This first-in-human surgical study can be classified as a “stage 1” study in accordance with the IDEAL (innovation, development, exploration, assessment, and long-term study) framework [25]. It is a single-center prospective clinical trial comprising 8 patients, assessing the safety of a combination of MFAT and BCP (BoneCeramic, Straumann) as bone graft material for alveolar cleft reconstruction. The BCP is a synthetic bone graft containing 60% HA and 40% β-tricalcium phosphate, a porosity of 90%, and an interconnected pore size of 100-500 µm. The BCP will be combined in a 1 g:1 cm³ ratio with MFAT prepared from the patients’ own BFP, which is processed with a 1.2-mm single-use sizing transfer Tulip Gen II Nanofat Kit (Tulip Medical). The primary end point will be set at 6 months. At each follow-up visit, adverse events (AEs) or serious AEs (SAEs) will be documented, and clinical assessments will be performed at time points specified in the Interventions section. After these 6 months, a bone biopsy sample will be taken using a hollow drill during dental implant preparation and subsequently processed for histological or histomorphometric analysis (Figure 1). Finally, a report on safety and proof of concept with regard to bone formation will be made and published.

The clinical trial protocol was approved by the ethical committee of Hasanuddin University, Makassar, Indonesia (1063/UN4.6.4.5.31/PP36/2019) and registered in the Indonesian trial registry (INA-EW74C1N). Informed consent will be obtained from candidates or their parents or legal guardians who are willing to join the trial after being fully educated about the trial procedure. This study complies with the principles of the Declaration of Helsinki. In the informed consent form signed by the patients or their legal representatives, consent to publish their data in a deidentified manner is included.

Patients will be included on the basis of the following criteria [26]: being healthy male or female participants aged ≥15 years, having unilateral alveolar cleft without any previous history of grafting procedures, being categorized as normal healthy patients for anesthetic risk per the American Society for Anesthesiologists’ criteria, and having a normal blood count.

Patients will be excluded on the basis of the following criteria [26]: having poor oral hygiene with mouth plaques; having systemic disease; having systemic or local infection; having received chemotherapy, radiotherapy, immunosuppressives, or anticoagulants that may interfere with the healing process; having received bone growth–inducing factors, malnutrition, or active influenza; and being pregnant.

Under general anesthesia and infiltration with lidocaine (1%) with epinephrine (1:100,000 dilution), the surgeon will identify the Stensen’s duct with a lacrimal probe and make an incision 2-3 cm below the duct [27]. A dissection penetrating the muscles and the superficial fascia will allow spontaneous herniation of the BFP [27]. This procedure will be carried out bilaterally on both cheeks in order to obtain approximately 3 cm³ of fat. After vasoconstrictor infiltration with epinephrine (1:100,000), a full mucoperiosteal flap spanning the first molar to the central incisor is lifted. After exposure of the full alveolar cleft and to separate the nasal layer from the oral mucosa, the tissue was meticulously dissected. Following the reflection of a palatal mucoperiosteal flap from either side of the cleft, the palatal tissues are elevated. The oronasal fistula is repaired cranially by elevating and suturing the nasal mucosa [4], thereby creating a pocket for BCP-MFAT deposition.

In parallel with the defect surgery, the harvested fat will be chopped into small pieces with a scissor and soaked in normal saline for 10-15 minutes. The normal saline then will be drained and the chopped fat will be processed into MFAT using 2 syringes (size 10 cm³) connected with the 1.2-mm single-use sizing transfer Tulip Gen II Nanofat Kit in accordance with the manufacturer’s protocol. MFAT will be mixed with BCP (Straumann Bone Ceramic) in a ratio of 1 g:1 cm³ until it reaches homogenous consistency. The BCP-MFAT mixture will be placed as a graft material into the alveolar cleft defect. If the defect is large and requires more bone graft, another mixture will be prepared with the same mixing ratio. If necessary, a membrane will be used to cover the grafted defect. Finally, the defect will be closed by suturing the palatal mucoperiosteal flaps using absorbable sutures with 3-0 vicryl sutures for mucosa and 4-0 vicryl sutures for nasal reconstruction. All patients will be prescribed antibiotics and analgesics postoperatively.

Any change in the health of subjects will be documented in their medical history, and required medical care will be provided. Any unexpected physical or laboratory change, symptom, or disease that occurs in a treated patient who has been administered the graft will be documented as an AE. An AE will be graded in accordance with the World Health Organization’s classification [28] as either serious or nonserious based on its intensity. The Clavien-Dindo Classification of Surgical Complications will also be used in case of any incidence [29]. In the case of an SAE, a report will be made to the sponsor within 24 hours and to the ethical committee within 3 days from the date of onset. If the SAE concerns severe toxicity or infection associated with graft products, the trial will be terminated immediately.

This is a first-in-human phase I clinical trial aimed to obtain insight on the safety and feasibility of the treatment with the BCP-MFAT combination. We assume that no SAEs or AEs will occur, based on our clinical experience with other applications of MFAT and the well-proven safety of BCP. Upon consultation with a statistician, a sample size of 8 individuals is expected to be sufficient for this trial.

Patients will be recruited from an existing database of the Hasanuddin University Dental Hospital, from general practices of Hasanuddin Dental Hospital and in the area around Makassar. Thereafter, we will determine whether the candidates fulfill the study’s inclusion and exclusion criteria. Thorough assessment and training regarding the safety measurements at the research site at Hasanuddin University Dental Hospital will be performed prior to the trial by the ethical and surgical teams.

Since we did not want to enroll children in a safety study with this novel concept in clinical practice, we chose to only include older adolescent and adult patients, being themselves capable of decision-making. Within Indonesia, this age group is more common due to cultural and religious backgrounds causing abstinence from cleft surgeries.

The trial will be conducted at Hasanuddin Dental Hospital. All participants will be asked to sign an informed consent form after risks and possible complications of the procedure (eg, bleeding, infection, cheek asymmetry, parotid duct injury, possibility of facial nerve branches injury, and—although not likely—nonclosure) were appropriately communicated with the patient. Data will be handled and stored in a coded—that is, deidentified—format, so that data cannot be traced back to the patient without a decoding key, which is stored in a locked place and only accessible to the study’s principal investigator. Implants will be offered free of charge.

Since this trial comprises only 1 type of treatment, no randomization or blinding to the treatment is possible.

The research team will be informed about the rules and their responsibilities. All members of the research team, which will collect the data in accordance with the evaluation table (Table 1), will receive training on how data collection should be performed. The data manager will document the data in a patient-coded manner (ie, each patient will be assigned a study-specific code under which the data will be stored in order to conceal their identity), which will subsequently be handed over to the clinical evaluators and investigators. The primary end point is set at 6 months.

After the primary end point assessment, the participants will be followed up for an additional period of 3 years to ensure their safety and to record whether any delayed side effect occurs as a result of treatment with the BCP-MFAT combination, as previously done in a similar study [26].

Internal monitors of the Ethics and Research Committee, Faculty of Medicine, Hasanuddin University, will evaluate whether the data are accurately collected. Since negligible risk to the patient is expected as both materials (MFAT and BCP) have been tested in other clinical trials [16,17,24], no data safety monitoring board will be installed. A safety report will be submitted every year to the Medical Research Ethics Committee, Faculty of Medicine, Hasanuddin University. No interim analysis is deemed necessary.

If deemed necessary, amendments to this protocol will be submitted to the ethical committee and competent authority and should be approved prior to implementation to ensure the safety and integrity of participants as well as the scientific value of the trial.

Since this is a single-arm safety study, statistical analyses will not be performed.