Tooth and Bone-borne Cutting/Repositioning Guide and Patient-specific Implant(PSI)

NCT07634276 | Not Yet Recruiting DMC

• 1 other identifier: 2026-4-4043
• Study Type: interventional
• Target: 50
• Locations: 1 country
• Sites: 1

Brief Summary

Dentofacial deformity refers to a group of disorders characterized by malocclusion and facial asymmetry resulting from developmental abnormalities of the maxilla and mandible, which cause morphological and positional anomalies of the jaws. Compared with the traditional orthodontics-orthognathic surgery-orthodontics treatment protocol, the surgery-first approach has witnessed a continuous expansion of its clinical application scope. Nevertheless, academic controversies persist regarding its indication boundaries, postoperative jaw stability, and adaptive changes of the temporomandibular joint. In orthognathic surgery, computer-aided design/computer-aided manufacturing (CAD/CAM) surgical guides indirectly determine the three-dimensional spatial positions of the maxilla and mandible through occlusal relationships. The tooth-bone dual-supported osteotomy and positioning guide combined with pre-bent patient-specific implants (PSIs) forms a novel surgical guide system that enables independent and direct positioning of the maxilla. Theoretically, this system can eliminate errors derived from mandibular positional instability and thereby improve surgical accuracy. However, comparative studies investigating the clinical application of these two types of guides in surgery-first orthognathic surgery are still lacking. This prospective, randomized, controlled, single-blind clinical study aimed to explore the clinical value of PSIs and conventional CAD/CAM guides in surgery-first orthognathic surgery, with primary outcomes focusing on surgical accuracy, postoperative jaw stability, and temporomandibular joint alterations. The findings will provide evidence-based medical support for the expanded application of this novel technique in precision orthognathic surgery.

Conditions

CAD/CAM; Patient Specific Implant; Orthognathic Surgery; Surgery-first

Outcome Measures

Primary Outcomes (1)

• Linear deviation

  Following the superimposition of preoperative virtual surgical planning models and postoperative actual craniomaxillofacial computed tomography (CT) datasets, manual registration was performed based on anatomical landmarks including the nasion, foramen magnum, infraorbital point, zygomatic bone, and zygomatic arch. Linear deviations of the A-point, B-point, canine teeth, and first molars relative to the Frankfort horizontal plane, facial midsagittal plane, and coronal plane were measured and recorded.

  7 days and 1 year

Secondary Outcomes (3)

• Angular deviation

  7 days and 1 year

• Soft tissue change

  1 year

• satisfatory questionnaire

  1 year

Study Arms (2)

PSI group

EXPERIMENTAL

Tooth-bone borne osteotomy and repositioning guides combined with patient-specific implants constitute the PSI group for short. Preoperative craniomaxillofacial computed tomography (CT) data of patients were imported for three-dimensional reconstruction. Surgical plans, including genioplasty procedures, were collaboratively formulated by surgeons and orthodontists with full consideration of patients' personal preferences. Custom tooth-bone dual-supported osteotomy and positioning guides for both the maxilla and mandible were digitally designed and subsequently fabricated. A partial skull model was printed preoperatively, on which custom titanium plates were pre-bent in advance in strict accordance with the established surgical protocol.

Procedure: bimaxillary surgery(Lefort I and SSRO)

CAD/CAM group

ACTIVE COMPARATOR

Patients' preoperative craniomaxillofacial computed tomography (CT) data were imported for three-dimensional (3D) reconstruction. Surgeons and orthodontists collaboratively formulated individualized surgical plans based on patients' preferences, including genioplasty procedures, followed by the design and fabrication of CAD/CAM intermediate and final surgical guides.

Procedure: bimaxillary surgery(Lefort I and SSRO)

Interventions

bimaxillary surgery(Lefort I and SSRO) PROCEDURE

All patients underwent surgery-first bimaxillary orthognathic surgery, with concomitant optional procedures including maxillary and mandibular subapical osteotomy and genioplasty.

CAD/CAM group; PSI group

Eligibility Criteria

• Age: 18 Years - 40 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Adult (18-64)

You may qualify if:

• Age ranged from 18 to 40 years old.
• Patients were diagnosed with dentofacial deformity and received treatment at the Plastic Surgery Hospital, Chinese Academy of Medical Sciences. The diagnosis was confirmed via comprehensive evaluation by two senior attending plastic surgeons.
• Patients were scheduled for bimaxillary orthognathic surgery, with optional adjunctive procedures including maxillary and mandibular subapical osteotomy and genioplasty.
• Patients were indicated for the surgery-first approach based on joint assessment by craniomaxillofacial surgeons and orthodontists. Orthodontists confirmed that satisfactory occlusal relationships could be achieved through postoperative orthodontic treatment. Preoperative dental conditions met the following requirements: no or mild anterior dental crowding, flat or shallow Spee's curve, slight incisor inclination, harmonious maxillary and mandibular dental arches, and at least three stable occlusal contacts under transitional occlusion.
• Patients agreed to complete follow-up examinations and provided signed informed consent.

You may not qualify if:

• Patients who refused to participate in the present study.
• Presence of comorbidities that may increase surgical risks or impair surgical outcomes, as assessed by two senior plastic surgeons, including but not limited to hypertension, diabetes, immune thrombocytopenic purpura, and hemoglobin (Hb) level ≤ 100 g/L.
• Presence of body dysmorphic disorder, a history of psychiatric disorders, or excessively demanding patients with unrealistic treatment expectations.
• Presence of facial skeletal tumors.
• Patients who required revision surgery after previous orthognathic procedures.
• Cases judged unable to achieve stable occlusal relationships through postoperative orthodontic treatment following joint evaluation by craniomaxillofacial surgeons and orthodontists, including patients with severe dental crowding, maxillomandibular arch width discrepancy, temporomandibular joint disorders, or periodontal diseases.

Sponsors & Collaborators

• Peking Union Medical College: lead
• Beijing Municipal Health Commission: collaborator

Study Sites (1)

Plastic Surgery Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College

Beijing, China

Location

Study Officials

• Guodong Song

  Chinese Academy of Medical Sciences, Peking Union Medical College, Plastic Surgery Hospital

  STUDY DIRECTOR

Central Study Contacts

Xiaoshuang Guo, M.D.

CONTACT

+86 13121234163; gxsinjnu@126.com

Xiaolei Jin, M.D.

CONTACT

zxyy16jxl@163.com

Study Design

• Study Type: interventional
• Phase: not applicable
• Allocation: RANDOMIZED
• Masking: SINGLE
• Who Masked: PARTICIPANT
• Purpose: TREATMENT
• Intervention Model: PARALLEL
• Sponsor Type: OTHER
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Director

Study Record Dates

• First Submitted: May 28, 2026
• First Posted: June 8, 2026
• Study Start: June 8, 2026
• Primary Completion (Estimated): June 8, 2028
• Study Completion (Estimated): December 31, 2028
• Last Updated: June 8, 2026

Record last verified: 2026-06

Data Sharing

• IPD Sharing: Will share
• Shared Documents: STUDY PROTOCOL
• Time Frame: Date of public release: The day of online publication of the article (expected December 2029)
• Access Criteria: The raw data will be published as supplementary materials alongside the full text on the official platform of the target journal, and available for free download and access by readers.

Locations

CN (1)