Bevels are the angulation which is made by 2 surfaces of a
prepared tooth which is other than 90 degrees. Bevels are given at various
angles depending on the type of material used for restoration and the purpose
the material serves.

Any abrupt incline between the 2 surfaces of a prepared tooth or between the
cavity wall and the Cavo surface margins in the prepared cavity

Bevels are the variations which are created during tooth preparation or cavity
preparation to help in increased retention and to prevent marginal leakage.

It is seen that in Bevels Occlusal cavosurface margin needs to be 40 degrees
which seals and protects enamel margins from leakage and the Gingival Cavo
surface margin should be 30 degrees to remove the unsupported enamel rods and
produce a sliding fit or lap joint useful in burnishing gold.



Types or Classification of Bevels based on the Surface they are placed
on:

Classification of Bevels based on the two factors – Based on the shape and
tissue surface involved and Based on the surface they are placed on –

Based on the shape and tissue surface involved:

1. Partial or Ultra short bevel
2. Short Bevel
3. Long Bevel
4. Full Bevel
5. Counter Bevel
6. Reverse / Minnesota Bevel

Partial or Ultra Short Bevel:

Beveling which involves less than 2/3rd of the Enamel thickness. This is not
used in Cast restorations except to trim unsupported enamel rods from the cavity
borders.

Short Bevel:

Entire enamel wall is included in this type of Bevel without involving the
Dentin. This bevel is used mostly with Class I alloys specially for type 1 and
2. It is used in Cast Gold restoration

Long Bevel:

Entire Enamel and 1/2 Dentin is included in the Bevel preparation. Long Bevel is
most frequently used bevel for the first 3 classes of Cast metals. Internal
boxed- up resistance and retention features of the preparation are preserved
with Long Bevel.

Full Bevel:

Complete Enamel and Dentinal walls of the cavity wall or floor are included in
this Bevel. It is well reproduced by all four classes of cast alloys, internal
resistance and retention features are lost in full bevel. Its use is avoided
except in cases where it is impossible to use any other form of bevel .

Counter Bevel:

It is used only when capping cusps to protect and support them, opposite to an
axial cavity wall , on the facial or lingual surface of the tooth, which will
have a gingival inclination facially or lingually.

There is another type of Bevel called the Minnesota Bevel or the Reverse Bevel,
this bevel as the name suggest is opposite to what the normal bevel is and it is
mainly used to improve retention in any cavity preparation

If we do not use functional Cusp Bevel –

1. It Can cause a thin area or perforation of the restoration borders
2. May result in over contouring and poor occlusion
3. Over inclination of the buccal surface will destroy excessive tooth structure
reducing retention

Based on the surface they are placed on:

1. Gingival bevel
2. Hollow ground bevel
3. Occlusal bevel or Functional cusp bevel

Gingival bevel:

1. Removal of Unsupported Enamel Rods.
2. Bevel results in 30° angle at the gingival margin that is burnishable because
of its angular design.
3. A lap sliding fit is produced at the gingival margin which help in improving
the fit of casting in this region.
4. Inlay preparations include of two types of bevel Occlusal bevel Gingival
bevel

Hollow Ground (concave) Bevel: Hollow ground bevel allows more
space for bulk of cast metal, a design feature needed in special preparations to
improve material’s castability retention and better resistance to stresses.
These bevels are ideal for class IV and V cast materials. This is actually an
exaggerated chamfer or a concave beveled shoulder which involves teeth greater
than chamfer and less than a beveled shoulder. The buccal slopes of the lingual
cusps and the lingual slope of the buccal cusps should be hollow ground to a
depth of at least 1 mm.

Occlusal Bevel:

1. Bevels satisfy the requirements for ideal cavity walls.
2. They are the flexible extensions of a cavity preparation , allowing the
inclusion of surface defects , supplementary grooves , or other areas on the
tooth surface.
3. Bevels require minimum tooth involvement and do not sacrifice the resistance
and retention for the restoration
4. Bevels create obtuse-angled marginal tooth structure, which is bulkiest and
the strongest configuration of any marginal tooth anatomy, and produce an acute
angled marginal cast alloy substance which allows smooth burnishing for alloy.

Functional cusp Bevel:

An integral part of occlusal reduction is the functional cusp bevel. A wide
bevel placed on the functional cusp provides space for an adequate bulk of metal
in an area of heavy occlusal contact.

Submasseteric Space Infection

Submasseteric Space Infection
Submasseteric space infection refers to an infection that
occurs in the submasseteric space, which is located beneath the masseter muscle.
This space is clinically significant in the context of dental infections,
particularly those arising from the lower third molars (wisdom teeth) or other
odontogenic sources. Understanding the anatomy and potential spread of
infections in this area is crucial for effective diagnosis and management.
Anatomy of the Submasseteric Space


Location:

The submasseteric space is situated beneath the masseter muscle,
which is a major muscle involved in mastication (chewing).
This space is bordered superiorly by the masseter muscle and
inferiorly by the lower border of the ramus of the mandible.



Boundaries:

Inferior Boundary: The extension of an abscess or
infection inferiorly is limited by the firm attachment of the masseter
muscle to the lower border of the ramus of the mandible. This attachment
creates a barrier that can restrict the spread of infection downward.
Anterior Boundary: The forward spread of infection
beyond the anterior border of the ramus is restricted by the anterior
tail of the tendon of the temporalis muscle, which inserts into the
anterior border of the ramus. This anatomical feature helps to contain
infections within the submasseteric space.



Posterior Boundary: The posterior limit of the
submasseteric space is generally defined by the posterior border of the
ramus of the mandible.


Clinical Implications


Sources of Infection:

Infections in the submasseteric space often arise from odontogenic
sources, such as:
Pericoronitis associated with impacted lower third molars.
Dental abscesses from other teeth in the mandible.
Periodontal infections.





Symptoms:

Patients with submasseteric space infections may present with:
Swelling and tenderness in the area of the masseter muscle.
Limited mouth opening (trismus) due to muscle spasm or swelling.
Pain that may radiate to the ear or temporomandibular joint
(TMJ).
Fever and systemic signs of infection in more severe cases.





Diagnosis:

Diagnosis is typically made through clinical examination and imaging
studies, such as panoramic radiographs or CT scans, to assess the extent
of the infection and its relationship to surrounding structures.



Management:

Treatment of submasseteric space infections usually involves:
Antibiotic Therapy: Broad-spectrum antibiotics
are often initiated to control the infection.
Surgical Intervention: Drainage of the abscess
may be necessary, especially if there is significant swelling or if
the patient is not responding to conservative management. Incision
and drainage can be performed intraorally or extraorally, depending
on the extent of the infection.
Management of the Source: Addressing the
underlying dental issue, such as extraction of an impacted tooth or
treatment of a dental abscess, is essential to prevent recurrence.