Positional changes of maxillary central incisors following orthodontic treatment using single-crown implants as fixed reference markers

Impact of maxillofacial growth on implants placed in adults: A narrative review

OBJECTIVE

To determine the effect of lifetime maxillofacial changes on dental implants placed in adults, analyze the clinical implications of these changes, identify prognostic factors, and offer possible solutions.

OVERVIEW

The relationship between implant placement and maxillofacial changes, occurring during not only the active growth period but also the entire span of adulthood, has not been extensively examined. Vertical differences between implants and adjacent teeth due to the ankylotic behavior of the former might be observed at any age and endanger restoration biologically, functionally, and esthetically. Regarding interproximal contacts, firm contact loss may occur within a few months after restoration, resulting in food impaction. Many prognostic factors have been reported, but most do not exhibit a statistically significant association with implant infraocclusion and interproximal contact loss. Incorporation of alternative solutions, accurate treatment planning, strict recall protocols, and retrievability of implant-supported restorations can facilitate efficient management of complications.

CONCLUSION

Maxillomandibular changes throughout adulthood may lead to complications such as implant infraocclusion and interproximal contact loss. Rehabilitation of edentulism should be characterized by well-designed and flexible treatment plans to resolve long-term complications efficiently. Further long-term clinical studies are needed to identify other risk factors.

CLINICAL SIGNIFICANCE

Treatment plans for implant therapy should be reconsidered for adults. Careful patient monitoring and early intervention are essential for securing treatment outcomes.

Interproximal contact loss at implant sites: a retrospective clinical study with a 10-year follow-up

AIM

To assess the frequency and quantity of interproximal contact loss (ICL) between implant restorations and adjacent teeth after at least 10 years of follow-up (FU).

METHODS

Thirty-nine patients (median age 57.3 years) with 80 implants were re-examined at least 10 years after insertion of final restorations (single-crowns or fixed dental prostheses (FDPs)). Baseline (insertion of the restorations) and FU examinations encompassed: stone casts were scanned and superimposed for metric assessment of tooth movements, radiographs and clinical measurements. Outcome measures at implant sites were: the extent of tooth movement and the frequency of interproximal contact loss [ICL], peri-implant marginal bone levels [MBLs], and clinical measurements (plaque control record [PCR], bleeding on probing [BOP] and probing depth [PD]). Data were analyzed statistically with generalized regression modelling with robust standard errors to account for within-patient clustering at 5%.

RESULTS

ICL for at least one contact point after 10 years was observed in 50% of all implants (with open interproximal spaces up to 1.64 mm). Mesial contact points were significantly more prone to ICL than distal ones (relative risk [RR]=1.79; 95% confidence interval [CI]=1.07-2.99; p=0.03). The type of restoration had a significant effect on ICL, with FDPs of 2 implants being significantly more prone to mesial ICL than single crowns (RR=1.52; 95% CI=1.02-2.25; p=0.04). ICL was also associated with a significant increase in PD (+0.46 mm (95% CI=0.04-0.88 mm; P=0.03)) compared to implant sites without ICL. BOP, MBLs and PCR were not significantly influenced by ICL.

CONCLUSION

ICL was a common finding in 50% of the implant sites and was significantly associated with an increase in PD.

3-D tooth movement adjacent to single anterior implants and esthetic outcome. A 14- to 20-year follow-up study

OBJECTIVES

To report three-dimensional (3-D) movement of teeth adjacent to single-implant crowns (SICs) in the anterior maxilla and to relate the findings to patient characteristics and esthetic outcome.

MATERIALS AND METHODS

3-D movements of teeth adjacent to anterior maxillary SICs were measured in 30 patients with original SICs in function after 14-20 years. The movements were related to facial type, lower anterior facial height (LAFH), age at crown delivery, sex, the position of the implant, implant occlusion, cause of tooth loss, follow-up period, orthodontic treatment prior to implant placement, and marginal bone-level changes. The esthetic outcome and quality were assessed using Visual Analog scale (VAS) and California Dental Association (CDA) index.

RESULTS

3-D movement of adjacent teeth between 0 and 2.5 mm was observed at follow-up with incisal and palatal movement being most pronounced. Incisal tooth movement of >1 mm was observed in 30% of the patients and was significantly associated with LAFH ≥70 mm. VAS rating associated poorly between patients and clinicians with scores of >80% in 63% and 20%, respectively. The CDA rating was assessed as satisfactory in 87% of the patients.

CONCLUSIONS

Significantly more extensive infraposition was observed in patients with SICs without occlusion, other causes of tooth loss than trauma, implant in lateral incisor and canine position, and a LAFH of ≥70 mm. Although infraposition occurs, patients are highly satisfied with the esthetics of their implants and the esthetic results are valued as higher by patients than dentists.

The risk for infraposition of dental implants and ankylosed teeth in the anterior maxilla related to craniofacial growth, a systematic review

BACKGROUND

The aim of the study was to evaluate a potential association between individuals with different craniofacial types or other exposures, and the risk of infraposition due to continued growth/eruption of adjacent teeth in the anterior maxilla.

MATERIALS AND METHODS

This is a systematic review in which primary studies as well as other systematic reviews are scrutinised. A search of PubMed (Medline), Scopus, Web of science and Health technology assessment (HTA) organisations and a complementary handsearch was carried out. Selected studies were read in full-text by several reviewers. The quality of the included primary studies was assessed using a protocol for assessment of risk of bias in exposure studies.

RESULTS

The literature search resulted in 3,296 publications. Title and abstract screening yielded 25, whereof one systematic review, potential publications allocated for full-text inspection. The quality assessment resulted in a total of seven studies with a low/moderate risk of bias and four studies with a high risk of bias.

CONCLUSION

In conclusion, a long-term risk for infraposition of dental implants, or ankylosed teeth, among natural teeth can be observed in some cases. The predisposing factors are still not fully understood since the current scientific evidence is very limited.

Frequency of infraposition and missing contact points in implant-supported restorations within natural dentitions over time: A systematic review with meta-analysis

OBJECTIVES

The aim of this systematic review was to assess clinical evidence on adverse effects of osseointegrated implants placed among natural teeth of a residual dentition.

METHODS

Seven databases were searched without restrictions up to January 2018 for clinical studies on implant infraposition (IIP) or proximal contact point (PCP) loss to the adjacent teeth. After duplicate selection, data extraction, and risk of bias assessment according to the Cochrane guidelines, random-effects meta-analyses of odds ratios (OR) or mean differences (MD) and their 95% confidence intervals (CI) were performed, followed by meta-regression and sensitivity analyses.

RESULTS

A total of 27 nonrandomized studies with 1,572 patients (mean age 42.2 years/51.2% female) followed up to 18.5 years after implant placement were included. The pooled %prevalence of IIP was 50.5% (nine studies; 95% CI = 26.3-74.5%), and the pooled IIP extent was 0.58 mm (six studies; 95% CI = 0.33-0.83 mm), while IIP > 1 mm was seen for 20.8% of placed implants (five studies; 95% CI = 8.3-37.1%), and male patients were less prone to IIP than female patients (three studies; OR = 0.30; 95% CI = 0.10-0.88; p = 0.03). The pooled %prevalence of PCP loss was 46.3% (nine studies; 95% CI = 32.3-60.6%), with increase through observation time (two studies; OR = 1.09; 95% CI = 1.03-1.16; p = 0.004) and predilection for mesial PCPs (five studies; OR = 2.25; 95% CI = 1.06-4.77; p = 0.03). However, the quality of evidence was very low due to bias.

CONCLUSIONS

Patients and doctors need to be aware that long-term adverse effects of dental implants among natural teeth can be observed in terms of IIP and PCP loss to the adjacent teeth.