) and a molar with three distal roots (Lee et al 2006).…”