Precision of manual landmark identification between as-received and oriented volume-rendered cone-beam computed tomography images.

INTRODUCTION: The objective of this study was to evaluate the effect of the orientation of cone-beam computed tomography (CBCT) images on the precision and reliability of 3-dimensional cephalometric landmark identification. METHODS: Ten CBCT scans were used for manual landmark identification. Volume-rendered images were oriented by aligning the Frankfort horizontal and transorbital planes horizontally, and the midsagittal plane vertically. A total of 20 CBCT images (10 as-received and 10 oriented) were anonymized, and 3 random sets were generated for manual landmark plotting by 3 expert orthodontists. Twenty-five landmarks were identified for plotting on each anonymized image independently. Hence, a total of 60 images were marked by the orthodontists. After landmark plotting, the randomized samples were decoded and regrouped into as-received and oriented data sets for analysis and comparison. Means and standard deviations of the x-, y-, and z-axis coordinates were calculated for each landmark to measure the central tendency. Intraclass correlation coefficients were calculated to analyze the interobserver reliability of landmark plotting in the 3 axes in both situations. Paired t tests were applied on the mean Euclidean distance computed separately for each landmark to evaluate the effect of 3-dimensional image orientation. RESULTS: Interobserver reliability (intraclass correlation coefficient, >0.9) was excellent for all 25 landmarks for the x-, y-, and z-axes on both before and after orientation of the images. Paired t test results showed insignificant differences for the orientation of volume-rendered images for all landmarks except 3: R1 left (P = 0.0138), sella (P = 0.0490), and frontozygomatic left (P = 0.0493). Also midline structures such as Bolton and nasion were plotted more consistently or precisely than bilateral structures. CONCLUSIONS: Orientation of the CBCT image does not enhance the precision of landmark plotting if each landmark is defined properly on multiplanar reconstruction slices and rendered images, and the clinician has sufficient training. The consistency of landmark identification is influenced by their anatomic locations on the midline, bilateral, and curved structures.

True intrusion of maxillary first molars with zygomatic and palatal miniscrew anchorage: a case report.

The intrusion of the maxillary first molar is indicated when occlusal clearance is needed for prosthetic rehabilitation. Maxillary molar intrusion may be undertaken using skeletal anchorage systems to avoid complicated mechanics delivered by conventional intra-oral fixed appliances. In the present case report, the efficient use of orthodontic miniscrew anchorage by applying simple mechanics for true maxillary first molar intrusion is described. This was followed by the rehabilitation of the mandibular first molar spaces with implant prostheses. A 16-year-old female patient had masticatory difficulty due to the bilateral overeruption of the maxillary first molars and carious mandibular first molars. True intrusion of each maxillary first molar was achieved using zygomatic and palatal paramedian miniscrews placed in line with the central axis of the teeth. Simultaneously, alignment of the upper arch was achieved via fixed appliance therapy. Using two orthodontic miniscrews to intrude each maxillary molar, orthodontic treatment was simplified by eliminating the need for miniplate placement by extensive surgery and the creation of intra-oral multiunit anchorage. Masticatory efficiency was improved by increasing the occlusal table with prosthetic rehabilitation of the mandibular first molar spaces with dental implant prostheses.

A Modified Clear Aligner.

In this article we describe a modified clear aligner with z spring for correction ofsingle tooth crossbite. It serves as an esthetic alternative to conventional removable appliance and at the same time, it is an inexpensive alternative to clear aligner technology.

Miniscrew supported Burstone intrusion arch.

Miniscrew supported Burstone intrusion arch is a novel method for achieving maxillary incisor intrusion. It offers the advantage of true incisor intrusion without causing reciprocal effects on the posterior teeth. In this article, we present an intrusion arch which is a modification of Burstone Intrusion arch taking posterior anchorage from buccal interradicular mini-screws instead of molar teeth and detailed description of the advantages offered by this technique.

Different approaches for management of Class III siblings: A long-term follow-up of two case reports.

Class III malocclusion can be varied in presentation and progression. This report describes the presentation, course of treatment and long-term follow-up of two siblings with Class III malocclusion. Two cases discussed in this report were different in their presentation. Sibling 1, a 19-year-old male patient had developed skeletal Class III malocclusion with severe maxillomandibular discrepancy, showing both components of maxillary hypoplasia and mandibular prognathism & asymmetry with average growth pattern. Sibling 2, a 13-year-old male patient had developed a Class III malocclusion with maxillary retrognathism with vertical growth pattern. An insight into the similarities and dissimilarities in the presentation, course of treatment and long-term follow-up of the two cases is provided. The two cases were successfully managed with entirely different treatment approaches. Sibling 1 underwent maxillary advancement with Le Fort I surgery and mandibular set back and rotation with bilateral sagittal split osteotomy which was preceded by pre-surgical orthodontic treatment with extraction of upper first premolars for orthodontic decompensation. Sibling 2 was treated with skeletally anchored facemask therapy followed by fixed mechanotherapy. Acceptable clinical outcome with long-term stability of the treatment results was observed in the two siblings. Orthognathic surgery may be completely avoided later if early orthopaedic treatment to advance the maxilla is initiated at an appropriate age.

Management of skeletal Class III with facial asymmetry using skeletal anchorage: 4-year follow-up.

INTRODUCTION: Skeletal Class III malocclusion with asymmetry is one of the most difficult problems to correct in orthodontics. A functional shift of the mandible in growing patients may occur accompanying a Class III, due to constricted maxillary arch and occlusal interferences. Studies have indicated that posterior unilateral crossbite develops early and has a low rate of spontaneous correction. It may further lead to development of mandibular and facial asymmetry by growth and displacement of mandible if left untreated in growing patients. OBJECTIVE: This article reports the clinical case of a thirteen-year-old female patient in CVMI transition stage that had maxillary hypoplasia with a developing facial asymmetry. RESULTS: The case was successfully managed with bone-anchored facemask therapy and with elimination of occlusal interferences with guided occlusion. Reverse twin block in the retention phase maintained the results achieved. CONCLUSION: A four-year follow-up evaluation revealed successful maintenance of the treatment results.

External apical root resorption in orthodontic patients: molecular and genetic basis.

External apical root resorption is one of the most deleterious complications after orthodontic treatment. Studies to explain the causal relationship between orthodontic tooth movement and external apical root resorption have been inconclusive till date. Individual variations in external apical root resorption sometimes overshadow the treatment related factors which indicate genetic predisposition and/or multifactorial etiology. Mechanism of root resorption is not completely understood. Inflammatory root resorption induced by orthodontic treatment is a part of process of elimination of hyaline zone. An imbalance between bone resorption and deposition may contribute to root resorption by the cementoclasts/osteoclasts. This narrative review article explains the molecular pathway involved in external apical root resorption and also role of various genes involved at different level. It also reviews the literature published during the past 20 years concerning the association studies linking EARR to genetic polymorphisms. This literature review provides an insight into genetic predisposition of external apical root resorption that can be used in orthodontic practice to enable 'high-risk' subjects to be identified on the basis of their genetic information before orthodontic treatment is initiated.

Impacted maxillary molars with rare etiology: A simplified approach to facilitated Eruption.

Impaction of maxillary molars is an extremely rare condition and difficult to manage. This case reports a rare cause for impacted maxillary molars which has not been reported in the literature till date. A 13-year-old patient with missing right maxillary first and second molars reported to the outpatient department. Cone beam computed tomography scan of maxilla revealed a complex relationship between the roots of first and second molars and a developing third molar crown. Surgical enucleation of third molar facilitated spontaneous eruption of both first and second molars. Dilaceration of the roots and pressure from developing third molar germ led to the impaction of both maxillary molars which has not been reported in literature yet. Hence, careful determination of etiologic factor for impaction and its elimination with periodic introspection may help in treating the problem with simple and conservative methods.

Aesthetic Retainer cum Trainer.

Tongue thrust habit is one of the contributing factors in the relapse of orthodontic treatment results. Compliance with removable habit breaking appliance is a major issue to the dental practitioners treating patients of any age group. Through this case we introduce a more aesthetic and comfortable option to the patients requiring habit control for tongue thrusting and retention of treatment results. Hence, this appliance acts as a retainer cum trainer in such patients.

A Custom Made Skeletal Class II Corrector Appliance in Late Adolescent Phase.

Skeletal Class II correction in deceleration phase of growth is both a challenge and dilemma with choice between extraction and myofunctional therapy. With marginal growth remaining the convenient choice is extraction for camouflage of the skeletal discrepancy. On the other hand, the treatment with Fixed Functional Appliances (FFAs) helps in resolution of the problem without sacrificing the dentition. However, the conventional FFAs requires a phase of alignment which results in further loss of time to utilize any remaining growth. The present report proposes the use of a novel custom made functional appliance for Class II skeletal correction which is simple to fabricate and convenient to use.

Serum IGF-1, IGFBP-3 and their ratio: Potential biochemical growth maturity indicators.

BACKGROUND: Determination of skeletal maturation and remaining growth potential is an essential part of treatment planning in orthodontics. The aim of our study was to determine the relationship between IGF-1 levels, IGFBP-3 levels with CVM staging to track the pre pubertal and pubertal growth spurts in female patients in North Indian population. METHODS: This cross-sectional study was conducted on ninety female subjects in the age group of 8-20 years. Blood samples were collected and centrifuged and serum samples were then analysed by Human IGF-1 and IGFBP-3 enzyme-linked immunosorbent assay kits, specific for IGF-1 and IGFBP-3, respectively. CVM staging on lateral cephalometric radiograph was determined for all patients. Analysis of variance test followed by a post hoc test was used to compare mean IGF-1 and IGFBP-3 corresponding to six stages of cervical vertebrae maturation stages. Linear Pearson's correlations were performed to determine the trends of IGF-1, IGFBP-3, and its ratio relating to CVM stage. The kappa statistic was used to measure inter and intra examiner reliability. P value <0.05 was considered as statistically significant. RESULTS: Mean serum IGF-1 levels were found to be highest (403.3 ± 12.3 ng/ml) at CVMI3 stage of CVMI. The post-hoc test revealed a significant difference in IGF-1 levels between all stages of CVMI, thereby indicating a specific range of IGF-1 levels for a specific skeletal stage. Mean serum IGFBP-3 levels were found to be highest (5186.8 ± 1384.2 ng/ml) at CVMI4 stage of CVMI. The mean serum IGFBP-3 levels at CVMI4 were found to be significantly higher than the levels at all other CVMI stages except CVMI3 stage. CONCLUSIONS: IGF-1 and IGFBP-3 can serve as a potential biochemical indicator for assessment of skeletal maturity.

A comparative evaluation of skeletal, dental, and soft tissue changes with skeletal anchored and conventional facemask protraction therapy.

OBJECTIVE: To cephalometrically evaluate and compare the skeletal, dentoalveolar, and soft tissue changes after maxillary protraction with skeletally anchored and conventional facemask. METHODS: The data for the study were collected from the pre- and post-treatment records of patients of maxillary retrusion treated with skeletally anchored and conventional facemask therapy. Twenty subjects were included in the study and were categorized into two groups, namely skeletal anchored maxillary protraction (SAMP) group with the mean age of 10.10 ± 1.1 years and conventional facemask maxillary protraction (CFMP) group with the mean age of 9.90 ± 1.1 years. Pre and post-treatment lateral cephalograms were assessed. RESULTS: The data were analyzed by Mann-Whitney test and Wilcoxon signed-rank test. The mean duration of treatment in SAMP group and CFMP group was 5.8 months and 10 months, respectively. The mean forward displacement of the maxilla (vertical point A) was 3.40 ± 1.07 mm in SAMP group and 2.80 ± 0.79 mm in CFMP group. The mandible showed downward and backward rotation in both the groups with more rotation in CFMP group. A significant increase in maxillary incisor inclination was seen in CFMP group as compared to SAMP group. A significant decrease was found in mandibular incisor inclination in both the treatment groups. The soft tissue changes corresponded to underlying skeletal tissue. CONCLUSIONS: SAMP is proven to be a better treatment modality as compared to CFMP for achieving true skeletal changes and minimal dental changes in cases with developing skeletal Class III with maxillary retrusion.

Management of skeletal Class III with facial asymmetry using skeletal anchorage: 4-year follow-up

ABSTRACT Introduction: Skeletal Class III malocclusion with asymmetry is one of the most difficult problems to correct in orthodontics. A functional shift of the mandible in growing patients may occur accompanying a Class III, due to constricted maxillary arch and occlusal interferences. Studies have indicated that posterior unilateral crossbite develops early and has a low rate of spontaneous correction. It may further lead to development of mandibular and facial asymmetry by growth and displacement of mandible if left untreated in growing patients. Objective: This article reports the clinical case of a thirteen-year-old female patient in CVMI transition stage that had maxillary hypoplasia with a developing facial asymmetry. Results: The case was successfully managed with bone-anchored facemask therapy and with elimination of occlusal interferences with guided occlusion. Reverse twin block in the retention phase maintained the results achieved. Conclusion: A four-year follow-up evaluation revealed successful maintenance of the treatment results.

RESUMO Introdução: A má oclusão de Classe III esquelética com assimetria é um dos problemas mais difíceis de se corrigir na Ortodontia. O desvio funcional da mandíbula em pacientes em fase de crescimento pode ocorrer acompanhado da Classe III, devido à atresia maxilar e interferências oclusais. Estudos têm indicado que a mordida cruzada posterior unilateral se desenvolve precocemente e apresenta baixo índice de correção espontânea. Isso pode levar ao desenvolvimento de assimetria mandibular e facial, resultante do crescimento e deslocamento da mandíbula, caso os pacientes não sejam tratados na fase de crescimento. Objetivo: O presente artigo relata o caso clínico de uma paciente com treze anos de idade, com IMVC em estágio de transição e que apresentava hipoplasia maxilar com assimetria facial em desenvolvimento. Resultados: O caso foi tratado com sucesso por meio de terapia com máscara facial osseossuportada, eliminando as interferências oclusais por meio de uma oclusão guiada. O uso do aparelho Twin-block reverso como contenção preservou os resultados atingidos. Conclusão: O acompanhamento após quatro anos confirmou a manutenção dos resultados do tratamento.

Does Hollowing of Complete Denture Enhance Retention? - A Pilot Study.

INTRODUCTION: Prosthetic rehabilitation is an extremely challenging task in extreme resorption cases of the maxillary denture-bearing area. Reducing the weight of a maxillary obturator has been seen as beneficial. But whether reducing the weight of conventional complete denture also increases retention or not, is still very dubious. The aim of this pilot study was to determine the effect of maxillary denture weight on denture retention and stability. MATERIALS AND METHODS: For this study, a total of 10 patients were considered for the pilot study (06 female and 04 male) with an average age of 70 y. Each patient was provided with two sets of maxillary complete dentures, one hollow labeled as A and one conventional maxillary denture labeled as B. RESULTS: It was shown that mean values for retention using MKIS for retention for hollow dentures (A) was 7.8 and for conventional dentures (B) it was 8.2 and the stability for maxillary dentures was more with conventional dentures (B) than hollow maxillary dentures (A) and it was significant as p-value was 0.015 (p<.1). CONCLUSION: The denture retention and stability, chewing and comfort values of conventional dentures and hollow dentures were slightly better for conventional dentures.

Evaluation of orthodontic mini-implant placement: a CBCT study.

BACKGROUND: Optimal positioning of orthodontic mini-implants is essential for a successful treatment with skeletal anchorage. This study aims to compare the accuracy of two-dimensional radiographs with a cone beam computed tomography (CBCT) for mini-implant placement. METHODS: An ideal site for mini-implant placement at the buccal interradicular space between the second premolar and the first molar was determined for 40 sites (in 13 patients aged 14 to 28 years) by using CBCT data. The mini-implant placement procedure was then divided into two groups. In CBCT group, mini-implants were placed at the sites determined from CBCT data. In RVG group, mini-implants were placed with the help of two-dimensional digital radiographs and a custom made guide. Postplacement CBCT scans were obtained to determine the accuracy of the mini-implant placement. The results were statistically analyzed with a Mann-Whitney test. RESULTS: A statistically significant difference (p value=0.02) was observed between the two groups for deviation from an ideal height of placement of the mini-implants. Deviations in mesiodistal positioning and angular deviation showed a statistically non-significant difference. Three out of twenty mini-implants in the RVG group showed root contact in the mandibular arch that may be attributed to the narrower interradicular space and reduced accessibility in the mandibular posterior region. CONCLUSIONS: Although CBCT provides an accurate three-dimensional visualization of the interradicular space, the two-dimensional intraoral radiograph of the interradicular area provides sufficient information for mini-implant placement. Considering the amount of radiation exposure and cost with the two techniques, it is recommended to use two-dimensional radiographs with a surgical guide for a routine mini-implant placement.