Airway AssessmentNCT07668297
Correlation of Neck Dimensions of Airway Evaluation
An observational study of Airway Assessment and Laryngoscopy, run by Sir Ganga Ram Hospital at 1 site in India.
Trial summary
The goal of this observational study is to evaluate thyromental distance (TMD) and mandibular triangle perpendicular length (MTPL); to know which correlates better with the incisor vallecula distance (IVD). Read more about this study
- Who is it for?
- Ages 18 to 65 years
- Conditions the study is for
- Airway Assessment, Laryngoscopy
- How many people
- 240 participants
- Where
- 1 siteIndia
- Study dates
- 25 Jun 2026to Aug 2027
- Phase
- Observational
- Are there results?
- Not yet: the study is under way
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 65 years
- All sexes
- Adult, Older adult
Study population: Patients undergoing elective surgery under general anaesthesia
Who may be able to join
- Age 18-65 years
- Males and females
- ASA (American Society of Anaesthesiologists) physical status I and II
- Patients scheduled for elective surgery with controlled ventilation through orotracheal tube conduit
Who cannot join
- Smokers (those who have smoked ≥100 cigarettes in their lifetime), chewing tobacco dependence or substance abuse
- Submucous fibrosis: progressive fibrosis of the submucosal tissue leading to rigidity, relative trismus, and progressive decrease of mouth opening
- Anticipated difficult airway
- Patients requiring intubation with MacIntosh blade #4 or #5
- Dental issues:
- missing tooth (upper/lower incisors, upper/lower premolar)
Show all 14Show fewer
- crowded dentition: - irregular, misaligned, or overlapping teeth within a relatively small oral cavity
- presence of artificial teeth and/or dental implants
- Mandible/mandibular structure related issues:
- Retrognathia: - posterior displacement of the mandible relative to the maxilla or cranial base
- Prognathia: - anterior displacement of the mandible relative to the maxilla or cranial base
- Emergency Surgery
- Those requiring urgent rapid-sequence intubation due to the presence of a full-stomach status secondary to gastro-esophageal reflux disease, diaphragmatic hernia, among others.
- Refusal to informed consent
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
India1 site, 1 recruiting
- Recruiting
Sir Ganga Ram Hospital
New Delhi, National Capital Territory of Delhi, 110060
Amitabh Dutta, MBBS, MD, PGDHR, 9810848064, duttaamitabh@yahoo.co.in
About this study
Official title: Correlation of Thyromental Distance And Mandibular Triangle Perpendicular Length With Incisor Vallecular Distance In Adult Pre-Surgical Patients: An Observational Study
The goal of this observational study is to evaluate thyromental distance (TMD) and mandibular triangle perpendicular length (MTPL); to know which correlates better with the incisor vallecula distance (IVD). Based on the direction and strength of the correlation measure, a multiple regression equation can then be created to first predict the IVD with external linear measure, and second, based on IVD length prediction, the appropriate laryngoscope blade size can be ascertained.
Read the detailed description
Preoperative evaluation of the upper airway is vital to the success, safety, and quality of airway access. The evaluation primarily aims to anticipate the course of direct laryngoscopy and intubation (DLI) of the trachea. While assessment of mouth opening, neck extension, and dentition forms the preliminary step of knowing whether DLI is feasible; there are certain other parameters whose evaluation facilitates understanding as to how the actual DLI will turn out. Among the secondary parameters, the linear thyromental distance (TMD) is an important measure that determines how the direct laryngoscopy aspect of conducting DLI will go - in terms of ease-of-laryngoscopy to gain the desired visual access to the view to the vocal cords. The ease of laryngoscopy involves as to how the laryngoscope blade would be able to displace tongue to one side, create forward space enhancement, and reach the vallecula at the base of the tongue; before lifting the epiglottis to view the cords. Though in use for over 4 decades, the TMD suffers from weakness, including, low sensitivity and specificity, not relating to the actual and direct teeth vallecular distance, and getting confounded by neck dimensions (thickness, length), state of dentition, and the tongue size.
The present study is built on the premise that it's the mandibular space to which the tongue is displaced at the time of DLI, the bony mandibular space is more exclusive of the confounders, and that the teeth (lower incisors) vallecular distance represent the actual distance that needs to be predicted.
The present study aims to evaluate TMD and mandibular triangle perpendicular length (MTPL); to know which correlates better with the incisor vallecula distance (IVD). Based on the direction and strength of the correlation measure, a multiple regression equation can then be created to first predict the IVD with external linear measure, and second, based on IVD length prediction, the appropriate laryngoscope blade size can be ascertained.
- Conditions
- Airway Assessment, Laryngoscopy
- Keywords
- Thyromental distance, Mandibular triangle perpendicular, Laryngoscope, incisor vallecula distance
What is being measured
The primary outcome is the main question the study is designed to answer.
Correlation of thyromental distance (TMD) and mandibular triangle perpendicular length (MTPL) with incisor vallecular distance (IVD)
In all patients thyromental distance (TMD) and mandibular triangle perpendicular length (MTPL) will be measured. TMD will be measured as a straight line distance between the bony mentum (tip of the chin) and the superior thyroid notch (upper border of the thyroid cartilage). MTPL will be measured as the perpendicular of the mandibular triangle formed by joining the mental protuberence and point at angle of mandible on either side. During direct larygngosocpoy when the tip of the laryngoscope blade lies on the vallecula, the distance between the laryngoscope blade tip and the point of laryngoscope blade flange overlying the lower incisors will be measured. A correlation between TMD and MTPL with IVD if any will be established.
Measured: From entry into preoperative area (0 minutes) to time patient is shifted to operating room ( 10-minutes)
Secondary outcomes (2)
Correlation of incisor vallecular distance (IVD), mandibular triangle perpendicular length (MTPL), and thyromental distance (TMD) with Macintosh blade (MCB) size#3 length
Macintosh blade size # 3 length will be determined by measuring the linear distance between the tip of the blade and the point where the concave surface of the blade flange joins the heel of the the laryngoscope blade. A correlation between IVD, MTPL, and TMD with Macintosh blade size # 3 length if any will be established
Measured: From induction of anaesthesia (0 minutes) to insertion of endotracheal tube ( 10-minutes)
Cormack and Lehane score
The grade view to the glottic-opening upon direct laryngoscopy will be done using the 4-point Cormack-Lehane grading system (grade 1: entire glottic opening is seen; grade 2: anterior larynx not visualised, only posterior laryngeal aperture is seen; grade 3: only tip of epiglottis is seen; grade 4: neither glottis or epiglottis is visible, only soft palate is seen)
Measured: From induction of anaesthesia (0 minutes) to insertion of endotracheal tube ( 10-minutes)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted25 Jun 2026
- Study start25 Jun 2026
- Primary completionJul 2027 (estimated)
- Study completionAug 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Airway AssessmentStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Cohort
- Time perspective
- Prospective
- Enrolment
- 240 participants (estimated)
Sponsor and investigators
- Lead sponsor
- Sir Ganga Ram Hospital
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Nitin Sethi, DNB, Sir Ganga Ram Hospital
- Investigators
- Amitabh Dutta, MD, Principal investigator, Sir Ganga Ram Hospital, New Delhi-110060, IndiaParidhi Saboo, MBBS, Principal investigator, Sir Ganga Ram Hospital, New Delhi-110060, IndiaNitin Sethi, DNB, Study director, Sir Ganga Ram Hospital, New Delhi-110060, India
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07668297
- Sponsor's protocol ID
- EC/06/26/2981
- Status last verified
- Jun 2026
- First submitted
- 19 Jun 2026
- Last updated
- 30 Jun 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Study at a glance
From the registry record, last updated by the sponsor on 30 Jun 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Correlation of Thyromental Distance And Mandibular Triangle Perpendicular Length With Incisor Vallecular Distance In Adult Pre-Surgical Patients: An Observational Study
- ClinicalTrials.gov ID
- NCT07668297
- Acronym / sponsor ID
- EC/06/26/2981
- Conditions
- Airway Assessment, Laryngoscopy
- Keywords
- Thyromental distance, Mandibular triangle perpendicular, Laryngoscope, incisor vallecula distance
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 240 participants (estimated)
- Lead sponsor
- Sir Ganga Ram HospitalUniversity, hospital or other
- Study start
- 25 Jun 2026 (actual)
- Primary completion
- Jul 2027 (estimated)
- Study completion
- Aug 2027 (estimated)
- First posted
- 25 Jun 2026 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The goal of this observational study is to evaluate thyromental distance (TMD) and mandibular triangle perpendicular length (MTPL); to know which correlates better with the incisor vallecula distance (IVD). Based on the direction and strength of the correlation measure, a multiple regression equation can then be created to first predict the IVD with external linear measure, and second, based on IVD length prediction, the appropriate laryngoscope blade size can be ascertained.
Detailed description
Preoperative evaluation of the upper airway is vital to the success, safety, and quality of airway access. The evaluation primarily aims to anticipate the course of direct laryngoscopy and intubation (DLI) of the trachea. While assessment of mouth opening, neck extension, and dentition forms the preliminary step of knowing whether DLI is feasible; there are certain other parameters whose evaluation facilitates understanding as to how the actual DLI will turn out. Among the secondary parameters, the linear thyromental distance (TMD) is an important measure that determines how the direct laryngoscopy aspect of conducting DLI will go - in terms of ease-of-laryngoscopy to gain the desired visual access to the view to the vocal cords. The ease of laryngoscopy involves as to how the laryngoscope blade would be able to displace tongue to one side, create forward space enhancement, and reach the vallecula at the base of the tongue; before lifting the epiglottis to view the cords. Though in use for over 4 decades, the TMD suffers from weakness, including, low sensitivity and specificity, not relating to the actual and direct teeth vallecular distance, and getting confounded by neck dimensions (thickness, length), state of dentition, and the tongue size.
The present study is built on the premise that it's the mandibular space to which the tongue is displaced at the time of DLI, the bony mandibular space is more exclusive of the confounders, and that the teeth (lower incisors) vallecular distance represent the actual distance that needs to be predicted.
The present study aims to evaluate TMD and mandibular triangle perpendicular length (MTPL); to know which correlates better with the incisor vallecula distance (IVD). Based on the direction and strength of the correlation measure, a multiple regression equation can then be created to first predict the IVD with external linear measure, and second, based on IVD length prediction, the appropriate laryngoscope blade size can be ascertained.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
Who may qualify
- Ages
- 18 to 65 years
- Sex
- All
- Age groups
- Adult, Older adult
- Study population
- Patients undergoing elective surgery under general anaesthesia
Key inclusion criteria (4 listed)
- Age 18-65 years
- Males and females
- ASA (American Society of Anaesthesiologists) physical status I and II
- Patients scheduled for elective surgery with controlled ventilation through orotracheal tube conduit
Key exclusion criteria (14 listed)
- Smokers (those who have smoked ≥100 cigarettes in their lifetime), chewing tobacco dependence or substance abuse
- Submucous fibrosis: progressive fibrosis of the submucosal tissue leading to rigidity, relative trismus, and progressive decrease of mouth opening
- Anticipated difficult airway
- Patients requiring intubation with MacIntosh blade #4 or #5
- Dental issues:
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Correlation of thyromental distance (TMD) and mandibular triangle perpendicular length (MTPL) with incisor vallecular distance (IVD)
Time frame: From entry into preoperative area (0 minutes) to time patient is shifted to operating room ( 10-minutes)
In all patients thyromental distance (TMD) and mandibular triangle perpendicular length (MTPL) will be measured. TMD will be measured as a straight line distance between the bony mentum (tip of the chin) and the superior thyroid notch (upper border of the thyroid cartilage). MTPL will be measured as the perpendicular of the mandibular triangle formed by joining the mental protuberence and point at angle of mandible on either side. During direct larygngosocpoy when the tip of the laryngoscope blade lies on the vallecula, the distance between the laryngoscope blade tip and the point of laryngoscope blade flange overlying the lower incisors will be measured. A correlation between TMD and MTPL with IVD if any will be established.
2 secondary outcomes
Correlation of incisor vallecular distance (IVD), mandibular triangle perpendicular length (MTPL), and thyromental distance (TMD) with Macintosh blade (MCB) size#3 length
Time frame: From induction of anaesthesia (0 minutes) to insertion of endotracheal tube ( 10-minutes)
Cormack and Lehane score
Time frame: From induction of anaesthesia (0 minutes) to insertion of endotracheal tube ( 10-minutes)
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 30 Jun 2026.
- Individual participant dataSharing planned: No
Related trials for Airway Assessment
Not yet recruitingObservational study
"Comparison of Oxygen Reserve Index (ORI), End-Tidal Oxygen, and Time-Based Preoxygenation Targets With Arterial Blood Gas During Preoxygenation
Preoxygenation Adequacy Assessed by Oxygen Reserve Index, End-tidal Oxygen and Arterial Blood Gas
RecruitingPhase 3
A Study to Learn About the Monthly Dosing Study Medicine Called Berobenatide in Adults With Breathing Problems During Sleep and Overweight or Obesity Who Do Not Use a Breathing Machine (PAP) (VESPER-OSA 2)
Apnea, Sleep Disorders
Not yet recruitingPhase 4
Effect of Prophylactic Dexamethasone vs Placebo on Airway Dimensions Assessed by Ultrasonography in Patients Undergoing Laparoscopic Cholecystectomy
Airway Edema, Postoperative Complications
RecruitingPhase 3
A Study to Learn About the Monthly Dosing Study Medicine Called Berobenatide in Adults With Breathing Problems During Sleep and Overweight or Obesity Who Use a Breathing Machine (PAP) (VESPER-OSA 1)
Apnea, Sleep Disorders
Active, not recruitingPhase 3
A Multicenter, Randomized, Double-blind, Placebo-controlled Phase III Clinical Study to Evaluate the Efficacy and Safety of HRS9531 Injection in Subjects With Obstructive Sleep Apnea (OSA) and Obesity Who Are on Positive Airway Pressure Ventilation (PAP) Therapy
Subjects With Moderate-to-severe OSA and Obesity Who Are on PAP Therapy
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part.
Amitabh Dutta, MD principal investigator
Sir Ganga Ram Hospital, New Delhi-110060, India
Paridhi Saboo, MBBS principal investigator
Sir Ganga Ram Hospital, New Delhi-110060, India
Nitin Sethi, DNB study director
Sir Ganga Ram Hospital, New Delhi-110060, India
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Airway Assessment and Laryngoscopy, run by Sir Ganga Ram Hospital at 1 site in India.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 14 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: looking for participants now, as of the sponsor's last update on 30 Jun 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in India. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Amitabh Dutta, MD (00919810848064, duttaamitabh@yahoo.co.in), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Correlation of thyromental distance (TMD) and mandibular triangle perpendicular length (MTPL) with incisor vallecular distance (IVD) (time frame: From entry into preoperative area (0 minutes) to time patient is shifted to operating room ( 10-minutes)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 30 Jun 2026.