The author experienced 8 cases of pericoronal radiolucency involving an incomplete tooth crown that had not developed to form the cemento-enamel junction, and the underdeveloped crown sometimes appeared to be floating within the radiolucency radiographically. The first impression was that these cystic lesions had odontogenic keratocysts, but half of them turned out to be dentigerous cysts histopathologically. There has been no report concerning odontogenic cysts involving an incompletely developed crown. The purpose of this paper is to report that dentigerous cysts may develop before the completion of the cemento-enamel junction of a developing crown.
Crowns* ; Dentigerous Cyst ; Odontogenic Cysts ; Tooth Crown ; Tooth, Unerupted

The calcifying epithelial odontogenic tumor is a rare benign odontogenic neoplasm which was first described by Pindborg in 1955 and accounts for less than 1% of all odontogenic tumors. The tumor occurs primarily in the molar-premolar region of the mandible, and 52% of cases are associated with an unerupted tooth. The clinical feature is most commonly a slow-growing painless swelling. The tumor may show considerable radiographic variation and usually characteristic histopathologic features. In this study, we report a case of the calcifying epithelial odontogenic tumor on the left mandibular body and ramus area in a 28-year-old male with a brief review of the concerned literatures.
Adult ; Humans ; Male ; Mandible ; Odontogenic Tumors ; Tooth, Unerupted

OBJECTIVETo investigate the clinical value of cone-beam computed tomography (CBCT) and nine partition method on alveolar bone for locating the relative orientation of the unerupted teeth.

METHODS125 bone unerupted teeth of 99 cases were collected. The bone unerupted teeth zones were scaned by CBCT. The dental corona and root apex of these bone unerupted teeth were classified by the new nine partition method.

RESULTSIn 125 bone unerupted teeth, 107 teeth located in maxilla, 18 teeth located in mandible. More frequent appearances (35.6%) in the alveolar bone were inner-middle and outer-superior. The representation of 125 bone unerupted teeth seen in surgery was the same with that of the CBCT before exodontia. The accurate rate of diagnosis was 100%.

CONCLUSIONCBCT is the most accurate and effective methods to determine the authentic orientation of the bone unerupted teeth. The nine partition method of alveolar bone has clinical value of accurate authentic orientation of the bone unerupted teeth in oral and maxillofacial surgery and orthodontics.

Impaction of tooth is a situation in which an unerupted tooth is wedged against another tooth or teeth or otherwise located so that it cannot erupt normally. The supernumerary tooth is also called as hyperdontia and defined as the condition of having additional tooth to the regular number of teeth. The most common supernumerary tooth is a mesiodens, which is a mal-formed, peg-like tooth that occurs between the maxillary incisors. The supernumerary tooth is commonly impacted but they are frequently impacted on maxilla. Ectopic impaction of supernumerary tooth on mandibular condyle, coronoid process, ascending ramus, and pterygomandibular space is very rare condition. In this case, we report a case of impacted supernumerary tooth on mandibular sigmoid notch without definite pathologic change.
Colon, Sigmoid ; Incisor ; Mandibular Condyle ; Maxilla ; Tooth ; Tooth, Supernumerary ; Tooth, Unerupted

Impacted teeth are usually involved in permanent dentition but not in primary dentition. This paper reports a clinical case of unerupted mandibular second deciduous molar inferior to the second premolar.
Bicuspid ; Dentition, Permanent ; Humans ; Mandible ; Molar ; Tooth, Deciduous ; Tooth, Impacted ; Tooth, Unerupted

The purpose of this study was to investigate the cause of eruption disturbance in the maxillary central incisor and establish the effective treatment plan by analyzing the vertical distance, angulation of long axis and root development of the tooth with eruption disturbance using the cone-beam CT.The average age of 134 patients diagnosed with unilaterally impacted maxillary central incisor was 7.9 years old and the male was 2.1 times higher than the female. The most common cause of eruption disorder was physical obstruction, especially mesiodens and odontoma. Of the teeth with unilateral eruption disorder, 78 cases erupted spontaneously and 56 cases erupted non-spontaneously after removal of physical obstruction.The possibility of spontaneous or non-spontaneous eruption in the unilaterally impacted maxillary central incisor depended on several factors, such as vertical distance, angulation of long axis and root development of unerupted tooth. The spontaneous eruption of the impacted maxillary cental incisor was most frequent at the angulation of long axis of 50 to 90 degrees, which is similar to the angulation of long axis of the normally erupted maxillary central incisor. In addition, the spontaneous eruption period of impacted maxillary central incisor was more influenced by the vertical distance than the angulation of long axis and the root development. Most of the teeth that showed non-spontaneous eruption had orthodontic traction, and these teeth were usually erupted within about 12 months. The period treated with orthodontic traction was no statistical significance with the vertical distance, the angulation of long axis, and the root development.This study will provide information on the cause of unilaterally impacted maxillary cental incisor and help to establish the future treatment plan.
Cone-Beam Computed Tomography ; Female ; Humans ; Incisor ; Male ; Odontoma ; Tooth ; Tooth, Impacted ; Tooth, Unerupted ; Traction

Adenomatoid odontogenic tumor (AOT) is a tumor of odontogenic epithelium with varying degrees of inductive changes in the connective tissue. The common radiographic appearance of AOT is a unilocular radiolucency associated with an unerupted tooth. Detectable radiopacities are reported in many cases. We present a case of AOT in a 9-year old-female patient. Cystic lesion with numerous, punctuate radiopaque foci was seen on the anterior region of the mandible. These radiopacities mostly were situated on the buccal side of impacted tooth on the multiplanar images of cone beam computed tomograph. Characteristic duct like structures and amyloid like material were observed on histopathologic finding.
Ameloblastoma ; Amyloid ; Connective Tissue ; Epithelium ; Humans ; Mandible ; Odontogenic Tumors ; Tooth, Impacted ; Tooth, Unerupted

A dentigerous cyst is an epithelium-lined sac that surrounds the crown of an unerupted tooth or odontoma. And the most common sites of this cyst are the mandibular and maxillary third molar and maxillary cuspid areas. Clinically, expansion of bone with subsequent facial asymmetry, extreme displacement of teeth, severe root resorption of adjacent teeth and pain are all possible sequelae of this cyst. The standard treatment for a dentigerous cyst is enucleation and extraction of the involved tooth. But in large cysts, this can lead to functional, cosmetic and psychologic consequences to the patients. So recently, more conservative methods are used. We report 5 cases of dentigerous cysts in pediatric patient which were treated by a conservative approach, By this methods, we can preserve teeth and guide eruption of the teeth which are involved in cystic area.
Crowns ; Cuspid ; Dentigerous Cyst* ; Facial Asymmetry ; Humans ; Molar, Third ; Odontoma ; Root Resorption ; Tooth ; Tooth, Unerupted

OBJECTIVE: The aim of this study was to evaluate and compare the shear bond strength (SBS) and failure-mode of orthodontic buttons bonded to erupted and unerupted teeth with conventional and self-etching adhesive systems. METHODS: Eighty-four erupted and 84 unerupted, human third-molar teeth were used. For both groups, the buccal surfaces of each tooth were assigned one of the following type of adhesive systems (n = 12). A, Conventional systems: 1, Transbond XT (3M Unitek, Monrovia, CA, USA); 2, Prime & Bond NT (Dentsply/Caulk, Milford, USA); 3, Single Bond (3M ESPE, Minnesota, USA); and B, Self-etching adhesives; 4, Clearfil SE Bond (Kuraray, Okayama, Japan); 5, Transbond Plus (3M Unitek, Monrovia, CA, USA); 6, Clearfil S3 (Kuraray, Tokyo, Japan); 7, G Bond (GC, Tokyo, Japan). The SBSs of the attachments and the adhesive remnant index (ARI) scores were recorded. Data were analyzed with analysis of variance (ANOVA), independent-sample t-test and chi-square tests. RESULTS: When the SBSs of erupted and unerupted teeth were compared, only the Clearfil-SE Bond and G-Bond were significantly different. Bond strengths of all adhesive systems were higher in unerupted teeth than erupted teeth, except the Single-Bond system. CONCLUSIONS: When using conventional adhesives, bonding to erupted and unerupted teeth may not be significantly different. However, clinicians need to take into consideration the types of self-etching systems before usage.
Adhesives ; Bisphenol A-Glycidyl Methacrylate ; Humans ; Methacrylates ; Minnesota ; Polymethacrylic Acids ; Resin Cements ; Tokyo ; Tooth ; Tooth, Unerupted

unerupted tooth. Usually this lesion can be asymptomatic. Such cysts are often discovered accidently on inspection of x-rays. In other advanced cases, cortical bone expansion, displacement of teeth, secondary infection can be observed. The treatment ofdentigerous cyst is enucleation. And according to size, location of lesion and environmental structure marsupialization can be considered. However, Marsupialization takes long treatment time and, cystic tissues are remained so secondary surgery may be needed for total removal., Risks of oroantral fistula, damage on maxillary sinus wall and infraorbital nerve can be considered as complications of conventional surgical treatment of cysts located in maxillary sinus. We treated third molar origin dentogerous cyst located in maxillary sinus removing endoscopically both the tooth and an associated dentigerous cyst. We report our clinical experience with literature review.]]>
Coinfection ; Crowns ; Dentigerous Cyst ; Maxillary Sinus ; Molar, Third ; Odontogenic Cysts ; Oroantral Fistula ; Tooth ; Tooth, Unerupted