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Effect of Early Versus Late Premolar Extraction on Orthodontic Tooth Movement

15 augustus 2026 bijgewerkt door: Shanzay Khan, Shifa College of Dentistry

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

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.

Studie Overzicht

Gedetailleerde beschrijving

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.

Studietype

Ingrijpend

Inschrijving (Geschat)

26

Fase

  • Niet toepasbaar

Contacten en locaties

In dit gedeelte vindt u de contactgegevens van degenen die het onderzoek uitvoeren en informatie over waar dit onderzoek wordt uitgevoerd.

Studiecontact

Studie Locaties

Deelname Criteria

Onderzoekers zoeken naar mensen die aan een bepaalde beschrijving voldoen, de zogenaamde geschiktheidscriteria. Enkele voorbeelden van deze criteria zijn iemands algemene gezondheidstoestand of eerdere behandelingen.

Geschiktheidscriteria

Leeftijden die in aanmerking komen voor studie

  • Kind
  • Volwassen

Accepteert gezonde vrijwilligers

Nee

Beschrijving

Inclusion Criteria:

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

Exclusion Criteria:

  1. History of dental trauma
  2. Poor oral hygiene
  3. Syndromic patients
  4. Systemic diseases or medications affecting bone metabolism

Studie plan

Dit gedeelte bevat details van het studieplan, inclusief hoe de studie is opgezet en wat de studie meet.

Hoe is de studie opgezet?

Ontwerpdetails

  • Primair doel: Behandeling
  • Toewijzing: Gerandomiseerd
  • Interventioneel model: Parallelle opdracht
  • Masker: Enkel

Wapens en interventies

Deelnemersgroep / Arm
Interventie / Behandeling
Actieve vergelijker: Healed Socket Group (Control Group)
Maxillary first premolars will be extracted before or within one week of fixed orthodontic appliance placement. Participants will subsequetly undergo leveling and alignment followed by en-masse anterior retraction after stabilization on a 0.019 x 0.025-inch stainless steel archwire.
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.
Experimenteel: Unhealed Socket Group (Intervention Group)
Maxillary first premolars will be extracted after the participant has completed leveling and alignment, and has been stabilizad on a 0.019 x 0.025-inch stainless steel archwire for one month. This will be followed immediately by en-masse anterior retraction.
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.

Wat meet het onderzoek?

Primaire uitkomstmaten

Uitkomstmaat
Maatregel Beschrijving
Tijdsspanne
Rate of Orthodontic Space Closure Measured on Digital 3D Dental Models
Tijdsspanne: 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).
Baseline (T0), 3 months (T1), and 6 months (T2) after initiation of en-masse anterior retraction

Secundaire uitkomstmaten

Uitkomstmaat
Maatregel Beschrijving
Tijdsspanne
Incidence and Severity of Gingival Clefts Assessed Clinically Using a Periodontal Probe
Tijdsspanne: 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.
Baseline (T0), 3 months (T1), and 6 months (T2) after initiation of en-masse anterior retraction
Linear Mesial Movement of Maxillary First Molars Measured on Digital Models
Tijdsspanne: 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.
Baseline (T0), 3 months (T1), and 6 months (T2) after initiation of en-masse anterior retraction
Ease of Maxillary First Premolar Extraction Assessed by Surgeon-Rated 4-Point Likert Scale and Extraction Duration
Tijdsspanne: 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.
Periprocedural
Patient-Reported Pain and Dental Anxiety Associated With Premolar Extraction
Tijdsspanne: 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.
Dental anxiety immediately before extraction; pain immediately following extraction.

Medewerkers en onderzoekers

Hier vindt u mensen en organisaties die betrokken zijn bij dit onderzoek.

Studie record data

Deze datums volgen de voortgang van het onderzoeksdossier en de samenvatting van de ingediende resultaten bij ClinicalTrials.gov. Studieverslagen en gerapporteerde resultaten worden beoordeeld door de National Library of Medicine (NLM) om er zeker van te zijn dat ze voldoen aan specifieke kwaliteitscontrolenormen voordat ze op de openbare website worden geplaatst.

Bestudeer belangrijke data

Studie start (Werkelijk)

22 juli 2026

Primaire voltooiing (Geschat)

1 januari 2028

Studie voltooiing (Geschat)

1 juni 2028

Studieregistratiedata

Eerst ingediend

12 augustus 2026

Eerst ingediend dat voldeed aan de QC-criteria

15 augustus 2026

Eerst geplaatst (Werkelijk)

19 augustus 2026

Updates van studierecords

Laatste update geplaatst (Werkelijk)

19 augustus 2026

Laatste update ingediend die voldeed aan QC-criteria

15 augustus 2026

Laatst geverifieerd

1 juli 2026

Meer informatie

Termen gerelateerd aan deze studie

Informatie over medicijnen en apparaten, studiedocumenten

Bestudeert een door de Amerikaanse FDA gereguleerd geneesmiddel

Nee

Bestudeert een door de Amerikaanse FDA gereguleerd apparaatproduct

Nee

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