Evaluation of the aesthetics and clinical findings in patients with missing maxillary lateral incisors treated with a 10-year interval

INTRODUCTION

The most common treatment approaches for patients missing maxillary lateral incisors are implant replacement (IT) and orthodontic space closure (SC). Treatment techniques change and improve over time, and it is of interest to know if improvements differ between the methods.

AIM

To compare the aesthetic outcome and other clinical findings in patients with one or two missing maxillary lateral incisors who were treated with a 10-year difference in time, with either orthodontic space closure or implant replacement.

MATERIAL AND METHODS

A total of 88 patients were included in the study. Forty-four patients treated between 2011 and 2018 were included as the latter cohort (LC). The LC was compared to the early cohort (EC; n = 44), treated between 2001 and 2008. A total of 132 teeth was analysed: 62 teeth in the EC (28 teeth in IT cases and 34 teeth in SC cases) and 70 teeth in the LC (34 teeth in IT cases and 36 teeth in SC cases). Long-term clinical and aesthetic outcomes were evaluated.

RESULTS

An improvement over time was found in crown length, BoP, papilla, the inclination of incisors, and overall appearance in IT cases and in crown colour and overbite in SC cases. A deterioration over time was found in crown length and BoP among the SC cases.

CONCLUSION

Among the IT cases, an improvement in outcomes was noted over time. When comparing SC cases the colour of the crown and overbite had improved, while crown length and BoP had deteriorated over time.

Prevalence and Characterization of External Cervical Resorption Using Cone Beam Computed Tomography

INTRODUCTION

The aim of this study was to assess the prevalence of external cervical resorption (ECR) and characterize the cases of ECR using cone beam computed tomography (CBCT).

METHODS

High-resolution CBCT scans of 6216 patients (2280 males and 3936 females), consecutively acquired during the period July 2021 to March 2022, were analyzed. Identified cases of ECR were characterized by 3 evaluators regarding lesion height, circumferential spread, portal of entry proximity to root canal, stage, location, and width.

RESULTS

In a total of 38 patients and 40 teeth, ECR cases demonstrated an incidence of 0.61%. The median age of the patients was 39 years. Prevalence of ERC was 0.78% among males and 0.50% among females. The most affected teeth were the maxillary incisors and canines. The most frequent characteristics of the lesion were: extension up to the cervical third (47.5%), more than 270° circumferential spread (42.55%), probable pulpal involvement (57.5%), progressive stage (65%), supracrestal (52.1%) and mesial (34.7%) localization of >1 mm in size (52.1%) portals of entry. Cases with greater longitudinal involvement also showed greater circumferential progression (P = .008). There was no association between portal of entry location and bone crest or ECR reparative phase (P = .42). Inter-rater agreement ranged from good to very good. No association between portal of entry and ECR progression was observed.

CONCLUSIONS

ECR showed low prevalence in the Brazilian population, affecting mostly anterior maxillary teeth of patients within a wide age range. CBCT allowed characterization of ECR lesions with good interobserver agreement.

Development of undergraduate students' diagnostic accuracy for the classification of molar incisor hypomineralization

INTRODUCTION

One of the major difficulties with respect to molar incisor hypomineralization (MIH) is its classification and differentiation from other enamel development defects (EDDs). The aim of this study was to evaluate diagnostic accuracy in dental students to classify MIH as well as its differentiation from other EDDs by combining conventional theoretical classes and e-learning-assisted pre-clinical practices.

METHODS

In this one-group pre-test and post-test study, 59 second-year students assessed 115 validated photographs using the MIH Index on the Moodle learning platform. This index assesses the clinical features and extent of MIH, differentiating it from other EDDs. Students received automatic feedback after the pre-test. Two weeks later, students re-evaluated the same photographs. Both pairwise accuracy and overall diagnostic accuracy were estimated and compared for pre- and post-testing, with the area under the curve AUC, along with 95% confidence intervals (95% CI).

RESULTS

The lowest diagnostic accuracy was for the ability to discriminate between white or cream-coloured demarcated opacities and hypomineralization-type defect that is not MIH. The overall pre-test accuracy was AUC = 0.83 and increased significantly post-test to AUC = 0.99 (p < .001). The overall accuracy to discriminate the extent of the lesion also increased significantly post-test (p < .001).

CONCLUSION

Diagnostic skills to classify MIH can be developed by combining conventional theoretical classes and e-learning-assisted pre-clinical practices.

Co-occurrence of periodontal lesions and dental wear in incisor and masticatory teeth in two sheep flocks in Brazil

BACKGROUND

Periodontitis and tooth wear are multifactorial diseases with distinct etiopathogenesis that affect the health, feed efficiency and welfare of sheep.

METHODS

This study evaluated the co-occurrence of tooth wear and periodontal lesions in 129 ewes from two Brazilian flocks, clinically classified the lesions and presence of dental calculus, and identified potential pathogens in the dental biofilm of 63 ewes by polymerase chain reaction.

RESULTS

Of the 129 ewes included in the study, 75 presented periodontal lesions, while all animals presented tooth wear and dental calculus. Of the animals with periodontal lesions, 16.2% had lesions in incisor teeth and 52.7% in masticatory teeth. Regarding excessive tooth wear, 38.6% had severe wear on the incisor teeth and 89.1% on the masticatory teeth. Ewes older than 36 months had a higher frequency of periodontal lesions in incisor teeth (p < 0.001) and a greater amount of dental calculus (p < 0.001), but there was no association between tooth wear and animal age. Fusobacterium nucleatum, Tannerella forsythia and Fusobacterium necrophorum predominated in periodontal lesions.

LIMITATION

This study is limited by the small sample size and lack of diagnostic imaging to assess periodontal disease.

CONCLUSION

The co-occurrence of periodontal lesions and excessive dental wear involving both the incisor and masticatory teeth suggests that although the two diseases have different aetiologies, they likely have common risk factors.

High frequency of dental caries and calculus in dentitions from a British medieval town

OBJECTIVE

Dental pathology and tooth wear data can offer valuable insights into the diet and behaviour of past populations. This study aimed to investigate the presence of dietary continuity by examining different types of dental pathology and tooth wear in a medieval sample from the United Kingdom, comparing them to earlier and later samples from the same location.

DESIGN

A comprehensive examination was conducted on 41 individuals (comprising 914 permanent teeth) retrieved from the medieval cemetery of St. Owens Church in Southgate Street, Gloucester, UK. The research focused on documenting and analysing various types of dental pathology and tooth wear, such as dental caries, calculus, and tooth chipping. The frequency of these specific pathologies and wear patterns was then compared to existing literature. Additionally, non-masticatory tooth wear was also evaluated as part of the study.

RESULTS

The sample exhibits high levels of carious lesions and calculus (24 % and 74 % of teeth respectively). Anterior teeth also show an elevated chipping frequency, and along with occlusal notches on the maxillary central incisors suggest teeth were regularly used for non-masticatory purposes.

CONCLUSIONS

Caries frequency is similar to sites from later periods and may relate to the early adoption of consuming refined carbohydrates. However, remains from the same area, but the earlier Roman period, also shows high rates of caries and calculus, suggesting a continuation of consuming certain cariogenic foods, or certain behavioural/environmental factors, may instead be responsible for these pathology and wear patterns.

Idiopathic bone cavity mimicking a botryoid odontogenic cyst: A rare radiographic presentation in an older adult

OBJECTIVES

This report describes an unusual case of a multilocular idiopathic bone cavity (IBC) that presented as a botryoid odontogenic cyst situated between the mandibular lateral incisor and canine in an older adult.

BACKGROUND

The IBC represents an intraosseous concavity that appears radiographically as a unilocular or multilocular radiolucent lesion found in various skeletal sites, including the jaw. Atypical cases of gnathic IBC have not been appreciated in the gerodontologic literature.

MATERIALS AND METHODS

The teeth adjacent to the bony lesion had normal pulpal responses to cold. A full-thickness flap was elevated and provided a direct entry into a bony concavity, which was devoid of an epithelial lining and fluid.

RESULTS

The lack of a cystic lining within the empty osseous lesion following surgical entry, concomitant with the vital pulpal status of the proximal teeth, led to a diagnosis of an IBC. The bony walls underwent curettage and copious irrigation prior to primary closure. A 10-month follow-up revealed partial evidence of osseous repair. The patient will continue to be monitored.

CONCLUSION

Timely surgical intervention of central lesions of the jaws may improve clinical outcomes. Variants of the IBC should be included in the differential diagnosis of multilocular lesions, particularly in the geriatric population.

A clinical and statistical study on enamel hypomineralization of the first permanent molar in the period of mixed dentition

BACKGROUND

The first permanent molar (FPM) is the first tooth in the permanent dentition that emerges in the oral cavity, at around the age of six and behind the deciduous teeth, thus converting the primary dentition into a mixed dentition. Its early formation represents a risk factor for the onset of hard dental tissues disorders, the most common being the molar incisor hypomineralization (MIH).

AIM

The aim of the study was to assess the hypomineralization type of developmental defects of enamel at FPM level during the mixed dentition stage, in a group of Romanian children.

PATIENTS, MATERIALS AND METHODS

The research was conducted on 87 patients, 44 females and 43 males, divided into the following age groups: 5-6 years, 6-7 years, 7-8 years, 8-9 years, 9-10 years, 10-11 years, 11-12 years and older than 12 years. All children were examined in the dental office by a pediatric dentist.

RESULTS

Of the subjects, 40.2% presented hypomineralization lesions on the FPM. Among the affected children, 62.9% were girls and 37.1% were boys. Mild forms were the most prevalent, being found in 71.4% of the affected subjects. Moderate forms were present in 22.9% and severe forms in 5.7% of the affected children. MIH prevalence significantly decreased with increasing age. Only two children belonging to the group 8-9 years and 10-11 years, respectively, showed severe MIH lesions. Statistically significant differences were determined in what regards the distribution of MIH children according to the severity of the lesions in relation to age (p=0.007).

CONCLUSIONS

Children 6- to 7-year-old have been the most affected by FPM hypomineralization, which indicates the need for early management of the disease, through a thorough diagnosis, and preventive and interceptive therapeutic approaches.

Root canal treatment of type Ⅱ and ⅢA double dens invaginatus in maxillary lateral incisor: a case report

Dens invaginatus is a rare developmental anomaly of the teeth that is caused by the infolding of enamel organs or the penetration of their proliferations into dental papillae before calcification has occurred. The presence of double dens invaginatus is extremely rare. This paper describes the use of cone beam computed tomography in the evaluation of a maxillary lateral incisor with double dens invaginatus and periapical periodontitis. The tooth was treated through microscopic root canal therapy. The tooth was free of clinical symptoms, and the periradicular lesion narrowed during the follow-up period of 1 year.

Symmetry of carious lesions in primary and permanent teeth in children as a predictor of future caries patterns

This study evaluated the bilateral symmetry of carious lesions in the primary and permanent teeth of children. The clinical records of patients aged 3 to 14 years who had carious lesions were evaluated. Dental caries was assessed using the modified decayed, missing, and filled teeth (dmft/DMFT) index, and the biofilm was assessed using the O'Leary plaque control record. The results were analyzed considering the presence or absence of caries and the stages of caries. The kappa coefficient between the left and right sides was calculated, and the chi-square test was applied (P < 0.05). The sample consisted of 206 children and 4802 teeth (2127 primary and 2675 permanent teeth). Fifty-one percent of the sample was female, and the mean age was 8.28 (SD 1.62) years. The mean number of dmft/DMFT was 4.45 (SD 3.61), and the mean O'Leary plaque index was 27.38%. The overall symmetry for the presence/absence of dental caries was 49.5% (n = 342), and the symmetry for the stage of caries was 43.5% (n = 301). The symmetry was similar in primary and permanent teeth for the presence/absence of caries (50.83% and 47.39%, respectively) and stages of caries (42.08% and 45.89%, respectively). Among the teeth that showed symmetry of carious lesions, there was an association between the hygiene condition and the presence of lesions in all maxillary and mandibular primary second molars and in the mandibular permanent right first molar (P < 0.05). A bilateral symmetric relationship of carious lesions was observed in the primary canines, primary first and second molars, permanent central and lateral incisors, first premolars, and permanent first molars in both the maxillary and mandibular arches. The results suggest that the presence of a carious lesion on a tooth surface can predict vulnerability to caries on the contralateral tooth, allowing the dentist to pursue targeted preventive action.

Familial Presentation of Ankyloglossia and Localized Periodontitis

An association between ankyloglossia and periodontitis has not previously been reported. This case series describes three sisters who each had ankyloglossia and a molar/incisor pattern of localized periodontitis. The concurrent presentation of both conditions within the family suggests that further investigation of genetic factors that might concurrently affect the pathogenesis of both disorders may be warranted.

MIH-Affected Teeth: Clinical Challenges from Diagnosis to Restorative Management

Teeth affected by molar incisor hypomineralization (MIH) present micromorphologic changes and hypersensitivity, which increase the risk of developing caries lesions and affect bonding procedures. Considering that practitioners still misdiagnose teeth affected by MIH, there is an urge for more knowledge about this topic in order to propose a more adequate and conservative treatment. The purpose of this study was to report the clinical challenges regarding the restorative management of a patient with MIH. A 13-year-old girl sought dental treatment, complaining about hypersensitivity in posterior teeth. Under clinical exams, notable enamel alterations mainly affecting posterior teeth (including molars) presented particular characteristics frequently attributed to MIH, and visible stains on maxillary central incisors were present. Because the mineral and organic content of MIH-affected enamel differ from sound enamel, it may imply special care for bonding of a restorative material. Thus, in order to promote a minimally invasive approach, selective removal of carious tissue and restoration with microhybrid composite resin was conducted after application of a universal bonding system used as self-etching strategy. After a 2-year follow-up, the restorations presented good clinical performance and the patient had limited hypersensitivity discomfort, suggesting a promising performance.

Pathological tooth migration-spontaneous correction of diastema after surgical periodontal therapy: a case report

A common consequence of moderate to extreme periodontitis is pathologic migration. This denotes tooth movement when the periodontal disease interjects the equilibrium among the elements that preserve physiological tooth position. The balancing factors can migrate the teeth in any direction. The etiology of pathological migration tends to be multifactorial, thus achieving early diagnosis is imperative, which will ultimately lead to the prompt removal of the etiological factors while avoiding severe bone destruction. In this case maxillary central incisors had diastema due to pathological migration with mobility grade I in maxillary left central incisor. Many cases of moderate to severe pathological migration need a suitable, interdisciplinary approach. Nevertheless, since it is possible to detect mild cases of Pathological tooth migration (PTM) at an early stage, spontaneous correction of migrated teeth can be accomplished by periodontal therapy alone. Regardless of the treatment selected, maintenance of stable results should be considered as an aim of treatment.

The prevalence of molar-incisor hypomineralization: a systematic review and meta-analysis

Molar-Incisor Hypomineralization (MIH) is a qualitative defect of enamel of unknown etiology, affecting one or more permanent molars and may include incisors. This condition is a clinical challenge and its prevalence is still uncertain given the recent increase in research. Thus, we aimed to comprehensively estimate the overall prevalence of MIH and associated characteristics. This systematic review is reported according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA). We searched articles using PubMed, MEDLINE, CENTRAL, Web of Science, SciELO, LILACS and TRIP databases, until July 2021. Heterogeneity and publication bias were computed via I2 test statistics and Egger's significance test, respectively. Random-effects meta-analysis of prevalence were processed. We used the Strength of Recommendation Taxonomy [SORT] to grading the strength of evidence. Overall, 116 observational studies were included, with one study with moderate methodological quality and the remaining of high methodological quality. Subgroup analysis confirmed an influence of not using the 2003 MIH case definition (p = 0.0066). The pooled prevalence of MIH was 13.5% (95% CI 12.0-15.1, I2 = 98.0%). Affected incisors were seen in 36.6% (95% CI 30.0-43.7, I2 = 92.5%) of the cases. Lastly, the prevalence of hypomineralization of the second primary molars was observed in 3.6% of the MIH cases (95% CI 1.9-6.8, I2 = 96.3%). America was the continent with highest prevalence (15.3, 95% CI 12.8-18.3, p < 0.001, I2 = 96.3%) and Asia had the lowest prevalence (10.7, 95% CI 8.5-13.5, p < 0.001, I2 = 98.7%), however no continental differences were found. Sample size and year of publication were slight contributing factors to the heterogeneity in the analysis. Overall, these results were classified with a SORT A recommendation.

DSPP dosage affects tooth development and dentin mineralization

Dentin Sialoprotein (DSP) and phosphophoryn (PP) are two most dominant non-collagenous proteins in dentin, which are the cleavage products of the DSPP (dentin sialophosphoprotein) precursor protein. The absence of the DSPP gene in DSPP knock-out (KO) mice results in characteristics that are consistent with dentinogenesis imperfecta type III in humans. Symptoms include thin dentin, bigger pulp chamber with frequent pulp exposure as well as abnormal epithelial-mesenchymal interactions, and the appearance of chondrocyte-like cells in dental pulp. To better understand how DSPP influences tooth development and dentin formation, we used a bacterial artificial chromosome transgene construct (BAC-DSPP) that contained the complete DSPP gene and promoter to generate BAC-DSPP transgenic mice directly in a mouse DSPP KO background. Two BAC-DSPP transgenic mouse strains were generated and characterized. DSPP mRNA expression in BAC-DSPP Strain A incisors was similar to that from wild-type (wt) mice. DSPP mRNA expression in BAC-DSPP Strain B animals was only 10% that of wt mice. PP protein content in Strain A incisors was 25% of that found in wt mice, which was sufficient to completely rescue the DSPP KO defect in mineral density, since microCT dentin mineral density analysis in 21-day postnatal animal molars showed essentially identical mineral density in both strain A and wt mice. Strain B mouse incisors, with 5% PP expression, only partially rescued the DSPP KO defect in mineral density, as microCT scans of 21-day postnatal animal molars indicated a reduced dentin mineral density compared to wt mice, though the mineral density was still increased over that of DSPP KO. Furthermore, our findings showed that DSPP dosage in Strain A was sufficient to rescue the DSPP KO defect in terms of epithelial-mesenchymal interactions, odontoblast lineage maintenance, along with normal dentin thickness and normal mineral density while DSPP gene dosage in Strain B only partially rescued the aforementioned DSPP KO defect.

Frequency Of Developmentally Malformed Permanent Maxillary Lateral Incisors In Patients Visiting The Three Teaching Dental Hospitals Of Peshawar

BACKGROUND

The permanent maxillary lateral incisor (PMLI) shows morphological variations, in the form of different crown shapes such as peg-shaped, cone-shaped, barrel-shaped and canine-shaped. The frequency of developmentally malformed permanent maxillary lateral incisors varies among different populations. The aim of this study was to document the frequency of different shapes of developmentally malformed permanent maxillary lateral incisors in patients visiting the three teaching dental hospitals of Peshawar.

METHODS

It was a cross-sectional study conducted in the Oral Diagnosis department of Peshawar Dental College, Sardar Begum Dental College, and Khyber College of Dentistry from 1st Sep 2018 to 15th June 2019. A total of 82 subjects were included that fulfilled the inclusion criteria. Shape of the malformed PMLI was determined using Computer-aided design/Computer-aided manufacturing software. Descriptive statistics including frequencies and percentages for observed developmental malformation and their types were computed and Chi-square test was applied to see the relation between various shapes and their occurrence with respect to site and position within the jaws.

RESULTS

The peg shaped PMLI was seen in 81 (98.87%) patients and barrel shaped was present in 1 (1.22%) patient. The malformed PMLIs was found to be unilateral in 38 (46.3%) and bilateral in 44 (53.7%) patients, with more common presence on both sides 44 (53.7%) followed by right side 20 (24.4%) and left side 18 (22.0%).

CONCLUSIONS

The subjects having predominant developmental malformation in case of permanent maxillary lateral incisor was peg-shaped permanent maxillary lateral incisor.

Anomalous incisor morphology indicates tissue-specific roles for Tfap2a and Tfap2b in tooth development

Mice possess two types of teeth that differ in their cusp patterns; incisors have one cusp and molars have multiple cusps. The patterning of these two types of teeth relies on fine-tuning of the reciprocal molecular signaling between dental epithelial and mesenchymal tissues during embryonic development. The AP-2 transcription factors, particularly Tfap2a and Tfap2b, are essential components of such epithelial-mesenchymal signaling interactions that coordinate craniofacial development in mice and other vertebrates, but little is known about their roles in the regulation of tooth development and shape. Here we demonstrate that incisors and molars differ in their temporal and spatial expression of Tfap2a and Tfap2b. At the bud stage, Tfap2a is expressed in both the epithelium and mesenchyme of the incisors and molars, but Tfap2b expression is restricted to the molar mesenchyme, only later appearing in the incisor epithelium. Tissue-specific deletions show that loss of the epithelial domain of Tfap2a and Tfap2b affects the number and spatial arrangement of the incisors, notably resulting in duplicated lower incisors. In contrast, deletion of these two genes in the mesenchymal domain has little effect on tooth development. Collectively these results implicate epithelial expression of Tfap2a and Tfap2b in regulating the extent of the dental lamina associated with patterning the incisors and suggest that these genes contribute to morphological differences between anterior (incisor) and posterior (molar) teeth within the mammalian dentition.

Gene-environment interaction in molar-incisor hypomineralization

Molar incisor hypomineralization (MIH) is an enamel condition characterized by lesions ranging in color from white to brown which present rapid caries progression, and mainly affects permanent first molars and incisors. These enamel defects usually occur when there are disturbances during the mineralization or maturation stage of amelogenesis. Both genetic and environmental factors have been suggested to play roles in MIH’s development, but no conclusive risk factors have shown the source of the disease. During head and neck development, the interferon regulatory factor 6 (IRF6) gene is involved in the structure formation of the oral and maxillofacial regions, and the transforming growth factor alpha (TGFA) is an essential cell regulator, acting during proliferation, differentiation, migration and apoptosis. In this present study, it was hypothesized that these genes interact and contribute to predisposition of MIH. Environmental factors affecting children that were 3 years of age or older were also hypothesized to play a role in the disease etiology. Those factors included respiratory issues, malnutrition, food intolerance, infection of any sort and medication intake. A total of 1,065 salivary samples from four different cohorts were obtained, and DNA was extracted from each sample and genotyped for nine different single nucleotide polymorphisms. Association tests and logistic regression implemented in PLINK were used for analyses. A potential interaction between TGFA rs930655 with all markers tested in the cohort from Turkey was identified. These interactions were not identified in the remaining cohorts. Associations (p<0.05) between the use of medication after three years of age and MIH were also found, suggesting that conditions acquired at the age children start to socialize might contribute to the development of MIH.

Clinico-radiologic features of molar-incisor malformation in a case series of 38 patients: A retrospective observational study

Molar-incisor malformation (MIM) is a recently defined dental abnormality of molar root and incisors, and introduced as one of the causes of periapical and periodontal abscess. The purpose of this study was to investigate the clinical and radiological features of MIM, with special emphasis on various medical history. A total of 38 patients with MIM were included in this study. Radiographic features and clinical data, including medical history, chief complaint, associated complications, treatment, and prognosis, were retrospectively investigated. On radiographs, the affected molars showed short, slender, underdeveloped roots and constricted pulp chambers. All affected incisors and canines exhibited dilacerated short roots, wedge-shaped defect on the cervical part of the crown. Complications included periodontal bone loss (52.6%), endodontic lesion (50.0%), and endodontic-periodontal lesion (28.9%). The medical histories of the patients with MIM indicate that almost all (94.7%) were hospitalized due to problems during the neonatal period. MIM may cause various dental problems, such as periapical and periodontal abscess and early loss of the affected teeth. The early diagnosis of MIM on radiographs and appropriate treatment will contribute to a favorable prognosis, especially for young and adolescent patients.

Spontaneous Development of Dental Dysplasia in Aged Parp-1 Knockout Mice

Poly(ADP-ribose) polymerase (Parp)-1 catalyzes polyADP-ribosylation using NAD⁺ and is involved in the DNA damage response, genome stability, and transcription. In this study, we demonstrated that aged Parp-1^-/- mouse incisors showed more frequent dental dysplasia in both ICR/129Sv mixed background and C57BL/6 strain compared to aged Parp-1^+/+ incisors, suggesting that Parp-1 deficiency could be involved in development of dental dysplasia at an advanced age. Computed tomography images confirmed that dental dysplasia was observed at significantly higher incidences in Parp-1^-/- mice. The relative calcification levels of Parp-1^-/- incisors were higher in both enamel and dentin (p < 0.05). Immunohistochemical analysis revealed (1) Parp-1 positivity in ameloblasts and odontoblasts in Parp-1^+/+ incisor, (2) weaker dentin sialoprotein positivity in dentin of Parp-1^-/- incisor, and (3) bone sialoprotein positivity in dentin of Parp-1^-/- incisor, suggesting ectopic osteogenic formation in dentin of Parp-1^-/- incisor. These results indicate that Parp-1 deficiency promotes odontogenic failure in incisors at an advanced age. Parp-1 deficiency did not affect dentinogenesis during the development of mice, suggesting that Parp-1 is not essential in dentinogenesis during development but is possibly involved in the regulation of continuous dentinogenesis in the incisors at an advanced age.

Analysis of Alveolar Bone Morphology of the Maxillary Central and Lateral Incisors with Normal Occlusion

Background and objectives: This study investigated the morphology of the labial and palatal bony wall of the maxillary central and lateral incisors using cone-beam computed tomography (CBCT). The difference between males and females and the measurement between right and left sides were measured. Materials and Methods: Twenty participants, consisting of 11 females and 9 males having normal occlusion, were used for the analysis. The mean age was 21.9 ± 3.0 years. The thickness of the labial bony wall and palatal bony wall, perpendicular to the long axis of the root, were evaluated at 3 and 5 mm apical from the cemento-enamel junction (CEJ) and at the root apex. The available bony wall below the apex of the central and lateral incisors, and the angulation between the long axis of the tested tooth and outer surface of the labial bone were measured. Results: The mean labial bony wall thickness at the 3 and 5 mm apical from the CEJ were 1.1 ± 0.3 mm and 1.0 ± 0.4 mm for central incisors, respectively, as well as 1.2 ± 0.4 mm and 1.0 ± 0.4 mm for lateral incisors, respectively. The mean palatal bony wall thickness at 5 mm from the CEJ was above 2 mm in the central and lateral incisors. The percentage of labial bony wall thickness 2 mm or greater at the root apex in central incisors was higher than in lateral incisors (62.5% vs. 55.0%). The percentage of palatal bony wall thickness ≥2 mm at 3 mm apical from the CEJ in the central incisors was higher than in the lateral incisors (37.5% vs. 15.0%). The results on the left and right sides did not show statistically significant differences, except in the labial and palatal bony wall thickness at 3 mm from the CEJ in the lateral incisor. Generally, no significant differences were seen between males and females, but males had a significantly higher labial bony wall thickness at 3 and 5 mm from the CEJ in the central and lateral incisors when compared with females. Conclusions: This study showed that a majority of the cases of Korean participants had less than 2 mm of labial bony wall thickness at 3 and 5 mm apical from the CEJ at central and lateral incisors, and this should be kept in mind while performing dental practices, including tooth extraction or immediate implantation in anterior regions. Preoperative analysis using CBCT may be beneficial for establishing the treatment plan.

Autologous transplantation of deciduous tooth pulp into necrotic young permanent teeth for pulp regeneration in a dog model

Objectives

To investigate the potential for pulpal regeneration via autologous transplantation of deciduous tooth pulp into immature necrotic permanent teeth using an experimental dog model.

Methods

Experimental apical periodontitis was induced in 60 teeth of six Beagle dogs. Following canal disinfection and pulpotomy, autologous deciduous pulp tissue was transplanted into the root canals (n = 30); as controls, contralateral teeth were treated in accordance with the recommendations of the American Association of Endodontists. Radiographic examinations were performed immediately before transplant, as well as 3 and 6 months after transplant. At the 6-month examination, root samples were collected and histological and immunohistochemical analyses were used to examine tissue regeneration.

Results

Radiographic analysis showed no significant differences in most histopathological parameters examined; however, apical diameter reduction was greater in the experimental group. Histological and immunohistochemical analyses showed that the canal walls of the experimental group had newly formed dentin-like tissue with dentinal tubules, while the control group had cementum-like deposits along the canal wall and apical foramina.

Conclusions

Autologous transplantation may be useful for regeneration of dental pulp in necrotic young permanent teeth.

An unusual case of invasive cervical resorption after piezosurgery-assisted en masse retraction

A 16-year-old patient sought orthodontic correction for profile improvement and labially inclined maxillary incisors. She had Class II malocclusion, protrusive maxillary and mandibular incisors, and increased overjet and overbite with an American Board of Orthodontics discrepancy index value of 25. She was treated with maxillary premolar extractions and miniscrew-supported en masse retraction assisted with piezoincisions. Extraction spaces (7.5 mm per side) were closed with maximum anchorage in 10 months. Total treatment time was 23 months. Twenty-seven months after debonding, a pink spot was noted at the buccocervial region of the left central incisor. Radiographic evaluation on cone-beam computed tomographic scans revealed a severe case of invasive cervical resorption on both central incisors, around which the piezosurgical cuts had been made. Treatment proceeded with a nonintervention approach and the affected teeth were reinforced with a lingual retainer.

New insights into odontological exploration of drowning using rat model - A pilot study

Dental forensics for the resolution of unnatural death remains an underdeveloped field. Accordingly, an experimental study was conducted with six to seven months old Wistar rats that were drowned in order to identify key postmortem features and pattern of dental decomposition. The visual, structural and elemental changes were assessed periodically. Based on mode of death, they were designated as SB (euthanized and soil buried), FWD (fresh water drowned) and SWD (sea water drowned). Postmortem features as well as the structural and elemental patterns of decomposition of teeth were analyzed with Field Emission Scanning Electron Microscopy (FE-SEM) and Energy Dispersive Spectroscopy (EDAX) periodically for two months. The periodic observation of elemental changes in the teeth of SB, FWD and SWD rats allowed us to derive an equation using linear regression analysis to relate the degree of dental decomposition with the time since death. The difference in pattern of surface deterioration was also observed. The present findings could provide a better knowledge in resolving unnatural deaths and supporting evidence for legal prosecution.

Cervical Enamel Projection - A Rare Case Report with its Management

A developmental anomaly like cervical enamel projection is a rare finding in the maxillary anterior region. Its ectopic presence attracts attention in literature. This type of anomaly is typically found in the furcation region of molars. The case report presented here deals with the ectopic presence of combined anomalous lesion and its management. A 18 year old male presented with pronounced bilobed cingulum extending as a cervical enamel projection on the maxillary right lateral incisor associated with pain, exudation and difficulty in mastication. Enameloplasty and regenerative procedure was performed. The possible etiology, its management and healing evaluated by CBCT are presented in this report. One year follow up showed satisfactory healing with no recurrence of abscess.

Molar incisor hypomineralization: Analysis of asymmetry of lesions

Clinically, Molar-Incisor Hypomineralization (MIH) lesions are not distributed symmetrically, and their severity varies even within the same arcade.

AIM

To estimate the frequency of asymmetries in hypomineralized lesions on permanent molars and incisors of children with MIH.

METHODS

Three pediatric dentists, calibrated following the diagnostic criteria of Mathu-Muju and Wright (2006) (Kappa 0.87) identified presence and severity of opacities on molars and incisors of patients with MIH. Six pairs of teeth (permanent maxillary and mandibular first molars, central and lateral incisors) were evaluated in each patient. Degree of lesion severity (0-none, 1-mild, 2-moderate, 3-severe) was recorded for each tooth. For each pair containing any affected teeth, asymmetry of presence (one tooth in the pair with lesion and the other intact), asymmetry of severity (both teeth with lesions but with different degrees of severity) or symmetry of severity (both affected teeth with the same degree of severity) were evaluated. The recorded values were entered into a database to calculate percentages, 95% confidence intervals and Chi-Square test for comparisons.

RESULTS

The sample consisted of475 of the 1032 pairs of teeth evaluated in the 172 patients included in the study, mean age 11±2.2 years, and 50% female. Asymmetry was found for 67.5% (63.1 - 71.7) of the pairs of the studied teeth. There was a significant relationship between asymmetries and symmetries (p=0.038). A total 50.1% of the pairs were asymmetrical for presence of opacities. Of these, 62.2% scored severity 1 (mild). Symmetry of severity was found for 32.5% of the lesions. Among the pairs of affected teeth, the most frequently observed degrees of lesion severity were mild and moderate, with the exception of lower molars, in which 49% had severe lesions.

CONCLUSIONS

In this study, MIH lesions were asymmetrical both in presence and severity for all tooth types.

Unilateral supplemental maxillary lateral incisor: report of three rare cases and literature review

Additional teeth to the normal dentition are called supernumerary teeth; they can be found in higher rates in permanent than in deciduous dentition, in both sexes, associated or not with other diseases or syndromes. The aim of this article is to report three rare cases of unilateral supplemental lateral incisors, in Romanian child and adult patients, and to evaluate the treatment options in each case, considering particularities such as age, physiognomy, associated issues and occlusion. The differential diagnosis between a supernumerary lateral incisor in formation and a rudimentary is sometimes difficult to make using only panoramic X-ray, so a cone-beam computed tomography analysis can be indicated. Usually, due to the pathological issues that they can cause, the supplemental maxillary lateral incisors are removed; although, in some cases, it may be necessary to remove the normal tooth, for example in cases of major crowding, in which the normal tooth is more displaced from the line of the arch than the supplemental one, or when there is a lack of periodontal support surrounding the normal tooth. This article highlights that even if, in younger patients, the majority of these teeth is extracted because later in life they can cause difficulties in orthodontic and prosthetic treatment, there are still rare cases which do not necessitate treatment, because they are asymptomatic, rather well aligned and go unnoticed. Also, the article includes a detailed literature review of reported cases of supplemental maxillary lateral incisor.

Short-term and long-term effects of osteoporosis on incisor teeth and femoral bones evaluated by Raman spectroscopy and energy dispersive X-ray analysis in ovariectomized rats

There are few published data on the relationship between loss of bone mass due to osteoporosis and poor tooth quality. This study analyzed the effects of osteoporosis on incisor teeth and femoral bones using optical techniques in rats. Twenty female Wistar rats aged 6 months (n = 20) were randomized into two groups: control group, non-ovariectomized rats (n = 10); ovariectomy group, ovariectomized rats to induce osteoporosis (n = 10). Each group was subdivided randomly into two groups containing five rats each as follows. Control group 1: non-ovariectomized rats euthanized at the age of 9 or 3 months post-ovariectomy (n = 5); Control group 2: non-ovariectomized rats euthanized at the age of 1 year or 6 months post-ovariectomy (n = 5); ovariectomy group 1: ovariectomized rats euthanized at the age of 9 months or 3 months post-ovariectomy (n = 5); ovariectomy group 2: ovariectomized rats euthanized at the age of 1 year or 6 months post-ovariectomy (n = 5). The incisor teeth and femoral bones of Wistar rats were removed to perform Raman spectroscopy using an excitation laser at 785 nm. In addition, an energy-dispersive X-ray spectrometer system was used to evaluate calcium (Ca) and phosphorus (P). The main findings included significant changes (p < 0.05) for phosphate and carbonate band areas for both incisor teeth and femur bones. In addition, there was significant negative correlation between the P concentration and phosphate/carbonate ratio (lower P content-larger ratio, p < 0.05) for incisor teeth and femoral bones. The proline and CH₂ wag band areas were significantly reduced only for the incisor teeth (p < 0.05). Therefore, Raman spectroscopy assessed the compositional, physicochemical and structural changes in hard tissue. The current study also pointed out the possible action mechanisms of these changes, bone fracture risk and dental fragility. It is important to emphasize that poor dental quality may also occur due to osteoporosis.

Bilateral dentoalveolar asymmetries in female patients with adolescent idiopathic scoliosis

PURPOSE

The aim of this cross-sectional research was to quantify left-right dentoalveolar fluctuating (FA) and directional asymmetries (DA) in patients with adolescent idiopathic scoliosis and to assess the relationship between these asymmetries and the side, location, and severity of scoliosis.

MATERIALS AND METHODS

The study group comprised of 60 females aged 12-16 years, with idiopathic scoliosis, and 54 healthy controls. Measurements were made with the use of digital caliper on full-mouth dental casts. The following variables were measured from each subject: a shift of the incisor midline, left and right incisor overjet, deviation of canine and buccal segment relation as well as maxillary and mandibular arch chords. The data were statistically analyzed with significance taken as p < 0.05.

RESULTS

Statistically significant differences in the mean shift of the incisor midline, buccal segment relation on the left and canine deviation on the left between the control group and the study group were detected ( p = 0.0419, p = 0.0.458 and p = 0.0204, respectively). FA of the midline deviation and canine deviation were statistically significantly higher for subjects with IS, compared to healthy controls ( p = 0.0315 and p = 0.0415, respectively). Neither direction of the curve nor apical vertebra's location or apical translation significantly affected the magnitude of dentoalveolar asymmetries.

CONCLUSIONS

Our results confirmed that bilateral asymmetries are a common feature of the young females' occlusion. Individuals with IS show higher tendency to Angle Class II malocclusion, as well as higher FA of incisor midline discrepancy and canine deviation, compared to the controls.

The Prevalence and Severity of Molar Incisor Hypomineralization and Molar Hypomineralization in Dubai, UAE

Purpose: The purpose of this study was to evaluate the prevalence and severity of molar incisor hypomineralization (MIH) among schoolchildren in Dubai, UAE.Methods: A randomized cluster sample of 342 eight to 12-year-old schoolchildren had their permanent first molars and incisors evaluated for prevalence and severity of MIH using the European Academy of Paediatric Dentistry criteria.Results: The prevalence of MIH in Dubai was found to be 27.2 percent and was significantly higher in girls (32.6%) compared to boys (18.1%;P=0.002). The prevalence of molar hypomineralization (MH) was higher than MIH: of the 27.2 percent diagnosed children, 65.6 percent had only MH while 34.4 percent had MIH. MH prevalence in maxillary molars was 20.8 percent, significantly higher than 14.6 percent in mandibular molars (P≤0.005). Almost nine percent of maxillary incisors were affected by MIH compared to 0.9 percent of mandibular incisors (P≤0.001). The presence of demarcated opacities was significantly higher in females than males (P =0.002). Fifty-three percent of the children with MIH had mild defects, 17 percent had moderate defects, and 30 percent had severe defects.Conclusions: Despite the high prevalence of MIH in schoolchildren in Dubai, the severity was mild. The prevalence of MIH and MH was significantly related to sex and location of tooth in the oral cavity.

Association between maxillary lateral incisors' root volume and palatally displaced canines: An instrumental variables approach to the guidance theory

OBJECTIVES:

To evaluate association and causation between maxillary lateral incisors' (MxI2) apical root volume (ARV) and palatally displaced canines (PDC).

MATERIALS AND METHODS:

In a retrospective cross-sectional study, computed tomography scans of 179 patients with unilateral PDC were analyzed. MxI2 root length and volume on the impaction and eruption side were measured. A mixed logit model was used to infer the association between ARV and PDC and an instrumental variables approach to interpret causality.

RESULTS:

MxI2 root length on the impaction side was shorter in 42%, equal in 33% and longer in 25% of the patients. ARV amounted for 13.5% of total root volume on the impaction and 14.9% on the eruption side. Reduced ARV was significantly associated with the impaction side ( P < .001). The causal effect of ARV on PDC in the instrumental variable approach amounted to less than half of the association in a standard noncausal approach.

CONCLUSIONS:

An association between PDC and reduced MxI2 root length and volume was confirmed. However, the lack of causality did not allow the researchers to draw a conclusion as to whether a reduced ARV is causing PDC or resulting from it; this should be considered in etiologic theories.

Tooth wear and gingival recession in 210 orthodontically treated patients: a retrospective cohort study

Aim

To assess the association between tooth wear (TW) and gingival recession (GR).

Materials and Methods

Two hundred and ten orthodontically treated participants (100 males) were evaluated. GR and TW were rated independently by four raters on plaster models at four time points: before treatment (T1), mean age 13.8 years (SD = 3.7); after treatment (T2), mean age 16.7 years (SD = 3.9); 3 years after treatment (T3), mean age 19.7 years (SD = 4.2); and 7 years after treatment (T4), mean age 23.9 years (SD = 4.8). Univariable and mulitvariable random effects logistic regression analyses were performed with scores for GR as dependent variables and with TW, age, gender, dental segments (maxillary and mandibular anterior and posterior segments), time points, and Angle classification as independent variables. Method reliability was assessed with kappa statistics.

Results

Mandibular incisors, mandibular and maxillary first premolars and maxillary first molars were most vulnerable to GR. The prevalence of GR increased during the observation period. At T1 20.5% participants had one or more recession sites, at T4 85.7 % of the participants had at least one GR. There was evidence of association between moderate/severe TW and GR-for a tooth with moderate/severe wear, the odds of recession were 23% higher compared to a tooth with no/mild wear (odds ratio 1.23; 95% CI: 1.08-1.40; P = 0.002). Age, dental segment, and time were also significant recession predictors, whereas gender was not.

Conclusions

There is evidence that moderate/severe TW is associated with the presence of gingival recession. Clinical significance of this can be limited.

U.S. Pediatric Dentists' Perception of Molar Incisor Hypomineralization

Purpose: The purpose of this survey-based study was to target U.S. pediatric dentists in the Midwest region to determine their knowledge, perceptions, and clinical management strategies of molar incisor hypomineralization (MIH). Methods: After obtaining appropriate authorizations, all pediatric dentists identified by the American Academy of Pediatric Dentistry's 2016 to 2017 membership directory in the 12 Midwest states were invited to take part in the study. The questionnaire, adopted from previous studies, incorporated information of the participants' demographics and educational/clinical backgrounds and MIH-focused questions. Descriptive statistics and chi-square tests were used for analysis. An alpha level less than 0.05 was considered statistically significant. Results: A total of 251 out of 975 surveys were completed (26 percent). Nearly all participants were familiar with MIH. The majority reported the MIH prevalence to be less than 10 percent in their clinical practice (62 percent). Most respondents were either very confident (65 percent) or confident (34 percent) when diagnosing teeth with MIH. The most cited clinical challenge in managing MIH teeth was "long-term success of restorations" (79 percent). When analyzed individually, responses differed significantly for different demographics and educational characteristics of the respondents (P<0.05). Conclusion: MIH is generally well acknowledged by U.S. Midwest pediatric dentists, with differences related to their perceptions of the condition's prevalence as well as clinical and restorative management challenges.

Dental enamel defects predict adolescent health indicators: A cohort study among the Tsimane' of Bolivia

OBJECTIVES

Bioarchaeological findings have linked defective enamel formation in preadulthood with adult mortality. We investigated how defective enamel formation in infancy and childhood is associated with risk factors for adult morbidity and mortality in adolescents.

METHODS

This cohort study of 349 Amerindian adolescents (10-17 years of age) related extent of enamel defects on the central maxillary incisors (none, less than 1/3, 1/3 to 2/3, more than 2/3) to adolescent anthropometrics (height, weight) and biomarkers (hemoglobin, glycated hemoglobin, white blood cell count, and blood pressure). Risk differences and 95% confidence intervals were estimated using multiple linear regression. Enamel defects and stunted growth were compared in their ability to predict adolescent health indicators using log-binomial regression and receiver operating characteristics (ROCs).

RESULTS

Greater extent of defective enamel formation on the tooth surface was associated with shorter height (-1.35 cm, 95% CI: -2.17, -0.53), lower weight (-0.98 kg, 95% CI: -1.70, -0.26), lower hemoglobin (-0.36 g/dL, 95% CI: -0.59, -0.13), lower glycated hemoglobin (-0.04 %A1c , 95% CI: -0.08, -0.00008), and higher white blood cell count (0.74 109 /L, 95% CI: 0.35, 1.14) in adolescence. Extent of enamel defects and stunted growth independently performed similarly as risk factors for adverse adolescent outcomes, including anemia, prediabetes/type II diabetes, elevated WBC count, prehypertension/hypertension, and metabolic health.

CONCLUSIONS

Defective enamel formation in infancy and childhood predicted adolescent health outcomes and may be primarily associated with infection. Extent of enamel defects and stunted growth may be equally predictive of adverse adolescent health outcomes.

Finite element investigation of human maxillary incisor under traumatic loading: Static vs dynamic analysis

BACKGROUND AND OBJECTIVE

Traumatic loading is the main form of injury sustained in dental injuries. In spite of the prevalence of dental trauma, little information is available on traumatic dental damage and the evaluation of tooth behavior under traumatic loading. Due to the short period of traumatic loading, at first sight, a dynamic analysis needs to be performed to investigate the dental trauma. However, it was hypothesized that dental traumatic loading could be regarded as quasi-static loading. Thus, the aim of the present study was to examine this hypothesis.

METHODS

Static and dynamic analyses of the human maxillary incisor were carried out under traumatic loading using a 3D finite element method. Also, modal analysis of the tooth model was performed in order to evaluate the assumption of the dental traumatic loading as a quasi-static one.

RESULTS

It was revealed that the static analysis of dental trauma is preferred to the dynamic analysis when investigating dental trauma, mainly due to its lower computational cost. In fact, it was shown that including the inertia of the tooth structure does not influence the results of the dental trauma simulation. Furthermore, according to the modal analysis of the tooth structure, it was found that the mechanical properties and geometry of the periodontal ligament play significant roles in the classification of dental traumatic loading as a quasi-static one, in addition to the time duration of the applied load.

CONCLUSIONS

This paper provides important biomechanical insights into the classification of dental loading as quasi-static, transient or impact loading in future dental studies.

Risk factors associated with open gingival embrasures after orthodontic treatment

OBJECTIVES

To investigate the incidence of and contributing factors to open gingival embrasures between the central incisors after orthodontic treatment.

MATERIALS AND METHODS

One hundred posttreatment patients (29 men and 71 women; mean age, 24.7 years) were divided retrospectively into occurrence and nonoccurrence groups based on intraoral photographs. Based on the severity, the occurrence group was further divided into mild, moderate, and severe groups. Parameters from periapical radiographs, superimposed lateral cephalograms, and study models were compared between the occurrence and the nonoccurrence groups by using independent t-tests and were also analyzed on the basis of severity via analysis of variance. Logistic regression analysis was performed to identify the contributing factors to open gingival embrasures.

RESULTS

The incidence of open gingival embrasures between the central incisors was 22% and 36% in the maxilla and the mandible, respectively. Lingual movement of the incisors, distance from the contact point to the alveolar crest after treatment, antero-posterior overlap of the two central incisors before treatment in the maxilla, and distance from the contact point to the alveolar crest after treatment in the mandible were significantly associated with the occurrence of open gingival embrasures ( P < .05). In the mandible, the amount of intrusion was significantly related to severity ( P < .05).

CONCLUSIONS

The incidence of open gingival embrasures following orthodontic tooth movement is high. Therefore, attention should be paid to the contributing factors to prevent or reduce the occurrence of open gingival embrasures.

Quantitative comparison of incisal tooth wear in patients receiving one-phase or two-phase treatment for skeletal Class III malocclusion with anterior crossbite

OBJECTIVES

The present study aimed to compare the amount of incisal tooth wear in the maxillary central incisors of patients with skeletal Class III malocclusion and anterior crossbite receiving one-phase or two-phase treatment. The hypothesis was that tooth wear would differ according to treatment modalities.

MATERIALS AND METHODS

Maxillary dental casts obtained before (T1) and after (T2) orthodontic treatment were divided into three groups. Group I consisted of casts from 21 patients (7 males, 14 females; mean age 9.8 years) who received two-phase treatment (maxillary protraction followed by fixed appliance therapy). Group II comprised casts from 37 patients who underwent orthodontic camouflage treatment for crossbite, subdivided according to age. Group IIa consisted of casts from 15 adolescents (8 males, 7 females; mean age 13.5 years), and group IIb consisted of casts from 22 adults (13 males, 9 females; mean age 24.5 years). Maxillary dental casts obtained at T1 and T2 were scanned. For each pair of digital images, T2 was superimposed on T1 using the best-fit method. Tooth wear was quantified and compared among groups.

RESULTS

Significantly less tooth wear was observed in group I compared to groups IIa and IIb, but no difference was found between groups IIa and IIb. Spearman correlation analysis revealed no significant correlation between tooth wear and age, treatment duration, or craniofacial morphology.

CONCLUSIONS

Despite the long duration of early treatment, it caused less wear of the maxillary central incisors than did orthodontic camouflage treatment.

Long-Term Effects of Lip Repair on Dentofacial Morphology in Patients with Unilateral Cleft Lip and Palate

Objective

Lateral cephalograms from the growth archive of the Sri Lankan Cleft Lip and Palate Project were analyzed in a cohort design to study the long-term effects of lip repair on dentofacial morphology in patients with unilateral cleft lip and palate.

Methods

A total of 71 patients were recruited, including 23 adult patients with nonsyndromic unilateral cleft lip and palate without surgical repair and 48 adult patients with nonsyndromic unilateral cleft lip and palate who had lip repair, but without management of alveolus or anterior vomer. The design utilized exact matching on ethnicity and statistical control for gender and age.

Results and Conclusions

The data support the hypothesis that lip repair primarily produces a bone-bending effect on the anterior maxillary alveolus (alveolar molding), accompanied by controlled uprighting of maxillary incisors, and secondarily produces a bone-remodeling effect (bone resorption) in the base of the anterior maxillary alveolus. When analyzed by the age at lip repair and the surgeon who performed lip repair, early lip repair produced a greater bone-remodeling effect than did late lip repair, and variation in the surgeon who performed lip repair had an insignificant impact on dentofacial morphology after adjusting for covariates.

Morbidity of Chin Bone Transplants Used for Reconstructing Alveolar Defects in Cleft Patients

Objective

The aim of this study was to evaluate the objective and subjective morbidity of symphyseal chin bone harvesting used for reconstruction of alveolar defects in young cleft patients.

Design

All patients who had undergone chin bone harvesting for alveolar cleft reconstruction in the period from 1992 through 2000 at the Department of Oral and Maxillofacial Surgery of the University Hospital Groningen, Groningen, The Netherlands, were invited to participate in this retrospective study. Patients’ acceptance, perioperative and postoperative morbidity were evaluated. A survey of the medical records was performed. In addition, the patients completed a questionnaire for their appreciation of the procedure. They were also subjected to a clinical and radiographic examination.

Patients

Thirty patients (21 males and 9 females; mean age 11.8 ± 3.6 years) participated in this study.

Results

Neither the medical records nor the experiences of the patients showed significant morbidity. The procedure was appreciated with 6.8 ± 3.5 (scale 0 to 10). Postoperative pain was scored as 1.2 ± 2.5 (scale 0 to 10). Three patients reported transient sensory disturbances at the donor site. Two patients showed a slight sensibility disorder in the symphyseal region. In three patients, an endodontic problem had developed in a lower incisor.

Conclusion

This study showed that chin bone harvesting for reconstructing alveolar cleft in young patients is a well-accepted procedure with low objective and subjective morbidity. Notwithstanding this low morbidity, the patients (and their parents) have to be informed about the risk of objective and subjective disturbances of the sensibility in the donor region and the risk of dental pulp necrosis.

Dentocraniofacial Morphology of 21 Patients with Unilateral Cleft Lip and Palate: A Cephalometric Study

Objective

To assess the skeletal and dental craniofacial proportions of unilateral cleft lip and palate patients who were operated upon using the Malek technique, and compare them with a normal group to highlight the effect of surgical correction on craniofacial development during growth.

Design

Retrospective.

Methods

The cleft palate was closed using the Malek technique in a single operation at 3 months for 11 patients (complete closure of lip and palate) and in a two-stage operation for 10 patients (soft palate at 3 months, lip and hard palate at 6 months). Comparisons were made with a normal control group. Angular and linear measurements of anterior and posterior dimensions of the upper and lower compartments of the face were measured in the 7th and 12th years.

Results and Conclusion

No significant differences were observed between the two groups of palate technique repair, although significant differences were observed between craniofacial dimensions of normal versus cleft lip and palate patients. At a skeletal level, the maxilla and mandible were retrusive relative to the cranial base in the cleft lip and palate group. In fact, there was a backward rotation of the palatal plane with repercussions on the maxillo-mandibular complex position. Furthermore, the maxilla was shorter than in normal patients, whereas the mandible was normally shaped. The upper incisors were retroclined and they locked the lower incisors in linguoversion. There was a posterior skeletal deficit of the respiratory compartment, compensated by more marked posterior maxillary alveolar growth. Facial growth in cleft lip and palate patients followed the same pattern, but was delayed compared with normal patients.

The Crown Size and Sexual Dimorphism of Permanent Teeth in Jordanian Cleft Lip and Palate Patients

Objective:

To provide a detailed description of crown size dimensions in the permanent dentition of Jordanian cleft lip and palate patients and to compare the findings with those of other populations.

Method:

The mesiodistal crown diameters of the permanent teeth of 47 patients with unilateral cleft lip and palate (UCLP), 25 patients with bilateral cleft lip and palate (BCLP), and 74 controls were measured.

Results:

The cleft group (UCLP and BCLP patients) generally demonstrated a smaller tooth size for both the maxillary and mandibular arches than did the control group. A sexual dimorphism pattern with males having larger teeth than females was observed for controls and UCLP patients. More males with BCLP had smaller teeth than did females. In the maxilla, the UCLP cleft-side teeth showed the largest percentage (4%) of sexual dimorphism, whereas the BCLP teeth achieved the highest percentage (3.4%) in the mandible. The UCLP cleft-side maxillary lateral incisors (13.2%) and BCLP mandibular canines (6%) displayed greater sexual dimorphism in crown size than did any other tooth class.

Conclusions:

Tooth size reduction occurred across all permanent tooth types and among early and late-forming teeth in cleft patients compared with the controls. This reduction was more pronounced in the maxillary incisor field. Males with UCLP and control males had larger teeth than did females, whereas a reversal of the normal dimorphism pattern was observed in patients with BCLP.

Relationship between voice function and skeletal effects of rapid maxillary expansion

OBJECTIVE

To evaluate the effects of rapid maxillary expansion (RME) on the vocal quality, maxillary central incisors, midpalatal suture, and nasal cavity in patients with maxillary crossbite.

MATERIALS AND METHODS

Coronal CT scans of 30 subjects (14 boys, 16 girls; mean age, 12.01 ± 0.75) were taken before RME (T0), and at the end of the expansion phase (T1). Voice samples of all patients were recorded with a high-quality condenser microphone (RODE NT2-A) on a desktop computer at T0 and T1. Statistical analyses were performed using a paired-sample t-test. The degree of association between the changes in the voice parameters and nasal width was assessed with Pearson's correlation.

RESULTS

RME treatment produced a significant increase in the transverse dimensions of the midpalatal suture and nasal cavity between T0 and T1 ( P < .05). The maximum F0 and jitter (%) results were shown to decrease statistically significantly from T0 to T1 ( P < .001 and P = .042, respectively). Between T0 and T1, shimmer (%) and shimmer (dB) exhibited statistically significant increases ( P = .037 and P = .019, respectively).

CONCLUSIONS

After RME therapy, voice quality differences were found to be associated with increases in nasal width.

Management of bilateral invasive cervical resorption lesions in maxillary incisors using a novel calcium silicate-based cement: A case report

Invasive cervical resorption is a pathologic process leading to progressive and usually destructive loss of tooth structure. The pathogenic mechanism is not completely understood and the diagnosis may be challenging. The aim of this article is to present an unusual case of bilateral presence of invasive cervical resorption lesions in maxillary central incisors and to discuss the treatment procedures using a novel repair material. The management of the present case was carried out in three phases. The first stage of the treatment aimed at curetting the active tissue from the resorption cavity and restoring the defect with the novel calcium silicate-based cement (Biodentine, Septodont). In the maxillary left central incisor it was not possible to remove the resorptive tissue without exposing the pulp, and therefore root canal treatment was performed. At the second phase, a full-thickness flap was raised in order to expose and repair the defect that was extending subgingivally. At the third phase teeth were restored with composite resin. The patient was kept under review and after a follow-up period of 2 years neither signs of periradicular lesion nor recurrence of resorption were observed. The teeth were asymptomatic, and restorations appeared to be in excellent condition. In conclusion, Biodentine seems to be a promising material for the treatment of invasive cervical resorption lesions.

Comparison of the force levels among labial and lingual self-ligating and conventional brackets in simulated misaligned teeth

Background/objective

The aim of this study was to evaluate force levels exerted by levelling arch wires with labial and lingual conventional and self-ligating brackets.

Materials/methods

The tested orthodontic brackets were of the 0.022-in slot size for labial and 0.018-in for lingual brackets and were as follows: 1. Labial brackets: (i) conventional bracket (GAC-Twin, Dentsply), (ii) passive self-ligating (SL) brackets (Damon-Q®, ORMCO; Ortho classic H4™, Orthoclassic; FLI®SL, Rocky Mountain Orthodontics) and (iii) active SL brackets (GAC In-Ovation®C, DENTSPLY and SPEED™, Strite). 2. Lingual brackets: (i) conventional brackets (Incognito, 3M and Joy™, Adenta); (ii) passive SL bracket (GAC In-Ovation®LM™, Dentsply and (iii) active SL bracket (Evolution SLT, Adenta). Thermalloy-NiTi 0.013-in and 0.014-in arch wires (Rocky Mountain Orthodontics) were used with all brackets. The simulated malocclusion represented a maxillary central incisor displaced 2 mm gingivally (x-axis) and 2 mm labially (z-axis).

Results

Lingual bracket systems showed higher force levels (2.4 ± 0.2 to 3.8 ± 0.2 N) compared to labial bracket systems (from 1.1 ± 0.1 to 2.2 ± 0.4 N). However, the differences between SL and conventional bracket systems were minor and not consistent (labial brackets: 1.2 ± 0.1 N for the GAC Twin and 1.1 ± 0.1 to 1.6 ± 0.1 N for the SL brackets with 0.013-in thermalloy; lingual brackets: 2.5 ± 0.2 to 3.5 ± 0.1 N for the conventional and 2.7 ± 0.3 to 3.4 ± 0.1 N for the SL brackets with 0.013-in Thermalloy).

Limitations

This is an in vitro study with different slot sizes in the labial and lingual bracket systems, results should be interpreted with caution.

Conclusions/implications

Lingual bracket systems showed higher forces compared to labial bracket systems that might be of clinical concern. We recommend highly flexible nickel titanium arch wires lower than 0.013-in for the initial levelling and alignment especially with lingual appliances.

Comparison of Cephalometric Hard and Soft Tissues of Adolescents with Angle Class II Division 1 Malocclusion between Northern Chinese Population and Northern Indian Population

OBJECTIVE

To determine if there was a difference in hard and soft tissue between northern Chinese and northern Indian adolescents with Angle Class II division 1 malocclusion.

METHOD

A total of 40 Angle Class II division 1 patients, including 20 boys and 20 girls aged 10 to 13 years with no prior treatment, were selected from northern China and northern India, respectively. Overall, 80 cephalometric data were analysed based on two-sample t-test with SPSS software.

RESULTS

The Chinese subjects had larger anterior facial height and mandibular plane angle. Analysis of dentoalveolar complex showed that the Chinese subjects had more proclined incisors, protruding upper lips and more upper posterior tooth height than that of the Indian subjects. The length of the maxilla and mandible was larger in the Indian subjects than that of the Chinese subjects, but the length of mandible was not significantly different between the two groups.

CONCLUSION

Compared with the Indian subjects, the Chinese subjects with Class II division 1 malocclusion had less prognathic maxillas, more protruding lips, steeper mandibular plane angles and more proclined maxillary incisors. Within the same gender, the Indian boys had more protruded faces and Indian girls had more protruded maxillas, steeper mandibular plane angles and fuller lips.

Conservative, Functional, and Esthetic Rehabilitation of Severe Palatal Erosion (Class IV) Using Modified Dahl Approach

This article demonstrates the clinical application of biomechanical and occlusal principles to conservatively provide optimal clinical outcomes in restoring an eroded anterior dentition. The authors manage a challenging case involving limited palatal clearance (ie, deep bite) coupled with palatal erosion and wear by combining the centric relation (CR) and Dahl principles to create anterior interocclusal space to reduce the need for more invasive palatal reduction. The combined use of adhesive restorations-resin composites on the palatal surface and indirect porcelain veneers on the facial/incisal surfaces-through enamel and dentin bonding helped optimize esthetic and functional/biomechanical aspects. This ultraconservative approach enabled the desired esthetic and biomechanical outcomes to be achieved through the treatment of localized anterior tooth erosion and wear. In short, when treating eroded maxillary anterior teeth with deep bite, adequate restorative space should first be created by conjoining CR and Dahl principles before using adhesive dentistry to restore with bonded composites and porcelain veneers.

Hypodontia: An Update on Its Etiology, Classification, and Clinical Management

Hypodontia, or tooth agenesis, is the most prevalent craniofacial malformation in humans. It may occur as part of a recognised genetic syndrome or as a nonsyndromic isolated trait. Excluding third molars, the reported prevalence of hypodontia ranges from 1.6 to 6.9%, depending on the population studied. Most affected individuals lack only one or two teeth, with permanent second premolars and upper lateral incisors the most likely to be missing. Both environmental and genetic factors are involved in the aetiology of hypodontia, with the latter playing a more significant role. Hypodontia individuals often present a significant clinical challenge for orthodontists because, in a number of cases, the treatment time is prolonged and the treatment outcome may be compromised. Hence, the identification of genetic and environmental factors may be particularly useful in the early prediction of this condition and the development of prevention strategies and novel treatments in the future.

[Diagnossis and treatment of complicated anterior teeth esthetic defects by combination of whole-process digital esthetic rehabilitation with periodontic surgery]

OBJECTIVE

To explore a new method of whole-process digital esthetic prosthodontic rehabilitation combined with periodontic surgery for complicated anterior teeth esthetic defects accompanied by soft tissue morphology, to provide an alternative choice for solving this problem under the guidance of three-dimensional (3D) printing digital dental model and surgical guide, thus completing periodontic surgery and digital esthetic rehabilitation of anterior teeth.

METHODS

In this study, 12 patients with complicated esthetic problems accompanied by soft tissue morphology in their anterior teeth were included. The dentition and facial images were obtained by intra-oral scanning and three-dimensional (3D) facial scanning and then calibrated. Two esthetic designs and prosthodontic outcome predictions were created by computer aided design /computer aided manufacturing (CAD/CAM) software combined with digital photography, including consideration of white esthetics and comprehensive consideration of pink-white esthetics. The predictive design of prostheses and the facial appearances of the two designs were evaluated by the patients. If the patients chose the design of comprehensive consideration of pink-white esthetics, they would choose whether they would receive periodontic surgery before esthetic rehabilitation. The dentition design cast of those who chose periodontic surgery would be 3D printed for the guide of periodontic surgery accordingly.

RESULTS

In light of the two digital designs based on intra-oral scanning, facing scanning and digital photography, the satisfaction rate of the patients was significantly higher for the comprehensive consideration of pink-white esthetic design (P<0.05) and more patients tended to choose priodontic surgery before esthetic rehabilitation. The 3D printed digital dental model and surgical guide provided significant instructions for periodontic surgery, and achieved success transfer from digital design to clinical application. The prostheses were fabricated by CAD/CAM, thus realizing the whole-process digital esthetic rehabilitation.

CONCLUSION

The new method for esthetic rehabilitation of complicated anterior teeth esthetic defects accompanied by soft tissue morphology, including patient-involved digital esthetic analysis, design, esthetic outcome prediction, 3D printing surgical guide for periodontic surgery and digital fabrication is a practical technology. This method is useful for improvement of clinical communication efficiency between doctor-patient, doctor-technician and doctors from different departments, and is conducive to multidisciplinary treatment of this complicated anterior teeth esthetic problem.

[Clinical evaluation of periodontal-orthodontic treatment in patients with aggressive periodontitis and malocclusion]

OBJECTIVE

To evaluate the clinical effect and safety of periodontal-orthodontic treatment in patients with aggressive periodontitis (AgP) and malocclusion.

METHODS

A retrospective analysis was conducted in 25 AgP patients, who had received periodontal-orthodontic treatment in Peking University School and Hospital of Stomatology. Clinical indexes, including probing depth (PD), bleeding index (BI) and percentage of sites with bleeding on probing (BOP%) were evaluated at three time points: Baseline (T0); active periodontal treatment finished and before orthodontic treatment (T1); and after orthodontic treatment (T2). Also changes of ratio of the residual alveolar bone height (RBH) and the occurrence of root resorption were evaluated by periapical radiographs.

RESULTS

(1) Compared with T0, all the clinical parameters including PD, BI, BOP% and percentage of sites with PD>3 mm were significantly improved (P<0.001). (2) Significant difference was observed in the average RBH between T0 (68.37%±15.60% and T2 (70.27%±14.23%). RBH in upper incisors [(58.79%±16.71% at T0, 65.54% (55.74%, 78.13%) at T2], upper canines [77.62% (66.06%, 87.17%) at T0, 79.57% (69.75%, 86.52%) at T2] and upper molars [74.30% (61.69%, 84.45%) at T0, 76.76% (68.12%, 85.09%) at T2] showed significant increase (P<0.05). (3) After orthodontic treatment, varying degrees of root resorption occurred in (23.94%±13.45%) of teeth per capita, among which the lower and upper incisors showed the highest incidence (68.48% and 65.31% in homogeneous teeth, respectively).

CONCLUSION

After active periodontal treatment, orthodontic treatment in AgP patients had not aggravated inflammation and alveolar bone resorption; root resorption occurred in two-thirds of incisors approximately.

Direct Resin Composite Restoration of Maxillary Central Incisors with Fractured Tooth Fragment Reattachment: Case Report

This article presents a clinical protocol to reconstruct two accidentally damaged maxillary central incisors using composite resin material and a fractured tooth component. A patient was referred to the clinic with fracture of the two maxillary central incisors. Clinical examination revealed that both teeth were fractured in the middle third of the crown and that the fractures involved enamel and dentin with no pulp exposure. The patient had also suffered a lower lip laceration. When the lip was evaluated, a fractured fragment of the maxillary right central incisor was found inside the wound. The missing part of the tooth was replaced via adhesive attachment. Due to the damage of the fractured part of the maxillary left central incisor, direct composite restoration of this tooth was performed. With the advent of adhesive dentistry, the process of fragment reattachment has become simplified and more reliable. This procedure provides improved function, is faster to perform, and provides long-lasting effects, indicating that reattachment of a coronal fragment is a realistic alternative to placement of conventional resin composite restorations.