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NCT Number: NCT07634276

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

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.

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Key information

Conditions

CAD/CAM Orthognathic Surgery Patient Specific Implant Surgery-first

Age range

18 year–40 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

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

Beijing, China

Location contact

Xiaoshuang Guo, M.D.

CONTACT

[email protected]

+86 13121234163

Who can participate

Healthy volunteers accepted: Yes

Only the study team can determine whether someone qualifies for participation.

Inclusion criteria

  • 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.

Exclusion criteria

  • 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.

Treatment and study plan

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.

Primary outcomes

  1. Linear deviation

    Time frame: 7 days and 1 year

    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.

Secondary outcomes

  1. Angular deviation

    Time frame: 7 days and 1 year

    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. Angular 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.

  2. Soft tissue change

    Time frame: 1 year

    Soft tissue changes were evaluated based on three-dimensional facial scan data acquired using a 3dMD system. Following the superimposition of preoperative virtual surgical planning models and postoperative actual facial scan datasets, changes in soft tissue landmarks were assessed, including the nasal base, lips, nose, etc.

  3. satisfatory questionnaire

    Time frame: 1 year

Study contacts

Contact information is provided by the study sponsor or research team.

Xiaolei Jin, M.D.

CONTACT

[email protected]

Xiaoshuang Guo, M.D.

CONTACT

[email protected]

+86 13121234163

Sponsors and collaborators

Lead sponsor

Peking Union Medical College

Other

Collaborators

  • Beijing Municipal Health Commission

Registry information

Official study title

A Prospective, Randomized, Controlled, Single-blind Study on the Hybrid Tooth and Bone-supported Cutting and Repositioning Guides Versus Computer-aided Design/Computer-aided Manufactured Splints in "Surgery-first" Orthognathic Surgery

Acronym: PSI

Important dates

Study start
2026
Primary completion
2028
Study completion
2028
First posted
Jun 8, 2026
Registry last updated
Jun 8, 2026

OpenTrials presents study information sourced from ClinicalTrials.gov. The official registry record should be consulted for the latest information.

View the official ClinicalTrials.gov record (opens in a new tab)

This listing is for discovery and informational purposes only. It is not medical advice, does not guarantee that a study is recruiting, and does not determine eligibility. Contact the study team and a qualified healthcare professional when considering participation.

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