Differences in the heritability of craniofacial skeletal and dental characteristics between twin pairs with skeletal Class I and II malocclusions

Different treatment strategies for monozygotic twins with Class II division 1 malocclusion: 10-year follow-up study

BACKGROUND

Early-stage growth modification has been demonstrated effective in treating prepubertal patients with Class II division 1 malocclusion. Since monozygotic twins are genetically identical, environmental factors, including oral habits and treatment strategies, may contribute to different treatment outcomes. To date, few reported comparisons of different treatment strategies in monozygotic twins with Class II division 1 malocclusion exist.

CASE DESCRIPTION

In this case report, we compare the effects of different functional appliances and extraction strategies in a pair of prepubertal monozygotic twins. Different compliance and treatment protocols may have different effects on their early changes in facial profile. Customized treatment plans are necessary for optimal treatment outcomes. Both twins achieved favourable improvements in facial profile, and their long-term stability of functional occlusion was also maintained after a ten-year follow-up.

PRACTICAL IMPLICATIONS

With the outcome of the case, we acknowledged that functional appliance therapy can affect the potentiality of mandibular growth. Individualized protocols should be approached aside from different functional appliances.

Do Specific Craniomaxillofacial Features Correlate with Psychological Distress in Adult Pretreatment Orthodontic Patients? A Cephalometric Study

Purpose

To explore the relationship between craniomaxillofacial features and psychological distress among adult pretreatment orthodontic patients.

Methods

A group of 190 patients (95 males and 95 females) was included. Questionnaires including the Kessler psychological distress scale (K10) were sent to patients, and cephalograms were collected. Patients were divided into two groups according to K10 score: psychological distress group (score ≥ 20) and no psychological distress group (score < 20). Nineteen hard tissue and thirteen soft tissue parameters were traced on cephalograms to characterize the craniomaxillofacial features.

Results

There was no significant difference in gender or age distribution between the two groups. Male patients with psychological distress showed statistically significantly larger anterior facial height (AFH) (126.62 mm vs. 120.97 mm), upper lip length (25.11 mm vs. 23.26 mm), and smaller overbite (1.21 mm vs. 2.75 mm) than patients without psychological distress. Male patients with hyperdivergent pattern and open bite were more likely to have psychological distress. None of the parameters showed statistical differences across groups in females. Frankfort-mandibular plane angle (r = 0.235), Bjork's sum (r = 0.311), AFH (r = 0.322), overbite (r = −0.238), AFH/posterior facial height (r = 0.251), and upper anterior facial height (UAFH)/lower anterior facial height (LAFH) (r = −0.230) were correlated with K10 score in males. After adjusting gender and age, the AFH (B = 0.147) and UAFH/LAFH (B = −14.923) were significantly related with the K10 score.

Conclusion

Psychological distress was mainly correlated with hyperdivergent pattern, open bite, and larger lower anterior facial height proportion in pretreatment orthodontic patients. Orthodontists should be aware of the possible underlying psychological distress in patients with specific craniomaxillofacial features. Clinical assessment of psychological distress may need to take into account gender differences in patients.