Evaluation of mandibular trabecular bone by fractal analysis in pediatric patients with hypodontia of the mandibular second premolar tooth.

BACKGROUND: It is still unclear whether the trabecular structure of the jaw is different in individuals with hypodontia than in those without hypodontia; this is important for clinicians. The aim was to determine whether the mandibular trabecular bone structure of children and adolescents with hypodontia differs from the control group by using the fractal analysis (FA) method in this study. METHODS: A total of 138 panoramic radiographs of 69 cases and 69 control subjects (mean age 13.2 ± 10.1) were evaluated. The age and gender of subjects in the case and control groups were matched. Three regions of interest (ROIs) were selected from the panoramic radiographs. ROI1 refers to the center of the ramus rising above the mandibular foramen. ROI2 refers to the area between the apical level of the mandibular molar and the upper border of the mandibular canal. ROI3, the missing tooth region, refers to the apical third of the mesial side of the erupting or fully erupted permanent mandibular first molar. Mann-Whitney U and Wilcoxon tests were used. p < 0.05 was accepted for the significance value. RESULTS: The mean fractal dimension (FD) values of ROI1, ROI2, and ROI3 were 1,25, 1,20, and 1,13, respectively. The means FD values obtained from the ramus region were higher than the other regions (p < 0.05). The FD values did not differ significantly according to gender and age (p > 0.05). The FD values of the case group were lower than the control group for ROI3 (p < 0.05). CONCLUSION: The results of this study showed that the mandibular trabecular bone quality of pediatric patients with one missing tooth was different from the healthy group. The difference in the mean FD values from the ROIs indicates that the ramus has a denser structure than the mandibular corpus. Clinicians should factor this into their dental treatment planning process.

Root resorption of primary molars and dental development of premolars in children with Osteogenesis Imperfecta medicated with bisphosphonates, grouped according to age and gender.

BACKGROUND: Osteogenesis imperfecta (OI) is an inherited disorder characterized by bone fragility and skeletal alterations. The administration of bisphosphonates (BPs) to patients with OI reduces pain, thereby improving their quality of life. The main mechanism of action of BPs is the inhibition of osteoclast action. In the oral cavity of children with OI during growth and development, physiological processes that require the function of osteoclasts occur. The aim of this investigation was to study the dental development of premolars and the root resorption of primary molars in children with OI medicated with BPs according to age and sex. METHODS: An observational and analytical study was designed. The study sample consisted of 26 6- to 12-year-old children with a confirmed diagnosis of OI treated with BPs with available panoramic radiographs. The control group consisted of 395 children with available panoramic radiographs. Both groups were divided into subgroups according to sex and age. The third quadrant was studied, focusing on the first left temporary molar (7.4), the second left temporary molar (7.5), the first left permanent premolar (3.4) and the second left permanent premolar (3.5). The Demirjian method was used to study the dental development of 3.4 and 3.5, and the Haavikko method was used to study the root resorption of 7.4 and 7.5. The Mann‒Whitney U test was used for comparisons, and p < 0.05 indicated statistical significance. RESULTS: The mean chronological age of the 421 patients was 9.21 years (95% CI 9.05-9.37). The sample was reasonably balanced by sex, with 52.5% (221 patients) boys versus 47.5% (200 patients) girls. Delayed exfoliation and tooth development were described in children with OI (p = 0.05). According to sex, the root resorption of primary molars and tooth development were significantly lower in boys in both groups and in girls in the OI group, but the differences between the age groups were not significant. CONCLUSIONS: Children with OI treated with BPs exhibit delayed dental development of the premolars and delayed root resorption of the primary molars. Boys exhibited delays in both variables, but the differences by age subgroup were not significant. These clinical findings support the importance of clinically and radiographically monitoring the dental development and root resorption of primary teeth in children with OI treated with BPs to avoid alterations of the eruptive process.

Three-dimensional evaluation of dental characteristics in patients with Cleidocranial dysplasia.

BACKGROUND: Cleidocranial dysplasia (CCD) is an autosomal dominant hereditary disorder. Besides skeletal abnormalities, CCD is often associated with dental complications, such as multiple supernumerary teeth and permanent teeth impaction or delayed eruption. METHODS: Supernumerary teeth of axial, sagittal and coronal CBCT view was characterized in detail and 3D image reconstruction was performed. Number and location of teeth, morphology of supernumerary teeth, positional relationship between supernumerary and adjacent permanent teeth, direction of supernumerary teeth in CCD patients were analyzed. RESULTS: The mean age of the 3 CCD patients in this study was 16.7 years. Among 36 supernumerary teeth, the majority of them were identified as apical side located and lingual side located. Normal orientation was the most common type in this study, followed by sagittal orientation, and horizontal orientation. Horizontal orientation teeth were all distributed in the mandible. Supernumerary teeth exhibited significantly shorter crown and dental-root lengths, as well as smaller crown mesiodistal and buccolingual diameters (P < 0.01). There was no difference in the number of supernumerary teeth between the maxilla and mandible, and the premolars region had the largest number of supernumerary teeth and the incisor region had the smallest number. CONCLUSIONS: This study compares number and location of teeth, morphology of supernumerary teeth, positional relationship between supernumerary and adjacent permanent teeth and direction of supernumerary teeth, this study also provides a reference for the comprehensive evaluation of CCD patients before surgery.

Multidisciplinary approach to multiple dental anomalies in pediatric patients: a case report with 4-year follow-up.

The objective of this article is to report the clinical case and 4-year follow-up of a 5-year-old child with multiple dental anomalies, emphasizing the importance of early diagnosis and use of combined pediatric surgery and orthodontic approaches. A 5-year-old boy, accompanied by his mother, sought dental care for dental caries and tooth pain. Clinical and radiographic examinations revealed active caries, a supernumerary primary tooth in the region of the mandibular right second premolar, and severe ankylosis of the primary mandibular right second molar. The treatment plan involved extraction of the supernumerary tooth as well as sectioning and extraction of the ankylosed molar. When the patient was 6 years old, the permanent mandibular right first molar showed signs of an altered eruptive process, and orthodontic treatment was initiated. A unilateral band-and-loop space maintainer with coil springs designed to move the permanent first molar was placed on the primary first molar. A new panoramic radiograph, obtained when the patient was aged 7 years, suggested the presence of an odontoma in the apical region of the primary maxillary right canine. Surgical removal and histopathologic examination of the lesion confirmed that it was a developing odontoma. After surgery, due to occlusal anomalies that included transverse maxillary deficiency, deep overbite, and midline deviation, the patient underwent rapid maxillary expansion therapy with a Haas-type appliance. When the patient was 8 years old, orthodontic treatment continued with a removable palatal Hawley expander and a orthodontic mandibular lingual arch. Currently, at the age of 9 years, the child is still undergoing fixed orthodontic treatment after surgical exposure of the impacted permanent maxillary right canine and bonding of an orthodontic attachment to enable traction. A multidisciplinary approach to the management of dental anomalies promotes a favorable prognosis and ensures comprehensive treatment of young patients.

[The second primary molar in the lower jaw in cases of agenesis of the second premolar; use it or break it?] / De tweede melkmolaar in de onderkaak bij agenesie van de tweede premolaar; use it or break it?

In cases of agenesis of the mandibular second premolar, a choice can be made from among several treatment options. Besides preserving the second primary molar, it can be decided to close the diastema orthodontically, following extraction of the primary molar. This can be done in several ways: full or partial (hemisection) removal of the primary molar. The procedure for a hemisection initially consists of removing only the distal part of the relevant primary molar, in order to preserve the breadth of the alveolar process and to enable spontaneous mesialization of the first permanent molar. Secondly, the mesial part of the primary molar is removed.

Mesiodistal angulation and developmental stages of unerupted mandibular second premolars in nonsyndromic oligodontia.

INTRODUCTION: Oligodontia is a serious developmental dental anomaly that requires long-term multidisciplinary treatment, but its clinical characteristics are not well understood because it is rare. This study evaluated the mesiodistal angulation and developmental stages of unerupted mandibular second premolars (MnP2s) in orthodontic patients with nonsyndromic oligodontia. METHODS: Thirty-seven patients with oligodontia with at least 1 unerupted MnP2 in Demirjian's developmental stages between D and G were selected. Age- and sex-matched patients without tooth agenesis, excluding third molars, were selected as the control group. Mesiodistal angulation between the long axis of the available MnP2 and the mandibular plane was measured on panoramic radiographs. RESULTS: The MnP2 was significantly more distally angulated in the oligodontia group than in the control group. The developmental stage of the MnP2 in the oligodontia group was significantly delayed (1.04 ± 0.26 years; 95% confidence interval, 0.53-1.55 years). No correlation between the mesiodistal angulation and the developmental stage of the MnP2 was found in both groups. CONCLUSIONS: Significant distal angulation and delayed developmental stages of MnP2s were found in patients with nonsyndromic oligodontia compared with age- and sex-matched patients without agenesis of permanent teeth, excluding third molars. However, no significant correlation was found between them. Regardless of the severity of the distal angulation of MnP2, observing delayed dental development in each patient is important.

How Does Hypodontia Compare in Nonsyndromic Pierre Robin Sequence Versus Isolated Cleft Palate and Isolated Cleft Lip?

OBJECTIVE: To assess the prevalence and patterns of hypodontia in nonsyndromic Pierre Robin sequence (PRS) and compare it with hypodontia in nonsyndromic isolated cleft palates and isolated cleft lips. DESIGN: Retrospective cohort study. SETTING: Alder Hey Children's Hospital, United Kingdom. PATIENTS: Patients with nonsyndromic PRS (group 1), isolated cleft palate (group 2), and isolated cleft lip (group 3). MAIN OUTCOME MEASURES: Hypodontia in the permanent dentition assessed from orthopantomographs. RESULTS: A total of 154 patients were included. Group 1 had the highest incidence of hypodontia with 47% having at least one tooth congenitally absent. Groups 2 and 3 had reduced rates of hypodontia with 27% and 19% of the groups missing teeth, respectively; 93% of cases of hypodontia in group 1 involved the absence of at least one second premolar. Of these patients, there was found to be bilateral agenesis of second premolars in 50% of cases. CONCLUSIONS: Patients with PRS and cleft palates are more likely to have hypodontia than those with isolated cleft palates or unilateral cleft lips. Patients with PRS have more severe hypodontia than those with isolated cleft palates or unilateral cleft lips. Bilateral agenesis of lower second premolars is a commonly seen pattern among patients with PRS. In this large UK study, a similar prevalence and pattern of hypodontia to other nonsyndromic PRS populations worldwide has been demonstrated.

Autotransplantation of premolars and space closure in a patient with inflamed sinuses.

Congenital absence of permanent teeth can be treated by means of dental implants and prosthetics. Tooth autotransplantation is an alternative in growing patients because continued eruption of the transplanted tooth and associated alveolar bone growth can be expected. This clinical report presents tooth autotransplantation in a 10-year-old boy with chronic maxillary rhinosinusitis, diagnosed by the department of otorhinolaryngology. The patient's mandibular second premolars were transplanted to a congenitally edentulous maxillary premolar region. There was insufficient alveolar bone during transplantation because of pneumatization, but normal root development with vertical alveolar bone growth was observed during a 3-year follow-up. Healing of the transplant in the right side without closing of the apex and without signs of obliteration after 4 years is exceptional.

Tooth agenesis patterns in Japanese orthodontic patients with nonsyndromic oligodontia.

INTRODUCTION: Tooth agenesis is the most common dental anomaly in humans and is often found in orthodontic patients. However, severe tooth agenesis (oligodontia) is rare and its characteristics are poorly understood. This study aimed to investigate tooth agenesis patterns of Japanese orthodontic patients with nonsyndromic oligodontia. METHODS: Panoramic radiographs of 228 orthodontic patients (141 females, 87 males) with nonsyndromic oligodontia were selected and permanent tooth agenesis excluding third molars was evaluated. Influence of cutoff age was tested, tooth agenesis patterns for each quadrant were calculated, and antagonistic maxillary and mandibular quadrants were merged as the occluding tooth agenesis pattern. Full-mouth tooth agenesis patterns were also evaluated. RESULTS: The highest prevalence of tooth agenesis was observed in maxillary and mandibular second premolars, followed by maxillary first premolars. Prevalence of a symmetric pattern between right and left quadrants was significantly higher than matched patterns between maxillary and mandibular antagonistic quadrants. Among 456 possible tooth agenesis patterns, 51 and 49 patterns were observed for the maxillary and mandibular quadrants, respectively, but 215 patterns for the occluding patterns were observed. In addition, 180 full-mouth tooth agenesis patterns were observed in the 228 patients. CONCLUSIONS: Distinct characteristics in highly ranked patterns were observed compared with studies from other geographic areas, especially in the maxillary arch. Occluding and full-mouth tooth agenesis patterns showed wide variation, suggesting difficulty in orthodontic diagnosis.

Conservative management of a rootless premolar: a case report with 4-year follow-up.

Any disturbance in the primary tooth can lead to an altered eruption pattern of the corresponding permanent tooth. This article presents a case of a carious permanent second premolar with an immature root that erupted prematurely following extraction of the infected primary second molar. The carious premolar was treated with a stepwise excavation, and a primary stainless steel crown was adapted to prevent microleakage and restoration failure. A follow-up evaluation at 4 years showed remarkable healing and complete root formation. To the authors' knowledge, this is the first case report in the literature that describes successful conservative management of a rootless premolar treated by pulp capping and restored with a primary stainless steel crown.

Contemporary endodontic treatment choices for adult patients with dens evaginatus and apical periodontitis: a case report with a 2-year follow-up.

Dens evaginatus (DE) frequently leads to pulp exposure and subsequent pulpal inflammation, pulpal necrosis, and periapical inflammation. This case report describes the application of regenerative endodontic therapy and mineral trioxide aggregate (MTA) apexification in a 22-year-old man with mandibular second premolars affected by DE and apical periodontitis. Regenerative endodontic therapy was performed after thorough debridement and placement of calcium hydroxide in the root canal of the left premolar. In contrast, an apical plug of MTA was placed prior to gutta percha compaction in the root canal of the right premolar. Both teeth were restored with adhesive composite resin. A 2-year follow-up examination revealed complete periapical healing.

Root canal preparation in 3-rooted maxillary premolars through hand, rotary, and reciprocating techniques: a microcomputed tomography evaluation.

Endodontic management of 3-rooted maxillary premolars is a challenge due to their complex anatomy and narrow root canal walls. This study aimed to evaluate, by microcomputed tomography (µCT), the apical enlargement and centering ability promoted by hand, rotary, and reciprocating instrumentation in 3-rooted maxillary premolars. Eighteen teeth were divided into 3 groups (n = 6) according to the preparation technique: crown-down hand, rotary, and reciprocating instrumentation. Instruments with similar apical diameters were used (25 and 40 mm for buccal and palatal canals, respectively). Centering ability and canal enlargement were evaluated through the comparison of µCT images obtained before and after instrumentation. Distances of 0, 2, 4, and 6 mm from the apical stop were considered. Differences between canal areas before and after instrumentation were calculated. In addition, distances between the original canal center and the prepared canal center at the apical stop were measured in both the mesiodistal and buccopalatal directions. Significant differences in enlargement areas and centering ability among the techniques were determined using 2-way analysis of variance and Tukey post hoc test (P > 0.05). Root canal enlargement was similar for all techniques. Excessive enlargement was observed in only a few specimens, and root perforation did not occur. Some specimens presented untreated canal areas. In mesiobuccal and distobuccal roots, reciprocating instrumentation promoted more centered preparations than hand instrumentation when measured in the mesiodistal direction (P > 0.05). There were no other statistically significant differences. The results established that hand, rotary, and reciprocating techniques presented similar safety margins for instrumentation of the apical third of 3-rooted maxillary premolars. Reciprocating instrumentation presented some advantages over hand preparation regarding centering ability.

Buccally impacted maxillary canines increase the likelihood of root separation in adjacent first premolars.

OBJECTIVE: To investigate the influence of maxillary impacted canines on the root morphology of adjacent premolars in a Chinese population. SUBJECTS AND METHODS: A sample of 370 Chinese subjects with maxillary canine impaction and 370 control subjects were collected in this study. CBCT data of all subjects were collected and analyzed. The prevalence of separate-rooted maxillary premolars was compared between subjects with and without impacted canines. Then, the prevalence of separate-rooted maxillary premolars was compared between subjects with buccal canine impaction (BIC) and those with palatal impaction (PIC). RESULTS: The prevalence of separate-rooted first premolars was significantly higher in the canine impaction group (P = 0.046), but the prevalence of separate-rooted second premolars was not different (P = 0.780). Furthermore, a significant higher prevalence of first premolar root separation was found on the impacted site in the BIC subgroup (P < 0.001), but not in the PIC subgroup (P = 0.508). Also, the prevalence of separate-rooted first premolars in the BIC subgroup was significantly higher than that of the control group (P = 0.008), but not so for the PIC subgroup (P = 0.097). CONCLUSIONS: Buccally impacted maxillary canines are associated with an increased prevalence of root separation in the adjacent maxillary first premolars. This is likely because that buccally impacted canines encroach on the space needed for root development of the first premolars.

Second premolar agenesis as a subclinical phenotype of isolated cleft palate.

OBJECTIVE: To compare the prevalence of dental anomalies in patients with isolated cleft palate with or without hypodontia of the second premolar. SETTING AND SAMPLE POPULATION: A total of 653 patients with isolated cleft palate aged 8-12 years were divided into two groups: G1-subjects without hypodontia of second premolar (n = 546) and G2-subjects with hypodontia of at least one-second premolar (n = 107). The control group consisted of 107 non-cleft orthodontic patients. MATERIALS & METHODS: Panoramic and periapical radiographs and dental casts were used to analyze the presence of dental anomalies. Intergroup comparisons were performed using the chi-square test complemented by Proportion test and Bonferroni test. RESULTS: G2 presented higher prevalence of hypodontia of other permanent teeth compared to G1 and control. Ectopic eruption of the maxillary canine and tooth transposition were more frequent in patients with a cleft compared to patients without a cleft, without statistical differences. Deciduous molar infra-occlusion and second premolar disto-angulation were less prevalent in G1 and G2 compared to the control group. G2 showed a higher prevalence of complete cleft palate than G1. CONCLUSION: Patients with cleft palate and second premolar agenesis showed increased prevalence of tooth agenesis and palatally displaced canines.

Association Between Odontoma and Impacted Teeth.

Odontoma is considered to be the most common odontogenic tumor of the oral cavity. Most odontomas are asymptomatic and are discovered during routine radiographic investigations and can cause disturbances in the eruption of the teeth, most commonly delayed eruption or deflection. By a retrospective study design, demographic and clinical data regarding patients who presented odontomas from year 1995 to 2015 were obtained in order and the influence of active therapy on the dentition and on the treatment of impacted teeth was analyzed. Forty-five patients (mean age 14.2 years) with 29 complex and 16 compound odontomas were included in this retrospective study. Initial symptoms were delayed eruption of permanent teeth (n = 25), pain (n = 6), swellings (n = 4), and no symptoms (n = 10); 31 patients were discovered by incidence, all of them via panoramic radiographs. The mandible/maxilla ratio was about 2:1 (31/15). Thirty-two out of 45 odontomas were in close proximity of at least 1 tooth (n = 21 at incisive). A total of 12 teeth were extracted (complex: n = 8; compound: n = 4). Of the nonextracted teeth, 33 teeth were displaced and retained. Of those, 29 teeth were aligned through orthodontic-surgical approach and 4 teeth erupted spontaneously after surgery during the follow-up period. An early detection of odontoma is more likely an accidental radiological finding, hence the need for routine radiographic analysis should be emphasized. Early diagnosis of odontomas in primary dentition is crucial in order to prevent later complications, such as impaction or failure of eruption of teeth.

Management of missing mandibular second premolars: a review.

Tooth agenesis is the most common developmental dental anomaly and it is frequently associated with other dento-skeletal disturbances, such as structural variations of other teeth, late dental eruption, transpositions and crowding. Except for the third molars, the mandibular second premolars are the most commonly missing teeth. Oral rehabilitation of patients with missing mandibular premolars often requires a multi-disciplinary approach, and usually results in prolonged treatment time and a greater burden of care. An understanding of the aetiology and clinical features of hypodlontia is essential for the planning phase and the outcome of treatment. The purpose of the present review is, therefore, to discuss the aetiology of hypodlontia as well as to evaluate the clinical options available for the treatment of missing mandibular second premolars. An insight into future research directions and their clinical applications will also be discussed.

A Technique for Utilizing Ankylosed Teeth for Anchorage.

We present a novel method of reinforcing anchorage by utilizing ankylosed teeth. This technique provides simple solutions in otherwise challenging and complex cases.

Methodology for Morphometric Analysis of Modern Human Contralateral Premolars.

OBJECTIVE: This study aimed at developing a standard methodology for morphometric analysis and comparison of contralateral human premolar pulp space using microcomputed tomography (micro-CT) and semiautomated software. The primary objective was to establish a method to compare the complex and minute morphological internal volumes of contralateral premolar pulp spaces and determine their degree of similarity. The secondary aim was to introduce new methodology for selecting contralateral premolars for the study of biomaterials and techniques. METHODS: Forty-one intact human premolar pairs (n = 82) extracted from 28 patients were scanned with micro-CT. Quantitative comparative evaluation was performed through geometric morphometric deviation analysis of the pulp spaces after mirroring, automatic alignment, and coregistration with semiautomated software. Geometric parameters compared included volume, surface, and surface over volume. Shape deviation analysis of transformed mean distances and root mean square errors was conducted. RESULTS: The geometric parameters of the contralateral premolar pulp spaces had significantly higher similarity coefficients than random pairs (P < 0.001). The shape deviation analysis and transformed mean distances had significantly lower values for contralaterals compared with random pairs (P < 0.001). The contralateral geometries had a statistically significant narrower distribution in deviation when compared with random pairs (P < 0.001). CONCLUSIONS: We present a methodology that sets a new standard for internal validation of the teeth to be used in ex vivo testing of endodontic materials and techniques. It also shows that the resolution of the CT scan is crucial and that studies using cone beam CT cannot be used for such studies.

Radiographic Study of the Prevalence and Distribution of Hypodontia Associated with Unilateral and Bilateral Clef Lip and Palate in a Hungarian Population.

BACKGROUND Cleft defects are one of the most frequent birth-deformities of the orofacial region and they are commonly associated with anomalies of the tooth structure, size, shape, formation, eruption, and tooth number. The aim of our study was to evaluate the prevalence, distribution, and potential association of combined hypodontia in cleft-affected patients with regard to all types of teeth in both jaws in the permanent dentition. MATERIAL AND METHODS This retrospective radiographic analysis included patients with various types of clefts treated orthodontically in the Department of Orofacial Orthopedics and Orthodontics at Heim Pàl Children's Hospital, Budapest. There were 150 patients (84 males, 66 females) with non-syndromic unilateral (UCLP; n=120 patients) or bilateral (BCLP; n=30 patients) cleft formation (lip, alveolus and palate) who met the inclusion criteria. Statistical analysis was performed using the chi-square test and Fisher's exact test (significance level p<0.05). RESULTS Hypodontia was significantly more frequent in patients with cleft-sided lateral incisor (104 patients, 69%), with a total of 235 missing teeth, followed by the second premolars of the upper and lower jaw. A significant correlation of congenital missing teeth was observed in left-sided clefts between the upper and lower second premolar in the cleft area CONCLUSIONS Hypodontia inside and outside the cleft area was frequently observed. This should affect the therapy plans, especially if the cleft-sided premolar is also absent. Further comprehensive research including numerous random samples is necessary for better estimating other possible associations.

Management of severely impacted mandibular canines and congenitally missing mandibular premolars with protraction of autotransplanted maxillary premolar.

Transmigrated mandibular canines increase the treatment complexity in terms of both anchorage and biomechanical planning. Additionally, a Class II malocclusion with a deep overbite and associated dental anomalies such as hypodontia can further increase the treatment complexity and the overall treatment time. This case report describes the successful interdisciplinary treatment of a patient, aged 12.5 years, with transmigrated and severely impacted mandibular canines and congenitally missing mandibular second premolars. The transmigrated mandibular right canine was extracted, and a maxillary second premolar was autotransplanted to the missing mandibular right second premolar site with the aid of a stereolithographic donor tooth replica fabricated with 3-dimensional cone-beam computed tomography and a rapid prototyping technique. Furthermore, the autotransplanted tooth was protracted by 4 to 5 mm to close the space caused by the extraction of the mandibular right canine. The impacted mandibular left canine was orthodontically guided into its normal position in the arch. Good esthetic outcome and functional occlusion were achieved.