Crown-root shape of the permanent maxillary central incisor

This study aimed to determine whether the lateral cephalometric crown-root shape differs among the permanent maxillary central incisor in Class I, Class II division 1, Class II division 2 and Class III malocclusions and to identify the nature of any differences. Of the 499 lateral cephalograms recorded at a university orthodontic clinic during 2001, 361 satisfied the inclusion criteria. Sixty cephalograms were selected from the four malocclusion groups and were digitized in random order. The configurations of the 10 landmarks characterizing the crown-root shape of the permanent maxillary central incisor were then optimally superimposed using Procrustes algorithms. Discriminant analysis of the principal components of shape determined the incisor shape differences between the malocclusion groups. The crown-root shape of the permanent maxillary central incisor did not differ significantly among the Class I, Class II division 1, and Class III groups (P > .05); however, the crown-root shape of the Class II division 2 permanent maxillary central incisor was significantly different (P < .001) from that of the Class 1, Class II division 1 and Class III. The shape discrimination involved axial bending of the Class II division 2 incisors. Principal components 1, 2, and 3 accounted for 63% of the Class II division 2 incisor shape variance, encompassing a shorter root, a longer crown, and axial bending of the incisor, in addition to a reduced labiopalatal thickness. These shape features could precipitate the development of a deep overbite in Class II division 2 malocclusion and may limit the amount of palatal root torque during fixed appliance therapy.     

Case report: autotransplantation for a missing permanent maxillary incisor

Patients with nonrestorable or missing anterior teeth are typically seen by their general or pediatric dentist who directs the course of consultation, referral, and treatment. In the mixed dentition stage, loss of permanent maxillary incisors is usually treated by various forms of removable/fixed prosthetic appliances. Because premolars are developing during this time period, transplantation of an available premolar to an incisor position is a viable alternative, that may provide a better biological substitute for a missing incisor than other choices. The purpose of this case report was to describe the treatment of the loss of a permanent maxillary central incisor by transplantation of a maxillary first premolar to the incisor position. Autotransplantation allowed normal alveolar bone development and a future option of permanent restoration without implants or partial dentures. Autotransplantation should be given consideration as a reasonable option for the treatment of missing incisors in mixed dentition.     

Enamel hypoplasia of a maxillary central incisor

Abstract This article describes a case of a permanent central incisor with enamel hypoplasia. A 7-year-old patient had suffered an injury in a car accident when she was 21/2 years old. The maxillary right central deciduous incisor was lost in the accident. At the time of examination a fistula was present buccally to the maxillary right permanent incisor, which had erupted only 3 mm into the mouth. The maxillary left central incisor had erupted fully. After clinical and radiographic examination the lost deciduous incisor was found in the bone buccally to the permanent incisor. The deciduous tooth was extracted surgically, the fistula healed and the gingiva became normal. The permanent incisor had a 3-mm-wide zone of hypoplastic enamel on the buccal surface of the crown.     

Enamel hypoplasia of a maxillary central incisor

This article describes a case of a permanent central incisor with enamel hypoplasia. A 7-year-old patient had suffered an injury in a car accident when she was 2 1/2 years old. The maxillary right central deciduous incisor was lost in the accident. At the time of examination a fistula was present buccally to the maxillary right permanent incisor, which had erupted only 3 mm into the mouth. The maxillary left central incisor had erupted fully. After clinical and radiographic examination the lost deciduous incisor was found in the bone buccally to the permanent incisor. The deciduous tooth was extracted surgically, the fistula healed and the gingiva became normal. The permanent incisor had a 3-mm-wide zone of hypoplastic enamel on the buccal surface of the crown.     

A supernumerary tooth fused to the facial surface of a maxillary permanent central incisor: case report

A case of a supernumerary tooth fused to the facial surface of a maxillary permanent central incisor is reported. Root canal therapy on the maxillary central incisor was performed due to pulpal communication between the supernumerary tooth and the maxillary central incisor after removing the supernumerary tooth structure. The communication was sealed with mineral trioxide aggregate. The difference between fusion and gemination is discussed.     

Surgical repositioning of a developing maxillary permanent central incisor in a horizontal position: spontaneous eruption and root formation

This report describes the surgical repositioning of a developing maxillary permanent central incisor in a horizontal position, followed by spontaneous eruption and root formation without orthodontic traction. Surgical exposure of the right central incisor was achieved. A 7-year-old boy referred for orthodontic consultation. Radiographic examination showed the crown of a maxillary right central incisor to be positioned horizontally with root formation at the initial stage. The surgically repositioned incisor (by a close-eruption surgical flap technique) spontaneously erupted into correct alignment after 2 years 3 months. The erupted incisor remained vital and responded normally to percussion, mobility and sensitivity testing. The soft tissue, periodontal attachment, gingival contour and probing depths were normal. Follow-up radiographs confirmed the continued development of the root, with revascularization of the pulp and a normal appearance of the periodontal space and lamina dura. There was, however, shorter root formation and a narrower root cavity compared with the contralateral incisor. As a result, no orthodontic traction and alignment were required. This method of surgical repositioning is a viable alternative to the traditional approach of extraction or surgical exposure followed by orthodontic traction for a developing maxillary permanent central incisor in a horizontal position.     

The relationship between a primary maxillary incisor with a talon cusp and the permanent successor: a study of 57 cases

BACKGROUND: Most reported cases of talon cusps in the primary dentition have been on the maxillary central incisors and the permanent successors have remained unaffected. Four of the five reported cases on a maxillary lateral incisor, however, have been associated with a supernumerary permanent successor. AIM: This paper describes the relationship between the presence of talon cusps on a primary maxillary incisor, and the morphology and number of the permanent successors in a population of Chinese children. DESIGN: The dental records of children diagnosed with a talon cusp on a primary incisor were retrieved for review. The diagnoses took place in a regional school dental clinic in Hong Kong between April 2002 and August 2005. RESULTS: Fifty-eight primary maxillary incisors with talon cusps were found. When the central incisors were involved, 32 of the 35 (91.4%) underlying permanent successors were not found to be associated with any odontogenic abnormalities. When the lateral incisors were involved, however, 18 of the 23 cases (78.3%) showed odontogenic abnormalities, 14 of which were associated with supernumerary teeth. CONCLUSIONS: The present study shows that, when there is a talon cusp on a primary maxillary lateral incisor, a high proportion of the underlying permanent successors can be expected to exhibit odontogenic abnormalities.     

Dilaceration of maxillary central incisor: a literature review

Abstract – The main purpose of this review is to present the aetiological factors and the mechanism that cause dilaceration of the maxillary central incisors. In early developmental stages, the permanent tooth germ of the maxillary incisor is situated palatally and superiorly to the apex of the primary incisor and gradually changes direction in a labial direction with its crown coming closer to the resorbing primary root. For reasons of this close relationship between the permanent tooth germ and the apex of the primary incisor, it is believed that an acute trauma to the primary predecessor can cause dilaceration of the long axis of the permanent successor. Clinically, dilaceration can be revealed by palpation high in the labial sulcus or in the hard palate, while its radiographic view is characteristic. The therapeutic approach to the dilacerated maxillary central incisors has to be carefully planned and needs the cooperation of several specialities to attain the final objective.     

Replantation of an avulsed maxillary primary central incisor and management of dilaceration as a sequel on the permanent successor

Abstract – This case report outlines the sequel and possible management of a permanent tooth traumatized through the predecessor, a maxillary right primary central incisor that was avulsed and replanted by a dentist 1 h after the trauma in a 3‐year‐old girl. Three years later, discoloration and fistula were present, so the primary tooth was extracted. The patient did not come to the scheduled follow‐ups to perform a clinical and radiographic control of the succeeding permanent incisor, and only returned when she was 10 years old. At that moment, the impaction and dilaceration of the maxillary right permanent central incisor were observed through radiographic examination. The dilacerated permanent tooth was then surgically removed, and an esthetic fixed appliance was constructed with the crown of the extracted tooth. Positive psychological influence of the treatment on this patient was also observed.     

Treatment of an avulsed maxillary permanent central incisor by autotransplantation of a primary canine tooth

Aim  To present a case in which an avulsed permanent maxillary central incisor was replaced by autotransplantation of a primary canine tooth.
Summary  The present case describes transplantation of a primary canine tooth into the space left by an avulsed permanent maxillary central incisor after a delay of several days. After root canal treatment, the primary canine tooth was extracted and placed into the prepared socket. To provide better adaptation of the donor tooth, the recipient alveolar site was remodeled using surgical burs. Semi-rigid splinting was maintained for 15 days. The crown of the primary canine was reshaped with composite resin and with an interim prosthesis, preventing movement of the lateral incisor tooth into the space of the transplanted canine. After 24-month follow-up the autotransplanted primary canine showed ankylosis but the tooth was in an acceptable state. The use of permanent tooth autotransplantation has been well documented. However a literature search revealed only one case report on the autotransplantation of primary teeth.
Key learning points • Long term results of primary tooth autotransplantation are scarce but the procedure in this case report could be considered as a temporary space maintainer for the treatment of a patient with a lost permanent incisor under 10 years of age.
• Success of primary tooth autotransplantation may be affected by several factors, such as case selection, extra oral time, surgical and endodontic procedures.     

Surgical and orthodontic treatment of an impacted permanent incisor: case report

Abstract –  This case report presented a combined surgical/orthodontic treatment of an impacted permanent incisor of a 10-year-old boy. Trauma to the primary dentition caused the impaction of the maxillary left permanent central incisor. Application of push coil spring between the adjacent teeth created space for the impacted tooth. A button with an extension of ligature wire was bonded to the maxillary left permanent central incisor to bring it into the arch. The maxillary left permanent central incisor was brought to its proper position after 16 months of active orthodontic treatment.     

Clinical evaluation of a patient with single maxillary central incisor

Hypodontia in permanent dentition is the most common developmental anomaly and frequently found in the second premolar and maxillary lateral incisor In the primary dentition, however, hypodontia appears to be less frequent, with the exception of cases such as ectodermal dysplasia and cleft lip and palate. We report a child with one primary maxillary central incisor at midline. The presence of a single permanent maxillary central incisor was also confirmed by radiological examination. Other intraoral abnormalities were detected including absence of upper labial frenulum and abnormal palatal structure, but no other facial or brain anomalies. Although the condition is exceedingly rare, a thorough examination for more serious anomalies should be conducted since it is suggested to be the mildest feature of holoprosencephaly.     

Odontoma-like malformation in a permanent maxillary central incisor subsequent to trauma to the incisor predecessor

Abstract –  This report describes a case of a patient (1 year and 8 months old) with traumatic avulsion of the maxillary right primary central incisor and morphological changes in the germ of the permanent successor. One year after the trauma, an odontoma-like malformation developed. This malformation was removed 6 years after trauma and orthodontic treatment was started. Clinical follow-up and periodic radiographs are necessary after traumatic avulsion of primary teeth to monitor possible sequelae in the permanent successor. An odontoma-like malformation requires a multidisciplinary approach.     

Developmental disturbance of maxillary lateral incisor after trauma

Abstract –  Traumatic injury to a primary tooth has a potential to damage the underlying permanent tooth germ. It may lead to developmental disturbance of permanent dentition. The impaction of the permanent maxillary central incisor because of the root dilaceration in children is rare. The purpose of this paper is to report a developmental disturbance of a permanent right maxillary lateral incisor in a 12-year-old girl with a history of trauma at an early age.     

Orthodontic treatment of an impacted dilacerated maxillary incisor: a case report

Dilaceration is one of the causes of permanent maxillary incisor eruption failure. It is a developmental distortion of the form of a tooth that commonly occurs in permanent incisors as result of trauma to the primary predecessors whose apices lie close to the permanent tooth germ. We present a case of post-traumatic impaction of a dilacerated central maxillary left incisor in a young patient with a class II malocclusion.     

Solitary median maxillary central incisor syndrome and holoprosencephaly: a case report

Solitary median maxillary central incisor syndrome (SMMCIS) is a rare anomaly that affects 1 in 50,000 live births. Of unknown etiology, SMMCIS is characterized by the presence of a single central incisor located on the maxillary midline and may be associated with developmental defects and systemic alterations. SMMCIS also is associated with short stature, mild forms of deviation in craniofacial morphology, and intellectual disability. The purposes of this paper were to: describe the clinical case of an 8-year-old boy with a permanent central incisor located at the midline in association with holoprosencephaly; and highlight the most important aspects related to diagnosis and treatment of solitary median maxillary central incisor syndrome.     

328颗上颌恒切牙异常萌出原因的临床分析

目的分析导致上颌恒切牙异常萌出的原因,为提高诊疗水平提供理论依据。方法收集上颌恒切牙异常萌出的患者239例,共计328颗上领恒切牙,记录并分析导致上颌恒切牙异常萌出的原因,对数据进行统计学分析。结果328颗异常萌出的上颌恒切牙中,阻生或弯曲牙者64颗;上颌恒切牙已萌出,但位置异常者264颗,其中唇侧异常萌出45颗,腭侧异常萌出187颗,远中异常萌出32颗。对异常萌出的原因进行分析,上颌乳前牙根尖感染患者92例（38．5％）,上颌乳前牙外伤患者30例（12．6％）,上颌乳前牙滞留患者（非感染和外伤所致）26例（10．9％）,多生牙患者18例（7．5％）,上唇系带肥厚患者11例（4．6％）,口腔不良习惯、骨量不足等其它原因患者19例（7．9％）,另有43例（18．0％）患者合并局部或全身多种相关疾病。结论乳前牙根尖周炎是导致上颌恒切牙异常萌出的主要病因,儿童口腔医生应积极治疗乳牙疾病,去除或减轻导致上颌恒切牙异常萌出的因素,诱导儿童牙列和咬合功能的正常发育。     

Change in supporting tissue following loss of a permanent maxillary incisor in children

Alveolar bone resorption is an inevitable consequence of tooth loss and may be detrimental to long-term dental aesthetics and function. The aim of the present study was to quantify the degree of tissue resorption following the loss of a permanent incisor in a young population. The study group comprised 11 boys and five girls who all required the extraction of a permanent maxillary central incisor due to trauma-related sequelae. Mean age at tooth loss was 10.8 years. Upper alginate impressions were taken at regular intervals following tooth loss and were cast in yellow dental stone. Study models were sectioned longitudinally through the mid-point of both the maxillary incisor socket and the contra-lateral incisor to provide a thin plaster section. Digital photographs were acquired of the edentulous (A1) and dentate (A2) surfaces of this section and image analysis software was employed to quantify the surface area of both A1 and A2. At 3 months postextraction, mean A1 was 15.7% less than mean A2. By 6 months mean A1 had further reduced and was 25.3% less than that of the corresponding dentate alveolus. However, at subsequent time intervals following tooth extraction (>6 months), tissue loss appeared to stabilise with an overall reduction in tissue area remaining at 22%. This reduction in supporting tissue area was found to be highly statistically significant (P = 0.002, anova). Furthermore, girls appeared to have an overall greater degree of tissue loss than boys (P = 0.015). Further research is indicated to explore factors influencing the degree of tissue loss following incisor extraction and the benefit of therapeutic interventions in limiting this resorption.     

Arrest of root formation in a permanent maxillary central incisor subsequent to trauma and pulp necrosis to the primary predecessor

Abstract – This paper reports a case in which a previous traumatic injury at the age of 2 and pulp necrosis to a primary incisor resulted in a rare injury to the permanent successor tooth. The radiographic examination at the age of 9 showed the arrest of root formation of the permanent maxillary right central incisor, which did not erupt. Tooth 11 was extracted and a functional removable space maintainer was prepared. At the age of 17, the patient received an anterior fixed prosthesis for re‐establishment of the esthetics, phonetics and deglutition.     

Permanent maxillary central incisor impaction: report of two cases.

Impaction of the permanent maxillary central incisor is rare. Trauma to the primary maxillary anterior teeth is the most common cause. Two case reports of impacted permanent maxillary central incisors with a history of trauma to the primary maxillary anterior teeth are presented. In one case there was radiographic evidence of complete arrest of root formation, and in the other case the root was dilacerated from the cervical third and the enamel surface was rough.