THESIS – SYNOPSIS
DR. NOUMIRA ABDULLA.P.M
POST GRADUATE STUDENT
DEPARTMENT OF ORTHODONTICS AND
DENTOFACIAL ORTHOPAEDICS
K.V.G.DENTALCOLLEGE & HOSPITAL
KURUNJIBAGH, SULLIA – 574327
DAKSHINA KANNADA
RAJIVGANDHIUNIVERSITY OF HEALTH SCIENCES
BANGALORE, KARNATAKA
ANNEXURE II
PROFORMA FOR REGISTRATION OF SUBJECT FOR DISSERTATION
1. / NAME OF THE CANDIDATE AND ADDRESS / : / DR.NOUMIRA ABDULLA.P.MPOST GRADUATE STUDENT,
DEPT OF ORTHODONTICS AND DENTOFACIAL ORTHOPAEDICS,
K.V.GDENTALCOLLEGE & HOSPITAL,
KURUNJIBAGH, SULLIA – 574 327
2. /
NAME OF THE INSTITUTION
/ : / K.V.G.DENTALCOLLEGE & HOSPITAL,KURUNJIBAGH, SULLIA – 574 327.
3. / COURSE OF THE STUDY AND SUBJECT / : / MASTER OF DENTAL SURGERY
ORTHODONTICS, BRANCH –V
4. / DATE OF ADMISSION TO COURSE / : / 25 MAY 2012
5. / TITLE OF THE TOPIC / “ A COMPARISON OF THE CRANIOFACIAL STRUCTURES AND OROFACIAL AIRWAY DIMENSIONS IN SUBJECTS WITH CLASS I AND CLASS II MALOCCLUSIONS WITH DIFFERENT GROWTH PATTERNS” – A CEPHALOMETRIC STUDY
6.BRIEF RESUME OF THE INTENDED STUDY
6.1 Need for the study
Pharyngeal space size is determined primarily by relative growth and size of the soft tissues surrounding the dentofacial skeleton.1 Craniofacial anomalies, including mandibular or maxillary retrognathism, short mandibular body and backward and downward rotation of the mandible, may lead to reduction of the pharyngeal airway passage.2
Decreased space between the mandibular corpus and the cervical column may lead to changes in posture of the tongue and soft palate posteriorly,may impair respiratory function during the day and may cause possible nocturnal problems such as snoring, upper airway resistance syndrome and obstructive sleep apnea.3
Some authors4,5 have reported associations between vertical growth pattern and obstruction of the upper and lower pharyngeal airways and mouth breathing.5Consequently, healthy patients with class II malocclusions and vertical growth patterns might have narrower airway passages than healthy patients with normal occlusion and horizontal growth pattern, or class I malocclusions.6
Thus this study intends to compare craniofacial dimensions and widths of the orofacial airways in class I and class II malocclusions with different growth patterns (low, normal and high angle).
6.2 Review of the literature
A longitudinal study was done to investigate craniofacial changes in untreated skeletal class I subjects with low(≤27o), average(>27o - <37o) and high(≥37o) MP-SN angles. Sample included 68 subjects. Result showed that for boys and girls at age 9,the low angle groups exhibited significantly larger SNA angle, SNB angle,facial taper,PFH,PFH:AFH and ramus height and high angle group showed larger ANS-Me and gonial angle. From ages 9-18 yrs,all groups showed increase in SNA and SNB and PFH:AFH and decrease in ANB angle,convexity, MP-SN angle and gonial angle.7
A study was doneto investigate the uvulo-glosso-pharyngeal dimensions in subjects with different anteroposterior jaw relationship. Cephalometric radiograph of 90 subjects (45 females and 45 males, aged ) were divided into three groups according to the ANB angle, ie, group 1, skeletal Class I; group 2, skeletal Class II ; and group 3, skeletal Class III . Results of the study showed that sex differences were found in Class I and III subjects, no sex differences were detected in Class II subjects.From this study, it was concluded that uvulo-glosso-pharyngeal dimensions were affected by anteroposterior skeletal pattern.8
A study was done to compare upper and lower pharyngeal widths in patients with untreated class I and class II malocclusions and normal and vertical growth patterns. The sample divided into 2 groups:40 class I and 40 class II and subdivided into normal and vertical growers. The result showed that the upper pharyngeal width in the subjects with class I and class II malocclusions and vertical growth patterns was significantly narrower than in the normal growth pattern group.6
A study was done to evaluate effects of sagittal mandibular development on the dimensions of awake pharyngeal airway passage. 91 subjects(age 15-25yrs) with normal vertical growth pattern were selected for the study. Group 1-37 subjects with normally positioned mandible, group 2- 31 subjects with retrognathic mandible, group 3- 23 subjects with prognathic mandible. The result showed that length of the soft palate was significantly smaller in mandibular prognathism than in mandibular retrognathism.9
A study was done to compare craniofacial dimensions and widths of the orofacial airways and tongue in healthy class I subjects with different growth patterns(low, normal and high angle). 104 subjects were divided into 3 groups. 27 craniofacial and 7 orofacial airway measurements were evaluated. Results showed that only 5 of the craniofacial measurements showed no significant differences among different growth patterns. For orofacial airway measurements, significant differences were found in nasopharyngeal airway space, palatal tongue space, upper posterior airway space and tongue gap.1
6.3Objectives of the study :
- To evaluate craniofacial dimensions and orofacial dimensions in subjects with class I and class II malocclusions and different growth patterns.
- To compare craniofacial dimensions and orofacial dimensions between subjects with class I and class II malocclusions and different growth patterns.
7.1 Source of the data:
60 pre-treatment cephalometric radiographs will be taken from patients reporting to the Department of Orthodontics, KVG Dental College and Hospital, Sullia.
Materials required:
Standardized Lateral Cephalograms of subjects with class I and class II malocclusions.
Inclusion criteria:
- Angle class Iand class II skeletal relationship according to Steiner.
- Permanent dentition.
- Age of patients : 13-23 years.
- Lack of orthodontic treatment and/or maxillary functional orthopedic treatment.
- No history of nasal respiratory complex surgery.
- Enough sharpness and contrast of radiographs for good visualization and identification of the structures.
- No radiographic distortions.
- Angle class III skeletal relationship according to Steiner.
- Mixed/deciduous dentition.
- Young people currently receiving or who had been receiving orthodontic treatment.
- Previous history of nasal respiratory complex surgery.
- Vestibular or equilibrium problems.
- Visual, hearing or swallowing disorders and with facial or spinal abnormalities.
- Extensive carious lesion.
- Radiographs without sharpness and contrast.
- Radiographic with image distortions.
- Pharyngeal pathology, nasal obstruction, enlarged adenoids or tonsils; mouth breathers.
Pretreatment cephalometric radiographs of 60 subjects will be taken by standard technique. All subjects will be divided into 2 groups. Group 1-with skeletal class I and group 2- with skeletal class II. In addition each group will be divided into 3 subgroups based on vertical growth pattern( low, normal, high angle).
Different vertical growth patterns will be categorized according to the SN-MP angle ( low angle < 26degrees ; normal angle 26-38 degrees ; high angle >38 degrees ). These factors will be considered for the diagnosis of vertical growth pattern according to Isaacson et al.10
GROUP / SUBGROUP / SAMPLE SIZE
Group I – Class I- / A – with low angle / 10
B – with high angle / 10
C – with normal growth / 10
Group II – Class II / A – with low angle / 10
B – with high angle / 10
C – with normal growth / 10
Before participation in the study written informed consents will be taken by the patients/ parents of the patient.
Lateral cephalograms of selected subjects will be obtained. Lateral cephalograms will be taken natural head posture with molars in maximum intercuspation and lips sealed in a relaxed position. All radiographs will be traced manually. Study period will be 1 year.
15 angular and 12 linear measurements will be used for craniofacial evaluation. Additionally, 7 measurements will be used for orofacial dimensions.
The following landmarks and reference lines will be used for craniofacial measurements and orofacial dimensions:
Description of measurements to be used in the study:
Craniofacial Analysis
Angular Measurements:
1.SNA angle : inward angle toward the cranium between the NA line and the SN
plane.
2.SNB angle : inward angle toward the cranium between the NB line and the SN
plane.
3.ANB angle : angle between the NA and NB lines, obtained by substracting
SNB from SNA.
4.Saddle/Sella angle (SN-Ar): ): inward angle toward the cranium between the S-Ar line
and the SN plane.
5. Articular angle: inward angle between the S-Ar line and the Ar-Go line
.
6.Gonial/ Jaw angle (Ar-Go/MP):inward angle toward the cranium between the Ar-Go
line andthe mandibular plane.
7. SN plane to mandibular plane angle (MP):angle between the SN plane and the MP.
8. Palatal-Mand angle (PP-GoGn):angle between the PP plane and the MP.
9.Y-Axis: inward angle toward the cranium between the S-Go line and the SN
plane.
10.SN-NPog: inward angle toward the cranium between the N-Pog line and the SN
plane.
11.NA-APog (convexity): inward angle between the NA line and the APog line.
12.FMA:angle between the Frankfort horizontal plane and the MP.
13. FMIA : angle between the Frankfort horizontal plane and the mandibular incisor axis.
14. IMPA: angle between the MP and the mandibular incisor axis.
15. Mand Plane to Occ Plane (MP-OP): angle between the MP and the occlusal plane(OP).
Linear Measurements:
1.A to N perp: distance between A point and N perpendicular line measured perpendicular to N
perpendicular line.
2.Pog to N perp : distance between pogonion and N perpendicular line measured from
Perpendicular to N perpendicular line.
3.S-N: distance between sella and nasion.
4.S-Ar: distance between sella and articular.
5.Ar-Go: distance between articular and gonion.
6.Go-Gn: distance between gonion and gnathion.
7.N-Go: distance between nasion and gonion.
8.Y-Axis length (S-Gn): distance between sella and gnathion.
9.S-Go: distance between sella and gonion .
10.Na-Me: distance between nasion and menton.
11.Overjet: distance between labial surfaces of upper and lower incisors.
12. Overbite: distance between upper and lower incisor.
Angular Measurements:
1.Nasopharyngeal airway space: area formed by palatal plane,Pt PNS line and posterior
pharyngeal wall.
2.Palatal tongue space:space between tongue and palate from the line perpendicular to the
palatal plane at the incisive foramen to the line perpendicular to the palatal plane at the PNS.
3.Tongue space:area formed by superior and posterior borders of tonguev and T, Me, H1, H2.
4.Upper PAS: point of intersection of line from soft palate center perpendicular to posterior
pharyngeal wall and posterior pharyngeal wall.
5. Lower PAS: distance of mandibular plane intersection between posterior pharyngeal wall and
tongue posterior wall.
6.Tonsil size: the wider line is parallel to the Frankfort horizontal plane on the palatal tonsil.
7.Tongue gap: line perpendicular to the palatal plane from the center of the palatal plane to the
tongue.
Statistical analysis :
- Group differences will be analyzed with ANOVA.
- For multiple comparisons, Tukey honestly significant difference (HSD) will be used.
Yes,this study requires the cephalometric radiographs of the individuals selected for the study.
.7.4 Has ethical clearance been obtained from your institution?
Yes, copy of Ethical Clearance is enclosed.
8. REFERENCES:
1)Ucar FI, Uysal T. Orofacial airway dimension in subjects with class I malocclusion and
different growth patterns. Angle Orthod. 2011;81:460-468.
2)Joseph AA, Elbaum J, Cisneros GJ, Eisig SB. A cephalometric comparative study of the
soft tissue airway dimensions in persons with hyperdivergent and normodivergent facial
pattern. J Oral Maxillofac Surg. 1998;56:135-139.
3)Ozbek MM, Miyamoto K, Lowe AA, Fleetham JA. Natural head posture, upper airway
anatomy and obstructive sleep apnoea severity in adults. Eur J Orthod. 1998;20:133-143.
4)Vig KW. Nasal obstruction and facial growth:the strength of evidence for clinical
assumptions. Am J Orthod Dentofacial Orthop. 1998;113:603-611.
5)Tourne LP. Growth of the pharynx and its physiologic implications. Am J Orthod
Dentofacial Orthop. 1991;99:129-139.
6)De Freitas MR, Alcazar NM, Janson G, De Freitas KMS, Henriques JFC. Upper and lower
pharyngeal airways in subjects with class I and class II malocclusions and different
growth patterns. Am J Orthod Dentofacial Orthop. 2006;130:742-745.
7)Chung CH, Mangovi VD. Craniofacial growth in untreated skeletal class I subjects with
low,average and high MP_SN angle : a longitudinal study. Am J Orthod Dentofacial
Orthop. 2003;124:670-678.
8)Alhaja AES, Alkhateeb SN. Uvuloglossopharyngeal dimensions in different
anterioposterior skeletal patterns. Angle Orthod. 2005;76:1012-1018.
9)Jena AK, Singh SP, Utreja AK. Sagittal mandibular development effects on the
dimensions of the awake pharyngeal airway passage. Angle Orthod. 2010;80:1061-1067.
10)Isaacson JR, Isaacson RJ, Speidel TM, Worms FW. Extreme variation in vertical facial
growth and associated variation in skeletal and dental relations. Angle Orthod. 1971;41:219-229.
9. / SIGNATURE OF CANDIDATE
10. /
REMARKS OF THE GUIDE
11. / NAME AND DESIGNATION OF11.1 GUIDE / DR.JACOB JOHN MDS,M Orth RCS
PROFFESSOR,
DEPT OF ORTHODONTICS AND DENTOFACIAL ORTHOPAEDICS
11.2 SIGNATURE
11.3 HEAD OF THE DEPARTMENT / DR.SHARATHKUMAR SHETTY, M.D.S.
DIRECTOR OF PG STUDIES,
PROFESSOR AND HOD,
DEPARTMENT OF ORTHODONTICS AND DENTOFACIAL ORTHOPAEDICS,
K.V.GDENTALCOLLEGE AND HOSPITAL, KURUNJIBAGH,SULLIA, D.K -574327
11.4 SIGNATURE
12. /
REMARKS OF THE PRINCIPAL
DR. MOKSHA NAYAK, M.D.S.PRINCIPAL,
K.V.G.DENTALCOLLEGE AND HOSPITAL, KURUNJIBAGH, SULLIA.
12.1 SIGNATURE