Bimaxillary Protrusion in Trinidad and Tobago Population

: Prevalence, Features and Management

Abstract

Aim: To study Bimaxillary Protrusion in the Trinidad and Tobago population; its prevalence, features and management.

Design: Two systematic reviews and meta - analyses, three cross sectional surveys, a clinical study and a retrospective study.

Subjects and Methods: The cross- sectional surveys were conducted on 672, 972 and 975 11 to 12 year old subjects. One orthodontist (T.H.) examined the students which were selected from some of the 141 public high schools which gave permission to conduct the research, located across the twin island republic, representing both rural and urban populations. The retrospective study was conducted using 109 standardised lateral cephalometric radiographs from patients receiving orthodontic treatment at the University of The West Indies dental hospital between September 2015 to March 2019.These patients gave consent for their records to be used.

Results: Prevalence of bimaxillary protrusion varies greatly among populations. Bimaxillary prognathism has a prevalence of 64.4% and bimaxillary proclination has a prevalence of 68.8% in Trinidad and Tobago. The overall prevalence of fractured incisors in Trinidad and Tobago is 4.72%. The overall prevalence of habits is 93%. 68.6% of subjects presented with more than one oral habit.
The use of Temporary Anchorage Devices (TADs) showed shorter treatment time in bimaxillary protrusion cases. There is however low quality evidence that TADs could be the preferred method for anchorage for bimaxillary protrusion cases.

The cephalometric norms for this population were unique compared to other bimaxillary protrusion societies. Higher ANB and MMPA were demonstrated in this society compared to Caucasians and Chinese populations with bimaxillary protrusion. The lower incisors were more protrusive compared to Nigerian populations

Conclusions:
1. Bimaxillary protrusion and certain oral habits are more prevalent in the Trinidad and Tobago population.
2. Bimaxillary protrusion is accompanied by unique dental and facial features.
3. Optimum treatment for bimaxillary protrusion will be dictated by presenting features, habits and tailored to cephalometric values.
4. More high quality research is required in the area of bimaxillary protrusion.

Date of Award	2020
Original language	English
Awarding Institution	University of Dundee
Supervisor	David Bearn (Supervisor) & Peter Mossey (Supervisor)