Novel approach for treating challenging implant – borne maxillary dental rehabilitation cases of cleft lip and palate: a retrospective study

Björn Rahlf, Philippe Korn, Alexander-Nicolai Zeller, Simon Spalthoff, Philipp Jehn, Fritjof Lentge, Nils-Claudius Gellrich

Full text links: https://pubmed.ncbi.nlm.nih.gov/35106688/

Novel approach for treating challenging implant-borne maxillary dental rehabilitation cases of cleft lip and palate: a retrospective study

1. Scientific Reference

• Study title: Novel approach for treating challenging implant-borne maxillary dental rehabilitation cases of cleft lip and palate: a retrospective study
• Authors: Björn Rahlf, Philippe Korn, Alexander-Nicolai Zeller, Simon Spalthoff, Philipp Jehn, Fritjof Lentge, Nils-Claudius Gellrich
• Scientific journal: International Journal of Implant Dentistry
• Year of publication: 2022
• DOI: 10.1186/s40729-022-00401-x

2. Scientific Background

Implant-supported rehabilitation of patients with cleft lip and palate represents one of the most complex challenges in oral and maxillofacial surgery. These patients frequently present a combination of bone deficiencies, soft tissue alterations, surgical scars and skeletal imbalances that may compromise conventional implantology protocols.

Conventional approaches generally rely on preliminary bone reconstruction followed by dental implant placement and multiple successive surgical procedures. However, bone graft resorption, anatomical difficulties and implant failures may limit long-term outcomes. In certain situations, patients have already undergone several reconstructive interventions without achieving durable prosthetic restoration.

In this context, the development of customized implants derived from CAD/CAM technologies and additive manufacturing represents an interesting avenue for simplifying implant-supported rehabilitation in the most complex cases.

3. Study Objective

The objective of the authors was to evaluate the clinical feasibility of a customized implant named IPS-preprosthetic® in patients with cleft lip and palate presenting anatomical situations that were particularly unfavorable for conventional implant treatments.

The study aimed to determine whether this approach could allow stable maxillary implant rehabilitation despite significant bone and mucosal deficiencies, often associated with a history of therapeutic failures.

4. Methodology

This was a retrospective study conducted within the Department of Oral and Maxillofacial Surgery of Hannover Medical School in Germany.

Among 63 patients who received a customized IPS-preprosthetic® implant, six patients presented with cleft lip and palate requiring maxillary rehabilitation. Four patients were completely edentulous in the maxilla and two were partially edentulous.

Prosthetic planning was performed digitally according to a backward planning protocol. The customized implants were manufactured using a CAD/CAM process combined with selective laser melting technology for titanium.

All procedures were performed as a single outpatient surgical intervention with multivector screw fixation. Postoperative follow-up ranged from 6 to 40 months depending on the patient.

5. Main Results

The reported results demonstrated favorable clinical stability during the observation period.

None of the six customized implants were lost during follow-up. The authors also reported that no screw loosening and no reduction in stability between the implant and the recipient site were observed. The average number of screws used for fixation was 21.

Healing proceeded without major complications despite unfavorable tissue conditions. Five patients notably presented persistent oro-nasal fistulas before treatment.

Partial exposure of the implant framework was observed around certain abutments in several cases. According to the authors, these exposures were associated with mucositis but did not result in implant loss nor require removal of the device.

6. Clinical Analysis

This study focuses on a particularly difficult population to treat in implantology: patients with cleft lip and palate presenting severe bone deficiencies, extensive scar tissue, or previous failures of bone grafts and implants.

The main interest of this publication lies in the use of a customized subperiosteal implant designed through a complete digital workflow. Unlike conventional protocols, which often require several interventions spread over many months, the proposed strategy aims to reduce the treatment pathway to a single procedure with the possibility of immediate loading.

The reported results suggest that multivector fixation away from deficient bone areas may provide sufficient mechanical stability even when anatomical conditions are severely compromised.

However, caution is required when interpreting these results. The data concern only six patients, and the study includes no control group allowing direct comparison with conventional implant protocols, bone reconstruction procedures, or other maxillary rehabilitation solutions.

The results should therefore be regarded as preliminary observations demonstrating the feasibility of this approach rather than definitive validation of its clinical superiority.

7. Clinical Applications

The presented data may be relevant in several complex implant rehabilitation situations:

• Patients with cleft lip and palate associated with significant bone loss.
• Complete maxillary edentulism associated with compromised anatomy.
• Previous failures of bone grafts or dental implants.
• Cases requiring implant-supported reconstruction in an unfavorable scarred environment.
• Rehabilitation based on a customized CAD/CAM digital workflow.
• Patients refusing or unwilling to undergo another major bone reconstruction procedure.

The study suggests that customized implants could represent a rescue option in situations where conventional approaches become difficult to implement.

8. Level of Evidence, Limitations and Transparency

This publication corresponds to a retrospective observational study involving a limited series of clinical cases. The level of evidence therefore remains moderate to low compared with controlled trials or large prospective studies.

Several limitations can be identified:

• very small sample size (six patients);
• absence of a control group;
• variable follow-up depending on the patient;
• absence of direct comparison with other surgical or implant protocols;
• limited data regarding long-term outcomes.

The authors indicate that Björn Rahlf and Nils-Claudius Gellrich received lecture or travel honoraria from KLS Martin, the manufacturer of the IPS-preprosthetic® system. The other authors declare no conflicts of interest.

9. Key Points of the Study

• Study type: Retrospective study
• Level of evidence: Retrospective case series
• Population analyzed: Patients with cleft lip and palate
• Number of patients: 6
• Number of implants: 6 IPS-preprosthetic® implants in CLP patients
• Follow-up duration: 6 to 40 months
• Primary outcome evaluated: Clinical feasibility and stability of the customized implant
• Main result: No implant failure observed during follow-up
• Scientific conclusion: The IPS-preprosthetic® customized implant appears feasible in complex anatomical situations associated with cleft lip and palate
• Potential limitations: Small sample size, absence of control, limited medium-term data

10. Scientific Impact

This study provides preliminary clinical data on the use of a customized implant intended for situations in which conventional protocols reach their limitations. It illustrates the integration of digital technologies, CAD/CAM implant planning and additive manufacturing in the management of patients presenting complex maxillary deficiencies.

The scientific value of this work lies less in demonstrating comparative effectiveness than in validating the feasibility of a new therapeutic strategy. The reported results show that implant-supported rehabilitation may be considered even after multiple reconstructive failures or in highly unfavorable anatomical contexts.

This publication therefore opens research perspectives regarding next-generation customized implants and their role in complex maxillofacial reconstruction. Studies including larger numbers of patients and longer follow-up periods will nevertheless be necessary to confirm these observations.

11. Editorial Conclusion

This retrospective study explores an innovative implant rehabilitation approach in patients with cleft lip and palate presenting particularly complex clinical situations. The observed results demonstrate favorable clinical stability of the IPS-preprosthetic® customized implant over a follow-up period of up to 40 months. Despite these encouraging data, the small sample size and the absence of comparison with other protocols require cautious interpretation. This publication primarily constitutes a proof of feasibility that may support future research in digital implantology and complex maxillofacial reconstruction.