Удаление премоляров, ВНЧС - список статей
Dec. 29th, 2024 11:41 pm![[personal profile]](https://www.dreamwidth.org/img/silk/identity/user.png){kind=small}
healthy_back К сожалению, все статьи - на английском в PDF, и у меня нет возможности сейчас всё переводить и перепощивать с картинками. Я просто сохраняю ссылки и где всё это потом можно найти.
Оригинал у Карин - оглавление: https://drive.google.com/drive/folders/1ZwLTkWNibO6aSgDJMRHTCKWPeN_3nptq
1) https://disk.yandex.ru/i/GfseERyOj_XTjA (https://t.me/CFS_UARS_TMJD_Ortho_Surgeries/211)
2) https://disk.yandex.ru/i/_0SeZvt2GV25JA (https://t.me/CFS_UARS_TMJD_Ortho_Surgeries/212)
3) https://disk.yandex.ru/i/O20jkGvQyde7bQ (https://t.me/CFS_UARS_TMJD_Ortho_Surgeries/213)
4) https://disk.yandex.ru/i/N4KfPBlOxusFjw (https://t.me/CFS_UARS_TMJD_Ortho_Surgeries/214)
5) https://disk.yandex.ru/i/bwrXTcQrw1tz5g (https://t.me/CFS_UARS_TMJD_Ortho_Surgeries/215)
6) https://disk.yandex.ru/i/9rA7OCu2g52aDw (https://t.me/CFS_UARS_TMJD_Ortho_Surgeries/216)
7) https://disk.yandex.ru/i/Y8uVqRKpq0Ifqw (https://t.me/CFS_UARS_TMJD_Ortho_Surgeries/217)
https://www.ajodo.org/article/0889-5406(92)70076-M/abstract Orthodontic risk factors for temporomandibular disorders (TMD). I: Premolar extractions
DDS, MS Charles R. Kremenaka ∙ DDS, MS D. David Kinserc ∙ DDS, MS Heidi A. Harmand ∙ DDS, MS Curtis C. Menarde ∙ BS, MA Jane R. Jakobsen
The research paper they probably presented was a 1992 study published in the AJO-DO. The 1992 journal has several publications that had been commissioned by the American Association of Orthodontists to protect themselves from lawsuits, after the 1.3 million dollar lawsuit from 19 year old Susan Brimm, who had severe TMD from extraction/retraction (PER). If you read these journal articles, they are absurd. They say that occlusion has nothing to do with the jaw joints hence no connection to TMD. TO combat them, you could collect articles on Bruxism and TMD which prove the correlation between....occlusion and TMD. There is also Witzig's 1960 article on TMD and premolar extractions. There is also the 2023 research article published in a high impact journal establishing that PER causes changes in mandibular kinematics and position and 'Is a risk for TMD."
Продолжение поста Список ссылок https://healthy-back.livejournal.com/477635.html (https://healthy-back.dreamwidth.org/461539.html)
172) https://pmc.ncbi.nlm.nih.gov/articles/PMC3770235/
Saudi Dent J. 2011 Jan 28;23(2):55–59. doi: 10.1016/j.sdentj.2011.01.003
Adverse effects of orthodontic treatment: A clinical perspective
Nabeel F Talic 1,⁎ PMCID: PMC3770235 PMID: 24151415
173) https://pubmed.ncbi.nlm.nih.gov/30664820/
J Oral Rehabil. 2019 Apr;46(4):388-397. doi: 10.1111/joor.12767. Epub 2019 Feb 10.
Dental occlusion and body balance: A question of environmental constraints?
Sonia Julià-Sánchez 1 , Jesús Álvarez-Herms 1 , Martin Burtscher 2 Affiliations PMID: 30664820 DOI: 10.1111/joor.12767
174) https://tmjsleepandbreathecenter.com/why-not-to-remove-teeth-for-braces/ Extraction Retraction Regret Syndrome: Truth about teeth removal for braces by Gary Adams DDS
175) https://pmc.ncbi.nlm.nih.gov/articles/PMC3989577/
"This issue has been noted by many researchers in academic dental training centers worldwide. The results of many studies in this field have shown surprisingly high prevalence rates of TMJ injuries (50-63 %) after extracting mandibular teeth by dental students".
176) https://healthy-back.livejournal.com/485458.html (https://healthy-back.dreamwidth.org/468470.html)
177) Orthodontist Zubad Newaz on tongue space after premolar extractions:
https://www.facebook.com/groups/extractionorthodonticsreversal/posts/8968905549790468/
https://www.tiktok.com/@peraf11/video/7414626139433471265?is_from_webapp=1&web_id=7413950856615691782
178) https://pmc.ncbi.nlm.nih.gov/articles/PMC11180030/
2024 Jun 15;28(7):374. doi: 10.1007/s00784-024-05713-3 PMCID: PMC11180030 PMID: 38878070
Orthodontic maxillary molar movement-induced zygomatic pillar remodeling and its consequences on occlusal characteristics and stress distribution
Size Li 1, Han Bao 1, Xiaojie Su 1, Liping Xiong 1, Qianwen Yin 1, Deao Gu 1, Leiying Miao 2, Chao Liu
Results
The morphological and structural remodeling of the zygomatic pillar after orthodontic treatment involving premolar extraction showed a decreased cross-sectional area of the lower segment of the zygomatic pillar. The zygomatic process point moved inward and backward, whereas the zygomatico-maxillary suture point moved backward. The thicknesses of the zygomatic pillar alveolar and cortical bones were thinner, and reduced alveolar bone density was observed. Simultaneously, the movement and angle change of the maxillary first molar could predict zygomatic pillar reconstruction to a certain extent. With decreasing the total occlusal force and the occlusal force of the first molar, occlusal force distribution was more uniform. With zygomatic pillar remodeling, occlusal stress distribution in the zygomatic alveolar ridge decreased, and occlusal stress was concentrated at the junction of the vertical and horizontal parts of the zygomatic bone and the posterior part of the zygomatic arch.
Conclusions
Orthodontic treatment involving premolar extraction led to zygomatic pillar remodeling, making it more fragile than before and reducing the occlusal force of the maxillary first molar and the entire dentition with stress concentrated in weak areas.
179) Видео (фильм-интервью) с Bill Hang PERAF Interview MP4 https://drive.google.com/file/d/1SnWlixRT99BpByasZ7rhxh0A44rGZbZT/view
180) https://pmc.ncbi.nlm.nih.gov/articles/PMC11180030/ Clin Oral Investig. 2024 Jun 15;28(7):374. doi: 10.1007/s00784-024-05713-3
Orthodontic maxillary molar movement-induced zygomatic pillar remodeling and its consequences on occlusal characteristics and stress distribution
Size Li 1, Han Bao 1, Xiaojie Su 1, Liping Xiong 1, Qianwen Yin 1, Deao Gu 1, Leiying Miao 2, Chao Liu
Results
The morphological and structural remodeling of the zygomatic pillar after orthodontic treatment involving premolar extraction showed a decreased cross-sectional area of the lower segment of the zygomatic pillar. The zygomatic process point moved inward and backward, whereas the zygomatico-maxillary suture point moved backward. The thicknesses of the zygomatic pillar alveolar and cortical bones were thinner, and reduced alveolar bone density was observed. Simultaneously, the movement and angle change of the maxillary first molar could predict zygomatic pillar reconstruction to a certain extent. With decreasing the total occlusal force and the occlusal force of the first molar, occlusal force distribution was more uniform. With zygomatic pillar remodeling, occlusal stress distribution in the zygomatic alveolar ridge decreased, and occlusal stress was concentrated at the junction of the vertical and horizontal parts of the zygomatic bone and the posterior part of the zygomatic arch.
Conclusions
Orthodontic treatment involving premolar extraction led to zygomatic pillar remodeling, making it more fragile than before and reducing the occlusal force of the maxillary first molar and the entire dentition with stress concentrated in weak areas.
EXCERPT FROM DISCUSSION:
Primarily, bone remodeling includes two parts, namely morphological reconstruction and structural reconstruction. Herein, the comparison of the cross-sectional areas of zygomatic pillars within a constant-height plane showed that the cross-sectional area of the lower part of the zygomatic pillar decreased significantly, thereby reflecting the overall remodeling and contraction of the lower part of the zygomatic pillar. The surface morphology landmarks of the middle section of the zygomatic pillar, namely ZM and ZP, moved backward, whereas the ZP point moved medially.
This phenomenon is probably associated with the pressure on the vertical direction of the zygomaticomaxillary suture and the transversal pressure on the zygomatic body when the first molar moves forward [19]. The pressure may have led to bone resorption. Simultaneously, the EKM point moved mesially and palatally and extended along with the maxillary first molar, implying that the starting point of the zygomatic pillar moved with the maxillary first molar, whereas the middle and upper sections shifted backward and medially, respectively.
Additionally, these findings may have implications for facial esthetics. The zygomatic–sphenoid suture point moves backward as the first molar moves mesially and lingually and the zygomatic point moves inward and backward.
These negative changes in the bony prominences may partly explain the negative changes in the soft tissues of the cheekbone and nasolabial groove observed in some patients after orthodontic treatment [20, 21], such as the phenomenon of “brace face” in Chinese female patients with orthodontic issues. These facial changes may not be solely attributed to soft tissue remodeling but the process may involve bony prominence remodeling.
Additionally, restricting the movement of the first molar may offer the possibility to reduce the effect of a “brace face.”
181) https://pubmed.ncbi.nlm.nih.gov/36920861/ Expert Rev Hematol. 2023 Mar;16(sup1):7-11. doi: 10.1080/17474086.2023.2178410. Lived experience experts: a name created by us for us Esmeralda Vázquez 1 2 , Michelle Kim 3 4 , Maria E Santaella 2
Affiliations PMID: 36920861 DOI: 10.1080/17474086.2023.2178410
182) https://www.genesispub.org/effects-of-four-first-premolar-extraction-on-the-upper-airway-dimension-in-a-non-growing-class-i-skeletal-patients:-a-systematic-review
Jae Yong Choi1* and Kenneth Lee2
1Dentist, Orthodontic and Dentofacial Orthopaedics Speciality Masters Program Universitat Jaume I (Spain), Bachelor of Dental Science (University of Queensland), Australia
2Professor Universitat Jaume I, Castellon, BDS (Syd), MSc Oral Implantology (Goethe), MSc Orthodontics (Castellon), FICD, FPFA, Private practice, Sydney, Australia
*Corresponding author: Jae Yong Choi, Student, Jaume I University, Orthodontic and Dentofacial Orthopaedics Specialty Masters Program, Brisbane, Australia.
Citation: Choi JY, Lee K. (2022) Effects of Four First Premolar Extraction on the Upper Airway Dimension in a Non-Growing Class I Skeletal Patients: A Systematic Review. J Oral Med and Dent Res. 3(1):1-16.
Received: March 22, 2022 | Published: May 10, 2022
183) https://www.researchgate.net/publication/350043270_A_case_of_sudden_onset_severe_Cephalgia_in_an_orthodontic_patient_has_demonstrated_how_occlusion_can_precipitate_orofacial_pain
https://adtt.scholasticahq.com/article/21478.pdf
Temporomandibular Joints (TMJ)
A Case Of Sudden Onset Severe Cephalgia In An Orthodontic
Patient Has Demonstrated How Occlusion Can Precipitate Orofacial
Pain
Patrick Girouard,, DMD. MS1, Svitlana Koval, BDS, MDS, DDS2
1 Acadia University, 2 Private Orthodontic Practice
Keywords: t-scan novus, orofacial pain, occlusion, orthodontics, cephalgia, Innobyte
184) https://www.facebook.com/groups/orthodonticmalpracticevictims/posts/1519659875659212/
or those who have experienced their mouths "shrinking" after their extraction orthodontics, and/or feeling their tongue does not have enough space---and need to prove it to someone:
All articles in journals on premolar extraction dental arch changes show that the dental arches get narrower and shorter due to the treatment.
Some articles note that if the extractions are done in adolescence, the growth of the arches is less than it would have been if patient had not been extracted.
Compare the photos of plaster models below: one is the dental arch of a 45 year old adult who had premolar extractions as a kid, the other a 17 year old who had no extractions.
Who do you think had the extractions?
------
DATA
I. See research article proving that dental arches shrink after premolar extractions, which according to the authors is potentially nefarious:
https://pmc.ncbi.nlm.nih.gov/articles/PMC10943680/
II. Here is an article proving that the width of the arches grows less in adolescents with extractions than in adolescents who get no extractions, and even less than those who get nonextraction with palate expansion. Check the charts. The intermolar width in extracted kids grows SMALLER during their two years of treatment (at a time it would naturally be increasing) while it grows at least 2.5 mm greater in non extracted people and even more in expanded people.
The authors highlight that the inter-canine space, however, grows bigger in extracted adolescents almost like the other groups, but point out that this is only because the canine has been pushed back into the premolar’s former space, which is a wider part of the arch. The actual canine area (now the laterals) will have shrunken.
https://academic.oup.com/ejo/article-abstract/27/6/585/400867?redirectedFrom=fulltext&login=false
A comparative study of dental arch widths: extraction and non-extraction treatment Get access Arrow
Fulya Işık , Korkmaz Sayınsu , Didem Nalbantgil , Tülin Arun
European Journal of Orthodontics, Volume 27, Issue 6, December 2005, Pages 585–589, https://doi.org/10.1093/ejo/cji057
Published:
28 October 2005
185) https://www.researchgate.net/publication/377825324_Effect_of_orthodontic_premolar_extraction_on_maxillary_teeth_angulation_and_arch_dimensions_in_adolescent_patients_A_3-D_digital_model_analysis
FINDINGS:
Width of palate decreases with premolar extractions. The width between the molars and remaining premilar narrows “significantly.” However, curiously, as you see in this chart, the width between the canines increases!
This is deceptive. There was no widening.. The width between the canines is wider than before only because the canines have been pushed back a full tooth during the retractive closing of the premolar extraction spaces, to position in a wider part of the jaw:m where the premolars were before extraction.
But even at this new part of the arch level, the width is narrower than it was was before the premolars were extracted, just wider than what the inter canine distance normally is.. Every part of the arch has narrowed.
186) Список статей. Они могут повторяться к предыдущему списку
https://www.facebook.com/groups/583182005973675?multi_permalinks=1541246176833915&hoisted_section_header_type=recently_seen
Bibliography: Airway Changes After Premolar Extraction
✅ Studies Showing Airway Narrowing
· Bhatia S, Jayan B, Chopra SS. (2016). Effect of retraction of anterior teeth on pharyngeal airway and hyoid bone position in Class I bimaxillary dentoalveolar protrusion. Med J Armed Forces India. 72(Suppl 1):S17-S23.
The size of the pharyngeal (velopharyngeal and glossopharyngeal) airway reduced and hyoid bone position changed after retraction of the incisors in extraction space in bimaxillary protrusive adult patients.
🔗 https://pubmed.ncbi.nlm.nih.gov/28050064/
· Chen Y, et al. (2012). Effect of large incisor retraction on upper airway morphology in adult bimaxillary protrusion patients. Angle Orthod. 82(6):964-70.
Large incisor retraction leads to narrowing of the upper airway in adult bimaxillary protrusion patients.
🔗 https://pubmed.ncbi.nlm.nih.gov/22462464/
· Choi JY, Lee K. (2022). Effects of Four First Premolar Extraction on the Upper Airway Dimension in a Non-Growing Class I Skeletal Patients: A Systematic Review. J Oral Med and Dent Res. 3(1):1-16.
Systematic review concludes that premolar extraction/retraction can cause narrowing of the pharyngeal airway, reduction of oral cavity space, and increased sleep apnea risk.
🔗 https://www.genesispub.org/effects-of-four-first-premolar-extraction-on-the-upper-airway-dimension-in-a-non-growing-class-i-skeletal-patients:-a-systematic-review
· Guilleminault C, et al. Missing teeth and pediatric obstructive sleep apnea.
Children missing permanent teeth due to extraction or agenesis had smaller oral cavities, predisposing to upper airway collapse during sleep.
🔗 · Hang WM, Gelb M. (2017). Airway Centric® TMJ philosophy / orthodontics. Cranio. 35(2):68-78.
Recommends avoiding retraction and arch constriction in orthodontics due to its airway-diminishing effects.
🔗 https://pubmed.ncbi.nlm.nih.gov/27356671/
· Hu Z, et al. (2015). The effect of teeth extraction for orthodontic treatment on the upper airway: a systematic review.
Extractions followed by large anterior retraction may lead to airway narrowing; mesial molar movement may increase space.
🔗 https://pubmed.ncbi.nlm.nih.gov/25628011/
· Mortezai O, et al. (2023). Effect of premolar extraction and anchorage type on upper airway dimensions and hyoid bone position. PeerJ. 11:e15960.
Significant reduction in airway dimensions and downward/backward hyoid displacement correlated with retraction magnitude.
🔗 https://pubmed.ncbi.nlm.nih.gov/37901473/
· Nagmode S, et al. Effect of First Premolar Extraction on Airway Dimension. J Indian Oral Sci. Upper airway volume increased slightly while lower airway volume decreased. Mixed results.
🔗 https://www.researchgate.net/publication/320351695
· Ozbek MM, et al. (1998). Oropharyngeal airway dimensions and functional-orthopedic treatment in skeletal class II cases. Angle Orthod. 68:327–36.
Closing extraction spaces leads to retrognathic mandibular position and oropharyngeal airway constriction.
🔗 https://pubmed.ncbi.nlm.nih.gov/9709833/
· Pliska BT, et al. (2016). Effect of orthodontic treatment on the upper airway volume in adults. Am J Orthod Dentofacial Orthop. 150(6):937-944.
While average airway volume loss was ~5% in patients with severe crowding, considered “insignificant”, patients with moderate or little crowding had “significant” narrowing due to dental arch retraction and the posterior positioning of the tongue.
При удалении зубов нижняя челюсть уезжает назад
Это создаёт риски возникновения нарушения дыхания во сне, что, в свою очередь, влечет за собой синдром СХУ.
🔗 https://pubmed.ncbi.nlm.nih.gov/27894542/
· Sharma K, et al. (2014). Effects of first premolar extraction on airway dimensions in young adolescents. Contemp Clin Dent. 5(2):190-4.
Premolar extractions caused narrowing in velopharyngeal, glossopharyngeal, hypopharyngeal regions, and posterior hyoid movement.
🔗 https://pubmed.ncbi.nlm.nih.gov/24963245/
· Sun FC, et al. (2018). Effect of incisor retraction on morphology of upper airway in bimaxillary protrusion. Zhonghua Kou Qiang Yi Xue Za Zhi. 53(6):398–403.
Oropharynx became constricted and pharyngeal resistance increased after retraction.
🔗 https://pubmed.ncbi.nlm.nih.gov/29886634/
· Zheng Z, et al. (2017). CFD simulation of upper airway response to large incisor retraction. Sci Rep. 7:45706.
Increased pharyngeal collapse risk after maximum anchorage retraction in bimaxillary protrusion patients.
🔗 https://pubmed.ncbi.nlm.nih.gov/28387372/
· Wang Q, et al. (2012). Changes in airway and hyoid bone position following orthodontics. Angle Orthod. 82(1):115-21.
Extraction and retraction led to airway narrowing and posterior/inferior hyoid movement.
🔗 https://pubmed.ncbi.nlm.nih.gov/21793712/
❌ Studies Not Showing Airway Narrowing
· Papageorgiou SN, Zyli M, Papadopoulou AK. (2025). Extraction of premolars does not negatively affect airway: meta-analysis. Eur J Orthod.
Systematic review found no significant decrease in airway volume or cross-sectional area after premolar extraction.
🔗· Choi JY, et al. (2022). Comparative analysis of pharyngeal airway changes following premolar extractions. Cureus.
Found airway narrowing, but concluded the change was not different among extraction patterns.
🔗 https://pubmed.ncbi.nlm.nih.gov/38882986/
· Al Maaitah E, et al. (2012). First premolar extraction effects on airway in bimaxillary proclination. Angle Orthod.
Reported no statistically significant changes in airway size following premolar extraction.
🔗 Comparative Analysis of Pharyngeal Airway Changes Following All Four Versus All Five Premolar Extractions in Orthodontic Treatments: A Cephalometric Study - PubMed
187) dental arches shrink after premolar extractions:
https://pmc.ncbi.nlm.nih.gov/articles/PMC10943680/
188) https://academic.oup.com/ejo/article-abstract/27/6/585/400867?redirectedFrom=fulltext&login=false
The results revealed that the distance between the upper canines was not affected by the treatment modality. Upper premolar and molar arch widths increased more in the non-extraction subjects when compared with those with extractions, with the greatest increase in patients with RME. In the lower canine area the extraction group showed the widest arch width at the end of treatment. There was also a 0.60 mm decrease in the lower canine width in the non-extraction group. A decrease was found in lower inter-premolar and molar distances due to consolidation of the extraction spaces.
189) When we use braces there is often alveolar bone loss. https://pmc.ncbi.nlm.nih.gov/articles/PMC8284009/
“Anterior alveolar bone and width and height often decreases after orthodontic treatment. Incisiors retraction led to a significant position of point A and B”.
https://pubmed.ncbi.nlm.nih.gov/22211303/
Human re-entry studies showed horizontal bone loss of 29-63% and vertical bone loss of 11-22% after 8 months following tooth extraction.
190) https://www.facebook.com/groups/1270654792948954/?multi_permalinks=24805332479054521&hoisted_section_header_type=recently_seen
Classic 2003 maxillofacial textbook by Dr. J. Reyneke, maxillofacial surgeon, recommended to me by a prominent US surgeon as a good read to learn about surgery.
http://43.230.198.52/lib/book/Orthodontics/Essentials%20of%20Orthognathic%20Surgery%20by%20Reyneke,%20Johan%20P..pdf
First chapter is about the difficult decision to "camouflage" with extractions or do surgery.
He states that premolar extractions can worsen facial aesthetics and cause functional problems.
Has some photos of people facially damaged by premolar extractions (from first chapter).
https://www.facebook.com/groups/extractionorthodonticsreversal/posts/25716594297928330/
Premolar Extractions and the Loss of Masticatory Efficiency
1) Chewing performance in orthodontic patients treated with extraction of premolars. J Chosun Obr. 2019; 43(3):196–203.
https://www.chosunobr.org/journal/download_pdf.php?doi=10.21851%2Fobr.43.03.201909.196
→ Direct extraction study comparing pre- and post-treatment masticatory function. Patients with premolar extractions showed shorter, slower chewing cycles and reduced efficiency versus baseline. Indicates that orthodontic extractions impair chewing kinetics, especially with narrowed arch form.
2) English J.D., Buschang P.H., Throckmorton G.S.
Does malocclusion affect masticatory performance? Angle Orthod. 2002; 72(1):21–27.
https://pubmed.ncbi.nlm.nih.gov/11881753/
→ Established that malocclusions—including those created by retractive mechanics—significantly reduce chewing efficiency, yielding larger bolus particle size and decreased breakdown rate.
3) Fathalla R., Samih H.M., Ramadan A.A.
Assessment of occlusal forces in patients treated with four first-premolar extractions: An in vivo study using the T-Scan III system. Dent Stud. 2023; 5(1):70-76.
https://pubmed.ncbi.nlm.nih.gov/38034277/→ Ten adolescent patients treated with four-premolar extractions showed reduced anterior bite-force contribution and slight posterior redistribution. Overall occlusal force balance achieved, but anterior functional weakness persisted, suggesting compensatory rather than normal adaptation.
4) Haraldson T., Carlsson G.E., Ingervall B.
Functional state of the masticatory system in denture and natural dentition subjects. Acta Odontol Scand. 1979; 37(6):333–341.
https://pubmed.ncbi.nlm.nih.gov/294451/
→ Classic physiologic reference: demonstrated that reduced dental arches or missing teeth sharply decrease bite-force and chewing efficiency. Provides the foundational evidence that smaller dental arches—whether edentulous or extraction-induced—mean weaker mastication.
5) Helkimo E., Ingervall B., Carlsson G.E.
Bite force and functional state of the masticatory system in young adults. Swed Dent J. 1971; 64(3):153–160.
https://pubmed.ncbi.nlm.nih.gov/5285249/
→ Measured normal bite-force in young adults and correlated it with occlusal contact area. Found that bite-force decreases linearly with loss of posterior support—a principle directly relevant to orthodontic extractions.
6) Kohyama K., Mioche L., Martin J.F.
Chewing patterns of subjects with occlusal disharmonies. Arch Oral Biol. 2002; 47(6):461–471.
https://pubmed.ncbi.nlm.nih.gov/12000302/
→ Subjects with narrow arches and occlusal disharmonies (often post-extraction) exhibited longer, less efficient chewing cycles and maladaptive muscular coordination. Supports the link between arch constriction and functional decline.
7) Miura H., Araki Y., Morita M.
Relationship between occlusal contact area and bite-force in adults. J Oral Rehabil. 1981; 8(5):465–471.
https://pubmed.ncbi.nlm.nih.gov/6945325/
→ Quantified bite-force as a direct function of occlusal contact area. Showed that any reduction in arch width or tooth number lowers maximal bite-force, forming the physiologic basis for extraction-related weakness.
8) Peyron M.A., Lassauzay C., Woda A.
Effects of dental and prosthetic status on masticatory performance. J Dent Res. 2002; 81(8):545–549.
https://pubmed.ncbi.nlm.nih.gov/12215566/
→ Demonstrated that fewer functional teeth and reduced occlusal surface area yield lower masticatory output, confirming the mechanical cost of arch reduction.
9) Scientific Reports (Open Access).
Changes in occlusal function after extraction of premolars: A two-year follow-up study. Sci Rep. 2021; 11:8357216.
https://pmc.ncbi.nlm.nih.gov/articles/PMC8357216/
→ Two-year follow-up of non-extraction vs. two- and four-premolar extraction groups. Occlusal contact area and bite-force fell sharply after treatment; only partial recovery at 24 months. Four-premolar group never regained baseline force, confirming persistent mechanical deficit.
10) Shinogaya T., Adachi A., Watanabe M.
Effects of occlusal condition on masticatory efficiency. J Oral Rehabil. 1999; 26(9):739–745.
https://pubmed.ncbi.nlm.nih.gov/10511269/
→ Showed that reducing the number of active occlusal contacts markedly impairs masticatory efficiency. The findings parallel post-extraction occlusal conditions and validate their functional impact.
SYNTHESIS
· Premolar extractions reduce occlusal contact area, arch width, and anterior bite-force, resulting in slower, less efficient chewing and maladaptive muscle patterns.
· Foundational bite-force studies (Helkimo 1971; Haraldson 1979; Miura 1981) established that any loss of dental units or arch constriction directly weakens masticatory power.
· Modern clinical studies confirm extraction patients experience longer chewing cycles, smaller bolus breakdown, and incomplete recovery of occlusal function over time.
· Functional adaptations may partially compensate but at the expense of efficiency and possibly joint over-use.
PUBMED.NCBI.NLM.NIH.GOV
Results of biomonitoring analyses in Biomonitoring Laboratory, Helsinki, Finland in 1997 - PubMed
In 1997 a total of 4848 results of 47 different analytes from blood or urine specimens, were performed in the Finnish Institute of Occupational Health, Biomonitoring Laboratory, Helsinki, Finland. The results of these service analyses were registered in a database with additional information concern...
Оригинал у Карин - оглавление: https://drive.google.com/drive/folders/1ZwLTkWNibO6aSgDJMRHTCKWPeN_3nptq
1) https://disk.yandex.ru/i/GfseERyOj_XTjA (https://t.me/CFS_UARS_TMJD_Ortho_Surgeries/211)
2) https://disk.yandex.ru/i/_0SeZvt2GV25JA (https://t.me/CFS_UARS_TMJD_Ortho_Surgeries/212)
3) https://disk.yandex.ru/i/O20jkGvQyde7bQ (https://t.me/CFS_UARS_TMJD_Ortho_Surgeries/213)
4) https://disk.yandex.ru/i/N4KfPBlOxusFjw (https://t.me/CFS_UARS_TMJD_Ortho_Surgeries/214)
5) https://disk.yandex.ru/i/bwrXTcQrw1tz5g (https://t.me/CFS_UARS_TMJD_Ortho_Surgeries/215)
6) https://disk.yandex.ru/i/9rA7OCu2g52aDw (https://t.me/CFS_UARS_TMJD_Ortho_Surgeries/216)
7) https://disk.yandex.ru/i/Y8uVqRKpq0Ifqw (https://t.me/CFS_UARS_TMJD_Ortho_Surgeries/217)
https://www.ajodo.org/article/0889-5406(92)70076-M/abstract Orthodontic risk factors for temporomandibular disorders (TMD). I: Premolar extractions
DDS, MS Charles R. Kremenaka ∙ DDS, MS D. David Kinserc ∙ DDS, MS Heidi A. Harmand ∙ DDS, MS Curtis C. Menarde ∙ BS, MA Jane R. Jakobsen
The research paper they probably presented was a 1992 study published in the AJO-DO. The 1992 journal has several publications that had been commissioned by the American Association of Orthodontists to protect themselves from lawsuits, after the 1.3 million dollar lawsuit from 19 year old Susan Brimm, who had severe TMD from extraction/retraction (PER). If you read these journal articles, they are absurd. They say that occlusion has nothing to do with the jaw joints hence no connection to TMD. TO combat them, you could collect articles on Bruxism and TMD which prove the correlation between....occlusion and TMD. There is also Witzig's 1960 article on TMD and premolar extractions. There is also the 2023 research article published in a high impact journal establishing that PER causes changes in mandibular kinematics and position and 'Is a risk for TMD."
Продолжение поста Список ссылок https://healthy-back.livejournal.com/477635.html (https://healthy-back.dreamwidth.org/461539.html)
172) https://pmc.ncbi.nlm.nih.gov/articles/PMC3770235/
Saudi Dent J. 2011 Jan 28;23(2):55–59. doi: 10.1016/j.sdentj.2011.01.003
Adverse effects of orthodontic treatment: A clinical perspective
Nabeel F Talic 1,⁎ PMCID: PMC3770235 PMID: 24151415
173) https://pubmed.ncbi.nlm.nih.gov/30664820/
J Oral Rehabil. 2019 Apr;46(4):388-397. doi: 10.1111/joor.12767. Epub 2019 Feb 10.
Dental occlusion and body balance: A question of environmental constraints?
Sonia Julià-Sánchez 1 , Jesús Álvarez-Herms 1 , Martin Burtscher 2 Affiliations PMID: 30664820 DOI: 10.1111/joor.12767
174) https://tmjsleepandbreathecenter.com/why-not-to-remove-teeth-for-braces/ Extraction Retraction Regret Syndrome: Truth about teeth removal for braces by Gary Adams DDS
175) https://pmc.ncbi.nlm.nih.gov/articles/PMC3989577/
"This issue has been noted by many researchers in academic dental training centers worldwide. The results of many studies in this field have shown surprisingly high prevalence rates of TMJ injuries (50-63 %) after extracting mandibular teeth by dental students".
176) https://healthy-back.livejournal.com/485458.html (https://healthy-back.dreamwidth.org/468470.html)
177) Orthodontist Zubad Newaz on tongue space after premolar extractions:
https://www.facebook.com/groups/extractionorthodonticsreversal/posts/8968905549790468/
https://www.tiktok.com/@peraf11/video/7414626139433471265?is_from_webapp=1&web_id=7413950856615691782
178) https://pmc.ncbi.nlm.nih.gov/articles/PMC11180030/
2024 Jun 15;28(7):374. doi: 10.1007/s00784-024-05713-3 PMCID: PMC11180030 PMID: 38878070
Orthodontic maxillary molar movement-induced zygomatic pillar remodeling and its consequences on occlusal characteristics and stress distribution
Size Li 1, Han Bao 1, Xiaojie Su 1, Liping Xiong 1, Qianwen Yin 1, Deao Gu 1, Leiying Miao 2, Chao Liu
Results
The morphological and structural remodeling of the zygomatic pillar after orthodontic treatment involving premolar extraction showed a decreased cross-sectional area of the lower segment of the zygomatic pillar. The zygomatic process point moved inward and backward, whereas the zygomatico-maxillary suture point moved backward. The thicknesses of the zygomatic pillar alveolar and cortical bones were thinner, and reduced alveolar bone density was observed. Simultaneously, the movement and angle change of the maxillary first molar could predict zygomatic pillar reconstruction to a certain extent. With decreasing the total occlusal force and the occlusal force of the first molar, occlusal force distribution was more uniform. With zygomatic pillar remodeling, occlusal stress distribution in the zygomatic alveolar ridge decreased, and occlusal stress was concentrated at the junction of the vertical and horizontal parts of the zygomatic bone and the posterior part of the zygomatic arch.
Conclusions
Orthodontic treatment involving premolar extraction led to zygomatic pillar remodeling, making it more fragile than before and reducing the occlusal force of the maxillary first molar and the entire dentition with stress concentrated in weak areas.
179) Видео (фильм-интервью) с Bill Hang PERAF Interview MP4 https://drive.google.com/file/d/1SnWlixRT99BpByasZ7rhxh0A44rGZbZT/view
180) https://pmc.ncbi.nlm.nih.gov/articles/PMC11180030/ Clin Oral Investig. 2024 Jun 15;28(7):374. doi: 10.1007/s00784-024-05713-3
Orthodontic maxillary molar movement-induced zygomatic pillar remodeling and its consequences on occlusal characteristics and stress distribution
Size Li 1, Han Bao 1, Xiaojie Su 1, Liping Xiong 1, Qianwen Yin 1, Deao Gu 1, Leiying Miao 2, Chao Liu
Results
The morphological and structural remodeling of the zygomatic pillar after orthodontic treatment involving premolar extraction showed a decreased cross-sectional area of the lower segment of the zygomatic pillar. The zygomatic process point moved inward and backward, whereas the zygomatico-maxillary suture point moved backward. The thicknesses of the zygomatic pillar alveolar and cortical bones were thinner, and reduced alveolar bone density was observed. Simultaneously, the movement and angle change of the maxillary first molar could predict zygomatic pillar reconstruction to a certain extent. With decreasing the total occlusal force and the occlusal force of the first molar, occlusal force distribution was more uniform. With zygomatic pillar remodeling, occlusal stress distribution in the zygomatic alveolar ridge decreased, and occlusal stress was concentrated at the junction of the vertical and horizontal parts of the zygomatic bone and the posterior part of the zygomatic arch.
Conclusions
Orthodontic treatment involving premolar extraction led to zygomatic pillar remodeling, making it more fragile than before and reducing the occlusal force of the maxillary first molar and the entire dentition with stress concentrated in weak areas.
EXCERPT FROM DISCUSSION:
Primarily, bone remodeling includes two parts, namely morphological reconstruction and structural reconstruction. Herein, the comparison of the cross-sectional areas of zygomatic pillars within a constant-height plane showed that the cross-sectional area of the lower part of the zygomatic pillar decreased significantly, thereby reflecting the overall remodeling and contraction of the lower part of the zygomatic pillar. The surface morphology landmarks of the middle section of the zygomatic pillar, namely ZM and ZP, moved backward, whereas the ZP point moved medially.
This phenomenon is probably associated with the pressure on the vertical direction of the zygomaticomaxillary suture and the transversal pressure on the zygomatic body when the first molar moves forward [19]. The pressure may have led to bone resorption. Simultaneously, the EKM point moved mesially and palatally and extended along with the maxillary first molar, implying that the starting point of the zygomatic pillar moved with the maxillary first molar, whereas the middle and upper sections shifted backward and medially, respectively.
Additionally, these findings may have implications for facial esthetics. The zygomatic–sphenoid suture point moves backward as the first molar moves mesially and lingually and the zygomatic point moves inward and backward.
These negative changes in the bony prominences may partly explain the negative changes in the soft tissues of the cheekbone and nasolabial groove observed in some patients after orthodontic treatment [20, 21], such as the phenomenon of “brace face” in Chinese female patients with orthodontic issues. These facial changes may not be solely attributed to soft tissue remodeling but the process may involve bony prominence remodeling.
Additionally, restricting the movement of the first molar may offer the possibility to reduce the effect of a “brace face.”
181) https://pubmed.ncbi.nlm.nih.gov/36920861/ Expert Rev Hematol. 2023 Mar;16(sup1):7-11. doi: 10.1080/17474086.2023.2178410. Lived experience experts: a name created by us for us Esmeralda Vázquez 1 2 , Michelle Kim 3 4 , Maria E Santaella 2
Affiliations PMID: 36920861 DOI: 10.1080/17474086.2023.2178410
182) https://www.genesispub.org/effects-of-four-first-premolar-extraction-on-the-upper-airway-dimension-in-a-non-growing-class-i-skeletal-patients:-a-systematic-review
Jae Yong Choi1* and Kenneth Lee2
1Dentist, Orthodontic and Dentofacial Orthopaedics Speciality Masters Program Universitat Jaume I (Spain), Bachelor of Dental Science (University of Queensland), Australia
2Professor Universitat Jaume I, Castellon, BDS (Syd), MSc Oral Implantology (Goethe), MSc Orthodontics (Castellon), FICD, FPFA, Private practice, Sydney, Australia
*Corresponding author: Jae Yong Choi, Student, Jaume I University, Orthodontic and Dentofacial Orthopaedics Specialty Masters Program, Brisbane, Australia.
Citation: Choi JY, Lee K. (2022) Effects of Four First Premolar Extraction on the Upper Airway Dimension in a Non-Growing Class I Skeletal Patients: A Systematic Review. J Oral Med and Dent Res. 3(1):1-16.
Received: March 22, 2022 | Published: May 10, 2022
183) https://www.researchgate.net/publication/350043270_A_case_of_sudden_onset_severe_Cephalgia_in_an_orthodontic_patient_has_demonstrated_how_occlusion_can_precipitate_orofacial_pain
https://adtt.scholasticahq.com/article/21478.pdf
Temporomandibular Joints (TMJ)
A Case Of Sudden Onset Severe Cephalgia In An Orthodontic
Patient Has Demonstrated How Occlusion Can Precipitate Orofacial
Pain
Patrick Girouard,, DMD. MS1, Svitlana Koval, BDS, MDS, DDS2
1 Acadia University, 2 Private Orthodontic Practice
Keywords: t-scan novus, orofacial pain, occlusion, orthodontics, cephalgia, Innobyte
184) https://www.facebook.com/groups/orthodonticmalpracticevictims/posts/1519659875659212/
or those who have experienced their mouths "shrinking" after their extraction orthodontics, and/or feeling their tongue does not have enough space---and need to prove it to someone:
All articles in journals on premolar extraction dental arch changes show that the dental arches get narrower and shorter due to the treatment.
Some articles note that if the extractions are done in adolescence, the growth of the arches is less than it would have been if patient had not been extracted.
Compare the photos of plaster models below: one is the dental arch of a 45 year old adult who had premolar extractions as a kid, the other a 17 year old who had no extractions.
Who do you think had the extractions?
------
DATA
I. See research article proving that dental arches shrink after premolar extractions, which according to the authors is potentially nefarious:
https://pmc.ncbi.nlm.nih.gov/articles/PMC10943680/
II. Here is an article proving that the width of the arches grows less in adolescents with extractions than in adolescents who get no extractions, and even less than those who get nonextraction with palate expansion. Check the charts. The intermolar width in extracted kids grows SMALLER during their two years of treatment (at a time it would naturally be increasing) while it grows at least 2.5 mm greater in non extracted people and even more in expanded people.
The authors highlight that the inter-canine space, however, grows bigger in extracted adolescents almost like the other groups, but point out that this is only because the canine has been pushed back into the premolar’s former space, which is a wider part of the arch. The actual canine area (now the laterals) will have shrunken.
https://academic.oup.com/ejo/article-abstract/27/6/585/400867?redirectedFrom=fulltext&login=false
A comparative study of dental arch widths: extraction and non-extraction treatment Get access Arrow
Fulya Işık , Korkmaz Sayınsu , Didem Nalbantgil , Tülin Arun
European Journal of Orthodontics, Volume 27, Issue 6, December 2005, Pages 585–589, https://doi.org/10.1093/ejo/cji057
Published:
28 October 2005
185) https://www.researchgate.net/publication/377825324_Effect_of_orthodontic_premolar_extraction_on_maxillary_teeth_angulation_and_arch_dimensions_in_adolescent_patients_A_3-D_digital_model_analysis
FINDINGS:
Width of palate decreases with premolar extractions. The width between the molars and remaining premilar narrows “significantly.” However, curiously, as you see in this chart, the width between the canines increases!
This is deceptive. There was no widening.. The width between the canines is wider than before only because the canines have been pushed back a full tooth during the retractive closing of the premolar extraction spaces, to position in a wider part of the jaw:m where the premolars were before extraction.
But even at this new part of the arch level, the width is narrower than it was was before the premolars were extracted, just wider than what the inter canine distance normally is.. Every part of the arch has narrowed.
186) Список статей. Они могут повторяться к предыдущему списку
https://www.facebook.com/groups/583182005973675?multi_permalinks=1541246176833915&hoisted_section_header_type=recently_seen
Bibliography: Airway Changes After Premolar Extraction
✅ Studies Showing Airway Narrowing
· Bhatia S, Jayan B, Chopra SS. (2016). Effect of retraction of anterior teeth on pharyngeal airway and hyoid bone position in Class I bimaxillary dentoalveolar protrusion. Med J Armed Forces India. 72(Suppl 1):S17-S23.
The size of the pharyngeal (velopharyngeal and glossopharyngeal) airway reduced and hyoid bone position changed after retraction of the incisors in extraction space in bimaxillary protrusive adult patients.
🔗 https://pubmed.ncbi.nlm.nih.gov/28050064/
· Chen Y, et al. (2012). Effect of large incisor retraction on upper airway morphology in adult bimaxillary protrusion patients. Angle Orthod. 82(6):964-70.
Large incisor retraction leads to narrowing of the upper airway in adult bimaxillary protrusion patients.
🔗 https://pubmed.ncbi.nlm.nih.gov/22462464/
· Choi JY, Lee K. (2022). Effects of Four First Premolar Extraction on the Upper Airway Dimension in a Non-Growing Class I Skeletal Patients: A Systematic Review. J Oral Med and Dent Res. 3(1):1-16.
Systematic review concludes that premolar extraction/retraction can cause narrowing of the pharyngeal airway, reduction of oral cavity space, and increased sleep apnea risk.
🔗 https://www.genesispub.org/effects-of-four-first-premolar-extraction-on-the-upper-airway-dimension-in-a-non-growing-class-i-skeletal-patients:-a-systematic-review
· Guilleminault C, et al. Missing teeth and pediatric obstructive sleep apnea.
Children missing permanent teeth due to extraction or agenesis had smaller oral cavities, predisposing to upper airway collapse during sleep.
🔗 · Hang WM, Gelb M. (2017). Airway Centric® TMJ philosophy / orthodontics. Cranio. 35(2):68-78.
Recommends avoiding retraction and arch constriction in orthodontics due to its airway-diminishing effects.
🔗 https://pubmed.ncbi.nlm.nih.gov/27356671/
· Hu Z, et al. (2015). The effect of teeth extraction for orthodontic treatment on the upper airway: a systematic review.
Extractions followed by large anterior retraction may lead to airway narrowing; mesial molar movement may increase space.
🔗 https://pubmed.ncbi.nlm.nih.gov/25628011/
· Mortezai O, et al. (2023). Effect of premolar extraction and anchorage type on upper airway dimensions and hyoid bone position. PeerJ. 11:e15960.
Significant reduction in airway dimensions and downward/backward hyoid displacement correlated with retraction magnitude.
🔗 https://pubmed.ncbi.nlm.nih.gov/37901473/
· Nagmode S, et al. Effect of First Premolar Extraction on Airway Dimension. J Indian Oral Sci. Upper airway volume increased slightly while lower airway volume decreased. Mixed results.
🔗 https://www.researchgate.net/publication/320351695
· Ozbek MM, et al. (1998). Oropharyngeal airway dimensions and functional-orthopedic treatment in skeletal class II cases. Angle Orthod. 68:327–36.
Closing extraction spaces leads to retrognathic mandibular position and oropharyngeal airway constriction.
🔗 https://pubmed.ncbi.nlm.nih.gov/9709833/
· Pliska BT, et al. (2016). Effect of orthodontic treatment on the upper airway volume in adults. Am J Orthod Dentofacial Orthop. 150(6):937-944.
While average airway volume loss was ~5% in patients with severe crowding, considered “insignificant”, patients with moderate or little crowding had “significant” narrowing due to dental arch retraction and the posterior positioning of the tongue.
При удалении зубов нижняя челюсть уезжает назад
Это создаёт риски возникновения нарушения дыхания во сне, что, в свою очередь, влечет за собой синдром СХУ.
🔗 https://pubmed.ncbi.nlm.nih.gov/27894542/
· Sharma K, et al. (2014). Effects of first premolar extraction on airway dimensions in young adolescents. Contemp Clin Dent. 5(2):190-4.
Premolar extractions caused narrowing in velopharyngeal, glossopharyngeal, hypopharyngeal regions, and posterior hyoid movement.
🔗 https://pubmed.ncbi.nlm.nih.gov/24963245/
· Sun FC, et al. (2018). Effect of incisor retraction on morphology of upper airway in bimaxillary protrusion. Zhonghua Kou Qiang Yi Xue Za Zhi. 53(6):398–403.
Oropharynx became constricted and pharyngeal resistance increased after retraction.
🔗 https://pubmed.ncbi.nlm.nih.gov/29886634/
· Zheng Z, et al. (2017). CFD simulation of upper airway response to large incisor retraction. Sci Rep. 7:45706.
Increased pharyngeal collapse risk after maximum anchorage retraction in bimaxillary protrusion patients.
🔗 https://pubmed.ncbi.nlm.nih.gov/28387372/
· Wang Q, et al. (2012). Changes in airway and hyoid bone position following orthodontics. Angle Orthod. 82(1):115-21.
Extraction and retraction led to airway narrowing and posterior/inferior hyoid movement.
🔗 https://pubmed.ncbi.nlm.nih.gov/21793712/
❌ Studies Not Showing Airway Narrowing
· Papageorgiou SN, Zyli M, Papadopoulou AK. (2025). Extraction of premolars does not negatively affect airway: meta-analysis. Eur J Orthod.
Systematic review found no significant decrease in airway volume or cross-sectional area after premolar extraction.
🔗· Choi JY, et al. (2022). Comparative analysis of pharyngeal airway changes following premolar extractions. Cureus.
Found airway narrowing, but concluded the change was not different among extraction patterns.
🔗 https://pubmed.ncbi.nlm.nih.gov/38882986/
· Al Maaitah E, et al. (2012). First premolar extraction effects on airway in bimaxillary proclination. Angle Orthod.
Reported no statistically significant changes in airway size following premolar extraction.
🔗 Comparative Analysis of Pharyngeal Airway Changes Following All Four Versus All Five Premolar Extractions in Orthodontic Treatments: A Cephalometric Study - PubMed
187) dental arches shrink after premolar extractions:
https://pmc.ncbi.nlm.nih.gov/articles/PMC10943680/
188) https://academic.oup.com/ejo/article-abstract/27/6/585/400867?redirectedFrom=fulltext&login=false
The results revealed that the distance between the upper canines was not affected by the treatment modality. Upper premolar and molar arch widths increased more in the non-extraction subjects when compared with those with extractions, with the greatest increase in patients with RME. In the lower canine area the extraction group showed the widest arch width at the end of treatment. There was also a 0.60 mm decrease in the lower canine width in the non-extraction group. A decrease was found in lower inter-premolar and molar distances due to consolidation of the extraction spaces.
189) When we use braces there is often alveolar bone loss. https://pmc.ncbi.nlm.nih.gov/articles/PMC8284009/
“Anterior alveolar bone and width and height often decreases after orthodontic treatment. Incisiors retraction led to a significant position of point A and B”.
https://pubmed.ncbi.nlm.nih.gov/22211303/
Human re-entry studies showed horizontal bone loss of 29-63% and vertical bone loss of 11-22% after 8 months following tooth extraction.
190) https://www.facebook.com/groups/1270654792948954/?multi_permalinks=24805332479054521&hoisted_section_header_type=recently_seen
Classic 2003 maxillofacial textbook by Dr. J. Reyneke, maxillofacial surgeon, recommended to me by a prominent US surgeon as a good read to learn about surgery.
http://43.230.198.52/lib/book/Orthodontics/Essentials%20of%20Orthognathic%20Surgery%20by%20Reyneke,%20Johan%20P..pdf
First chapter is about the difficult decision to "camouflage" with extractions or do surgery.
He states that premolar extractions can worsen facial aesthetics and cause functional problems.
Has some photos of people facially damaged by premolar extractions (from first chapter).
https://www.facebook.com/groups/extractionorthodonticsreversal/posts/25716594297928330/
1) Chewing performance in orthodontic patients treated with extraction of premolars. J Chosun Obr. 2019; 43(3):196–203.
https://www.chosunobr.org/journal/download_pdf.php?doi=10.21851%2Fobr.43.03.201909.196
→ Direct extraction study comparing pre- and post-treatment masticatory function. Patients with premolar extractions showed shorter, slower chewing cycles and reduced efficiency versus baseline. Indicates that orthodontic extractions impair chewing kinetics, especially with narrowed arch form.
2) English J.D., Buschang P.H., Throckmorton G.S.
Does malocclusion affect masticatory performance? Angle Orthod. 2002; 72(1):21–27.
https://pubmed.ncbi.nlm.nih.gov/11881753/
→ Established that malocclusions—including those created by retractive mechanics—significantly reduce chewing efficiency, yielding larger bolus particle size and decreased breakdown rate.
3) Fathalla R., Samih H.M., Ramadan A.A.
Assessment of occlusal forces in patients treated with four first-premolar extractions: An in vivo study using the T-Scan III system. Dent Stud. 2023; 5(1):70-76.
https://pubmed.ncbi.nlm.nih.gov/38034277/→ Ten adolescent patients treated with four-premolar extractions showed reduced anterior bite-force contribution and slight posterior redistribution. Overall occlusal force balance achieved, but anterior functional weakness persisted, suggesting compensatory rather than normal adaptation.
4) Haraldson T., Carlsson G.E., Ingervall B.
Functional state of the masticatory system in denture and natural dentition subjects. Acta Odontol Scand. 1979; 37(6):333–341.
https://pubmed.ncbi.nlm.nih.gov/294451/
→ Classic physiologic reference: demonstrated that reduced dental arches or missing teeth sharply decrease bite-force and chewing efficiency. Provides the foundational evidence that smaller dental arches—whether edentulous or extraction-induced—mean weaker mastication.
5) Helkimo E., Ingervall B., Carlsson G.E.
Bite force and functional state of the masticatory system in young adults. Swed Dent J. 1971; 64(3):153–160.
https://pubmed.ncbi.nlm.nih.gov/5285249/
→ Measured normal bite-force in young adults and correlated it with occlusal contact area. Found that bite-force decreases linearly with loss of posterior support—a principle directly relevant to orthodontic extractions.
6) Kohyama K., Mioche L., Martin J.F.
Chewing patterns of subjects with occlusal disharmonies. Arch Oral Biol. 2002; 47(6):461–471.
https://pubmed.ncbi.nlm.nih.gov/12000302/
→ Subjects with narrow arches and occlusal disharmonies (often post-extraction) exhibited longer, less efficient chewing cycles and maladaptive muscular coordination. Supports the link between arch constriction and functional decline.
7) Miura H., Araki Y., Morita M.
Relationship between occlusal contact area and bite-force in adults. J Oral Rehabil. 1981; 8(5):465–471.
https://pubmed.ncbi.nlm.nih.gov/6945325/
→ Quantified bite-force as a direct function of occlusal contact area. Showed that any reduction in arch width or tooth number lowers maximal bite-force, forming the physiologic basis for extraction-related weakness.
8) Peyron M.A., Lassauzay C., Woda A.
Effects of dental and prosthetic status on masticatory performance. J Dent Res. 2002; 81(8):545–549.
https://pubmed.ncbi.nlm.nih.gov/12215566/
→ Demonstrated that fewer functional teeth and reduced occlusal surface area yield lower masticatory output, confirming the mechanical cost of arch reduction.
9) Scientific Reports (Open Access).
Changes in occlusal function after extraction of premolars: A two-year follow-up study. Sci Rep. 2021; 11:8357216.
https://pmc.ncbi.nlm.nih.gov/articles/PMC8357216/
→ Two-year follow-up of non-extraction vs. two- and four-premolar extraction groups. Occlusal contact area and bite-force fell sharply after treatment; only partial recovery at 24 months. Four-premolar group never regained baseline force, confirming persistent mechanical deficit.
10) Shinogaya T., Adachi A., Watanabe M.
Effects of occlusal condition on masticatory efficiency. J Oral Rehabil. 1999; 26(9):739–745.
https://pubmed.ncbi.nlm.nih.gov/10511269/
→ Showed that reducing the number of active occlusal contacts markedly impairs masticatory efficiency. The findings parallel post-extraction occlusal conditions and validate their functional impact.
SYNTHESIS
· Premolar extractions reduce occlusal contact area, arch width, and anterior bite-force, resulting in slower, less efficient chewing and maladaptive muscle patterns.
· Foundational bite-force studies (Helkimo 1971; Haraldson 1979; Miura 1981) established that any loss of dental units or arch constriction directly weakens masticatory power.
· Modern clinical studies confirm extraction patients experience longer chewing cycles, smaller bolus breakdown, and incomplete recovery of occlusal function over time.
· Functional adaptations may partially compensate but at the expense of efficiency and possibly joint over-use.
PUBMED.NCBI.NLM.NIH.GOV
Results of biomonitoring analyses in Biomonitoring Laboratory, Helsinki, Finland in 1997 - PubMed
In 1997 a total of 4848 results of 47 different analytes from blood or urine specimens, were performed in the Finnish Institute of Occupational Health, Biomonitoring Laboratory, Helsinki, Finland. The results of these service analyses were registered in a database with additional information concern...