Nail Biting Habits

Nail biting, also known as onychophagia, is one of the most common habits observed in children and can persist into adulthood. It is often associated with internal tension, anxiety, or stress. Understanding the etiology, clinical features, and management strategies for nail biting is essential for addressing this habit effectively.

Etiology

1. Emotional Problems:

   • Persistent nail biting may indicate underlying emotional issues, such as anxiety, stress, or tension. It can serve as a coping mechanism for dealing with these feelings.

2. Psychosomatic Factors:

   • Nail biting can be a psychosomatic response to stress or emotional discomfort, manifesting physically as a way to relieve tension.

3. Successor of Thumb Sucking:

   • For some children, nail biting may develop as a successor to thumb sucking, particularly as they transition from one habit to another.

Clinical Features

• Dental Effects:

  • Crowding: Nail biting can contribute to dental crowding, particularly if the habit leads to changes in the position of the teeth.
  • Rotation: Teeth may become rotated or misaligned due to the pressure exerted during nail biting.
  • Alteration of Incisal Edges: The incisal edges of the anterior teeth may become worn down or altered due to repeated contact with the nails.

• Soft Tissue Changes:

  • Inflammation of Nail Bed: Chronic nail biting can lead to inflammation and infection of the nail bed, resulting in redness, swelling, and discomfort.

Management

1. Awareness:

   • The first step in management is to make the patient aware of their nail biting habit. Understanding the habit's impact on their health and appearance can motivate change.

2. Addressing Emotional Factors:

   • It is important to identify and treat any underlying emotional issues contributing to the habit. This may involve counseling or therapy to help the individual cope with stress and anxiety.

3. Encouraging Outdoor Activities:

   • Engaging in outdoor activities and physical exercise can help reduce tension and provide a positive outlet for stress, potentially decreasing the urge to bite nails.

4. Behavioral Modifications:

   • Nail Polish: Applying a bitter-tasting nail polish can deter nail biting by making the nails unpalatable.
   • Light Cotton Mittens: Wearing mittens or gloves can serve as a physical reminder to avoid nail biting and can help break the habit.

5. Positive Reinforcement:

   • Encouraging and rewarding the individual for not biting their nails can help reinforce positive behavior and motivate them to stop.

Ashley Howe’s Analysis of Tooth Crowding

Introduction

Today, we will discuss Ashley Howe’s analysis, which provides valuable insights into the causes of tooth crowding and the relationship between dental arch dimensions and tooth size. Howe’s work emphasizes the importance of arch width over arch length in understanding dental crowding.

Key Concepts

Tooth Crowding

• Definition: Tooth crowding refers to the lack of space in the dental arch for all teeth to fit properly.
• Howe’s Perspective: Howe posited that tooth crowding is primarily due to a deficiency in arch width rather than arch length.

Relationship Between Tooth Size and Arch Width

• Howe identified a significant relationship between the total mesiodistal diameter of teeth anterior to the second permanent molar and the width of the dental arch in the first premolar region. This relationship is crucial for understanding how tooth size can impact arch dimensions and overall dental alignment.

Procedure for Analysis

To conduct Ashley Howe’s analysis, the following measurements must be obtained:

1. Percentage of PMD to TTM
   PMD X 100
         TTM
2. Percentage of PMBAW to TTM
   PMBAW X 100
       TTM

3. Percentage of BAL to TTM: [ \text{Percentage of BAL} = \left( \frac{\text{BAL}}{\text{TTM}} \right) \times 100 ]

Where:

• PMD = Total mesiodistal diameter of teeth anterior to the second permanent molar.
• PMBAW = Premolar basal arch width.
• BAL = Basal arch length.
• TTM = Total tooth mesiodistal measurement.

Inferences from the Analysis

The results of the measurements can lead to several important inferences regarding treatment options for tooth crowding:

1. If PMBAW > PMD:

   • This indicates that the basal arch is sufficient to allow for the expansion of the premolars. In this case, expansion may be a viable treatment option.

2. If PMD > PMBAW:

   • This scenario can lead to three possible treatment options:
     1. Contraindicated for Expansion: Expansion may not be advisable.
     2. Move Teeth Distally: Consideration for distal movement of teeth to create space.
     3. Extract Some Teeth: Extraction may be necessary to alleviate crowding.

3. If PMBAW X 100 / TTM:

   • Less than 37%: Extraction is likely required.
   • 44%: This is considered an ideal case where extraction is not necessary.
   • Between 37% and 44%: This is a borderline case where extraction may or may not be required, necessitating further evaluation.

Mouth Breathing

Mouth breathing is a condition where an individual breathes primarily through the mouth instead of the nose. This habit can lead to various dental, facial, and health issues, particularly in children. The etiology of mouth breathing is often related to nasal obstruction, and it can have significant clinical features and consequences.

Etiology

• Nasal Obstruction: Approximately 85% of mouth breathers suffer from some degree of nasal obstruction, which can be caused by:
  • Allergies: Allergic rhinitis can lead to inflammation and blockage of the nasal passages.
  • Enlarged Adenoids: Hypertrophy of the adenoids can obstruct airflow through the nasal passages.
  • Deviated Septum: A structural abnormality in the nasal septum can impede airflow.
  • Chronic Sinusitis: Inflammation of the sinuses can lead to nasal congestion and obstruction.

Clinical Features

1. Facial Characteristics:

   • Adenoid Facies: A characteristic appearance associated with chronic mouth breathing, including:
     • Long, narrow face.
     • Narrow nose and nasal passage.
     • Short upper lip.
     • Nose tipped superiorly.
     • Expressionless or "flat" facial appearance.

2. Dental Effects (Intraoral):

   • Protrusion of Maxillary Incisors: The anterior teeth may become protruded due to the altered position of the tongue and lips.
   • High Palatal Vault: The shape of the palate may be altered, leading to a high and narrow palatal vault.
   • Increased Incidence of Caries: Mouth breathers are more prone to dental caries due to dry oral conditions and reduced saliva flow.
   • Chronic Marginal Gingivitis: Inflammation of the gums can occur due to poor oral hygiene and dry mouth.

Management

1. Symptomatic Treatment:

   • Gingival Health: The gingiva of mouth breathers should be restored to normal health. Coating the gingiva with petroleum jelly can help maintain moisture and protect the tissues.
   • Addressing Obstruction: If nasal or pharyngeal obstruction has been diagnosed, surgical intervention may be necessary to remove the cause (e.g., adenoidectomy, septoplasty).

2. Elimination of the Cause:

   • Identifying and treating the underlying cause of nasal obstruction is crucial. This may involve medical management of allergies or surgical correction of anatomical issues.

3. Interception of the Habit:

   • Physical Exercise: Encouraging physical activity can help improve overall respiratory function and promote nasal breathing.
   • Lip Exercises: Exercises to strengthen the lip muscles can help encourage lip closure and discourage mouth breathing.
   • Oral Screen: An oral screen or similar appliance can be used to promote nasal breathing by preventing the mouth from remaining open.

Lip Bumper

A lip bumper is an orthodontic appliance designed to create space in the dental arch by preventing the lips from exerting pressure on the teeth. It is primarily used in growing children and adolescents to manage dental arch development, particularly in cases of crowding or to facilitate the eruption of permanent teeth. The appliance is typically used in the lower arch but can also be adapted for the upper arch.

Indications for Use

1. Crowding:

   • To create space in the dental arch for the proper alignment of teeth, especially when there is insufficient space for the eruption of permanent teeth.

2. Anterior Crossbite:

   • To help correct anterior crossbites by allowing the anterior teeth to move into a more favorable position.

3. Eruption Guidance:

   • To guide the eruption of permanent molars and prevent them from drifting mesially, which can lead to malocclusion.

4. Preventing Lip Pressure:

   • To reduce the pressure exerted by the lips on the anterior teeth, which can contribute to dental crowding and misalignment.

5. Space Maintenance:

   • To maintain space in the dental arch after the premature loss of primary teeth.

Design and Features

• Components:

  • The lip bumper consists of a wire framework that is typically made of stainless steel or other durable materials. It includes:
    • Buccal Tubes: These are attached to the molars to anchor the appliance in place.
    • Arch Wire: A flexible wire that runs along the buccal side of the teeth, providing the necessary space and support.
    • Lip Pad: A soft pad that rests against the lips, preventing them from exerting pressure on the teeth.

• Customization:

  • The appliance is custom-fitted to the patient’s dental arch to ensure comfort and effectiveness. Adjustments can be made to accommodate changes in the dental arch as treatment progresses.

Mechanism of Action

• Space Creation:

  • The lip bumper creates space in the dental arch by pushing the anterior teeth backward and allowing the posterior teeth to erupt properly. The lip pad prevents the lips from applying pressure on the anterior teeth, which can help maintain the space created.

• Guiding Eruption:

  • By maintaining the position of the molars and preventing mesial drift, the lip bumper helps guide the eruption of the permanent molars into their proper positions.

• Facilitating Growth:

  • The appliance can also promote the growth of the dental arch, allowing for better alignment of the teeth as they erupt.

SEQUENCE OF ERUPTION OF DECIDUOUS TEETH

Upper/Lower   A B D C E 

SEQUENCE OF ERUPTION OF PERMAMENT TEETH 

Upper:   6 1 2 4 3 5 7           Lower:    6 1 2 3 4 5 7   
      
or       6 1 2 4 5 3 7              or  6 1 2 4 3 5 7 
 

ANTHROPOID SPACE / PRIMATE SPACE / SIMIEN’S SPACE  

The space mesial to upper deciduous canine and distal to lower deciduous  canine is characteristically found in primates and hence it is called primate space.  

INCISOR LIABILITY 

When the permanent central incisor erupt, these teeth use up specially all the spaces found in the normal dentition. With the eruption of permanent lateral incisor the space situation becomes tight. In the maxillary arch it is just enough to accommodate but in mandibular arch there is an average 1.6 mm less space available. This difference between the space present and space required is known as incisor liability. 
These conditions overcome by;  

      1. This is a transient condition and extra space comes from slight increase in arch width.   
      2. Slight labial positioning of central and lateral incisor. 
      3. Distal shift of permanent canine.        

      
LEE WAY SPACE (OF NANCE)  

The combined mesiodistal width of the permanent canines and pre molars is usually less that of the deciduous canines and molars. This space is 
called leeway space of Nance.     

Measurement of lee way space: 
 
Is greater in the mandibular arch than in the maxillary arch  It is about 1.8mm [0.9mm on each side of the arch] in the maxillary arch. 
And about 3.4mm [1.7 mm on side of the arch] in the mandibular arch. 
 
Importance:  

 This lee way space allows the mesial movement of lower molar there by correcting flush terminal plane.     
 LWS can be measure with the help of cephalometry.    

FLUSH TERMINAL PLANE (TERMINAL PLANE RELATIONSHIP) 

Mandibular 2nd deciduous molar is usually wider mesio-distally then the maxillary 2nd deciduous molar. This leads to the development of flush terminal plane which falls along the distal surface of upper and lower 2nd deciduous molar. This develops into class I molar relationship. 

Distal step relationship leads to class 2 relationship.
Mesial step relationship mostly leads to class 3 relationship.  

FEATURE OF IDEAL OCCLUSION IN PRIMARY DENTITION 

1. Spacing of anterior teeth. 
2. Primate space is present. 
3. Flush terminal plane is found. 
4. Almost vertical inclination of anterior teeth. 
5. Overbite and overjet varies.  

UGLY DUCKLING STAGE  

Definition:  
Stage of a transient or self correcting malocclusion is seen sometimes is called ugly duck ling stage. 
 
Occurring site: Maxillary incisor region 

Occuring age: 8-9 years of age.  

This situation is seen during the eruption of the permanent canines. As the developing p.c. they displace the roots of lateral incisor mesially this results is transmitting of the force on to the roots of the central incisors which also gets displaced mesially. A resultant distal divergence of the crowns of the two central incisors causes midline spacing.  

This portion of teeth at this stage is compared to that of ugly walk of the duckling and hence it is called Ugly Duckling Stage. 

Described by Broad bent. In this stage children tend to look ugly. Parents are often apprehensive during this stage and consult the dentist.  

Corrects by itself, when canines erupt and the pressure is transferred from the roots to the coronal area of the incisor.  
IMPORTANCE OF 1ST MOLAR
 
1. It is the key tooth to occlusion. 
2.  Angle’s classification is based on this tooth. 
3.  It is the tooth of choice for anchorage. 
4.  Supports occlusion in a vertical direction. 
5.  Loss of this tooth leads to migration of other tooth. 
6.  Helps in opening the bite.   

Key Cephalometric Landmarks

1. Sella (S):

   • The midpoint of the sella turcica, a bony structure located at the base of the skull. It serves as a central reference point in cephalometric analysis.

2. Nasion (N):

   • The junction of the frontal and nasal bones, located at the bridge of the nose. It is often used as a reference point for the anterior cranial base.

3. A Point (A):

   • The deepest point on the maxillary arch, located between the anterior nasal spine and the maxillary alveolar process. It is crucial for assessing maxillary position.

4. B Point (B):

   • The deepest point on the mandibular arch, located between the anterior nasal spine and the mandibular alveolar process. It is important for evaluating mandibular position.

5. Pogonion (Pog):

   • The most anterior point on the contour of the chin. It is used to assess the position of the mandible in relation to the maxilla.

6. Gnathion (Gn):

   • The midpoint between Menton and Pogonion, representing the most inferior point of the mandible. It is used in various angular measurements.

7. Menton (Me):

   • The lowest point on the symphysis of the mandible. It is used as a reference for vertical measurements.

8. Go (Gonion):

   • The midpoint of the contour of the ramus and the body of the mandible. It is used to assess the angle of the mandible.

9. Frankfort Horizontal Plane (FH):

   • A plane defined by the points of the external auditory meatus (EAM) and the lowest point of the orbit (Orbitale). It is used as a reference plane for various measurements.

10. Orbitale (Or):

    • The lowest point on the inferior margin of the orbit (eye socket). It is used in conjunction with the EAM to define the Frankfort Horizontal Plane.

11. Ectocanthion (Ec):

    • The outer canthus of the eye, used in facial measurements and assessments.

12. Endocanthion (En):

    • The inner canthus of the eye, also used in facial measurements.

13. Alveolar Points:

    • Points on the alveolar ridge of the maxilla and mandible, often used to assess the position of the teeth.

Importance of Cephalometric Landmarks

• Diagnosis: These landmarks help orthodontists diagnose skeletal and dental discrepancies, such as Class I, II, or III malocclusions.
• Treatment Planning: By understanding the relationships between these landmarks, orthodontists can develop effective treatment plans tailored to the individual patient's needs.
• Monitoring Progress: Cephalometric landmarks allow for the comparison of pre-treatment and post-treatment radiographs, helping to evaluate the effectiveness of orthodontic interventions.
• Research and Education: These landmarks are essential in orthodontic research and education, providing a standardized method for analyzing craniofacial morphology.