Structurally compromised teeth. Part I: Clinical considerations and novel classification proposal.

OBJECTIVE: A comprehensive classification of structurally compromised teeth (SCT) was introduced. CLINICAL CONSIDERATIONS: Dental injuries or operative mismanagement undermine the structural integrity of the tooth abutment, reducing its biomechanical strength and rendering restorative procedures challenging. To standardize the overall pre-operative evaluations and determine the biological and mechanical features, a classification of the coronal and cervical tooth defects, as well as an attentive analysis of the most apical location of the residual cervical tooth structure along the whole perimeter and the most coronal location of the bucco/lingual residual structure was presented. Considering the residual cervical structure, five possible clinical scenarios were individuated with respect to the gingival margin, gingival sulcus, supracrestal tissue attachment and bone crest (BC). The latter prevents the isolation procedures rendering the adhesive restorations unfeasible. Instead, the location of the most apical portion of residual cervical structure within subgingival/intrasulcular depth (>1.5 mm above BC) can be considered restorable. CONCLUSIONS: This classification is threefold: to enclose all the possible clinically encountered tooth defects, to identify the apical problems of SCT to appropriately manage the perio-restorative interfaces, and to evaluate the tooth resistance capacity of SCT, as to plan and perform the most adequate biomechanical restorative approach. CLINICAL SIGNIFICANCE: The present classification is proposed to provide a complete perspective of structurally compromised teeth to standardize the biologic and biomechanical evaluations during planning of restorative procedures.

Evaluation of one-piece zirconia dental implants: An 8-year follow-up study.

OBJECTIVES: Long-term studies of modern zirconia implants are still insufficient. This prospective 8-year follow-up study investigated one-piece zirconia implants. MATERIALS AND METHODS: Patients who had received a one-piece zirconia dental implant (PURE ceramic implant, Institut Straumann GmbH, Basel, Switzerland) were included in this study. Next to the implant survival and success rates, the radiographic and clinical implant parameters were assessed. RESULTS: The overall survival rate of 67 zirconia implants in 39 patients was 100%. The overall success rate was 89.6%. Around the immediate zirconia implants, the success rate was 94.7%, and around the delayed implants, 87.5%. The immediate implants showed a significantly higher bone crest compared to the delayed implants (p = 0.0120). According to the pink esthetic score, the immediate implants revealed more favorable esthetic results compared to the delayed implants after an 8-year follow-up (p = 0.0002). CONCLUSIONS: After 8 years, the one-piece zirconia implants presented an 89.6% success rate. Regarding the timing of implantation, in individual cases, immediate implantation can have slight advantages over delayed implantation. CLINICAL RELEVANCE: Immediate implants can also be considered for zirconia implants and should not be excluded on principle.

Influence of miniscrew-assisted rapid palatal expansion (MARPE) on the interdental papilla height of maxillary central incisors.

OBJECTIVES: To evaluate the influence of miniscrew-assisted rapid palatal expansion (MARPE) on the interdental papilla height of maxillary central incisors. MATERIALS AND METHODS: Patients who completed MARPE treatment at the Radboud University Medical Center between 2018 and 2021 were included in this retrospective study. The papilla height between the maxillary central incisors was evaluated on frontal intraoral photographs taken before expansion (T0) and 1.5 years after MARPE treatment (T1) using the Jemt classification. The difference in Jemt score at T0 and T1 was the primary outcome variable. In addition, gender, age, Angle classification, MARPE duration, midpalatal suture maturation stage, maximal central diastema (MCD) immediately after expansion, crown width to length ratio (W/L), pretreatment overlap of maxillary central incisors, and the distance between the approximal contact point of the central incisors and the bone crest (CP-B) were also record. RESULTS: Twenty-two patients were included (2 men, 20 women, mean age 27.3 ± 8.8 years) and 4 patients (18%) showed a significant reduction in the Jemt score following MARPE (p = 0.04), indicating papilla recession. Interdental papilla recession was significantly associated with the increase of CP-B (p = 0.02), smaller W/L (p < 0.01), overlapping of maxillary central incisors (p < 0.01), and smaller MCD immediately after expansion (p = 0.02). CONCLUSIONS: One and a half years after MARPE, 18% of patients exhibited mild recession of papilla height of the maxillary central incisors. Overlapping and smaller W/L of maxillary central incisors were prognostic factors for interdental papilla recession. CLINICAL RELEVANCE: Clinicians have to be aware of and inform the patients about the occurrence of papilla recession following MARPE.

A Technique to Record and Transfer the Distance Between the Bone Crest and the Interproximal Contact Point to the Dental Laboratory to Maintain the Interdental Papilla While Fabricating Implant Supported Restorations.

The interdental papilla plays an important role in terms of esthetics and function. Management of the interdental papilla, especially around implants can be challenging. One of the factors mentioned in the literature that affects the viability of the papilla is the distance of the interdental contact point from the crest of the bone. The following case report describes a technique to predictably achieve an interdental contact area within the proper distance from the crest of the bone to help maintain the papilla for the long term.

Evidence-based knowledge on the aesthetics and maintenance of peri-implant soft tissues: Osteology Foundation Consensus Report Part 3-Aesthetics of peri-implant soft tissues.

OBJECTIVES: Working Group 2 at the 2nd Consensus Meeting of the Osteology Foundation had a focus on the influence of vertical implant placement on papilla height at single implants adjacent to teeth and on the inter-implant mucosa fill at two adjacent implants in the anterior maxilla. MATERIALS AND METHODS: Two systematic reviews were prepared in advance of the consensus meeting. Due to the heterogeneity among the studies with regard to study design, study population, method of assessment, meta-analyses were not possible. Consensus statements, clinical recommendations, and implications for future research were based on structured group discussions until consensus was reached among the entire expert group. RESULTS: The systematic review about single-tooth implants included a total of 12 studies demonstrating that the vertical distance from the crestal bone level to the base of the interproximal contact point varied considerably from 2 mm up to 11 mm, and a partial or complete papilla fill was reached in 56.5% to 100% of the cases. For the systematic review regarding two adjacent implants, only four studies reported on horizontal inter-implant distances which ranged between 2.0 and 4.0 mm. More than half of the papilla presence was indicated in 21% to 88.5% of the cases. CONCLUSIONS: It was concluded that for single-tooth implants, the papilla height between an implant and a tooth is predominantly dependent on the clinical attachment level of the tooth. In cases with two adjacent implants, it was concluded that it is not possible to define the optimal horizontal distance between two adjacent implants restored with fixed dental prosthess.

Enhancing surgical outcomes of posterior iliac bone harvesting through a pivotal modification.

Traditionally, patients are positioned in the prone position to access the donor site during the posterior iliac bone graft harvesting procedure. However, this well-established method is associated with complications such as pressure injuries, displacement of the endotracheal tube and intravenous catheter, and blindness. Moreover, the process of turning patients 180° between the supine and prone positions is both laborious and time consuming. However, no updates have been made in the approaches published in the literature to counteract these problems. Therefore, to overcome these challenges and improve patient outcomes, we proposed a pivotal modification: change prone position to the lateral decubitus position. This approach allowed us to effectively avoid the aforementioned complications. In addition, this modification offered significant advantages, including ease of implementation and timesaving benefits. The article presented results of the modification and a comprehensive evaluation of clinical and anesthetic considerations comparing the two methods.

Estimating Crestal Thickness of Alveolar Bones on Intra-oral Ultrasonograms.

OBJECTIVE: Alveolar crestal bone thickness and level provide important diagnostic and prognostic information for orthodontic treatment, periodontal disease management and dental implants. Ionizing radiation-free ultrasound has emerged as a promising clinical tool in imaging oral tissues. However, the ultrasound image is distorted when the wave speed of the tissue of interest is different from the mapping speed of the scanner and, therefore, the subsequent dimension measurements are not accurate. This study was aimed at deriving a correction factor that can be applied to the measurements to correct for discrepancy caused by speed variation. METHODS: The factor is a function of the speed ratio and the acute angle that the segment of interest makes with the beam axis perpendicular to the transducer. The phantom and cadaver experiments were designed to validate the method. DISCUSSION: The comparisons agree well with absolute errors not more than 4.9%. Dimension measurements on ultrasonographs can be properly corrected by applying the correction factor without recourse to the raw signals. CONCLUSION: The correction factor has reduced the measurement discrepancy on the acquired ultrasonographs for the tissue whose speed is different from the scanner's mapping speed.

Reliability of an indirect bone-probing method for diagnosis of labial bone crest level of the mandibular anterior teeth.

OBJECTIVES: To evaluate the null hypothesis that there would be no difference between the labial bone crest level of the mandibular anterior teeth evaluated with an indirect bone-probing method (IBP) and cone-beam computed tomography (CBCT). MATERIALS AND METHODS: Twenty-nine adult patients with a mean age of 32.15 ± 8.75 years were enrolled. An IBP based on indirect tactile perception was used to determine the labial bone crest level of the mandibular anterior teeth clinically. Bone crest perception degree, gingival thickness, and patient discomfort during IBP were also recorded. CBCT scans were used to evaluate the level and thickness of the labial bone crest. IBP and CBCT methods were compared statistically. The significance level was set at 5%. RESULTS: There was a significant difference between the labial bone crest level diagnosed by IBP and CBCT. However, the difference was not clinically significant. IBP and CBCT measurements were significantly and strongly correlated (R = 0.74). Thinner gingival tissue was associated with a higher perception of bone crest. Only two patients reported mild to moderate discomfort during IBP. CONCLUSIONS: IBP allowed the labial bone crest level to be determined with acceptable clinical accuracy, especially in patients with thinner gingival tissue.

Influence of surgically assisted rapid maxillary expansion on the interdental papilla height of maxillary central incisors.

PURPOSE: To evaluate the influence of orthodontic treatment with surgically assisted rapid maxillary expansion (SARME) on the interdental papilla height of maxillary central incisors. METHODS: In this retrospective study, patients who completed orthodontic treatment including SARME at the Radboud University Medical Center Orthodontic Department before December 2019 were included. Frontal intraoral photographs taken before (T1) and after completion of treatment (T2) were examined to determine the papilla height between the maxillary central incisors using the Jemt classification. The difference between the Jemt classification at T1 and T2 (∆Jemt) was defined as the primary outcome variable. Secondary outcome variables were gender, age, treatment duration, type of expansion appliance, maximal central diastema during expansion, pretreatment overlapping between the central incisors, gingival biotype, crown morphology and the distance between the bone crest and incisal contact point. Kappa statistics and paired t­tests were used to determine reliability of the measurements. Pearson's Χ2 test and independent t­tests were used to compare the variables between the groups of patients with and without papillary recession. Finally, multiple logistic regression analysis was performed. RESULTS: In all, 93 patients fulfilled the inclusion criteria and were included in the study. The Jemt score worsened for 30 patients (32%) between T1 and T2, indicating the occurrence of papillary recession. Incisal overlapping, crown morphology, small width to length ratio, increasing age and an increasing distance between crestal bone and the incisal contact point were factors associated with papillary recession. CONCLUSION: After orthodontic treatment including SARME, one third of patients exhibited recession of papilla height of the maxillary central incisors.

Occurrence of tympanic bone spicules and bone crests in domestic cats.

Small and hyperostotic tympanic bone spicules (STBS and HTBS) extending from the tympanic wall or from the septum bullae into the tympanic cavity have been described in large feline species such as Siberian tigers or African lions and in canids such as dogs, red foxes and wolves. Detailed descriptions of prevalence, location and orientation were performed for dogs and African lions by means of necropsy and conventional computed tomography (cCT). Aims of the current study were to describe same characteristics for domestic cats by means of microcomputed tomography (µCT) and cCT. A total of 15 cats or rather 30 ears were examined. Furthermore, new bone formations extending into the tympanic cavity shaped like small lamellae were found and named "tympanic bone crests" (TBCs). The registered phenomenon of a thickened tympanic wall in some cats was named "tympanic wall thickening" (TWT). STBS appeared in 43% of the ears being bilateral in 44% of the cases, whereas HTBS appeared in one ear. TBC was present in 33% of the ears with a bilateral prevalence of 67%, and TWT could be detected in 13% of the ears. The mentioned structures are just barely or not at all detectable with cCT; therefore, µCT is necessary for an identification and detailed description. The origin and the factors inducing the development of examined phenomena are unknown, and it is hypothesized that the occurrence can be assessed as anatomical norm variations.

The Effectiveness of Micro-osteoperforations during Canine Retraction: A Three-dimensional Randomized Clinical Trial.

AIM: A major challenge in orthodontics is decreasing treatment time without compromising treatment outcome. The purpose of this split-mouth trial was to evaluate micro-osteoperforations (MOPs) in accelerating orthodontic tooth movement. MATERIALS AND METHODS: Eight patients of both genders were selected, age ranging between 15 and 40 years, with Class II Division 1 malocclusion. The participants in this trial with MOPs were randomly allocated to either the right or the left side, distal to the maxillary canine. First maxillary premolars were extracted as part of the treatment plan on both sides and then canine retraction was applied. Miniscrews were used to support anchorage. MOP side received (three small perforations) placed on the buccal bone, distal to the maxillary canine, on randomly selected side using an automated mini-implant driver and the other side was the control side. Blinding was used at the data collection and analysis stages. The primary outcome was the rate of canine retraction measured with a three-dimensional (3D) digital model from the baseline to the first 2 weeks superimposed at the rugae area from the baseline to the first, second, and third months. The following secondary outcomes were examined: anchorage loss, canine tipping, canine rotation, root resorption, plaque index, and gingival index. Pain level, pain interference with the patients' daily life, patients' satisfaction with the procedure and degree of ease, willingness to repeat the procedure, and recommendation to others were also evaluated. RESULTS: No statistically significant difference was observed in the rates of tooth movement between the MOP and the control sides at all-time points (first month: P = 0.77; mean difference, 0.2 mm; 95% CI, -0.13, 0.18 mm; second month: P = 0.50; mean difference, -0.08 mm; 95% CI, -0.33, 0.16 mm; third month: P = 0.76; mean difference, -0.05 mm; 95% CI, -0.40, 0.29 mm). There were also no differences in anchorage loss, rotation, tipping, root resorption, plaque index, periodontal index, and pain perception between the MOP and control sides at any time point (P > 0.05). MOPs had no effect on the patients' daily life except for a feeling of swelling on the first day (P = 0.05). Level of satisfaction and degree of easiness of the procedure were high. CONCLUSION: According to our clinical trial, MOPs cannot help in speeding up a canine retraction.

Evaluation of peri-implant bone levels and soft tissue dimensions around zirconia implants-a three-year follow-up study.

The aim of this study was to measure bone levels around zirconia implants during follow-up of up to 3 years. Additionally, the effect of clinical contact point positions on the papilla deficit was evaluated. Eighty-one patients with 105 zirconia implants were examined at the 3-year follow-up. Bone levels were measured on the date of implant placement and at 3 months, 1year, and 3 years thereafter. Distances between the first bone-implant contact and the contact point of the crowns and between the bone level at the adjacent tooth and the contact point of the crowns were assessed. The effect of the clinical contact point position on the papilla deficit was also assessed. Significant reductions in the distances between the bone-implant contact and the implant shoulder, as well as the contact point of the crowns, and between the bone level at the adjacent tooth and the contact point of the crowns, were found. A significant association was found between the papilla deficit and the height of the contact point. Implant survival was 100% and implant success was 95.4%. While zirconia implants presented little bone loss up to 1year, significant bone apposition was observed up to 3years. Low contact points correlated with full papillae, whereas high contact points were associated with a papilla deficit.

Cone-beam computed tomographic evaluation of changes in maxillary alveolar bone after orthodontic treatment.

This study examined the relationship of vertical and horizontal changes in the alveolar bone crest with upper incisor movement after orthodontic treatment. Tooth movement was measured on lateral cephalograms. Vertical and horizontal changes in the median alveolar crest and distance from the cementoenamel junction and anterior nasal spine to the alveolar crest were measured with cone-beam computed tomography. The incisal edge moved distally, and the cervical point intruded significantly and moved distally. The median alveolar crest decreased by 3.80 ± 2.05 mm. The distance from the labial cementoenamel increased significantly, by 0.35 ± 0.38 mm. The vertical distance from the anterior nasal spine decreased significantly, and the alveolar crest moved distally. Vertical tooth movement was positively associated with change in the distance from the labial cementoenamel junction and inversely associated with vertical change in the distance from the anterior nasal spine on the labial and palatal sides. Lingual tooth movement was positively and negatively correlated with horizontal changes in the labial and palatal alveolar crest and vertical change in the palatal alveolar crest. The lingual movement of incisors was related to labial bone resorption. Greater lingual and extrusive movement of incisors led to a greater decrease in the alveolar bone crest.

Comparación del nivel de la cresta ósea en desdentados totales rehabilitados con implantes mandibulares y prótesis removible / Comparison of the level of the bone crest in total edentulous rehabilitated with mandibular implants and removable prosthesis

RESUMEN: Objetivo: Se desarrolló una investigación que tuvo por propósito determinar el patrón de reabsorción del tejido óseo de implantes rehabilitados con coronas de acrílico que actúan como pilares de una prótesis parcial removible con retenedores extracoronarios. Materiales y métodos: Para medir tal efecto se diseñó un dispositivo que permitió estandarizar el registro del nivel óseo mediante una radiografía retroalveolar con técnica de paralelismo, considerando que este procedimiento permite observar gran cantidad de detalles, ofreciendo una imagen de alta definición, con una mínima distorsión, bajo costo y mínimo riesgo de radiación. Los resultados: indican que en un intervalo de seis meses medido después de realizada la rehabilitación a los 24 y 30 meses respectivamente se observa una reabsorción ósea que en promedio alcanza 0,12 mm siendo esta diferencia estadísticamente significativa entre ambos tiempos de registros. Conclusión: Los patrones de reabsorción de nuestra investigación son similares a los que ocurren con otras formas de rehabilitación sobre implantes oseointegrados.

ABSTRACT: Objetive: The purpose of this research was to determine the pattern of reabsorption of bone tissue from rehabilitated implants with acrylic crowns that act as supports of a removable partial denture with extra-coronary retainers. Material and method: To measure this effect, a device was designed to standardize the measurement of the bone level by a retro-alveolar radiography with parallelism exposure technique, considering that this procedure allows to observe great amount of details, offering an image of high definition, with a minimum distortion, low cost and minimal risk of radiation. The results: indicate that in a six-month interval measured after rehabilitation at 24 and 30 months respectively a bone resorption is observed, which on average reaches 0.12 mm, this difference being statistically significant between both recording times. Conclusion: The resorption patterns of our research are similar to those that occur with other forms of rehabilitation on osseointegrated implants.

Vertical alveolar crest bone maintenance around implants in two-stage surgery: an in situ study in dogs

The aim of this study was to evaluate in situ changes in the alveolar crest bone height around immediate implant-supported crowns in comparison to tooth-supported crowns (control) with the cervical margins located at the bone crest level, without occlusal load. In Group I, after extraction of 12 mandibular premolars from 4 adult dogs, implants from Branemark System (MK III TiU RP 4.0 x 11.5 mm) were placed to retain complete acrylic crowns. In Group II, premolars were prepared to receive complete metal crowns. Sixteen weeks after placement of the crowns (38 weeks after tooth extraction), the height of the alveolar bone crest was measured with a digital caliper. Data were analyzed statistically by the Mann-Whitney test at 5 percent significance level. The in situ analysis showed no statistically significant difference (p=0.880) between the implant-supported and the tooth-supported groups (1.528 + 0.459 mm and 1.570 + 0.263 mm, respectively). Based on the findings of the present study, it may be concluded that initial peri-implant bone loss may result from the remodeling process necessary to establish the biological space, similar to which occurs with tooth-supported crowns.

O objetivo do presente estudo foi comparar in situ modificações ocorridas na crista óssea alveolar induzidas por implantes imediatos e às induzidas por dentes naturais, ambos preparados para suportarem dispositivos protéticos situados sobre a margem óssea cervical, sem carga oclusal. No grupo I, após a extração de 12 pré-molares inferiores de 4 cães adultos, foram instalados implantes do Sistema Branemark (MK III TiU RP 4,0 x 11,5 mm) e coroas totais acrílicas. No grupo II, os pré-molares, foram submetidos a preparos convencionais, sendo cimentadas coroas totais metálicas. Após 16 semanas da instalação das coroas (38 semanas após a extração), a reabsorção da crista óssea alveolar foi avaliada in situ, por meio da mensuração das peças, com paquímetro digital. Para obtenção das medidas do grupo I, os pontos de referência foram a plataforma de assentamento do implante e a crista óssea alveolar. No grupo II, a posição do limite cervical da prótese e o início da crista óssea. Os valores obtidos foram comparados pelo teste de Mann-Whitmey com nível de significância de 5 por cento. A média de reabsorção da crista óssea foi de 1,528 + 0,459 mm para o grupo I e de 1,570 + 0,263 mm para o grupo II, não havendo diferença estatisticamente significante (p=0,880) entre os grupos. Os resultados do presente estudo permitiram concluir que a reabsorção perimplantar inicial que ocorre na crista óssea resulta de um padrão de remodelação necessário para o estabelecimento do espaço biológico na área, assim como ocorre nos dentes naturais preparados para receberem próteses convencionais.

Reconstrução e reabilitação de mandíbula severamente atrófica com enxerto da crista do osso ilíaco e implantes osseointegrados: acompanhamento clínico e radiográfico de 36 meses / Reconstruction and rehabilitation of severely atrophic mandible with iliac crest bone graft and osseointegrated implants: a clinical and radiological 36-month follow-up

O objetivo deste trabalho foi relatar um caso no qual foi realizado enxerto onlay de crista ilíaca em uma mandíbula severamente atrófica, visando ganho de altura para futura instalação de implantes, já que a paciente não conseguia fazer uso de prótese total. Através de um acesso do tipo cervicotomia alta, foi feita a exposição de toda a região anterior da mandíbula. O bloco de osso removido da crista ilíaca anterior direita foi dividido em seis blocos menores, modelado e adaptado para servir de enxerto aposicional tanto sobre a porção superior quanto inferior da mandíbula, entre forâmenes mentonianos. O uso sobre as duas corticais foi devido à extrema atrofia do rebordo alveolar. Após quatro meses, a paciente apresentava excelente integração do enxerto. Foi realizada, então, a instalação de cinco implantes para suportar uma prótese total fixa, do tipo protocolo, confeccionada cinco meses após a colocação dos implantes. A paciente encontra-se em acompanhamento clínico e radiográfico há 36 meses, sem sinais clínicos/radiográficos de mobilidade dos implantes e boa adaptação da prótese.

The aim of this study was to report a case where a free onlay, iliac crest graft was made in an extremely atrophic mandible to gain height for further implant placement, since the patient could not cope with her conventional denture. First, the anterior mandibular region was surgically exposed and later a bone block was removed from the right iliac crest being divided into six smaller pieces, shaped and adapted between the mental foramina at the lower and upper regions. The use of both cortices was due to extreme alveolar ridge atrophic nature. After four months, the patient presented with excellent graft incorporation. Then, five dental implants were placed and a fixed complete prosthesis was fabricated five months later. According to the last clinical and radiographic follow-ups, no implant loss or loosening was seen after 36 months and the prosthesis demonstrates good marginal fit.