Journal of Clinical and Diagnostic Research, ISSN - 0973 - 709X

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On Sep 2018

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Sanjay Gandhi institute of trauma and orthopedics,
On Aug 2018

Dr. Mamta Gupta,
"It gives me great pleasure to be associated with JCDR, since last 2-3 years. Since then I have authored, co-authored and reviewed about 25 articles in JCDR. I thank JCDR for giving me an opportunity to improve my own skills as an author and a reviewer.
It 's a multispecialty journal, publishing high quality articles. It gives a platform to the authors to publish their research work which can be available for everyone across the globe to read. The best thing about JCDR is that the full articles of all medical specialties are available as pdf/html for reading free of cost or without institutional subscription, which is not there for other journals. For those who have problem in writing manuscript or do statistical work, JCDR comes for their rescue.
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Reviewing articles is no less a pain staking process and requires in depth perception, knowledge about the topic for review. It requires time and concentration, yet I enjoy doing it. The JCDR website especially for the reviewers is quite user friendly. My suggestions for improving the journal is, more strict review process, so that only high quality articles are published. I find a a good number of articles in Obst. Gynae, hence, a new journal for this specialty titled JCDR-OG can be started. May be a bimonthly or quarterly publication to begin with. Only selected articles should find a place in it.
An yearly reward for the best article authored can also incentivize the authors. Though the process of finding the best article will be not be very easy. I do not know how reviewing process can be improved. If an article is being reviewed by two reviewers, then opinion of one can be communicated to the other or the final opinion of the editor can be communicated to the reviewer if requested for. This will help one’s reviewing skills.
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Dr. Mamta Gupta
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Aug 2018

Dr. Rajendra Kumar Ghritlaharey

"I wish to thank Dr. Hemant Jain, Editor-in-Chief Journal of Clinical and Diagnostic Research (JCDR), for asking me to write up few words.
Writing is the representation of language in a textual medium i e; into the words and sentences on paper. Quality medical manuscript writing in particular, demands not only a high-quality research, but also requires accurate and concise communication of findings and conclusions, with adherence to particular journal guidelines. In medical field whether working in teaching, private, or in corporate institution, everyone wants to excel in his / her own field and get recognised by making manuscripts publication.

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Salient features of the JCDR: It is a biomedical, multidisciplinary (including all medical and dental specialities), e-journal, with wide scope and extensive author support. At the same time, a free text of manuscript is available in HTML and PDF format. There is fast growing authorship and readership with JCDR as this can be judged by the number of articles published in it i e; in Feb 2007 of its first issue, it contained 5 articles only, and now in its recent volume published in April 2011, it contained 67 manuscripts. This e-journal is fulfilling the commitments and objectives sincerely, (as stated by Editor-in-chief in his preface to first edition) i e; to encourage physicians through the internet, especially from the developing countries who witness a spectrum of disease and acquire a wealth of knowledge to publish their experiences to benefit the medical community in patients care. I also feel that many of us have work of substance, newer ideas, adequate clinical materials but poor in medical writing and hesitation to submit the work and need help. JCDR provides authors help in this regards.
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In the era of fast growing newer technologies, and in computer and internet friendly environment the manuscripts preparation, submission, review, revision, etc and all can be done and checked with a click from all corer of the world, at any time. Of course there is always a scope for improvement in every field and none is perfect. To progress, one needs to identify the areas of one's weakness and to strengthen them.
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Every one of us: authors, reviewers, editors, and publisher are responsible for enhancing the stature of the journal. I wish for a great success for JCDR."

Thanking you
With sincere regards
Dr. Rajendra Kumar Ghritlaharey, M.S., M. Ch., FAIS
Associate Professor,
Department of Paediatric Surgery, Gandhi Medical College & Associated
Kamla Nehru & Hamidia Hospitals Bhopal, Madhya Pradesh 462 001 (India)
On May 11,2011

Dr. Shankar P.R.

"On looking back through my Gmail archives after being requested by the journal to write a short editorial about my experiences of publishing with the Journal of Clinical and Diagnostic Research (JCDR), I came across an e-mail from Dr. Hemant Jain, Editor, in March 2007, which introduced the new electronic journal. The main features of the journal which were outlined in the e-mail were extensive author support, cash rewards, the peer review process, and other salient features of the journal.
Over a span of over four years, we (I and my colleagues) have published around 25 articles in the journal. In this editorial, I plan to briefly discuss my experiences of publishing with JCDR and the strengths of the journal and to finally address the areas for improvement.
My experiences of publishing with JCDR: Overall, my experiences of publishing withJCDR have been positive. The best point about the journal is that it responds to queries from the author. This may seem to be simple and not too much to ask for, but unfortunately, many journals in the subcontinent and from many developing countries do not respond or they respond with a long delay to the queries from the authors 1. The reasons could be many, including lack of optimal secretarial and other support. Another problem with many journals is the slowness of the review process. Editorial processing and peer review can take anywhere between a year to two years with some journals. Also, some journals do not keep the contributors informed about the progress of the review process. Due to the long review process, the articles can lose their relevance and topicality. A major benefit with JCDR is the timeliness and promptness of its response. In Dr Jain's e-mail which was sent to me in 2007, before the introduction of the Pre-publishing system, he had stated that he had received my submission and that he would get back to me within seven days and he did!
Most of the manuscripts are published within 3 to 4 months of their submission if they are found to be suitable after the review process. JCDR is published bimonthly and the accepted articles were usually published in the next issue. Recently, due to the increased volume of the submissions, the review process has become slower and it ?? Section can take from 4 to 6 months for the articles to be reviewed. The journal has an extensive author support system and it has recently introduced a paid expedited review process. The journal also mentions the average time for processing the manuscript under different submission systems - regular submission and expedited review.
Strengths of the journal: The journal has an online first facility in which the accepted manuscripts may be published on the website before being included in a regular issue of the journal. This cuts down the time between their acceptance and the publication. The journal is indexed in many databases, though not in PubMed. The editorial board should now take steps to index the journal in PubMed. The journal has a system of notifying readers through e-mail when a new issue is released. Also, the articles are available in both the HTML and the PDF formats. I especially like the new and colorful page format of the journal. Also, the access statistics of the articles are available. The prepublication and the manuscript tracking system are also helpful for the authors.
Areas for improvement: In certain cases, I felt that the peer review process of the manuscripts was not up to international standards and that it should be strengthened. Also, the number of manuscripts in an issue is high and it may be difficult for readers to go through all of them. The journal can consider tightening of the peer review process and increasing the quality standards for the acceptance of the manuscripts. I faced occasional problems with the online manuscript submission (Pre-publishing) system, which have to be addressed.
Overall, the publishing process with JCDR has been smooth, quick and relatively hassle free and I can recommend other authors to consider the journal as an outlet for their work."

Dr. P. Ravi Shankar
KIST Medical College, P.O. Box 14142, Kathmandu, Nepal.
On April 2011

Dear team JCDR, I would like to thank you for the very professional and polite service provided by everyone at JCDR. While i have been in the field of writing and editing for sometime, this has been my first attempt in publishing a scientific paper.Thank you for hand-holding me through the process.

Dr. Anuradha
On Jan 2020

Important Notice

Original article / research
Year : 2023 | Month : March | Volume : 17 | Issue : 3 | Page : ZC06 - ZC11 Full Version

Evaluation of Hard Tissue, Soft Tissue and Airway Changes Post Twin Block Therapy: An In-vitro Study

Published: March 1, 2023 | DOI:
Karishma Jaiswal, Sonali Saha, Kavita Dhinsa, Sudhir Kapoor, Gaurav Singh, Raj Kumar Jaiswal

1. Lecturer, Department of Paediatric and Preventive Dentistry, Sardar Patel Postgraduate Institute of Dental and Medical Sciences, Lucknow, Uttar Pradesh, India. 2. Professor and Head, Department of Paediatric and Preventive Dentistry, Sardar Patel Postgraduate Institute of Dental and Medical Sciences, Lucknow, Uttar Pradesh, India. 3. Professor, Department of Paediatric and Preventive Dentistry, Sardar Patel Postgraduate Institute of Dental and Medical Sciences, Lucknow, Uttar Pradesh, India. 4. Professor and Head, Department of Orthodontics and Dentofacial Orthopaedics, Sardar Patel Postgraduate Institute of Dental and Medical Sciences, Lucknow, Uttar Pradesh, India. 5. Professor and Head, Department of Oral and Maxillofacial Surgery, Sardar Patel Postgraduate Institute of Dental and Medical Sciences, Lucknow, Uttar Pradesh, India. 6. Professor, Department of Orthodontics and Dentofacial Orthopaedics, Sardar Patel Postgraduate Institute of Dental and Medical Sciences, Lucknow,

Correspondence Address :
Sonali Saha,
Professor and Head, Department No. 5; Department of Paediatric and Preventive Dentistry, Sardar Patel Postgraduate Institute of Dental and Medical Sciences, Uttarathia-226002, Lucknow, Uttar Pradesh, India.


Introduction: Aesthetic improvement happens to be one of the main reasons for seeking orthodontic treatment in patients with Angle’s Class II malocclusion. Prognathic maxilla, retrognathic mandible or a combination of both are the main aetiological factors for this malocclusion. Growth modification treatment with different methods can be performed in order to correct skeletal class II malocclusion. Appliance therapy to correct similar malocclusions should immaculately be directed towards addressing the dentoskeletal discord, in order to gain a favourable facial aesthetic result.

Aim: To assess the effects of twin block on mandibular length, soft tissue profile and Oropharyngeal Airway (OAW) dimensions in skeletal class II malocclusion patients.

Materials and Methods: An in-vitro study was carried out in the Department of Paedodontics at Sardar Patel Postgraduate Institute of Dental and Medical Sciences, Lucknow from June 2018 to March 2021. Study was done on lateral cephalograms of 15 growing children with Angle’s Class II Division 1 malocclusion in the age group of 9-12 years, who had undergone functional appliance therapy with twin block appliance. Standardised lateral cephalograms were evaluated at pretreatment (0 month) and postactive phase of twin-block therapy (9-12 months). Selected hard tissue, soft tissue and airway landmarks were marked and traced to evaluate hard tissue, soft tissue and airway changes. The data was analysed using statistical package for social sciences (SPSS) version 21.

Results: There was a statistically significant increase in effective mandibular length (Condyle-Gnathion) and mandibular base length Gonion-Pogonion (Go-Pog) values (p<0.001). Significant decrease in the facial convexity Glabella- Soft tissue Nasion (G-Sn) Soft tissue Nasion- Soft tissue Pogonion (Sn-Pog) was observed and airway dimensions showed significant increase after twin block therapy.

Conclusion: Correction of Class II malocclusion by twin block appliance resulted in significant cephalometric changes in the hard tissue profile (increase in mandibular length), together with clinically favourable soft tissue changes and OAW dimensions.


Facial profile, Malocclusion, Pharyngeal airway passage, Skeletal class II Division I

Aesthetic improvement happens to be one of the main reasons for seeking orthodontic treatment in patients with Angle’s Class II malocclusion. Prognathic maxilla, retrognathic mandible or a combination of both are the main aetiological factors for this malocclusion, amongst which retrognathic mandible is considered to be the major factor as compared to prognathic maxilla (1),(2). Retrognathic mandible not only affects the aesthetics and profile but, it also leads to deficient chin prominence, crowding and even reduction in airway dimensions (3). The specific clinical characteristics of subjects with Class II division 1 malocclusion are convex profile, an increased overjet and incompetent lips leading to an unpleasant facial appearance and may produce negative feelings of self-image and esteem (4).

Growth modification treatment with different methods can be performed in order to correct skeletal class II malocclusion (2). Favourable facial aesthetics can be achieved in similar malocclusions using appliance therapy which immaculately directs towards addressing the dentoskeletal discord. One of the effects of functional appliance, it induces supplementary elongation of the mandible which thereby stimulates increased growth at the condylar cartilage. The effect of functional appliance treatment on mandibular growth firmly depends on the biological response of the condylar cartilage, which eventually depends on the growth rate of the mandible (1). Twin-block appliance, developed by Dr Williams J. Clark in 1977 is the most favoured type of functional appliance for the correction of Class II malocclusions and it has become gradually more popular due to its convenient design and ease of use (5).

Along with the hard tissue changes, Twin Block also brings about pleasant changes in soft tissue profile as well. The forward movement of mandible and the lower dentition furthermore, results in an increase in the lower lip prominence and a reduced interlabial gap which in turn reduces the upper lip strain and the nasolabial angle after treatment with Twin block functional appliance (6). Twin block appliance is not only used for correction of mandibular retrognathia, but, is also recommended as one of the treatment options for Obstructive Sleep Apnoea (OSA), which is caused due to the reduction in space present between the mandibular body and the cervical column thereby, resulting in posterior positioning of the tongue and soft palate, leading to deterioration in the airway passage. Enhancement in respiration is seen gradually as the shape and size of the nasopharyngeal space enlarges with the use of functional appliances (7).

There are numerous former studies which have assessed the skeletal, dental, soft tissue and airway dimension due to the use of twin block functional appliance individually or in one or two combinations, but as far as we know, no similar studies were conducted to investigate the effects of Twin Block (functional appliance) in Class II Division I malocclusion patients on hard tissues, soft tissues and airway changes altogether (1),(6),(7). Hence, the present study was designed to assess the effects of Twin Block on hard tissue, soft tissue and OAW dimensions on lateral cephalograms in patients with Skeletal Class II malocclusion.

Material and Methods

The present in-vitro study was conducted in the Department of Paedodontics and Preventive Dentistry in collaboration with Department of Orthodontics and Dentofacial Orthopaedics at Sardar Patel Postgraduate Institute of Dental and Medical Sciences, Lucknow from June 2018 to March 2021 to evaluate the pretreatment and post-treatment lateral cephalograms of 15 growing children amongst which eight were males and seven were females. The study was approved by the Institutional Ethical Committee of Sardar Patel Post Graduate Institute of Dental and Medical Sciences, Lucknow, Uttar Pradesh, India, with approval Number: PEDO/02/521920.

Sample size calculation: Sample size was calculated by using GPower software (version 3.0). Sample size was estimated for t-test and means: difference between two dependent means (matched pairs i.e., pre and post) was chosen. A minimum total sample size of 10 was found to be sufficient for an alpha of 0.05, power of 80%, 1.0 as effect size with Class II division 1 malocclusion aged 9-12 years in terms of their hard tissue, soft tissue and OAW dimension changes post twin block therapy (1).

Inclusion criteria: Good quality standardised lateral cephalograms of children within age group of 9 to 12 years having skeletal Class II condition with Angle between A point–N–B point (ANB) ≥4 degrees, overjet ≥5 mm, crowding ≤4 mm. Children showing horizontal growth pattern and children treated with twin block were included in the study.

Exclusion criteria: Whereas, lateral cephalograms of un-cooperative children, mentally challenged children, children with craniofacial syndromes/congenital maxillofacial deformity, children previously treated orthodontically, severe facial asymmetry and with other chronic disease or syndromes, were excluded from the study. However, records of the five out of twenty subjects, who were non compliant during the functional treatment phase were withdrawn from the study.

Study Procedure

Cephalometric records (pretreatment and post twin block phase) were manually traced. The tracing was done on tracing sheet of 8”x10” size (inches) 0.003”(inches)” thickness made of cellulose acetate. Backlight LED and light source, 3H pencil, protractor and metallic scale were used to mark the selected cephalometric landmarks (8). Both Angular and Linear measurements were recorded by the investigator with least count of 0.5° and 0.5 mm respectively. The following cephalometric landmarks were used for the study (Table/Fig 1)a,b,(Table/Fig 2)a,b.

Hard tissue parameters: The following angular and linear measurements were recorded to analyse the antero-posterior (sagittal) relation of maxilla and mandible (9):

Angular measurements:
• S-N-A
• S-N-B
• A-N-B
• Facial convexity- (N-A-Pog)
• Facial angle- {(N-Pog)-FH}

Linear measurements:
• Effective Mandibular length- (Co-Gn)
• Mandibular base length- (Go-Pog)

Soft tissue parameters: were measured as angles, linear dimensions from soft tissue landmarks (9).

Angular measurements:
• Facial convexity- {(G-N’)-POg’}
• Facial angle- {FH plane- (N’-Pog’)}
• Z-angle {FH-Profile line}

Linear measurements:
• Upper lip E-line
• lower lip E-line
• Upper lip S-line
• Lower lip S-line
• Lower lip H-line

Oro-pharyngeal airway dimensions:

• Upper pharyngeal width: It was measured from a point on the posterior outline of the soft palate to the closest point on pharyngeal wall.
• Lower pharyngeal width: It was measured from the point of intersection of the posterior border of the tongue and the inferior border of the mandible to the closest point on the posterior pharyngeal wall (10).

Various landmarks (pretreatment and post-treatment), linear and angular parameters, reference planes were used for the evaluation of hard tissue, soft tissue and airway changes were measured thrice and their mean was subjected for statistical analysis.

Measurement of cephalometric error:

• Error due to fatigue: Two cephalograms in a day were analysed on an average to eliminate the error due to fatigue of the investigator.
• Intra-observer error: The intra-observer variability and reproducibility of landmark location and its assessment along with measurement errors were analysed by re-tracing the randomly selected cephalograms within a gap of 15 days. Dahlberg formula was used to calculate the method error (1).

The pretreatment and post-treatment lateral cephalograms of selected samples were traced and the values were recorded for each patient. All the values were further compiled and subjected to statistical analysis.

Statistical Analysis

Microsoft Excel spreadsheet was used to enter the data, using SPSS version 21. As all the variables were continuous, thus summarised as standard and mean deviation. Graphs were prepared on Microsoft Excel. Normality of the continuous data was checked by Shapiro-Wilk test. Data was found to be normal. Inferential statistics were performed using parametric tests of significance (paired t-test & independent t-test).


In the present study, the gender wise age distribution of study population was done. Mean age of males and females were 10.88±1.35 and 11.14±1.34 years, respectively. No statistically significant difference was found in the mean age of both the groups (p-value-0.47) (Table/Fig 3). The pre and post-treatment cephalometric values for all the parameters have been tabulated in (Table/Fig 4).

The paired differences mean values of SNB (-3.03°±.85), facial angle {(N-Pog)-FH} (-3.10°±0.96), effective mandibular length {(Cd-Gn)} (-5.46 mm±2.94), base length {(Go-Pog)} (-3.60 mm±1.68), facial angle {(FH-(N-Pog)} (-3.20°±1.69), Z-angle {(FH-Profile line)} (-4.53°±2.82), E-line lower lip (-1.76 mm ±2.12), H-line lower lip (-1.16 mm±1.53), Upper pharynx (-2.73 mm ±1.03) and Lower pharynx (-3.73 mm±1.28) increased significantly from pretreatment to post-treatment (Table/Fig 5).

The paired differences mean values of ANB (3.23°±0.86), facial convexity {(N-A)-(A-Pog)} (4.10°±1.92), facial convexity {(Glabella- Soft tissue Nasion)- (Soft tissue Nasion- Soft tissue Pogonion)} (3.10°±2.86) and S-line upper lip (1.40 mm±2.19) decreased significantly from pretreatment to post-treatment. No significant change was found in the paired differences mean values of SNA (0.26°±0.70), E-line upper lip (0.80 mm ±1.78) and S-line lower lip (-0.66 mm ±2.12) from pretreatment to post-treatment. Mandibular length (hard tissue) is denoted by effective mandibular length {(Cd-Gn)} and mandibular base length {(Go-Pog)} parameters. The present showed a statistically significant increase in effective mandibular length {(Cd-Gn)} and mandibular base length {(Go-Pog)} values.

Soft tissue profile is denoted by facial convexity {(G-Sn)-(Sn-Pog)}, Facial angle {FH-(N-Pog)}, Z-angle {FH-Profile line)}, E-line lower lip, S-line upper lip and H-line lower lip parameters. In the present study, a statistically significant increase in the facial angle {(FH-(N-Pog)}, Z-angle {(FH-Profile line)}, E-line lower lip and H-line lower lip values and statistically significant decrease in the facial convexity {(G-Sn)-(Sn-Pog)} and S-line upper lip values were found. OAW dimensions are denoted by upper pharynx and lower pharynx parameters. A statistically significant increase in upper pharynx and lower pharynx dimensions were noted in the present study.


A pleasing and an aesthetic facial appearance occur when a proportionate relationship among different facial structures exists. Along with various physical, psychological, and social factors, perceptions of dentofacial attractiveness also affect the development and maintenance of self-image (11). Class II malocclusion manifests in a wide variety of skeletal and dental configurations. Amongst the possible causative factors, maxillary protrusion and mandibular retrognathism, McNamara JA et al., reported that mandibular retrognathism is the most consistent diagnostic finding in skeletal Class II malocclusions (12).

Reduced OAW dimensions are also associated with severe mandibular deficiency. Functional appliance therapy also shows its effectiveness in OSA by increasing the posterior airway space. Ozbek et al., were the first to evaluate the effects of functional appliance therapy on the OAW in patients with deficient mandible with skeletal Class II morphology (13).

Hence, our present study aimed to assess the effects of twin block on mandibular length, soft tissue profile and OAW dimensions in patients with skeletal Class II malocclusion by evaluating the pretreatment and post-treatment lateral cephalograms of 15 growing children with Class II division 1 malocclusion aged 9-12 years.

Primary change post twin block therapy is mostly in mandibular length and subsequently the other cephalometric skeletal and soft tissue profile parameter changes are seen corresponding to it. Thus, for the mandibular length measurements and soft tissue profile, the following landmarks were used for the study (14). The mandibular length (hard tissue) was denoted by effective mandibular length {(Cd-Gn)} and mandibular base length {(Go-Pog)} parameters (15). The soft tissue profile was denoted by facial convexity {(G-Sn)-(Sn-Pog)}, facial angle {Frankfort Horizontal Plane-(Nasion-Pogonion)}, Z-angle {FH-Profile line)}, E-line lower lip, S-line upper lip and H-line lower lip parameters (16). The OAW dimensions were denoted by upper pharynx and lower pharynx parameters. To minimise the cephalometric errors, precautions were taken and their mean was subjected for statistical analysis (14).

The results of the present study revealed that the effective mandibular length and the mandibular base length increased after twin block therapy. Increased effective mandibular length, enhanced soft tissue profile and increase in OAW dimensions of the present study were in accordance with previous studies done (Table/Fig 6) (1),(5),(13),(17),(18),(19),(20).

Thus, the finding of the present study suggested that, twin block therapy could be used effectively in growing children with retrusive mandible to achieve positive changes not only in skeletal hard tissue profile but, also in soft tissue profile and OAW dimensions.


The limitations of this study were the limited sample size and thus, large study groups should be taken in the future for more precise results and several other analyses (like: COGS analysis, Jarabak index etc.,) can also be done to evaluate the dental and skeletal effects of Twin Block therapy.


Twin Block was an effective myofunctional appliance which was used to increase the effective mandibular and base length in patients with skeletal Class II Division I malocclusion. Soft-tissue profiles also improved significantly, reflecting the changes that took place in the skeletal and dentoalveolar structures. These soft-tissue changes helped improve convex facial profiles. Twinblock treatment was effective in improving the OAW passage dimensions as well.


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DOI and Others

DOI: 10.7860/JCDR/2023/59327.17554

Date of Submission: Aug 07, 2022
Date of Peer Review: Oct 17, 2022
Date of Acceptance: Dec 22, 2022
Date of Publishing: Mar 01, 2023

• Financial or Other Competing Interests: None
• Was Ethics Committee Approval obtained for this study? Yes
• Was informed consent obtained from the subjects involved in the study? No
• For any images presented appropriate consent has been obtained from the subjects. NA

• Plagiarism X-checker: Aug 08, 2022
• Manual Googling: Oct 15, 2022
• iThenticate Software: Dec 15, 2022 (4%)

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