This systematic review examines the relationship between temporomandibular disorders (TMD) and malocclusions. The review identified 9 studies that provided moderately strong evidence. These studies found that large overjets were associated with higher prevalence of TMD symptoms, though specific malocclusions could not be definitively linked to TMD. Longitudinal studies observing subjects from teenage years to age 30 showed reduction in most TMD signs over time. Psychological health and muscle strength may be as associated with TMD as malocclusion. More research is still needed, especially longitudinal studies observing subjects before and after treatment.

1. Literature review

2. Type of study Systematic Review
Authors Mohlin et.al
Date of publication 2007
Name of Journal Angle Orthodontist

3. Introduction
 Two main questions about temporomandibular disorders (TMD) :
1. Correlations between TMD and different kinds of functional or morphologic malocclusions.
2. The severity and prevalence of TMD are influenced or even caused by orthodontic treatment.

4. Introduction
 Signs and symptoms of TMD, such as:
 Pain from the temporomandibular joints (TMJs)
 Pain from jaw muscles
 Pain on mandibular movement
 Joint sounds
 Locking/luxation of joints
 Restricted mandibular movement.

5. Introduction
 The etiology of TMD is usually considered multifactorial.
 Possible etiologic factors:
 Untreated malocclusions
 Unstable occlusion
 Stress and other psychologic factors
 Trauma
 Individual predisposition, and structural conditions

6. Settling the evidence grade
‫ج‬
 The papers were evaluated according to the following criteria, which are based on the criteria for
assessing study quality from the Centre for Reviews and Disseminations in York, United Kingdom:
Strong evidence (A) Moderately strong evidence (B) Limited evidence (C)
 Randomized controlled trial
 Prospective studies/ large study
 Samples Well-defined and adequate
control group
 Clearly defined and clinically
relevant variables
 Low dropout rate
 Relevant statistical analysis
 Prospective study, cohort, controlled
clinical trial
 Well-defined retrospective study
with large study group
 Clearly defined and clinically
relevant variables
 Low dropout rate
 Relevant statistical analysis
 Cross-sectional study
 Clinically inadequate result variables
High dropout rate
 No control group of its own in the
study Limited/no statistical analysis

7.  The search resulted in 58 papers.
 Forty nine (49) papers were excluded
due to limited evidence.
 Nine papers were judged to give
moderately strong evidence (Table 4).

17. According to studies of Egemark et. al and Henriksson et. al:
 Large overjet showed a higher prevalence of signs and symptoms of TMD.
 Followed patients to about 30 years of age showed a general reduction in signs and
symptoms of TMD and an overall low prevalence at that age.
 The prevalence of clicking remained fairly unchanged, whereas prevalence of locking of the
TMJ decreased.

18. According to studies of Egemark et. al and Henriksson et. al:
 Psychologic health and muscular endurance showed associations with TMD that were at least
as obvious as that between TMD and malocclusion.
 Muscle strength and muscle endurance have previously been associated with craniofacial
morphology. Vertically growing faces are often characterized by low muscle strength.
 It is interesting to note that deep bites tend to be more common among subjects without
TMD.

19. Conclusions
 Associations between specific types of malocclusions and development of significant signs and symptoms
of TMD could not be verified.
 There is still a need for longitudinal studies.
 Observations should be made before treatment as well as by long-term observation of untreated and
treated subjects.
 The differentiation of patients into control and study groups is a constant problem.

20. Conclusions
 A proper observation period appears to be from the late teenage years to young adulthood (age about 30
years).
 Individual variations in TMD over time must be controlled in the study design.
 The main focus in the observations should be on TMD signs and symptoms of such a magnitude that
treatment of TMD seems likely to be demanded.

21. Post-orthodontic Periodontal Treatment
After orthodontic treatment, the patient should remain on a 3 month periodontal maintenance program.
A nightguard is indicated to control parafunction and can also be used as a post-orthodontic retainer.
Occlusal adjustment to diminish any fremitus from lateral interferences
Take a new set of periapical radiographs.
It takes at least 6 months after band removal for adequate bone remodeling and cessation of mobility.