Adaptations of the masticatory system after bilateral fractures of the mandibular condylar process

Reena M. Talwar, Edward Ellis, Gaylord S. Throckmorton

Research output: Contribution to journalArticle

41 Citations (Scopus)

Abstract

Purpose: The objective of this investigation was to evaluate the adaptations that occur in the masticatory system after treatment of bilateral fractures of the mandibular condylar process. Patients and Methods: Twenty- two patients (15 men and seven women) with bilateral condylar process fractures treated by open reduction and rigid internal fixation (n = 6), closed therapy (n = 14), or a combination of these techniques (n = 2) were compared with 22 sex- and age-matched controls. Measures of mandibular range of motion, bite force, muscle activity, estimated joint forces, and skeletal morphology were determined at 6 weeks, 6 months, and 1, 2, and 3 years after treatment in all subjects. Various statistical tests were used for comparing differences between patients and controls. Results: There was no significant difference in the patients' morphologic measures for the open and closed reduction procedures; therefore, all of these patients were tested as a single group. After treatment, patients had significantly increased mandibular plane and gonial angles and decreased facial axis angles. They also showed a significant reduction in posterior facial height and moment arm length for the masseter and pterygoid muscles. Anterior and posterior temporalis muscle direction also was significantly different between patients and controls. Patients had significantly limited mobility during the first year after fracture. Bite forces were lower for patients at all times and tooth positions, with a significant difference at 6 weeks after treatment. Patients had a tendency to use proportionally higher temporalis muscle activity during maximum biting; however, the differences were not statistically significant, probably because of the small sample size. The estimated joint force magnitudes were essentially identical between patients and controls; however, the direction of the patients' joint forces were more posteriorly directed for both incisor and molar bites. Conclusion: The results of this study suggest that early reduction in mandibular range of motion, bite force, and the distribution of masticatory muscle activity assist in preventing overloading of the bilaterally fractured mandibular condylar processes.

Original languageEnglish (US)
Pages (from-to)430-439
Number of pages10
JournalJournal of Oral and Maxillofacial Surgery
Volume56
Issue number4
DOIs
StatePublished - Apr 1998
Externally publishedYes

Fingerprint

Stomatognathic System
Mandibular Fractures
Bite Force
Articular Range of Motion
Muscles
Pterygoid Muscles
Masticatory Muscles
Therapeutics
Masseter Muscle
Bites and Stings
Incisor
Sample Size

ASJC Scopus subject areas

  • Dentistry(all)
  • Surgery

Cite this

Adaptations of the masticatory system after bilateral fractures of the mandibular condylar process. / Talwar, Reena M.; Ellis, Edward; Throckmorton, Gaylord S.

In: Journal of Oral and Maxillofacial Surgery, Vol. 56, No. 4, 04.1998, p. 430-439.

Research output: Contribution to journalArticle

@article{457b71205aa94ba29fc6e08b51ab4676,
title = "Adaptations of the masticatory system after bilateral fractures of the mandibular condylar process",
abstract = "Purpose: The objective of this investigation was to evaluate the adaptations that occur in the masticatory system after treatment of bilateral fractures of the mandibular condylar process. Patients and Methods: Twenty- two patients (15 men and seven women) with bilateral condylar process fractures treated by open reduction and rigid internal fixation (n = 6), closed therapy (n = 14), or a combination of these techniques (n = 2) were compared with 22 sex- and age-matched controls. Measures of mandibular range of motion, bite force, muscle activity, estimated joint forces, and skeletal morphology were determined at 6 weeks, 6 months, and 1, 2, and 3 years after treatment in all subjects. Various statistical tests were used for comparing differences between patients and controls. Results: There was no significant difference in the patients' morphologic measures for the open and closed reduction procedures; therefore, all of these patients were tested as a single group. After treatment, patients had significantly increased mandibular plane and gonial angles and decreased facial axis angles. They also showed a significant reduction in posterior facial height and moment arm length for the masseter and pterygoid muscles. Anterior and posterior temporalis muscle direction also was significantly different between patients and controls. Patients had significantly limited mobility during the first year after fracture. Bite forces were lower for patients at all times and tooth positions, with a significant difference at 6 weeks after treatment. Patients had a tendency to use proportionally higher temporalis muscle activity during maximum biting; however, the differences were not statistically significant, probably because of the small sample size. The estimated joint force magnitudes were essentially identical between patients and controls; however, the direction of the patients' joint forces were more posteriorly directed for both incisor and molar bites. Conclusion: The results of this study suggest that early reduction in mandibular range of motion, bite force, and the distribution of masticatory muscle activity assist in preventing overloading of the bilaterally fractured mandibular condylar processes.",
author = "Talwar, {Reena M.} and Edward Ellis and Throckmorton, {Gaylord S.}",
year = "1998",
month = "4",
doi = "10.1016/S0278-2391(98)90707-8",
language = "English (US)",
volume = "56",
pages = "430--439",
journal = "Journal of Oral and Maxillofacial Surgery",
issn = "0278-2391",
publisher = "W.B. Saunders Ltd",
number = "4",

}

TY - JOUR

T1 - Adaptations of the masticatory system after bilateral fractures of the mandibular condylar process

AU - Talwar, Reena M.

AU - Ellis, Edward

AU - Throckmorton, Gaylord S.

PY - 1998/4

Y1 - 1998/4

N2 - Purpose: The objective of this investigation was to evaluate the adaptations that occur in the masticatory system after treatment of bilateral fractures of the mandibular condylar process. Patients and Methods: Twenty- two patients (15 men and seven women) with bilateral condylar process fractures treated by open reduction and rigid internal fixation (n = 6), closed therapy (n = 14), or a combination of these techniques (n = 2) were compared with 22 sex- and age-matched controls. Measures of mandibular range of motion, bite force, muscle activity, estimated joint forces, and skeletal morphology were determined at 6 weeks, 6 months, and 1, 2, and 3 years after treatment in all subjects. Various statistical tests were used for comparing differences between patients and controls. Results: There was no significant difference in the patients' morphologic measures for the open and closed reduction procedures; therefore, all of these patients were tested as a single group. After treatment, patients had significantly increased mandibular plane and gonial angles and decreased facial axis angles. They also showed a significant reduction in posterior facial height and moment arm length for the masseter and pterygoid muscles. Anterior and posterior temporalis muscle direction also was significantly different between patients and controls. Patients had significantly limited mobility during the first year after fracture. Bite forces were lower for patients at all times and tooth positions, with a significant difference at 6 weeks after treatment. Patients had a tendency to use proportionally higher temporalis muscle activity during maximum biting; however, the differences were not statistically significant, probably because of the small sample size. The estimated joint force magnitudes were essentially identical between patients and controls; however, the direction of the patients' joint forces were more posteriorly directed for both incisor and molar bites. Conclusion: The results of this study suggest that early reduction in mandibular range of motion, bite force, and the distribution of masticatory muscle activity assist in preventing overloading of the bilaterally fractured mandibular condylar processes.

AB - Purpose: The objective of this investigation was to evaluate the adaptations that occur in the masticatory system after treatment of bilateral fractures of the mandibular condylar process. Patients and Methods: Twenty- two patients (15 men and seven women) with bilateral condylar process fractures treated by open reduction and rigid internal fixation (n = 6), closed therapy (n = 14), or a combination of these techniques (n = 2) were compared with 22 sex- and age-matched controls. Measures of mandibular range of motion, bite force, muscle activity, estimated joint forces, and skeletal morphology were determined at 6 weeks, 6 months, and 1, 2, and 3 years after treatment in all subjects. Various statistical tests were used for comparing differences between patients and controls. Results: There was no significant difference in the patients' morphologic measures for the open and closed reduction procedures; therefore, all of these patients were tested as a single group. After treatment, patients had significantly increased mandibular plane and gonial angles and decreased facial axis angles. They also showed a significant reduction in posterior facial height and moment arm length for the masseter and pterygoid muscles. Anterior and posterior temporalis muscle direction also was significantly different between patients and controls. Patients had significantly limited mobility during the first year after fracture. Bite forces were lower for patients at all times and tooth positions, with a significant difference at 6 weeks after treatment. Patients had a tendency to use proportionally higher temporalis muscle activity during maximum biting; however, the differences were not statistically significant, probably because of the small sample size. The estimated joint force magnitudes were essentially identical between patients and controls; however, the direction of the patients' joint forces were more posteriorly directed for both incisor and molar bites. Conclusion: The results of this study suggest that early reduction in mandibular range of motion, bite force, and the distribution of masticatory muscle activity assist in preventing overloading of the bilaterally fractured mandibular condylar processes.

UR - http://www.scopus.com/inward/record.url?scp=0031961133&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0031961133&partnerID=8YFLogxK

U2 - 10.1016/S0278-2391(98)90707-8

DO - 10.1016/S0278-2391(98)90707-8

M3 - Article

C2 - 9541341

AN - SCOPUS:0031961133

VL - 56

SP - 430

EP - 439

JO - Journal of Oral and Maxillofacial Surgery

JF - Journal of Oral and Maxillofacial Surgery

SN - 0278-2391

IS - 4

ER -