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NCT Number: NCT07773389

Effect of Early Versus Late Premolar Extraction on Orthodontic Tooth Movement

The goal of this randomized controlled trial is to evaluate whether the timing of premolar extraction affects the rate of orthodontic space closure during en-masse anterior retraction. The study will also assess gingival cleft formation, mesial movement of the upper first molars, ease and duration of premolar extraction, and patient-reported pain and anxiety.

The main question it aims to answer is:

Does early versus late premolar extraction affect the rate of orthodontic space closure?

Researchers will compare two groups of patients. In the early extraction group the maxillary first premolars will be extracted before or within one week of start of fixed orthodontic treatment. In the late extraction group, the premolars will be extracted after alignment and immediately before the start of space closure.

Participants will:

* Receive fixed orthodontic treatment and bilateral extraction of the maxillary first premolars. * Be randomly assigned to either the early-extraction or late-extraction group. * Undergo orthodontic alignment followed by en-masse anterior retraction. * Have dental impressions/digital models obtained at the start of retraction and at 3 and 6 months to measure orthodontic tooth movement and space closure. * Be assessed for gingival clefts and mesial movement of the upper first molars. * Have the ease and duration of their premolar extraction recorded and report their pain and anxiety associated with the extraction procedure.

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Key information

Conditions

Malocclusion Class II Malocclusion Malocclusion, Angle Class I Stomatognathic Diseases Tooth Diseases

Age range

13 year–25 year

Sex eligibility

All sexes

Study type

Interventional

Phase

Not applicable

Primary location

Shifa College Of Dentistry

Islamabad, 44000, Pakistan

Location status: Recruiting

Location contact

Shanzay Khan

CONTACT

[email protected]

03245555716

About this study

This randomized controlled trial will evaluate the effect of early versus late maxillary first premolar extraction on the rate of orthodontic space closure during en-masse anterior retraction. A total of 26 participants aged 13 to 25 years requiring bilateral maxillary first premolar extractions as part of their orthodontic treatment will be randomly allocated in a 1:1 ratio to an early-extraction or late-extraction group.

In the early-extraction group, the maxillary first premolars will be extracted before or within one week of fixed appliance placement. Participants will subsequently undergo leveling and alignment, and en-masse anterior retraction will begin after stabilization on a 0.019 × 0.025-inch stainless steel archwire. In the late-extraction group, leveling and alignment will be completed first using the same archwire sequence. The maxillary first premolars will then be extracted immediately before initiation of en-masse anterior retraction. Thus, space closure will occur through relatively healed extraction sites in the early-extraction group and relatively fresh extraction sites in the late-extraction group.

Orthodontic space closure will be assessed at baseline and at 3 and 6 months after initiation of retraction. Secondary assessments will include mesial movement of the maxillary first molars, incidence and severity of gingival clefts, ease and duration of premolar extraction, and patient-reported pain and anxiety. Digital models will be used to assess orthodontic tooth movement, while gingival clefts will be evaluated clinically.

Who can participate

Healthy volunteers accepted: No

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

Inclusion criteria

  • Age 13-25 years
  • No prior orthodontic treatment
  • Overjet 4-8 mm
  • Symmetric dental arches with mild to moderate crowding requiring bilateral first premolar extractions.
  • Probing depth less than 4 mm on all teeth

Exclusion criteria

  • History of dental trauma
  • Poor oral hygiene
  • Syndromic patients
  • Systemic diseases or medications affecting bone metabolism

Treatment and study plan

Early Maxillary First Premolar Extraction

Procedure

Bilateral extraction of the maxillary first premolars will be performed prior to or within one week of fixed orthodontic appliance placement, allowing the extraction sockets to heal during leveling and alignment before commencement of en-masse anterior retraction.

Late Maxillary First Premolar Extraction

Procedure

Bilateral extraction of the maxillary first premolars will be performed after completion of leveling and alignment and one month of stabilization on a 0.019 × 0.025-inch stainless steel archwire, immediately before commencement of en-masse anterior retraction.

Primary outcomes

  1. Rate of Orthodontic Space Closure Measured on Digital 3D Dental Models

    Time frame: Baseline (T0), 3 months (T1), and 6 months (T2) after initiation of en-masse anterior retraction

    Intraoral scans will be obtained to generate digital 3D dental models at baseline (T0), 3 months (T1), and 6 months (T2) after initiation of en-masse anterior retraction. The extraction space will be measured in millimeters as the linear distance between the highest convexity on the mesial surface of the maxillary second premolar and the distal surface of the maxillary canine. The rate of space closure will be calculated as the reduction in extraction-space width over the corresponding observation period and expressed in millimeters per month (mm/month).

Secondary outcomes

  1. Incidence and Severity of Gingival Clefts Assessed Clinically Using a Periodontal Probe

    Time frame: Baseline (T0), 3 months (T1), and 6 months (T2) after initiation of en-masse anterior retraction

    Gingival clefts will be assessed clinically using a periodontal probe.The presence, severity (depth and width in mm), and type (buccal, lingual, or through-and-through) of gingival clefts will be recorded. Cleft severity will be assessed by measuring depth and width in millimeters. Depth will be measured perpendicular to the occlusal plane, and the width will be measured parallel to the occlusal plane from the buccal and lingual aspect, with the greater of the two measurements recorded as the cleft width.

  2. Linear Mesial Movement of Maxillary First Molars Measured on Digital Models

    Time frame: Baseline (T0), 3 months (T1), and 6 months (T2) after initiation of en-masse anterior retraction

    Measurements will be performed on digital dental models obtained by intraoral scanning. Linear mesial movement of the maxillary first molars will be measured in millimeters. Perpendicular reference lines to the mid-palatal suture will be constructed through the mesial contact point of the maxillary first molar and the medial end of the third palatal rugae. The distance between these reference lines will be measured in millimeters. The change in this distance from baseline (T0) to 3 months (T1) and from baseline to 6 months (T2) will represent linear mesial movement.

  3. Ease of Maxillary First Premolar Extraction Assessed by Surgeon-Rated 4-Point Likert Scale and Extraction Duration

    Time frame: Periprocedural

    Surgeon-perceived ease of extraction will be assessed using a 4-point Likert scale: 1 = very easy, 2 = easy, 3 = difficult, and 4 = very difficult, with higher scores indicating greater extraction difficulty. Extraction duration will also be recorded from the time the forceps are clamped onto the tooth until the tooth is completely removed from the socket.

  4. Patient-Reported Pain and Dental Anxiety Associated With Premolar Extraction

    Time frame: Dental anxiety immediately before extraction; pain immediately following extraction.

    Pain will be assessed using a 0-10 Visual Analogue Scale, where 0 represents no pain and 10 represents the worst pain. Dental anxiety will be assessed using a 5-item questionnaire, with each item rated from 1 (not anxious) to 5 (extremely anxious), giving a total score of 5-25. Higher scores indicate greater pain or anxiety.

Study contacts

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

Shanzay Khan, BDS, Post Graduate Resident

CONTACT

[email protected]

03245555716

Sponsors and collaborators

Lead sponsor

Shifa College of Dentistry

Other

Registry information

Official study title

Effect of Early vs Late Premolar Extraction on the Rate of Orthodontic Tooth Movement: A Randomized Controlled Trial

Important dates

Study start
2026
Primary completion
2028
Study completion
2028
First posted
Aug 19, 2026
Registry last updated
Aug 19, 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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